Wastewatertreatment
Clean WaterTreatment
Wastewatertreatment
Clean WaterTreatment
About Dryden Aqua
• Started trading 1984, focus molecular sieve ion exchange filtration
• Primarily a research and development company, initial focus, water treatment in aquaculture & aquarium systems
• New products had to be developed to try and resolve water treatment issues. One of our main products is AFM (Active Filter Media)
• Dryden Aqua became a manufacturing company
• Products and technology now applied to;• Aquaculture & Public aquaria• Swimming pools• Landfill leachate• Drinking water , surface, borehole and ground water• Pre-treatment prior to UF ultra filtration, and replacement of UF• Pre-treatment prior to RO membranes for desalination• Part of the treatment system in high purity water for semi-conductor manufacture
AFM is the recommended filter media for all public aquaria, aquatic mammals and
zoological parks
40,000 AFM systems installed in Europe.AFM is the leading manufactured filtration media for the industry.
Dryden Aquawins top award in Dubai October 2012
Dubai Channel 1 News
Activated sludge fine bubble diffused SBR system supplied to Saudi Arabia for the city of Medina, AFM filtration can be used on the discharge from the system to provide class 1 irrigation water.
FP7 Research Eco-India, drinking water treatment for India, arsenic, flouride, iron and biosecurity
Research and Ethics
• Eco-India and FP7 research project to remove arsenic
• Scottish Government survey of pool industry to quantify environmental status of the industry
• Nation Health Service collaborative project to determine the toxicity of disinfection by-products
• Technology Strategy Board of the UK, development of zero waste, water treatment strategy
• Scottish Government Hydro-Nation initiative
AFM filters getting ready for dispatch, from Dryen Aqua warehouse and AFM production facilities in the back-ground
Direct replacement for sand in all types of sand filters, for clean water and waste water.
Wastewater
AFM mechanical filtrationtertiary treatment
Wastewater tertiary treatment• AFM may be used in existing pressure sand
filters or rapid gravity filters
• There is no requirement to use moving bed filters, but AFM can also be used in moving bed filters to improve performance
• Bed depth 300mm to 1200mm
• Hydraulic loading, relates to solids load, usually around 5 m/hr, when solids are over 50mg/l. Under 50 mg/l SS, flows can be increase to 10 m/hr
• Back-wash at 55 m/hr after air scour
• AFM media will last for the life of the filters. Should never need to be changed.
AFM is being used to treat landfill leachate SBR no sedimentation, AFM solids load, approx 200 mg/l. Product water After AFM < less that 20 mg/l
Other waste water applications
•municipal waste water•brewery effluent, yeast control•farm / agricultural waste•effluent from anaerobic digesters•Industrial waste water; circuit board manufactures, chemical industry, oil platforms•Effective for hydrocarbon polishing, and heavy metal removal
Wastewater after humus tanks from fixed film biofilters or activated sludge
Before & after AFM filtrationfull scale installation… solids 80mg/l down to <5 mg/l using a pressure AFM filter, single pass no flocculation
TYPE OF FILTERSS. (mg/l) Performanc
e %
Turbidity ntuPerformance
%
bacteriaPerformance
%Velocity
inlet outlet inlet outlet inlet outletm3/m2/h
RGF sand filter with sand
7.14 2.2 69 3.5 2.23 36 23120.0 12300.0 46 1.2
Pressure filter with sand8.18 3.82 53 5.87 4.76 18 22311 18023 19 4.96
Moving bed sand filter with sand
7.08 3.82 46 2.13 1.79 16 14067 10307 26 5.4
Drum filter 10 micron
14.66 7.33 50 7.16 3.88 45 56712 38460 32 3.23
Disc Filter 10 micron
5.6 3.1 44 2.22 2.06 7 30450 21138 30 2.12
Ring Filter 10 micron
7.41 3.98 46 3.01 3.17 9447 7761 17 2.5
AFM® Pressure filter 10.60 0.89 96% 2.98 0.24 92 % 23000 10000 58 % 3.59
AFM performance for the tertiary treatment of sewage effluent compared against different technologiesIndependent tests conducted by Spanish Water Company and reported in Technology del Agua , December 2009, page 47.
