www.inweh.unu.edu Cost and Efficiency of Arsenic Removal from Groundwater: A Review Yina Shan, Praem Mehta, Duminda Perera and Yurissa Varela UNU-INWEH REPORT SERIES 05
w w w. i n w e h . u n u . e d u
Cost and Efficiency of Arsenic Removal from Groundwater: A Review
Yina Shan, Praem Mehta, Duminda Perera and Yurissa Varela
UNU-INWEHREPORT SERIES
05
About the Authors
Yina Shan is a student at Faculty of Health Sciences at McMaster University, Hamilton, ON, Canada. Praem Mehta was a researcher (water and health) at United Nations University Institute for Water, Environment and Health (UNU-INWEH), Hamilton, ON, Canada (current position: Research Office for Administration, Development, and Support (ROADS) at McMaster University, Hamilton, ON, Canada). Duminda Perera is a senior researcher (hydrology and water resources) at UNU-INWEH. Yurissa Varela is a student at School of International Development and Global Studies at the University of Ottawa, ON, Canada, and an intern at UNU-INWEH.
© United Nations University Institute for Water, Environment and Health (UNU-INWEH), 2018
Suggested Citation: Shan, Y. Mehta, P., Perera, D., Varela, Y. 2018. Cost and Efficiency of Arsenic Removal from Groundwater: A Review. UNU-INWEH Report Series, Issue 05. United Nations University Institute for Water, Environment and Health, Hamilton, Canada.
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Design: Kelsey Anderson (UNU-INWEH)
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ISBN: 978-92-808-6093-1
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UNU-INWEH Report SeriesIssue 05
Cost and Efficiency of Arsenic Removal from Groundwater: A Review
Yina Shan, Praem Mehta, Duminda Perera and Yurissa Varela
CONTENTS
EXECUTIVE SUMMARY 5
INTRODUCTION 6
METHODOLOGY 7
RESULTS AND DISCUSSION 8 Summary of Reviewed Studies 8 Laboratory Studies 8 Field Studies 9 Review Limitations 14
CONCLUSIONS AND RECOMMENDATIONS 14
ACKNOWLEDGMENTS 16 REFERENCES 16
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 5
EXECUTIVE SUMMARY
Hundreds of millions of people worldwide are exposed to arsenic-contaminated drinking water, leading to significant health complications, and social and economic losses. Currently, a wide range of technologies exists to remove arsenic from water. However, despite ongoing research on such technologies, their widespread application remains limited. To bridge this gap, this review aims to compare the effectiveness and costs of various arsenic remediation technologies while considering their practical applicability. A search conducted using the Medline and Embase databases yielded 31 relevant articles published from 1996 to 2018, which were categorized into laboratory and field studies. Data on the effectiveness of technologies in removing arsenic and associated costs were extracted and standardized for comparison as much as was possible, given the diversity of ways that studies report their key results.
The twenty-three (23) technologies tested in laboratory settings demonstrated efficiencies ranging from 50% to ~100%, with the majority reaching relatively high removal efficiencies (>90%). Approximately half achieved the WHO standard of 10 µg/L. Laboratory studies used groundwater samples from nine (9) different countries - Argentina, Bangladesh, Cambodia, China, Guatemala, India, Thailand, the United States, and Vietnam. The fourteen (14) technologies tested in the field achieved removal efficiency levels ranging between 60% and ~99%, with ten (10) attaining above 90% removal efficiency. Of these, only five (5) reached established the WHO standard. Some of the technologies under-performed when their influent water contained excessive concentrations of arsenic. Only six (6) countries (Argentina, Bangladesh, Chile, China, India, and Nicaragua) were represented among the studies that implemented and tested technologies in the field, either at household or community level.
For technologies tested in the laboratory, the cost of treating one cubic meter of water ranged from near-zero to ~USD 93, except for one technology which cost USD 299/m³. For studies conducted in the field, the cost of treating one cubic meter of water ranged from near-zero to ~USD 70. Key factors influencing the removal efficiencies and their costs include the arsenic concentration of the influent water, pH of the influent water, materials used, the energy required, absorption capacity, labour used, regeneration period and geographical location. Technologies that demonstrate high removal efficiencies when treating moderately arsenic-contaminated water may not be as efficient when treating highly contaminated water. Also, the lifetime of the removal agents is a significant factor in determining their efficiency.
It is suggested that remediation technologies that demonstrate high arsenic removal efficiencies in a laboratory setting need to be further assessed for their suitability for larger-scale application, considering their high production and operational costs. Costs can be reduced by using locally available materials and natural adsorbents, which provide near zero-cost options and can have high arsenic removal efficiencies.
A notable feature of many arsenic removal approaches is that some countries with resource constraints or certain environmental circumstances – like typically high arsenic concentrations in groundwater –aim to reach resultant arsenic concentrations that are much higher than WHO’s recommended standard of 10 µg/L. This report maintains that – while this may be a pragmatic approach that helps progressively mitigate the arsenic-related health risks – it is unfortunately not a sustainable solution. Continuing exposure to higher levels of arsenic ingestion remains harmful for humans. Hence arsenic-removal technology should only be seen efficient if it can bring the water to the WHO standard. A less radical approach effectively shifts the attention from the origin of the problem in addressing the impacts and postpones achieving the best possible outcome for populations.
The quantitative summary of costs and effectiveness of arsenic remediation technologies reviewed in this report can serve as a preliminary guideline for selecting the most cost-effective option. It may also be used as an initial guideline (minimum standard) for summarising the results of future studies describing arsenic remediation approaches.
Looking ahead, this study identifies four priority areas that may assist in commercializing wide-scale implementation of arsenic removal technologies. These include: i) focusing efforts on determining market viability of technologies, ii) overcoming practical limitations of technologies, iii) determining technology contextual appropriateness and iv) concerted effort to increase knowledge sharing in and across regions to accelerate the implementation of research on the ground. Overall, the current science and knowledge on arsenic remediation technologies may be mature enough already to help significantly reduce the global numbers of affected populations. The missing link for today’s arsenic removal challenge is the ability to translate research evidence and laboratory-level successes into quantifiable and sustainable impacts on the ground. Achieving this requires a concerted and sustained effort from policymakers, engineers, healthcare providers, donors, and community leaders.
Keywords: Arsenic; drinking water; groundwater; arsenic removal technology; arsenic removal efficiency; remediation cost
Cost and Efficiency of Arsenic Removal from Groundwater: A Review6
INTRODUCTION
Contamination of groundwater with arsenic is a major environmental concern affecting the health of some 140 million people in over 50 countries worldwide (WHO, 2018). Arsenic, a naturally occurring metalloid, is present in inorganic and organic forms (Carlin et al., 2016). Organic arsenic is relatively safe, but its inorganic form is toxic. In natural water, arsenic takes its inorganic form - most commonly as arsenite [trivalent arsenic, As(III)] and arsenate [pentavalent arsenic, As(V)] (Abernathy et al., 1999; Hughes et al., 2011). These two forms of inorganic arsenic can be absorbed and accumulated in tissues and bodily fluids.
Sources of arsenic contamination can be categorized into two main groups: geogenic (naturally occurring) and industrial. Under natural conditions, specific geological settings facilitate the mobilization of arsenic. These can include the weathering of arsenic-rich rocks or conditions in arid areas, where high pH can mobilize arsenic in oxygen-rich groundwater (Schwarzenbach et al., 2010; Liao et al., 2011). Arsenic contamination is also mobilized by human interventions, such as mining, the use of fertilizers and pesticides, waste disposal, and industrial manufacturing (Duker et al., 2005). Globally, the primary route of human exposure to arsenic is through the ingestion of contaminated drinking water, or irrigation water that makes its way into food through plant roots (Hughes et al., 2011; Naujokas et al, 2013; Chung et al., 2014; EFSA, 2014; WHO, 2018).
Exposure to arsenic leads to severe health, social and economic implications, including arsenicosis (e.g. muscular weakness, mild psychological effects), skin lesions and cancers of lung, liver, kidney, bladder, and skin (Ahmed et al., 2011; Mahmood and Halder, 2011; Naujokas et al 2013; Abdul et al., 2015). The social implications of arsenic-induced health impacts include stigmatization, isolation, and social instability for affected individuals (Brinkel et al., 2009). In addition, arsenic-related health complications and mortality lead to significant economic losses. In Bangladesh, the economic burden resulting from lost productivity due to arsenic-attributable mortality is estimated to reach USD 13.8 billion by around 2030 (Flanagan et al., 2012).
The toxicity and carcinogenicity of arsenic attract international attention and response (Ng et al., 2003; Tchounwou et al., 2003). In 2010, the WHO designed 10 µg/L as the acceptable limit for arsenic concentrations in drinking water (WHO, 2011). Furthermore, Sustainable Development Goal 3 (SDG 3 - “good health and well-being”) of the 2030 Agenda, adopted by all United Nations (UN) the Member States in 2015, recognized the need to remove hazardous chemicals, including arsenic, from the world’s ecosystems. SDG target 3.9
specifically aims to “substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water, and soil pollution and contamination” (https://sustainabledevelopment.un.org). This was further recognized under SDG 6 (“Clean water and sanitation”) which includes target 6.3 calling for an “improvement to water quality by reducing pollution, eliminating dumping and minimizing the release of hazardous chemicals and materials” (https://sustainabledevelopment.un.org). The SDGs clearly state that addressing the arsenic challenge is a critical step in achieving sustainable development.
