1st Block: Decentralized WWT Systems (10:30 11:30) 2nd (11 ... · • Advantages: simple, durable, underground, area required: 0,5m²/m³ wwpd • Disadvantages: only pre-treatment,

1st Block: Decentralized WWT Systems (10:30 – 11:30)

• Definition of decentralized wastewater management

in Germany and in Jordan

• Technologies for decentralized wastewater treatment

2nd Block: Exercise: Decentralized WWT – City Sanitation Planning

(11:30 – 12:30)

3rd Training Block: Organization of Decentralized WWT (13:15 -14:45)

• Operational/business models for decentralized wastewater manage-

ment

• Financing of decentralized wastewater management

• Operation and maintenance of decentralized wastewater treatment

systems

Overview Training Blocks

Decentralized WWTS, T. Reckerzügl, 26.09.2016

Decentralised wastewater treatment systems

1st Block

Thorsten Reckerzügl, BORDA, 26.09.2016

Training financed by GIZ - BMZ




1st Training Block:

Decentralized WWT Systems


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Size structure of wastewater treatment facility operators

in Germany 2010

(without DWWT)

German Wastewater Ordinance, Annex 1


Size classificationCOD

(mg/l)

BOD5

(mg/l)

NH4-N

(mg/l)

Ntotal

(mg/l)

Ptotal

(mg/l)

1

< 1.000 pe

150 40 - - -

2

< 5.000 pe

110 25 - - -

3

< 10.000 pe

90 20 10 - -

4

< 100.000 pe

90 20 10 18 2

5

> 100.000 pe

75 15 10 13 1

pe – population equivalents

No clear definition of decentralized WWT exist in Germany (smooth

transition).

Common understanding:

• Decentralized WWT exist where single houses or some neighboring

houses have an individual WWTS (normally no pubic sewer)

• WWTS’s operated by a municipality can be understood as semi-

centralized or centralized system depending on the size.

• WWTS operated by bigger municipalities and by multiple

municipalities can be classified as centralized systems

Decentralised WWT in Germany


single houses - housing clusters - settlements – municipality - multiple municipalities

decentralized semi-centralized centralized

Small sewage treatment plants for WWT below 50 population equivalent (pe).

• They are commonly applied in individual houses, small villages etc. where connection to large municipal WWTS is not possible for technical, legal or financial reasons

• A whole range of technical solutions from simple, cheap to expensive high-tech solutions exists

• For a long time small sewage treatment plants have not been a standard solution in Germany

• Understanding changed in the last 20 years. It is now more common to consider DWWT where the right framework conditions exist

Def. small sewerage treatment plant


• For a long time centralised treatment systems (96% coverage) have

been in favour of decentralised solutions (3% coverage).

• Central WWT very sophisticated with high coverage and discharge

standards.

• But Germanys existing sewerage systems has evolved in a period of

150 to 200 years. Investment cost are very high. Replication on a

short term would not be feasible.

• It can be questioned whether a lot of these centralised systems

especially in rural settings are the most cost efficient and

sustainable solution.

• Views have changed meanwhile and decentralised systems are

more accepted. But also in future they will probably play a minor role

since centralised system coverage is already very high.

Conclusion Decentralised WWT in

Germany


Titel der Präsentation/Name des Autors/Datum

• What is the status of decentralized WWT in Jordan?

• What is the current way forward?

• What is different to the situation on Germany?

Decentralised WWT in Jordan

Decentralsied WWTS, T. Reckerzügl, 26.09.2016

Demo Site Fuhais, Jordan Source: UFZ Leipzig

• Strong National Framework for decentralized treatment of

domestic WW exists

• Decentralized WWT has been identified and is promoted as

sustainable solution for rural and suburban communities

• It has been identified that a strict framework is required to

assure effectiveness and sustainability of the sector

• Decentralized WWT is understood as a complementary

approach to centralized WWT in rural and suburban settings

• Under this conditions Decentralized WWT are seen as more

cost effective, reliable, resource efficient, environmental friendly,

and equal convenient

• Strong emphasize on groundwater protection and freshwater

substitution (reuse & recharge of aquifers)