AFM media in a pressure filter out-performed all other technologies, some of which were 10 times the cost
Tertiary treatment of
sewage effluent
comparative evaluation of a high quality
Sand
against
AFM
using Gravity Sand filters independently certified under identical conditions
AFM Run-phase & back-wash profile Tertiary treatment using Rapid Gravity Sand filter
The graph shows the build up of pressure in the Sand filter followed by the back-wash. Run phase performance & back-wash frequency is variable. Periods where most of the water channels through the sand bed are self evident.
Channelling through bed
Run-phase & back-wash profile Tertiary treatment using Rapid Gravity AFM filter
. AFM filter media, run phase performance and back-wash frequency. Same run phase duration between a back-wash, no by-passing or channelling of waste water through the bed, stable & predictable effluent quality
AFM removes chemicals
Works effluent AFM product water AFM back-wash
4.6 <3.8 6.3
<3.8 <3.8 4.5
<3.8 <3.8 11.1
5.2 4.0 10.4
6.1 <3.8 9.9
TBT concentrations ug/l, from a working WWT systems. BioActive chemicals are link to causing damage to the marine ecosystem and impact on climate change.
AFM can perform well to remove chemicals such as ferric, manganese, TBT, copper, mercury, arsenic and PCB`s
Clean Water TreatmentAFM mechanical filtration of drinking water
AFM is certified under Reg 31, it is the only filter media that is certified
Drinking water
AFM is used in gravity flow system as well as pressure filters.
Bed depth 1200 to 1400mm
Run phase water flow <10m/hr
Air purge 55 to 100m/hr
Back-wash at >45 m/hr
AFM in simple gravity flow filters with no pre coagulation or flocculation used in Africa to produce clean water with a turbidity less than 0.5 ntu
AFM is used as a pre-treatment for RO and UF membranes. Full scale trials in progress to compare AFM against UF as primary drinking water treatment process in SE Asia
Africa
before AFM after AFM
Filtration AFM verses sand filtration
What goes into a filter must come out in the back-wash
The graph opposite is the back-wash profile for identical sand and AFM filters after 10 weeks.
The profile shows that 30% more solids are back-washed out of the AFM. 30% more solids have there been removed during the run phase
AFM performance is maintained while sand filters continue deteriorate with time.
Data from trials conducted by Suez Lyonnaise des Eaux 30% improvement after 10 weeks, 50% after 52 weeks.
Trials conducted on parallel systems with AFM and Leighton Buzzard Sand
Bacteria levels before and after sand and AFM
Plate count at 22 deg C. The linear trend line shows a 50% performance benefit over sand.
Plate count at 37 deg C confirm bacteria levels from AFM are half the level from sand filters.
The data confirms the bio-instability of sand filters, and due to transient worm-hole channelling they may occasionally discharge into the product water. This does not happen with AFM
The above trials were conducted with parallel filters in Scotland operating on a drinking water treatment facility. Data was collected and analysed by Scottish Water.
AFM is an active filter mediaAdsorption
• Sand generates dissolved organic matter (DOC) through autotrophic bacterial cell growth
• Hydrophilic surface with a negative Zeta potential of AFM adsorbs small particles and dissolved organic molecules from water.
• Major reduction in DOC and this is without coagulation
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
17/07
24/07
31/07
07/08
14/08
21/08
DOC
mg/
l
Dissolved Oranic Carbon mg/l
inlet
afm
sand
DOC levels approx 50% lower after AFMTests conducted by Suez Lyonnaise des Eaux
Iron & Manganese levels before and after sand and AFM
Iron levels, linear trend line confirms AFM performance is improving, sand performance is deteriorating over time. AFM performance twice as good as sand.
Manganese linear trend line confirms AFM 400% better performance than sand.