High natural levels of inorganic arsenic exceeding the WHO limit are a characteristic feature of groundwater in many countries, including Bangladesh, India, Nepal, Mongolia, and the United States (WHO, 2018). Some countries with resource constraints and with certain social or environmental context have set limits higher than WHO’s recommended 10 µg/L to mitigate the arsenic-related health risks progressively. But this policy approach is not well-conceived as it does not effectively resolve the issue. On the contrary, it shifts the attention from the origin of the problem in addressing the impacts and does not prevent humans from exposure to higher arsenic concentrations. For example, in Bangladesh, where the nationally acceptable arsenic limit in water is set to 50 µg/L (Smith et al., 2000), over 20 million people are estimated to still consume water with even higher arsenic levels than the national standard (Yunus et al., 2016). Furthermore, despite international efforts, millions of people globally continue to be exposed to concentrations reaching and exceeding 100 µg/L (WHO, 2011, 2018).
The primary strategies for the provision of safe, arsenic-free or low-arsenic water are mitigation and remediation. Mitigation involves providing safe water from alternative sources. For example, high-arsenic groundwater can be replaced with low-arsenic rainwater. Remediation involves removing arsenic from water using centralized or household arsenic removal technologies (WHO, 2018). The success of any of these interventions relies on effective community education and engagement (Smith et al., 2000). Remediation is the most viable solution, particularly in regions with limited or no access to alternative sources of clean water. Globally, significant investments are being made in these kinds of treatments, but the total positive impact of these efforts is difficult to assess. Despite this progress, the global population affected by arsenic-contaminated water remains high. This is due largely to a lack of commercially available remediation technologies. These technologies vary widely, and their implementation depends on the quality of the source water (Ravencroft et al., 2009). Given the economic limitations of certain nations, communities, and households, it is critical to have a clear understanding of what are the most cost-effective remediation options
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 77
for low-income settings. Currently, there is a myriad of reportedly ‘low-cost’ technologies for treating arsenic-contaminated water (Kabir and Chowdhury, 2017). But the specific costs associated with these technologies are rarely documented.
This report examines peer-reviewed literature on the state-of-the-art of technologies for remediation of arsenic-contaminated water. It evaluates the relative costs and effectiveness of these technologies and considers any limitations of their applicability. The scope of the report is global. The main objective is to help accelerate the wide-scale implementation of remediation solutions to alleviate, and ultimately eradicate, the problem over the next decade – over the remaining duration of the SDGs timeline. This report aims to inform decision-makers who face an arsenic public health challenge, of the specific costs and effectiveness of technologies tested in laboratory or field settings. It also urges researchers to present cost and effectiveness data cohesively to better inform planners’ and policymakers’ choice of the best arsenic remediation technologies.
METHODOLOGY
Over the past few years, numerous studies have been done on the problem of arsenic contamination of groundwater, and comprehensive literature on the subject has been published (e.g., Ravenscroft et al., 2009; Eawag, 2015). A quick survey done for this report on the Scopus database (www.scopus.com/home.uri) suggests that from 2014 to 2018, over 17,400 arsenic-related publications were produced (in various related fields including medicine, biology, engineering, socio-economic, and environment) by the top ten countries publishing on the subject – China, USA, India, Germany, UK, Italy, Spain, Japan, Australia, and Canada. A significant number of publications have originated from arsenic-hit countries such as China, USA, India, Taiwan, Poland, Bangladesh, Argentina, and Brazil.
For this study, focusing exclusively on arsenic-remediation technologies, the two major databases of biomedical scholarly literature searched to identify relevant entries for analysis were Medline (www.nlm.nih.gov/bsd/pmresources.html) and Embase (www.elsevier.com/solutions/embase-biomedical-research). Medline database provides free access to information on biomedical literature from around the world. Embase provides access to additional 2,900 peer-reviewed biomedical and life sciences journals.
Search terms were organized under three categories combined with the “and” operator: water sources (“drinking water” or “fresh water” or “groundwater” or “lake water” or “river water” or “sea water” or “surface
water” or “tap water” or “well water” or “drinking water” or “water supply” or “water resources”), arsenic (“arsenic”), and cost (“cost” or “economic” or “investment”). Only peer-reviewed literature published between 1996 and 2018 and written in the English language was included. The query was not geographically limited.
After the search was conducted in each database, the titles and abstracts of the resulting articles were examined for relevance to this review, yielding 62 articles in Medline and 20 articles in Embase after the removal of duplicates. Articles that only made general statements regarding costs (i.e., ‘low-cost’) without providing numerical values were excluded. Articles focusing on mitigation efforts beyond remediation or removal methods, such as screening programs and field test kits, mass media and communication tools, and alternative water supply sources, were also excluded. In the case of different papers evaluating identical technologies, only the first was included, if the cost and effectiveness were consistent between the papers. The above screening and filtering resulted in 31 full-text papers that were eventually included in this review.
The following information was extracted from the included studies when provided:
• Geographic location• Study design (i.e., laboratory, field, or review)• The Scale of research (i.e., laboratory, household, or
community)• Water source• Remediation technology and process• Efficiency outcomes (i.e., influent and effluent
concentrations, removal efficiency, meeting national or WHO standards)
• Cost of producing and/or operating remediation technology
The extracted data were used to calculate specific parameters for technology effectiveness and cost, when possible. To standardize the data on effectiveness, the following formula was used to calculate the arsenic removal efficiency of each technology, where n is the arsenic removal efficiency, C₀ is the influent arsenic concentration of the water sample, and Ce is the effluent arsenic concentration.
To compare costs, all non-USD currencies were converted to USD based on the exchange rate for January 1 of the year of publication. Wherever possible, the cost of treating one cubic meter (m³) of water was calculated to facilitate cost comparison between technologies. In certain cases, this calculation involved a unit conversion from the cost per litre of treated water. For other studies,
(C₀-Ce) C₀ ×100n(%)=
Cost and Efficiency of Arsenic Removal from Groundwater: A Review8
the total reported cost was divided by the volume of treated water. To standardize costs, all values were adjusted for inflation using the US Inflation Calculator tool (www.usinflationcalculator.com) which converts the cost value from the year in which the article was published to their equivalent value for 2018.
RESULTS AND DISCUSSION
Summary of Reviewed Studies
The review covered six (6) major types of remediation technologies presently available to remove arsenic from water: i) oxidation; ii) coagulation, precipitation and filtration iii) adsorption, iv) membrane technologies, v) bio-remediation and vi) ion exchange. Some remediation technologies and processes utilized a combination of these types (Garelick et al., 2005; Alçada et al., 2009; Singh et al., 2015).
Oxidation (OXI) involves the transformation of trivalent arsenic [As(III)] to pentavalent arsenic [As(V)]; the latter can form oxyanions, which facilitate many of the remediation technologies mentioned above process (Bissen and Frimmel, 2003). Many technologies benefit from this oxidative process which can be biologically catalyzed by bacterial species to enhance arsenic removal (Katsoyiannis and Zouboulis, 2004). For example, solar oxidation and removal of arsenic (SORAS) is a multi-step process involving the photochemical oxidation of As(III) to As(V), which is subsequently adsorbed onto ferric oxides and co-precipitated (Bundschuh et al., 2010). In general, co-precipitation (Co-P) requires arsenic to bind to the surface of the precipitate, which could occur via adsorption or another mechanism (Twidwell et al., 2005).
Coagulation (C), Precipitation (P) and Filtration (F): These combined processes typically follow three-steps: i) arsenite is oxidized to arsenate; ii) metal coagulants, usually iron or aluminum salts, convert arsenate to an insoluble compound; and iii) the solid particles are removed by filtration (Wickramasinghe et al., 2004; Sancha, 2006).
Adsorption (ADS) technologies are also very common, and a wide range of naturally occurring and synthetic adsorbents are currently being used or investigated. Many adsorbents, such as those based on aluminum, require the oxidation of arsenite to arsenate, but other adsorptive media can function without pre-oxidation (Mohan and Pittman, 2007).
Membrane (MEM) technologies rely on the use of synthetic membranes that contain billions of microscopic holes that act as selective barriers which control the
movement of molecules. This is often done under pressure ranging from low to high (Figoli et al., 2016).
Bio-remediation (BIO) involves the use of biological techniques found in nature to remove arsenic from contaminated water. Among these are such methods as phytoremediation, where renewable plant biomass is used as an adsorbent, and bio-filtration (Tu et al., 2004; Pokhrel and Viraraghavan, 2009).