Jordan National Framework for

decentralized WWT


Jordan's National Implementation

Committee (NICE) and framework topics


Source: Effective Decentralized Wastewater Policy, MWI & NICE, 2015

• Groundwater Protection: (a) contamination hotspots, (b) WW mgt. in groundwater protection zones

• Technology Selection: 25 technical modules are listed and procedure for multi criteria analysis is proposed

• Urban Planning: (a) enforce structured planning. (b) integrate WW planning

• Participatory Planning: CLUES (Community-Led Urban Environmental Sanitation Planning)

• Economic Feasibility: ALLOWS (Assessment of Local Lowest –Cost wastewater solutions

• Standards & Monitoring: Requirements < 500 pe and between 500 and 5000 are different; Standards vary depending on discharge option, multi barrier approach for irrigation is proposed

• Operation & Maintenance: Technical and Institutional Challenges are identified and Operator models are summarized

NICE framework topics


Jordan's three categories for Decentralized

WWT



Discharge standards for WWTS of 501 to

5000 pe




500 pe



• Standards equal to 50 to 500 pe discharge standard; except for TSS

standard

• Secondary biological treatment compulsory


49 pe


• Very comprehensive and innovative framework for

decentralized WWT exist in Jordan

• If this can be put into practice on a large scale, Jordan

has a very good practice example for complementary

approaches of centralized and decentralized WWT on

national level.

• For successful implementation of this framework an

emphasize should be put on sustainable finance,

performance monitoring, operator models and O&M, as

well as user awareness and willingness to contribute.

Conclusion Decentralised WWT in

Jordan



Comparison between Decentralized

and Centralized Systems

• Centralized

– High capital costs

(especially of sewer lines)

– Energy intensive

(especially where pumping

is required)

– Requires skilled, fulltime

man power

– System failure affects the

entire settlement

– Centralized and therefore

more complex for O&M

– Treatment costs may be

lesser than DEWATS

– Low social control

• Decentralized

– Shallow sewers reduce

overall costs considerably

– Almost no electrical energy

is required

– Less skilled man power

required

– Effects of system failure is

localized

– Sustainability (less risky,

easier reuse)

– Easy to add units/scale up

– Also require proper

management and O&M

– Chance for TAP high20

Whether a centralized, a semi centralized decentralized clustered or a

completely decentralized system is the best choice depends on framework

conditions (mostly similar to points from Jordan's Decentralized WW policy):

Systems choice & framework conditions


Framework conditions Relevant factors

Economy Settlement structure, discharge standards …

Safety Health, environmental safety, resource efficiency, disaster risk (flood, drought) …

Environment/ Natural resources Groundwater, ecosystems, GHG, space availability…

Operation & Maintenance WW composition (variation), HR, finances, accessibility, electricity …

Social Cultural acceptance, experiences, participation …

Legislation Effluent values, monitoring schemes …

… …

Multi criteria analysis for technology choice



Summer of key issues for DWWT


Key issues for decentralization in municipal wastewater treatment, Bernal, Restrepo, 2012

SDG will have substantial influence on

WW policy and practice


Other relevant agreements:

• UN Climate Change Conference, COP 21

• Sendai Framework for Disaster Risk Reduction

• Conf. on Financing Developm. Adis Abbeba

• Habitat III, Quito

SDG‘s require a more holistic and complex

approach on water & sanitation





1st Training Block:

Decentralized WWT Systems


DEWATS- Combination of Treatment

systems

sedimentation pond biogas digester

Sedimentationseptic tank

Anaerobic

digestion

Aerobic and

facultative

decomposition

Post treatment

aerobic-facultative ponds and aerobic polishing ponds

Other systems such as UASB, sequencing batch reactors, rotating discs, activated sludge reactors, etc. do currently not belong to DEWATS

Wastewater Treatment Systems (DEWATS)

anaerobic filter anaerobic baffled reactor

planted gravel filter

Primary treatment• Anaerobic treatment unit (no oxygen)

• Biogas (methane and carbon dioxide) formed due to the anaerobic digestion of settled organic matter in the biogas settler