The data confirms the bio-instability of sand filters, and due to transient worm-hole channelling they may occasionally discharge iron and manganese back into the water. Again this this does not happen with AFM
The above trials were conducted with parallel filters in Scotland operating on a drinking water treatment facility. Data was collected and analysed by a water company.
Autotrophic bacteria growth on sand
• Autotrophic nitrifying bacteria rapidly become established on sand
• The autotrophs increase the suspend solids as well as DOC level in the product water by converting inorganic carbon to organic carbon.
• The extracellular alginate excreted by bacteria form worm holes and coagulation of sand.
• AFM resists biofouling and stays clean
Ammonium -N mg/l
00.10.20.30.40.5
17/0
7/03
31/0
7/03
14/0
8/03
28/0
8/03
11/0
9/03
25/0
9/03
09/1
0/03
23/1
0/03
NH
4-N
mg
/l inlet
AFM
sand
Nitrite N mg/l
0
0.05
0.1
0.15
0.2
0.25
0.3
17/0
7/03
31/0
7/03
14/0
8/03
28/0
8/03
11/0
9/03
25/0
9/03
09/1
0/03
23/1
0/03
NO
2-N
mg
/l
inlet
AFM
sand
The above two graphs show that the sand is becoming a biofilter as indicated by the reduced ammonium and high nitrite levels. Test conducted by Scottish Water.
Biofouling of sand and AFM
Electron micro graphs of sand and AFM
Sand has 100% bacteria coverage after 3 days in a drinking water filter
AFM stays free of biofilm, even after 5 years in sewage effluent
Alginates excreted by bacteria coagulate the sand and cause wormhole channeling.
New sand Used sand
New AFM Used AFM
Parameter sand AFM comments
Solids removal Performance in terms of solids removed, 25% to 50% better than sand.
Bacteria levels AFM will remove 100% more bacteria from the water than sand
Iron AFM is very good at removing iron and manganese, due to surface –ve charge
Manganese
DOC Sand can generate organic matter (clean water), AFM will remove organic matter
Particle size 10-15 < 5 um AFM will remove most particles down to 5 micron, but also many sub-micron and dissolved components by surface adsorption
Biofilter capacity AFM does not become a biofilter, not subjected bio-mechanical coagulation and worm-hole channelling
Performance AFM vs Sand
Bacteria levels on sand and AFMtransient worm holes
Sand filters are biological, bio-mechanical instability results in media coagulation, transient worm hole channel and discharge of solids into the product water
AFM is electro-mechanical, media does not suffer from bacterial coagulation so no channeling of water through the filter bed.
Total colony count ( aerobic) at 37 deg C, on 5 grams Total colony count ( aerobic) at 37 deg C, on 5 grams of filter mediaof filter media
AFMAFM 1818
sandsand 3,600,0003,600,000
Media samples were taken just prior to a back-wash at a depth of 200mm into the bed, and 500 mm from the side of the filter.
Bacterial levels on AFM and sand after 3 months in a clean water filter. The Table is certified data showing total bacterial levels of 3.6 million with sand, and essentially zero with AFM.
technical specification & mechanism
How does AFM work?For clean water and waste water applications
AFM active filter media, performance summary
Typically improves performance by 30% to 50% in terms of solids removed for both waste water and clean water applications.
AFM does not need to be replaced, the media may be used for the life of the filter, and can be recycled and used again.
AFM does not bio-coagulate or experience worm-hole channelling.
Performance is stable and predictable
AFM® is certified under Regulation 31 of the UK Drinking Water inspectorate, AFM® is compliance with European Water Directive (98/83/EC) & (80/778/EEC).
Some technical aspects of AFM.. catalysis
• Manufactured by Dryden Aqua in Scotland from reprocessed glass and glass manufactured to Dryden Aqua specifications.
• The glass is reduced to a precise particle size distribution and shape to maximise the hydraulic flow characteristics and mechanical filtration performance.
• The raw material is chemically processed to open up the aluminosilcate atomic lattice and activate the surface physio-chemistry.