Ion Exchange (ION) is a physical-chemical process in which ions are swapped between a solution phase and solid resin phase. For an effective ion exchange process oxidization of arsenite to arsenate is essential (Clifford et al., 1990).
Most of the investigated technologies used adsorption or precipitative processes, reflecting the greater volume of literature on adsorbents and precipitation. Several technologies employed both processes.
Technologies were also grouped into ‘laboratory’ or ‘field’ categories based on the settings in which they were implemented and evaluated. Significantly more of the reviewed studies were conducted in laboratories (23) than in the field or community (14). In both categories, the majority of studies originated from either Bangladesh or India and followed by fewer studies from Argentina, Chile, China, Cambodia, Guatemala, Nicaragua, Thailand, USA, and Vietnam.
Table 1 summarizes, in alphabetic order of the lead author, the efficiency of arsenic removal and costs of the remediation technologies from identified studies.
Laboratory studies
The 23 technologies tested in laboratory settings demonstrated efficiencies ranging from 50% to ~100%, with the majority reaching high removal efficiencies (>90%). It is important to note though that only 12 of these technologies achieved arsenic levels within the WHO 10 µg/L standard. Of the eight technologies that did not meet the WHO standard, four were able to achieve effluent concentrations below 50 µg/L, which is the national standard in Bangladesh and India. As mentioned earlier in this report, this hardly resolves the problem of arsenic remediation, and hence such technologies should be seen, strictly speaking, as inefficient. There were no data on whether four of the technologies extracted from the review by Visoottiviseth and Ahmed (2008) met the WHO standard. One of the critical factors to achieve WHO or national threshold limits is the influent arsenic concentration. Most of the technologies which failed to achieve these standards, remove arsenic from the highly concentrated influent. So, while they could not reach the required standards, they may be seen as useful in reducing arsenic concentrations from very high
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 9
to lower levels. There may be a scope here to combine/cascade technologies to achieve the required standard.
The cost differences between these technologies ranged from nearly zero to ~USD 299. Six technologies were nearly zero-cost as they used only naturally-occurring materials or processes, such as biomass or natural co-precipitation processes in groundwater. The removal efficiency of the near zero-cost technologies ranged from 50% to 99%. There were discrepancies in the outcomes reported by studies investigating laterite, a natural geological adsorbent. Visoottiviseth and Ahmed (2008) reported a 50% to 90% range for removal efficiency, where Bundschuh et al. (2011) reported a removal efficiency of up to 99%. Similarly, for natural co-precipitation with metals in groundwater, the review by Visoottiviseth and Ahmed (2008) reported a lower efficiency than the study by Mamtaz and Bache (2000). Discrepancies between these removal efficiency figures are due to various factors including the concentration of the materials used and the composition of influent water. Options that demonstrate high removal efficiencies when treating moderately contaminated water may not be as efficient when treating highly contaminated water sources.
Six technologies cost under USD 1 per cubic meter of treated water. For instance, the Mg-Fe-based hydrotalcite-like compound evaluated by Kato et al. (2013) and Kumasaka et al. (2013), which had a removal efficiency of 99.8%, cost between USD 0.01 and USD 0.38 per cubic meter. Another novel adsorption-based technology - Arsenic Removal Using Bottom Ash (ARUBA) - achieved 98% removal efficiency and cost USD 0.74 per cubic meter (Mathieu et al., 2010).
Three technologies proved to be significantly more expensive (in the range of USD 15.8 to USD 299). The most expensive of these was the ZeroWater® water pitcher filter which required replacing filters every 15 gallons (~57 litres). The original price of the ZeroWater® water pitcher (and filter) is ~USD 36 and requires the use of 17 more filters (~USD 15 /filter) to treat one cubic meter of water, bringing the total to ~USD 299/m³ of treated water. The hydrogel adsorbent and chitosan goethite bio-nanocomposite beads are two novel adsorbents that demonstrated very high removal efficiencies – up to 99.8% and 98% respectively – but were relatively costly at ~USD 93 and ~USD 16 per cubic meter of treated water (Bundschuh et al., 2010; He et al., 2016). Eight laboratory studies published their estimated costs based on the operational duration of the technology or material used (such as cost per cubic meter of filter materials, cost per year, cost per a 1 kg of absorbent etc.) that could not be standardized into cost per cubic meter of treated water, limiting direct cost comparisons.
Field Studies
Studies that reported implemented and technologies tested in the field – at the household or community level – originated from six countries, including Argentina, Bangladesh, Chile, China, India, and Nicaragua. The cost of treating one cubic meter of water ranged from near-zero to USD ~70.
Among the 14 field-tested technologies, ten attained 90% removal efficiency, and only three achieved 98%. Of these, only five technologies reached the WHO standard of 10 µg/L. Many of the field studies referenced 50 µg/L as the target effluent concentration. Six of the eight technologies that did not consistently reach the WHO standard were able to lower arsenic concentrations to below this target.
For the most part, the field studies investigated community-level treatment plants and household-level filtration systems. Four of the five treatment plants included in this review used adsorption processes with various adsorbents, including activated alumina and ferric hydroxide, and one used electrocoagulation. The technologies had high removal efficiencies of 90% to 99%. The cost to treat one cubic meter of water ranged from near-zero to USD 1.76, with the exception of the treatment plant using iron filings and sand, which costs ~USD 70 (Visoottiviseth and Ahmed, 2008). The most inexpensive option used ferric hydroxide as the adsorbent and was able to reduce arsenic concentrations to below 10 µg/L (Sen Gupta et al., 2009). However, it is unclear whether the same parameters were used to derive the costs for each plant. Certain publications explicitly mentioned capital and maintenance costs, where others only presented the cost per unit of treated water.
The studies evaluating household filters reported similar removal efficiencies and costs. The three filters employing adsorption techniques demonstrated efficiencies from 86% to over 95% (Shafiquzzaman et al., 2009; Shan et al., 2013; Smith et al., 2017). One of the filters reached the WHO standard, and the remaining two reached 50 µg/L level. The cost of each filtration unit was approximately USD 40. The filters using only conventional filtration techniques were much lower in cost, at under USD 5 per unit, but varied widely in efficiency (Hoque et al., 2004; Hasan et al., 2012). In all cases, the longevity of the filter is one key factor influencing the long-term cost.
Technologies applied in the field face challenges such as the presence of competing ions in natural groundwater, longer periods of use, the need for maintenance by users and lack of community awareness and acceptance (de Esparza, 2006; Baig et al., 2013; Inauen et al., 2013). For example, the removal efficiency of treatment plants and household filters may decrease with sustained periods of
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•In-situ
syn
thesisproce
ss
•La
rge-scaletrialtestin
gre
quiredtodeterminelocal
so
cial
acc
epta
nce
[AD
S, O
XI]
<10
(usi
ng >
2.3
g/L
CG
B b
ead
s)
Kum
asak
a et
al.,
2013
Ban
gla
des
hM
g-F
e-b
ased
hyd
rota
lcite
-like
com
po
und
(MF-
HT)
308
99.8
Yes
0.01
•Highlyeffective
•Lo
wcost
•Lo
wadso
rptio
nperiod(<
15s)
•Highlytech
nicalp
roce
ss
•Limite
daccesstom
aterialsnee
ded
[AD
S, IO
N]
0.5
Kat
o e
t al
., 20
13B
ang
lad
esh,
Vie
tnam
Mg
-Fe-
bas
ed
hyd
rota
lcite
-like
com
po
und
(MF-
HT)
92.3
- 4
59 (m
ean
= 2
98)
99.8
Yes
0.38
•Highlyeffective
•Lo
wcost
•Controlle
dla
bexp
erim
ent
•Notco
mmerciallyavailable
[AD
S]<
10 (m
ean
= 0
.5)
Tab
le 1
. Sal
ient
feat
ures
of p
ublis
hed
tec
hno
log
ies
for
rem
edia
tion
of a
rsen
ic-c
ont
amin
ated
wat
er
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 11
Kim
et
al.,
2006
Wat
er
synt
hesi
sed
in la
bo
rato
ry
Lig
noce
llulo
se
adso
rptio
n m
ediu
m
(LA
M)
4100
72.7
No
N/A
•Effe
ctive
•Lo
wtreatmen
ttim
e
•Sh
ortlifetim
e(only5tim
eregen
eration)
•Morere
search
nee
ded
toensureefficienc
y,affo
rd
ab
ility
, sca
lab
ility
and
co
st-e
ffect
iven
ess
[AD
S]11
18
Lee
et a
l., 2
016
Wat
er
synt
hesi
sed
in la
bo
rato
ry
Car
bo
n co
mp
osi
te
elec
tro
de
1000
98.8
No
‡N
/A•Highlyeffective
•Highlytech
nicalp
roce
ss
•Accesstoelectric
ityre
quired
•Highpreparationco
sts
•Produc
essludge
[Cap
aciti
ve
dei
oni
satio
n]
12
Maj
umd
er e
t al
.,
2013
Ind
iaC
itric
aci
d fr
om
lem
on,
to
mat
o, a
nd
lime
(SO
RA
S)
430,
270
, 110
82.2
(lem
on)
;
93.9
(to
mat
o);
67 (l
ime)
No
0.84
(lem
on)
,
0.65
(to
mat
o),
0.49
(lim
e)
•Effe
ctivean
dlo
wcost
•Affo
rdab
le
•Accessible
•Eco
-frie
ndly
•Efficien
t(4hr)
•Nohazardouswastesproduc
ts
•Reliesonuse/repea
teduseofp
lasticbottles
•Relianton>4ho
ursofsun
light
•Trea
tedwaterm
ustbedec
anted
•Morere
search
nee
ded
onmonitorin
g[O
XI]
30, 7
0, 3
0 (le
mo
n);
10, 3
0, 1
0
(to
mat
o);
50, 1
20,
60 (l
ime)
Mam
taz
and
Bac
he,
2000
Ban
gla
des
hN
atur
ally
occ
urrin
g
iron
in g
roun
dw
ater
200
91.9
No
‡N
ear
zero
-co
st•Effe
ctive
•Affo
rdab
le
•Lo
ngtreatmen
ttim
e(24ho
urs)
•Notpracticalfo
rho
useh
olds
•Usesha
rmfulche
micals
•Inacce
ssiblem
aterials
[Co
-P]
16.2
Mat
hieu
et
al.,
2010
Ban
gla
des
h,
Cam
bo
dia
AR
UB
A (A
rsen
ic
Rem
ova
l Usi
ng
Bo
tto
m A
sh)
2000
± 1
00
(syn
thet
ic),
67-8
80
(In s
itu)
98.1
,
64.3
- 9
8.4
No
(Yes
with
hig
her
do
ses
of A
RU
BA
)
0.74
•Effe
ctive
•Affo
rdab
lealte
rnative
•Sc
alab
lepractical(<
1hr)
•Nosec
ond
aryco
ntam
inan
ts
•Alsore
move
sman
gan
ese
•Sa
fefo
rdisposalinordinaryland
fill
•Req
uiresuseofw
astem
aterial
•Accesstom
aterialm
aybelim
ited
[AB
S]39
± 5
.3, 4
-50
Mis
bah
udd
in a
nd
Farid
udd
in, 2
002
Ban
gla
des
hW
ater
hya
cint
h
(Eic
hho
rnia
cras
sip
es)
400
98.2
5Ye
sN
ear
zero
-co
st•Highlyeffectivean
dlo
wcost
•Rem
ove
sotherim
purities
•Lo
wtreatmen
ttim
e(6hr)
•Minim
altoolsnee
ded
•La
rge-scaletrialtestin
gre
quired
•Resea
rchonacce
ssibilitynee
ded
•Resea
rchonco
mmercializationne
eded
[BIO
]6.