• Treatment efficiency 25% to 40% organic matter

Raw sewagepartially treated

wastewater

Sludge Sludge

Scum

Biogas

Septic Tank

• Kind of treatment: sedimentation, sludge stabilisation,

CODrem 20 - 50%

• Type of wastewater: domestic and others with settleable

solids

• Advantages: simple, durable, underground, area

required: 0,5m²/m³ wwpd

• Disadvantages: only pre-treatment,

effluent not odourless

Characteristics of Septic Tanks

Imhoff-Tank

►Sedimentation

► Protection against upflow of sludge particles

► Fermentation of bottom sludge

cross section

longitudinal section

Inflow

Outflow

Floatation

outside

funnel

Sedimen-

tation

inside

funnel

Imhoff Tank

Cross Section Longitudinal Section

liquid

flow tank scum

sludge

1

2

3

• Imhoff-Tank before placing the cover

DEWATS

Treatment Systems.

Characteristics of Imhoff-Tanks

• Kind of Treatment: Sedimentation, sludge

stabilisation, CODrem 20 - 50%

• Type of wastewater: Domestic and others with

settleable solids

• Advantages: Simple, durable, underground,

odourless effluent, area required: 0,5m²/m³ wwpd

• Disadvantages: Less simple than septic tank,

needs very regular desludging

Secondary treatment• Anaerobic treatment unit (no oxygen)

• Activated sludge formation at the bottom of each chamber

• Treatment efficiency 75% - 85% organic matter

part. treated

wastewater

from settler

Biogas

Activated

Sludge

Gas Gas

partially treated

wastewater

Anaerobic Baffled Reactor

Characteristics of Anaerobic Baffled

Reactors

• Kind of Treatment: Anaerobic degradation of suspended

and dissolved solids, CODrem 60 - 90%

• Type of wastewater: Pre-settled domestic & strong

industrial wastewater of narrow COD/BOD ratio

• Advantages: Simple, reliable and durable, high

efficiency, underground, area required: 1 m²/m³ wwpd

• Disadvantages: Larger space during construction, less

efficient with weak wastewater, longer time for

maturation

Principle of the Anaerobic Filter

• Sedimentation/floatation of solids

• Anaerobic digestion of suspended and dissolved matter inside the filter

• Anaerobic digestion (fermentation) of bottom sludge

gas manhole

inflow

outflow

sedimentation tank filter units

sludge

scum

Different packing materials

• kind of treatment: anaerobic degradation of suspended • and dissolved solids, CODrem 65 - 85%

• Type of wastewater: pre-settled domestic and industrial • wastewater of narrow COD/BOD ratio

• Advantages: simple and durable if well constructed, high treatment efficiency, underground, area required: 1 m²/m³ wwpd

• Disadvantages: costly in construction because of filter material, clogging possible, effluent smells slightly

Characteristics of Anaerobic Filters

Principle of the Vertical Filter

plants keep filter surface porous

flooded with wastewater

fine sand

coarse sand

coarse gravel

ventilated channel

O2O2

O2

O2

O2

O2O2

O2

O2

waste

water

• submerged for equal distribution of wastewater through flush charging

• oxygen follows the percolating wastewater by vacuum

• oxygen is available for decomposition during resting time

• plants keep filter

• surface porous

• Continuous oxygen supply to the upper layers only

• Anaerob-facultative conditions in the lower layers

• Roots of plants provide favourable environment for bacteria diversity

internal water level

inflow manhole

upper sand layer central outlet shaft

final outlet

cross

distribution

trench filled

with rocks

main filter body filled with coars gravel cross

collection

trench filled

with rocks

perforated pipe

connected to

swivel pipe for

adjustable height

O2O2O2O2

Principle of the Horizontal Filter

• Horizontal filter and polishing pond for a bungalow

• (Auroville, Tamil Nadu, India, CSR)

DEWATS

Treatment Systems.