99
Ng
uyen
et
al.,
2009
Vie
tnam
Trea
ted
mag
netit
e
was
te (T
MW
)
380
92.1
No
‡N
/A•Effe
ctive
•Mad
efromwastem
aterial
•Lo
wcost
•To
xicby-produc
tstha
tcann
otberemove
d
[AD
S]9
to 2
4
Thak
ur a
nd M
ond
al,
2017
Ind
iaA
lum
inum
elec
tro
de
550
98.5
Yes
0.37
•Highlyeffective
•Lo
wcost
•Highlypractical
•Produc
essludge
[C,P
,F]
8.19
Vis
oo
ttiv
iset
h an
d
Ahm
ed, 2
008
Ban
gla
des
hIro
n fil
ing
s (z
ero
vale
nce)
—>
94
- 99
—N
/A•Highlyeffective
•Unitused
localm
aterials
•Rap
idlyclogged
ifgroun
dwatercontainsexcessive
iro
n
•Highmainten
ance
ove
rtim
e[C
,P,F
]—
Vis
oo
ttiv
iset
h an
d
Ahm
ed, 2
008
Ban
gla
des
hIro
n sa
lts—
> 9
0 —
N/A
•Effe
ctiveove
rawiderran
geofp
H
•Sh
orttreatmen
ttim
e
•pHdep
enden
t
•(betwee
n6.0to8.5)
•Efficien
cyaffe
cted
byco
mpositio
nofinfl
uentwater
Vis
oo
ttiv
iset
h an
d
Ahm
ed, 2
008
Thai
land
Imm
ob
ilise
d g
reen
alg
a (C
hlo
rella
vulg
aris
)
—85
- 9
0 —
Nea
r ze
ro-c
ost
•Highlyeffective
•Lo
wcostnaturalm
aterials
•Mainten
ance
required(a
lginatebea
dsmustbe
ch
ang
ed e
very
3 m
ont
hs)
•Req
uiresdisposalfollo
wingabso
rptio
n
[BIO
]—
Vis
oo
ttiv
iset
h an
d
Ahm
ed, 2
008
—La
terit
e—
50 -
90
—N
ear
zero
-co
st•Effe
ctivean
dlo
w-cost
•Accessibilitym
aybelim
iteddep
endingonlocal
co
ntex
t[A
DS]
—
Cost and Efficiency of Arsenic Removal from Groundwater: A Review12
Aut
hor(
s); y
ear
Ori
gin
of
In
fluen
t W
ater
Rem
edia
tio
n te
chno
log
y
des
crip
tio
n
Init
ial
conc
entr
atio
n (µ
g/L
)R
emo
val
effic
ienc
y (%
)
WH
O
stan
dar
d
reac
hed
?
Co
st p
er m
³ o
f tr
eate
d
wat
er (U
SD)
Ben
efits
Lim
itat
ions
[Tec
hno
log
y ty
pe]
Fina
l co
ncen
trat
ion
(µg
/L)
Vis
oo
ttiv
iset
h an
d
Ahm
ed, 2
008
Ban
gla
des
hN
atur
ally
occ
urrin
g
iron
and
/or
man
-
gan
ese
—70
- 8
0N
o ‡
Nea
r ze
ro-c
ost
•Effe
ctive
•Lo
wcost
•A
s co
ncen
trat
ion
mus
t b
e b
elo
w 1
00 µ
g/L
to
be
effe
ctiv
e
[C,P
,F]
25-3
6
Yavu
z et
al.,
201
0U
nite
d S
tate
sM
agne
tic c
ryst
als
500
99.2
Yes
N/A
•Highlyeffective
•Lo
wm
ainten
ance
•Accessiblefo
rrurala
reaswith
noelectric
ityorpum
ps
•La
rgeinitialand
mainten
ance
costs
•Exten
sive
nee
dofm
aterials
•Highlytech
nicalp
roce
ss
Mag
netit
e na
no-
crys
tals
3.9
Fiel
d R
esul
ts
Am
rose
et
al.,
2014
Ind
iaE
lect
ro-C
hem
ical
Ars
enic
Rem
edia
tion
(EC
AR
) rea
cto
r
266
± 4
299
.2Ye
s0.
89-1
.11
•Highlyeffectivean
dlo
wcost
•Reliable
•Slud
gecanbeturned
intoconc
rete(tobeev
alua
ted
fu
rthe
r)
•Produc
esA
s sl
udg
e (d
eem
ed n
on-
haza
rdo
us)
•A
s le
achi
ng r
isk
•Tu
rbidity
leve
lsdidnotmee
tWHOstand
ard
[Ele
ctro
-C,P
,F]
2.1
± 1
.0, a
ll <
5
Bo
rdo
loi e
t al
., 20
13In
dia
NaH
CO₃,
KM
nO₄,
FeC
l₃19
6 -
238
96.8
- 9
8.2
Yes
0.17
•Highlyeffectivean
dlo
wcost
•Noelectric
ityre
quired
•Simplicity
ofo
peration
•Lo
wre
siden
cetim
e(1-2hr)
•Notoxicresidue
•Reliesonch
emicalstosyn
thesise
•Sm
allq
uantity
ofsludge(fe
rrihyd
ritewith
adso
rbed
ar
sena
te)
[OX
I, C
,P,F
]3.
69 -
7.5
8
Bun
dsc
huh
et a
l.,
2010
Arg
entin
a,
Ban
gla
des
h
Chi
le,
Nic
arag
ua
Mo
difi
ed S
OR
AS
1250
Up
to
95
No
Nea
r ze
ro-c
ost
•Highlyeffectivean
dlo
wcost
•Te
chno
logiesareavailable,b
utm
oretria
lresea
rch
ne
eded
•Nee
dsab
undan
tIro
n
[OX
I, C
,P,F
]62
.5
Che
n et
al.,
201
5C
hina
Ferr
ic c
hlo
ride
117
82.1
No
‡0.
01•Effe
ctivean
dlo
wcost
•Easyoperation
•Marginaleco
logicalim
pact
•Reliedonoutsidech
emicals
•La
rge-scaleim
plemen
tatio
nrequireseq
uipmen
tan
d
sp
rayi
ng m
achi
nes
[C,P
,F]
21
Has
an e
t al
., 20
12B
ang
lad
esh
Ho
useh
old
cer
amic
filte
r
178
- 58
560
- 9
3N
oN
/A•Effe
ctivean
dlo
wcost
•Mad
eoflocallyavailablem
aterials
•Minim
alm
ainten
ance
•Highe
ruseraccep
tanc
e,satisfactionan
dsustained
use
•Lo
werefficien
cytha
notheralte
rnatives
•Metthe
Ban
gladeshstan
dard(<
50µg/L)b
utnot
WH
O s
tand
ard
(<10
µg
/L)
[F]
32 -
190
Ho
que
et
al.,
2004
Ban
gla
des
hH
ous
eho
ld fi
lters
40
0 —
—
N/A
•Effe
ctive
•Usefulinem
ergen
cies
•Lo
wpracticality
(slowfilte
rrates)
•High/diffi
cultmainten
ance
•Disch
arged
poorqua
litywater
[F]
Und
etec
tab
le -
100
Mo
ndal
et
al.,
2017
Ind
iaA
ctiv
ated
late
rite
60 -
504
Up
to
98
Yes
0.36
•Highlyeffectivean
dlo
w-cost
•Lo
wm
ainten
ance
•Nopowerre
quired
•Naturallyprepared
•Abun
dan
tlyavailablem
aterial
•Sc
alab
letola
rgescale
•Doesnotrequirere
gen
eration
•Doesnotleachup
ondisposal
•Highlocala
ccep
tanc
e
•Five
-yea
rlifespan
[AD
S, F
]<
10
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 13
Sark
ar e
t al
., 20
10In
dia
Act
ivat
ed a
lum
ina
or
hyb
rid a
nio
n
exch
ang
er a
s
adso
rben
t
140
—N
o ‡
0.74
(plu
s 16
06
cap
ital,
591
annu
al
mai
nten
ance
)
•Nosignifican
tA
s le
achi
ng•Produc
esharmfulsludge
•Slud
gerequiresdisposal
[AD
S]<
10 <
50 (i
ncre
ases
with
incr
easi
ng
bed
vo
lum
e)
Sen
Gup
ta e
t al
.,
2009
Ind
iaFe
rric
hyd
roxi
de
as
adso
rben
t
>50
—Ye
s0.
59•E
ffective
•Nosludgeproduc
ed
•Req
uiresinstallatio
nan
dequipmen
t(i.e.oxidation
sta
tion,
sto
rag
e ta
nk, p
ipel
ines
, etc
.)
[AD
S]<
10
Shafi
quz
zam
an e
t al
.,
2009
Ban
gla
des
hSo
no a
rsen
ic fi
lter
200
93N
o ‡
0.31
-0.3
3•Effe
ctive
•Highlocalsocialaccep
tanc
e
•Metthe
Ban
gladeshstan
dard(<
50µg/L)b
utnot
WH
O s
tand
ard
(<10
µg
/L)
•Highmainten
ance
cost
•Produc
essludge
•Slowflowrate
•La
ckoflong
-termsustainab
ility
[AD
S, P
,F]
14 ±
10
Shan
et
al.,
2013
Chi
naIro
n m
iner
als
and
limes
tone
318
- 63
5>
95
Yes
0.11
•Effe
ctivean
dlo
wcost
•Minim
alm
ainten
ance
•Su
itablefo
rrurala
reas
•Lo
callyavailablem
aterials
•Effe
ctiven
essdep
endsonpartic
lesise,
gro
und
wat
er p
H, a
nd r
atio
of l
imes
tone
to
Fe-
min
eral
in s
olid
mix
ture
•Rep
lace
men
tofm
ateriala
fter5yea
rs
•Le
aching
ofA
s af
ter
abso
rptio
n
[AD
S, C
,P,F
]<
10
Smith
et
al.,
2017
Chi
naM
od
ified
bio
-san
d
filte
r
226
- 24
086
- 9
5 N
o ‡
N/A
•Highlyeffective
•Can
purch
asematerialslo
cally
•Filte
rclogs
•Resea
rchonmonitorin
glo
ngtermA
s re
mo
val o
f the
filte
r ne
eded
[F]
<50
Vis
oo
ttiv
iset
h an
d
Ahm
ed, 2
008
Ind
ia,
Ban
gla
des
h
Act
ivat
ed a
lum
ina
met
al o
xid
e as
adso
rben
t
—90
- 9
6N
o ‡
1.17
-1.7
6•Highlyeffective
•Lo
wCost
•Sa
fedisposal
•Non-leacha
ble
•Sh
ortlifesp
an(three
tofo
urre
gen
erations)
•Onlyeffectivewith
pH5.5to6.0
•Req
uiresen
vironm
entallysafedisposalforresidua
ls
[AD
S]10
- 2
5
Vis
oo
ttiv
iset
h an
d
Ahm
ed.,
2008
— Ir
on
filin
gs
and
sand
as
adso
rben
t
—90
No
‡70
.5•Effe
ctive
•Exp
ensive
•Doesnotmee
tWHOstand
ard
[AD
S]<
27
‡ Th
e st
and
ard
of 5
0 µg
/L w
as m
et
Cost and Efficiency of Arsenic Removal from Groundwater: A Review14 14
use, especially if the technologies are not correctly used or maintained (Sarkar et al., 2010). Additionally, field studies may involve larger installation costs and ancillary costs for transportation or sludge disposal, for example (Sarkar et al., 2010; Amrose et al., 2014).
Conversely, laboratory studies may only consider the cost of producing the technology and not quantify the overall benefit to a community who may use them. There are more variables influencing the effectiveness and cost of field studies. For these reasons, researchers and decision-makers need to consider the implications of replicating laboratory results in the field.
The field experiments were predominantly conducted in Bangladesh and India, the countries with widely and severely arsenic-contaminated water sources (Rahman et al., 2001). Some studies aimed to reduce arsenic concentrations to national standards (such as 50 μg/L of Bangladesh) as opposed to the WHO standard of 10 μg/L. Lower targets are seen locally as being more feasible, considering the high degree of natural arsenic contamination of groundwater, and the limited availability of economic and infrastructural resources. As mentioned earlier, this approach constitutes only a partial solution. Also, some field studies only reported whether or not the national standard was met, without including specific effluent concentrations or removal efficiencies. In this contest, the ability of these filters to meet the WHO standard remained unclear.
Review limitations
This review suggests that there are gaps in the literature related to the cost of arsenic remediation technologies. The initial search yielded a high number of studies evaluating options labelled as ‘low-cost’ but lacked specific cost data. Consequently, these studies were not included in this review, even though they may have presented economically and technically viable options. It is important that future reports on ‘low-cost’ technologies provide specific costs associated with their production and use. The inconsistencies in the parameters used to assess cost between the reviewed studies limited direct comparison in some cases. For example, the total cost associated with point-of-use filters, which are typically used at the household level, depends on the cost and longevity of the filter apparatus, and the cost and capacity of each cartridge (Campos and Buchler, 2008). Costs associated with a community filter plant would depend on different factors, such as the plant’s installation, maintenance, and operation (Sarkar et al., 2010). In contrast, the laboratory studies included in this review typically only reported the cost of raw materials, which account for a portion of total costs required to use the technology in a household or community setting.
The studies reviewed also used a number of different standards to report on effectiveness. The standards chosen depended on the technology itself and the study design. For example, most of the laboratory studies examining adsorbents measured adsorption capacity, which is not applicable to other remediation processes such as electrocoagulation. Due to the difficulty in directly comparing the range of technologies, most literature reviews have focused on a specific category, such as adsorbents. This review used arsenic removal efficiency to compare various technologies, as it depends solely on arsenic influent and effluent concentrations. When comparing the removal efficiencies, it is important to consider the influent concentration of the contaminated water, as options demonstrating high removal efficiencies when treating moderately contaminated water may not be as efficient when treating highly contaminated water sources.
The water samples varied in their initial arsenic concentration and sources. Certain laboratory studies used only synthetically prepared samples (mixed clean water and contaminant), where other experiments used synthetic and in-situ groundwater. Arsenic removal depends on various parameters of the water sample, including the pH, the presence of other ions, and the initial arsenic concentration (Gao et al., 2011). The differences in these properties will influence the removal efficiency that is observed. This aspect was not accounted for in this review.
CONCLUSIONS AND RECOMMENDATIONS
One observation that emerged from this assessment was a that some countries have set a higher national threshold for arsenic content in water than the WHO limit of 10 µg/L. While this may help national policymakers report better results for their national arsenic reduction efforts, it may have the opposite effect on public health. Higher thresholds will not help solve this public health crisis. On the contrary, if a country has a feeling that the arsenic situation is coming under control, this may reduce the sense of urgency in policy circles to eradicate the problem, while the population continues to suffer from arsenic poisoning.
For technologies tested in the laboratory and the field, the key factors influencing the removal efficiencies include the concentration of arsenic in the influent water as well as the presence of other components. Technologies that demonstrate high removal efficiencies when treating moderately contaminated water may not be as efficient when treating highly contaminated water. The lifetime of the removal agents is also a significant factor in determining their efficiency. Key factors influencing the range of costs include materials used,
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 15
energy and labour required, regeneration period and geographical location.