Characteristics of Horizontal

Gravel Filters

• Kind of treatment: Aerobic-facultative-anaerobicdegradation of dissolved and fine suspendedsolids,CODrem 60 - 95%

• Type of wastewater: Suitable for pre-treated domesticand weak industrial wastewater

• Advantages: High treatment efficiency when properlydesigned and constructed, pleasantlandscaping possible, no wastewater above ground, no nuisance of odour

• Disadvantages: Large permanent space, costly, difficult construction, experienced supervisionrequired in the beginning, area required: 30m²/m³ wwpd

Principle of Treatment Ponds

Treatment Ponds

Aerobic-facultative pond at a rice mill (SIITRAT, Delhi)

Characteristics of Anaerobic Ponds

► Kind of treatment: sedimentation, anaerobic degradation,

sludge stabilisation, CODrem 50 - 70%

► Adequacy: strong and medium industrial wastewater

► Maintenance: regular removal of scum and aquatic plants,

every 2 to 5 years: removal of sludge

► Advantages: simple in construction, flexible degree of

treatment, little maintenance, no electrical energy and

chemicals required

► Disadvantages: occupies open land, can be stinky, difficult

mosquito control, area required: 4m²/m³ wwpd

Caracteristic of Aerobic Ponds

► Kind of treatment: aerobic-facultative degradation, pathogen

reduction, CODrem 60 - 95%

► Adequacy: weak, pre-treated domestic and industrial wastewater

► Maintenance: regular removal of scum and aquatic plants, every 2

to 5 years: removal of sludge

► Advantages: simple in construction, reliable if properly designed,

high pathogen removal rate, fish farming possible, no electrical

energy and chemicals required

► Disadvantages: large permanent space requirement, mosquitoes

and odour can become a nuisance if undersized, algae can

increase effluent BOD, area required: 25m²/m³ wwpd

BODin CODin BODout CODout

333 625 10 22

Byproducts of the process & re-use

Irrigation

Gardening

Flushing

Cooking

Heating

Lighting

Treated Water Biogas Sludge

Horticulture

Sludge Drying

Closing the loop

Laundry

Toilet

Kitchen

Sources of WastewaterUse of treated

WW for Gardening &

Flushing Use of Sludge for Gardening

Use of residues for Biogas

DEWATS- Combination of Treatment

systems

sedimentation pond biogas digester

Sedimentationseptic tank

Anaerobic

digestion

Aerobic and

facultative

decomposition

Post treatment

aerobic-facultative ponds and aerobic polishing ponds

Other systems such as UASB, sequencing batch reactors, rotating discs, activated sludge reactors, etc. do currently not belong to DEWATS

Wastewater Treatment Systems (DEWATS)

anaerobic filter anaerobic baffled reactor

planted gravel filter

DEWATS Applications at Aravind Eye

Hospital Chennai, India

52

DEWATS Aravind Eye Hospital, India


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• Decentralized Wastewater Treatment Systems (DEWATS) and Sanitation in Developing Countries – A Practical Guide

• CLUES Guideline (https://www.eawag.ch/fileadmin/ Domain1/Abteilungen/sandec/schwerpunkte/sesp/CLUES/CLUES_Guidelines.pdf)

• Compendium of Sanitation Systems and Technologies, EAWAG/ Sandec; http://www.iwa-network.org/wp-content/uploads/2016/06/Compendium-Sanitation-Systems-and-Technologies.pdf

• SWWM online-compendium; http://www.sswm.info/

• MOOC EAWAG/ SANDEC: e.g. Planning & Design of Sanitation Systems and Technologies, https://www.youtube.com/watch?v=bNSQz3zInwM

Further Information on

Decentralised WWT


https://www.eawag.ch/fileadmin/Domain1/Abteilungen/sandec/schwerpunkte/sesp/CLUES/CLUES_Guidelines.pdf

http://www.iwa-network.org/wp-content/uploads/2016/06/Compendium-Sanitation-Systems-and-Technologies.pdf

http://www.sswm.info/

https://www.youtube.com/watch?v=bNSQz3zInwM

water, sanitation, energy: essential public services for all.

Thorsten Reckerzügl

Regional Advisor West & Central Asia

E-Mail [email protected]

Phone +49.421.40 89 52 – 29

Thank you very much!


1st Block: Decentralized WWT Systems (10:30 11:30) 2nd (11 ... · • Advantages: simple, durable, underground, area required: 0,5m²/m³ wwpd • Disadvantages: only pre-treatment,

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