Results suggest that technologies implemented in the field are marginally different in cost-effectiveness from those tested in the laboratory, except for the ZeroWater®. Technologies that demonstrate high removal efficiencies in the laboratory need further assessment to assess their suitability for larger-scale application, considering their high production and operation costs. However, costs can be reduced by using locally available materials and natural adsorbents, which provide near zero-cost options and are highly efficient for arsenic removal. In this review, the removal efficiencies for these technologies ranged from 50% to ~100%. Conversely, various household filters that have been tested in community-wide field studies are inexpensive but may exhibit lower removal efficiencies, high maintenance costs, and lower social acceptance.
The quantitative summary of costs and effectiveness of remediation technologies reported in peer-reviewed literature over more than 20 years (in English language publications – see Table 1) can be used as a preliminary guideline for selecting the most cost-effective remediation methods for arsenic-contaminated water. It can also possibly be used as an initial tentative format (minimum standard) for summarising the results of every new study describing arsenic remediation approaches. Moving forward, to “arsenic-free water world”, the following recommendations can be made.
More focus must be put on determining the market viability of remediation technologies. One of the major limitations to the practical application of existing arsenic remediation methods is a lack of attention to their market viability. As a result, methods proven to be effective in laboratory settings may remain trapped in the research and development phase and unable to continue to commercialization. This is true for environmentally-friendly, low-cost and simple arsenic removal methods which require follow-up field trials. Assessing market viability is crucial for attracting investment and developing efficient supply chains to make new arsenic removal technologies more accessible in remote regions.
Dealing with the practical limitations of existing remediation methods need to receive more attention. Limitations of existing remediation technologies may include high maintenance, issues of leaching and disposal of toxic components. Some methods that are effective and low-cost also result in secondary contaminants and require additional treatment or disposal. Other highly-effective and low-cost solutions require chemicals to synthesize the process, which may be impractical for regions without abundant access to these materials. Finally, many treatment solutions require
specific controlled conditions to be effective in removing arsenic from groundwater. This means that training needs to be provided. This factor has to be considered and includes in cost calculations if the technology is to be widely implemented.
Remediation methods must be contextually appropriate. A key challenge to the practical application of arsenic remediation technologies is that different contexts require different technologies. One technology [process] may work in one region but not in another. The viability and long-term sustainability of each technology are highly dependent upon its social acceptance, and this can be influenced by costs, access to materials, maintenance needs or cultural settings. Community willingness to use and maintain a technology are key factors that influence if an approach or technology can be effective in practice. Even if a technology is more expensive, it may be a more economical long-term solution when considering the reduced risk of microbial contamination and gastrointestinal illness.
For example, studies of arsenic-contaminated groundwater in West Bengal and Argentina using laterite (Bundschuh et al., 2011; Mondal et al., 2017) generated two very different results. In West Bengal, activated laterite proved to be extremely effective, scalable, low cost, low maintenance and with high local acceptance. In contrast, in Argentina, field trials with laterite found that remediation approaches met with varied social acceptance due to high transportation costs for laterite - depending on the area; and low absorption rates - depending on soils used.
An extensive study conducted by Ahmad et al. (2006) surveying 2700 rural households in Bangladesh found that 72% of the respondents would prefer a community-based system over a household filter due to its perceived convenience of use and maintenance. Users may also prefer more environmentally friendly options with moderate effectiveness over highly effective methods that produce toxic sludge as a byproduct, such as electrocoagulation (Hossain et al., 2015). Overall, the contextual appropriateness of technology for a particular setting or population needs to be assessed and understood, alongside the technology’s cost and removal efficiency.
A concerted effort to increase knowledge sharing across the global research and development community and across the regions is needed. A major obstacle to the practical application of arsenic remediation technologies at scale across affected areas is the lack of knowledge sharing at the R&D level on existing/proven methods. This leads to inefficiencies and duplication of effort in research and development. One example is a field study using household filters in Bangladesh (Hoque
Cost and Efficiency of Arsenic Removal from Groundwater: A Review16
et al., 2004) that recommended a shift from household filters to community-based water treatment solutions, as the former registered low social acceptability with the affected communities. Despite this, numerous subsequent reports continued to focus on developing low-cost household filters, ignoring field-based recommendations. They continued to develop methods that the local population had said were undesirable (Hoque et al., 2004; Amrose et al., 2014). Language barriers may add another obstacle to technology promotion and information exchange across regions.
Today, the current science and knowledge on arsenic remediation technologies may be mature enough to help significantly reduce the numbers of people affected by this public health problem. However, the effective translation of research evidence and laboratory-level successes into quantifiable and sustainable impacts on the ground requires a concerted and sustained effort
REFERENCES
Abdul, K. S. M., Jayasinghe, S. S., Chandana, E. P., Jayasumana, C., & De Silva, P. M. C. (2015). Arsenic and human health effects: A review. Environmental Toxicology and Pharmacology, 40(3), 828-846. DOI:10.1016/j.etap.2015.09.016.
Abernathy, C. O., Liu, Y. P., Longfellow, D., Aposhian, H. V., Beck, B., Fowler, B., Goyer, R., Menzer, R., Rossman, T., Thompson, C., & Waalkes, M. (1999). Arsenic: health effects, mechanisms of actions, and research issues. Environmental Health Perspectives, 107(7), 593-597. DOI: 10.1289/ehp.99107593
Ahmed, A. M., Alam, M. J. B., & Ahmed, A. M. (2011). Evaluation of socio-economic impact of arsenic contamination in Bangladesh. Journal of Toxicology and Environmental Health Sciences, 3(10), 298-307. Article No: 6BA27C93491
Ahmad, J., Goldar, B., & Misra, S. (2006). Rural communities’ preferences for arsenic mitigation options in Bangladesh. Journal of Water and Health, 4(4), 463-477. DOI: 10.2166/wh.2006.027
Alçada, A.J., Cardoso, S.J., & Duarte, A.A. (2009). Emerging and innovative techniques for arsenic removal applied to a small water supply system. Sustainability, 1(4), 1288-1304. DOI: 10.3390/su1041288
Amrose, S.E., Bandaru, S.R.S., Delaire, C., van Genuchten, C.M., Dutta, A., DebSarkar, A., Orr, C., Roy, J., Das, A., & Gadgil, A.J. (2014). Electro-chemical arsenic remediation: field trials in West Bengal. Science of the Total Environment, 488, 539-546. DOI: 10.1016/j.scitotenv.2013.11.074
Baig, S. A., Sheng, T., Hu, Y., Xu, J., & Xu, X. (2013). Arsenic removal from natural water using low cost granulated adsorbents: a review. CLEAN–Soil, Air, Water, 43(1), 13-26. DOI: 10.1002/clen.201200466
Barnaby, R., Liefeld, A., Jackson, B. P., Hampton, T. H., & Stanton, B. A. (2017). Effectiveness of table top water pitcher filters to remove arsenic from drinking water. Environmental Research, 158, 610-615. DOI: 10.1016/j.envres.2017.07.018
Bissen, M., & Frimmel, F. H. (2003). Arsenic—a review. Part II: oxidation of arsenic and its removal in water treatment. CLEAN–Soil, Air, Water, 31(2), 97-107. DOI: 10.1002/aheh.200300485
Bordoloi, S., Nath, S. K., Gogoi, S., & Dutta, R. K. (2013). Arsenic and iron removal from groundwater by oxidation–coagulation at optimized pH: laboratory and field studies. Journal of Hazardous Materials, 260, 618-626. DOI: 10.1016/j.jhazmat.2013.06.017
Brinkel, J., Khan, M. H., & Kraemer, A. (2009). A systematic review of arsenic exposure and its social and mental health effects with special reference to Bangladesh. International Journal of Environmental Research and Public Health, 6(5), 1609-1619. DOI: 10.3390/ijerph6051609
from policymakers, engineers, healthcare providers, donors, and community leaders.
ACKNOWLEDGEMENTS
Thanks are due to Dr. Vladimir Smakhtin and Dr. Manzoor Qadir (both – UNU-INWEH) for the editorial comments on the report and Dr. Hamid Mehmood (UNU-INWEH) for conducting the Scopus database search of arsenic-related publications. We would like to acknowledge the time and support of Denise Smith, the Librarian of the Health Sciences Library at McMaster University, in constructing the search strategy. We are also grateful to Dr. Sanmugam A. Prathapar of the Asian Development Bank who provided an insightful review of the manuscript. This research is supported by the funds received by UNU-INWEH through the long-term agreement with Global Affairs Canada.
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 17
Bundschuh, J., Bhattacharya, P., Sracek, O., Mellano, M., Ramírez, A.; Storniolo, A., Martín, R., Cortes, J., Litter, M. & Jean, J.-S. (2011). Arsenic removal from groundwater of the Chaco-Pampean Plain (Argentina) using natural geological materials as adsorbents. Journal of Environmental Science and Health, Part A, 46(11), 1297-1310. DOI: 10.1080/10934529.2011.598838
Bundschuh, J., Litter, M., Ciminelli, V. S., Morgada, M. E., Cornejo, L., Hoyos, S. G., Hoinkis, J, Alarcón-Herrera, M. T., Armienta, M.A., & Bhattacharya, P. (2010). Emerging mitigation needs and sustainable options for solving the arsenic problems of rural and isolated urban areas in Latin America–A critical analysis. Water Research, 44(19), 5828-5845. DOI: 10.1016/j.watres.2010.04.001
Campos, V., & Buchler, P. M. (2008). Trace elements removal from water using modified activated carbon. Environmental Technology, 29(2), 123-130. DOI: 10.1080/09593330802028295.
Carlin, D. J., Naujokas, M. F., Bradham, K. D., Cowden, J., Heacock, M., Henry, Lee, J. S., Thomas, D. J., Thompson, C., Tokar, E. J., Waalkes, M. P., Birnbaum, L.S. & Suk, W, A. (2016). Arsenic and environmental health: state of the science and future research opportunities. Environmental Health Perspectives, 124(7), 890-899. DOI: 10.1289/ehp.1510209
Chakravarty, S., Dureja, V., Bhattacharyya, G., Maity, S., & Bhattacharjee, S. (2002). Removal of arsenic from groundwater using low cost ferruginous manganese ore. Water Research, 36(3), 625-632. DOI: 10.1016/S0043-1354(01)00234-2
Chen, J., Wang, S., Zhang, S., Yang, X., Huang, Z., Wang, C., Wei, Q., Zhang, G., Xiao, J., Jiang, F., Chang, J., Xiang, X., & Chang, J. (2015). Arsenic pollution and its treatment in Yangzonghai lake in China: In situ remediation. Ecotoxicology and Environmental Safety, 122, 178-185. DOI: 10.1016/j.ecoenv.2015.07.032
Chung, J. Y., Yu, S. D., & Hong, Y. S. (2014). Environmental source of arsenic exposure. Journal of Preventive Medicine and Public Health, 47(5), 253-257. DOI: 10.3961/jpmph.14.036
Clifford, D, A., Sorg, T. J., Ghurye, G. L. (1990) Ion exchange and inorganic adsorption In: Pontius F (Eds) Water Quality and Treatment. (pp. 1-90), American Water Works Association, McGraw Hill, New York.
Cui, J., Jing, C., Che, D., Zhang, J., & Duan, S. (2015). Groundwater arsenic removal by coagulation using ferric (III) sulfate and polyferric sulfate: a comparative and mechanistic study. Journal of Environmental Sciences, 32, 42-53. DOI: 10.1016/j.jes.2014.10.020
de Esparza, M. C. (2006). Removal of arsenic from drinking water and soil bioremediation. In Natural arsenic in groundwater of Latin America international congress (pp. 20-24). Retrieved from http://www.bvsde.ops-oms.org/bvsacd/cd51/arsenic-water.pdf
Duker, A. A., Carranza, E., & Hale, M. (2005). Arsenic geochemistry and health. Environment International, 31(5), 631-641. DOI: 10.1016/j.envint.2004.10.020
EFSA- European Food Safety Authority. (2014). Dietary exposure to inorganic arsenic in the European population. EFSA Journal, 12(3), 3597. DOI: 10.2903/j.efsa.2014.3597
EAWAG (2015) Geodenic contamination handbook – Addressing Arsenic and Fluoride in drinking water. C.A. Johnson, A. Bretzler (Eds.) Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dubendorf, Switzerland
Figoli, A., Hoinkis, J. and Bundschuh, J. (Eds.) (2016). Membrane technologies for water treatment: Removal of toxic trace elements with emphasis on arsenic, fluoride and uranium. Boca Raton: CRC Press. (Sustainable water developments, Volume 1).
Flanagan, S. V., Johnston, R. B., & Zheng, Y. (2012). Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation. Bulletin of the World Health Organization, 90(11), 839-846. DOI: 10.2471/BLT.11.101253
Gao, X., Wang, Y., Hu, Q., & Su, C. (2011). Effects of anion competitive adsorption on arsenic enrichment in groundwater. Journal of Environmental Science and Health, Part A, 46(5), 471-479. DOI: 10.1080/10934529.2011.551726
Garelick, H., Dybowska, A., Valsami-Jones, E., & Priest, N. (2005). Remediation technologies for arsenic contaminated drinking waters. Journal of Soils and Sediments, 5(3), 182-190. DOI: 10.1065/jss2005.06.140
Hasan, M. M., Shafiquzzaman, M., Nakajima, J., & Bari, Q. H. (2012). Application of a simple arsenic removal filter in a rural area of Bangladesh. Water Science and Technology: Water Supply, 12(5), 658-665. DOI: 10.2166/ws.2012.039
He, J., Bardelli, F., Gehin, A., Silvester, E., & Charlet, L. (2016). Novel chitosan goethite bio-nanocomposite beads for arsenic remediation. Water Research, 101, 1-9. DOI: 10.1016/j.watres.2016.05.032.
Hoque, B. A., Hoque, M. M., Ahmed, T., Islam, S., Azad, A. K., Ali, N., Hossain, M., & Hossain, M. S. (2004). Demand-based water options for arsenic mitigation: an experience from rural Bangladesh. Public Health, 118(1), 70-77. DOI: 10.1016/S0033-3506(03)00135-5
Cost and Efficiency of Arsenic Removal from Groundwater: A Review18
Hughes, M. F., Beck, B. D., Chen, Y., Lewis, A. S., & Thomas, D. J. (2011). Arsenic exposure and toxicology: a historical perspective. Toxicological Sciences, 123(2), 305-332. DOI: 10.1093/toxsci/kfr184
Inauen, J., Hossain, M. M., Johnston, R. B., & Mosler, H. J. (2013). Acceptance and use of eight arsenic-safe drinking water options in Bangladesh. PLoS One, 8(1), e53640. DOI: 10.1371/journal.pone.0053640
Kabir, F. and Chowdhury, S. (2017). Arsenic removal methods for drinking water in the developing countries: technological developments and research needs. Environmental Science and Pollution Research, 24 (31), 24102-24120. DOI: 10.1007/s11356-017-0240-7
Kato, M., Kumasaka, M. Y., Ohnuma, S., Furuta, A., Kato, Y., Shekhar, H. U., Kojima, M., Koike, Y., Nguyen Dinh Thang, N. D., Ohgami, N., Ly, T. B., Xiaofang Jia, X., Yetti, H., Naito, H., Ichihara, G., & Yajima, I. (2013). Comparison of barium and arsenic concentrations in well drinking water and in human body samples and a novel remediation system for these elements in well drinking water. PloS One, 8(6). DOI: 10.1371/journal.pone.0066681
Katsoyiannis, I. A., & Zouboulis, A. I. (2004). Application of biological processes for the removal of arsenic from groundwaters. Water Research, 38(1), 17-26. DOI: 10.1016/j.watres.2003.09.011
Kim, J., Mann, J. D., & Spencer, J. G. (2006). Arsenic removal from water using lignocellulose adsorption medium (LAM). Journal of Environmental Science and Health Part A, 41(8), 1529-1542. DOI: 10.1080/10934520600754284
Kumasaka, M. Y., Yamanoshita, O., Shimizu, S., Ohnuma, S., Furuta, A., Yajima, I., Nizam, S., Khalequzzaman, M., Shekhar, H. U., Nakajima, T. & Kato, M. (2013). Enhanced carcinogenicity by coexposure to arsenic and iron and a novel remediation system for the elements in well drinking water. Archives of Toxicology, 87(3), 439-447. DOI: 10.1007/s00204-012-0964-6 Lee, J. Y., Chaimongkalayon, N., Lim, J., Ha, H. Y., & Moon, S. H. (2016). Arsenic removal from groundwater using low-cost carbon composite electrodes for capacitive deionization. Water Science and Technology, 73(12), 3064-3071. DOI: 10.2166/wst.2016.135 Liao, V. H. C., Chu, Y. J., Su, Y. C., Hsiao, S. Y., Wei, C. C., Liu, C. W., Liao, C. M., Shen, W. C., & Chang, F. J. (2011). Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan. Journal of Contaminant Hydrology, 123(1-2), 20-29. DOI: 10.1016/j.jconhyd.2010.12.003.
Mahmood, S. A. I., & Halder, A. K. (2011). The socioeconomic impact of Arsenic poisoning in Bangladesh. Journal of Toxicology and Environmental Health Sciences, 3(3), 65-73. Article No: 1AEF32A1062
Majumder, S., Nath, B., Sarkar, S., Islam, S. M., Bundschuh, J., Chatterjee, D., & Hidalgo, M. (2013). Application of natural citric acid sources and their role on arsenic removal from drinking water: A green chemistry approach. Journal of Hazardous Materials, 262, 1167-1175. DOI: 10.1016/j.jhazmat.2012.09.007
Mamtaz, R., & Bache, D. H. (2000). Low-Cost Separation of Arsenic from Water: With Special Reference to Bangladesh. Water and Environment Journal, 14(4), 260-269. DOI: 10.1111/j.1747-6593.2000.tb00259.x
Mathieu, J. L., Gadgil, A. J., Addy, S. E., & Kowolik, K. (2010). Arsenic remediation of drinking water using iron-oxide coated coal bottom ash. Journal of Environmental Science and Health, Part A, 45(11), 1446-1460. DOI: 10.1080/10934529.2010.500940.
Misbahuddin, M. I. R., & Fariduddin, A. T. M. (2002). Water hyacinth removes arsenic from arsenic-contaminated drinking water. Archives of Environmental Health: An International Journal, 57(6), 516-518. DOI: 10.1080/00039890209602082
Mohan, D., & Pittman Jr, C. U. (2007). Arsenic removal from water/wastewater using adsorbents—a critical review. Journal of Hazardous Materials, 142(1-2), 1-53. DOI: 10.1016/j.jhazmat.2007.01.006
Mondal, S., Roy, A., Mukherjee, R., Mondal, M., Karmakar, S., Chatterjee, S., Mukherjee, M., Bhattacharjee, S., & De, S. (2017). A socio-economic study along with impact assessment for laterite based technology demonstration for arsenic mitigation. Science of the Total Environment, pp. 583, 142-152. DOI: 10.1016/j.scitotenv.2017.01.042
Naujokas, M. F., Anderson, B., Ahsan, H., Aposhian, H. V., Graziano, J. H., Thompson, C., & Suk, W. A. (2013). The broad scope of health effects from chronic arsenic exposure: update on a worldwide public health problem. Environmental Health Perspectives, 121(3), 295-302. DOI: 10.1289/ehp.1205875
Ng, J. C., Wang, J., & Shraim, A. (2003). A global health problem caused by arsenic from natural sources. Chemosphere, 52(9), 1353-1359. DOI: 10.1016/S0045-6535(03)00470-3
Cost and Efficiency of Arsenic Removal from Groundwater: A Review 19
Nguyen, T. V., Nguyen, T. V. T., Pham, T. L., Vigneswaran, S., Ngo, H. H., Kandasamy, J., Nguyen, H. K., & Nguyen, D. T. (2009). Adsorption and removal of arsenic from water by iron ore mining waste. Water Science and Technology, 60(9), 2301-2308. DOI: 10.2166/wst.2009.667
Pokhrel, D., & Viraraghavan, T. (2009). Biological filtration for removal of arsenic from drinking water. Journal of Environmental Management, 90(5), 1956-1961. DOI: 10.1016/j.jenvman.2009.01.004
Rahman, M. M., Chowdhury, U. K., Mukherjee, S. C., Mondal, B. K., Paul, K., Lodh, D., Biswas, B. K., Chanda, C. R., Basu, G. K., Saha, K. C., Roy, S., Das, R., Palit, S. K., Quamruzzaman, Q., & Chakraborti, D. (2001). Chronic arsenic toxicity in Bangladesh and West Bengal, India—a review and commentary. Journal of Toxicology: Clinical Toxicology, 39(7), 683-700. DOI: 10.1081/CLT-100108509
Ravenscroft, P., Brammer, H. and Richards, K. (2009) Arsenic Pollution: A Global Synthesis. (588 pp), Wiley-Blackwell, Chichester, UK.
Sancha, A. M. (2006). Review of coagulation technology for removal of arsenic: case of Chile. Journal of Health, Population, and Nutrition, 24(3), 267-272. PMCID: PMC3013246
Sarkar, S., Greenleaf, J. E., Gupta, A., Ghosh, D., Blaney, L. M., Bandyopadhyay, P., BiswasbAmal, R. K., Dutta, K., & Sen-Gupta, A. K. (2010). Evolution of community-based arsenic removal systems in remote villages in West Bengal, India: assessment of decade-long operation. Water Research, 44(19), 5813-5822. DOI: 10.1016/j.watres.2010.07.072
Schwarzenbach, R., Egli, T., Hofstetter, T., von Gunten, U. and Wehrli, B. (2010). Global Water Pollution and Human Health. Annual Review of Environment and Resources. DOI: 10.1146/annurev-environ-100809-125342
Sen Gupta, B., Chatterjee, S., Rott, U., Kauffman, H., Bandopadhyay, A., DeGroot, W., Nag, N. K., Carbonell-Barrachina, A. A. & Mukherjee, S. (2009). A simple chemical free arsenic removal method for community water supply–A case study from West Bengal, India. Environmental Pollution, 157(12), 3351-3353. DOI: 10.1016/j.envpol.2009.09.014
Shafiquzzaman, M., Azam, M. S., Mishima, I., & Nakajima, J. (2009). Technical and social evaluation of arsenic mitigation in rural Bangladesh. Journal of Health, Population, and Nutrition, 27(5), 674-683. PMCID: PMC2928078
Shan, H., Ma, T., Wang, Y., Zhao, J., Han, H., Deng, Y., Xin, H., & Dong, Y. (2013). A cost-effective system for in-situ geological arsenic adsorption from groundwater. Journal of Contaminant Hydrology, 154, 1-9. DOI: 10.1016/j.jconhyd.2013.08.002
Singh, R., Singh, S., Parihar, P., Singh, V. P., & Prasad, S. M. (2015). Arsenic contamination, consequences and remediation techniques: a review. Ecotoxicology and Environmental Safety, 112, 247-270. DOI: 0.1016/j.ecoenv.2014.10.009
Smith, A. H., Lingas, E. O., & Rahman, M. (2000). Contamination of drinking-water by arsenic in Bangladesh: a public health emergency. Bulletin of the World Health Organization, 78(9), 1093-1103. PMCID: PMC2560840 Smith, K., Li, Z., Chen, B., Liang, H., Zhang, X., Xu, R., Li, Z., Dai, H., Wei, C., & Liu, S. (2017). Comparison of sand-based water filters for point-of-use arsenic removal in China. Chemosphere, 168, 155-162. DOI: 10.1016/j.chemosphere.2016.10.021
Tchounwou, P. B., Patlolla, A. K., & Centeno, J. A. (2003). Invited reviews: carcinogenic and systemic health effects associated with arsenic exposure—a critical review. Toxicologic Pathology, 31(6), 575-588. DOI: 10.1080/01926230390242007
Thakur, L. S., & Mondal, P. (2017). Simultaneous arsenic and fluoride removal from synthetic and real groundwater by electrocoagulation process: parametric and cost evaluation. Journal of Environmental Management, 190, 102-112. DOI: 10.1016/j.jenvman.2016.12.053
Tu, S., Ma, L. Q., Fayiga, A. O., & Zillioux, E. J. (2004). Phytoremediation of arsenic-contaminated groundwater by the arsenic hyperaccumulating fern Pteris vittata L. International Journal of Phytoremediation, 6(1), 35-47. DOI: 10.1080/16226510490439972
Twidell, L.G., Robins, R.G., Hohn, J.W., 2005. The removal of arsenic from aqueous solution by coprecipitation with iron (III). In: Reddy, R.G., Ramachandran, V. (Eds.), Arsenic Metallurgy. TMS (The Minerals, Metals & Materials Society) (pp. 3-24), Warrendale, PA.
Visoottiviseth, P., & Ahmed, F. (2008). Technology for remediation and disposal of arsenic. In D. M. Whitacre, H. Garelick, & H. Jones (Eds.), Reviews of Environmental Contamination Volume, 197 (pp. 77-128). New York, NY: Springer.
Wickramasinghe, S. R., Han, B., Zimbron, J., Shen, Z., & Karim, M. N. (2004). Arsenic removal by coagulation and filtration: comparison of groundwaters from the United States and Bangladesh. Desalination, 169 (3), 231-244. DOI: 10.1016/j.desal.2004.03.013
Cost and Efficiency of Arsenic Removal from Groundwater: A Review20
WHO- World Health Organization. (2011). Guidelines for drinking-water quality (4th ed.). Retrieved from http://apps.who.int/iris/bitstream/handle/10665/44584/9789241548151_eng.pdf
WHO- World Health Organization. (2018). Arsenic [Fact sheet no. 372]. Retrieved from http://www.who.int/mediacentre/factsheets/fs372/en/
Yavuz, C. T., Mayo, J. T., Suchecki, C., Wang, J., Ellsworth, A. Z., D’Couto, H., Quevedo, E., Prakash, A., Gonzalez, L., Nguyen, C., Kelty, C., & Colvin, V. L. (2010). Pollution magnet: nano-magnetite for arsenic removal from drinking water. Environmental Geochemistry and Health, 32(4), 327-334. DOI: 10.1007/s10653-010-9293-y
Yunus, F., Khan, S., Chowdhury, P., Milton, A., Hussain, S. & Rahman, M. (2016). A Review of Groundwater Arsenic Contamination in Bangladesh: The Millenium Development Goal Era and Beyond. International Journal of Environmental Research and Public Health, 13 (215): 1-18. DOI: 10.3390/ijerph13020215
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