O2 + H20 3O + OH Water containing oxygen to free radicals by surface catalytic reactions
The free radicals help prevent biofouling and will cause some oxidation of dissolved organic matter and heavy metals and metaloids. Dissolved oxygen levels must be above 2mg/l for the reactions to proceed
Catalytic reactionsAFM catalysis
Some technical aspects of AFM…surface charge• AFM mechanically removes most particles down to 5 microns. • Sand surface area, approx 3000m2/tonne, AFM surface area >1,000,000 m2/tonne • The high surface negative charge potential helps to adsorb micron and sub-micron particles as well as some
dissolved organics• Works synergistically with +ve charged cationic flocculants and polymers • AFM rejects bacteria growth and worm-hole channelling
-ve charge AFM surface
stern layer (slip zone) predominantly divalent and trivalent cations
Anion diffuse layer sulphate and bicarbonates
Zeta –ve potential+ve cationic flocculated solids+ve charge coagulated and polar & dipolar dissolved organics
Zeta Potential reactions
on the surface of AFM and the behaviour of +ve and –ve ions as well as sub-micron particles and dissolved organics.
Cost benefit analysis
AFM is around 2 to 3 x the cost of sand, however we are already dealing with a relatively low cost product.
AFM has been confirmed to work a great deal better than sand, and will give a return in capital out of revenue savings measured in months through savings in;
a. water; back wash water reduced by up to 50%
b. energy; increased run phase and reduced back-wash could give 15% savings
C. chemicals; reduced chemical consumption, chlorine, ammonium & flocculants
d. filter media; no requirement to replace AFM for the life of the filter
Performance summary?
Wastewater Clean water Performance advantage
Suspended solids 100 to 400%
COD/BOD/TOC 200%
Turbidity 100% to 400%
Ammonium No change with AFM
Bacteria TTC 50% reduction
THMs 50% to 90% reduction
Back-wash profile Used to check performance
Dryden Aqua
Dryden Aqua LTDButlerfieldBonnyriggEdinburgh EH19 3JQ Scotland. UK
Tel +44 (0) 18758 22222Tel +44 (0) 18758 22222Fax +44 (0) 18758 22229Fax +44 (0) 18758 [email protected]@drydenaqua.com
aeruginosa
Annex
• Bacteria analytical report• Spanish waste water reports• AFM back-wash video• Scottish Water recommendations• Certification under UK regulations Reg 31 for drinking water.
AFM is also compliant with NSF Reg 61. UK regulations are much more strict than NSF.
Bacterial analysis reportFilter media samples taken from a swimming pool water treatment system, free chlorine level 0.5 to 1.5mg/l, pH 7.2 to 7.4 at 28 deg C
Sample Enterococci cfu/100ml
Faecal coliforms cfu/100ml
P. aeruginosacfu/100ml
S. aureuscfu/10ml
APC @ 37 degC cfu/ml
Silica sand <1 <1 <1 <1 3,600,000
AFM <1 <1 <1 <1 18
Standard methods of water analysis 20th edition 1998
9230C 9222D 9213E 9213B 9215B
Aerobic Plate Count
ClientJonkers filtration P.O Box 708, KumeuNew Zealand
Date received 22/07/04Dated completed 29/07/04
LaboratorySGS New Zealand Ltd.
Analyst name Marnie Sleeman NZCS
Laboratory Number 3567-04
Filter media sample bacteriological analysis.
Spanish water company reports may be downloaded at the following link;
Click here
French NGO reports AFM twice as good as the best available crushed glass
Click here
AFM back-wash video
Dear Sir/Madam TO WHOM IT MAY CONCERN
I wish to confirm that Scottish Water has used AFM solutions and is in the process of developing a much closer working relationship with Dryden Aqua. Scottish Water tested AFM on-line for approximately 1 year in 2004. The results demonstrated significant performance advantage over sand in relation to suspended solids/iron removal and process efficiencies. I can also confirm that Scottish Water has been using AFM for targeted effluent treatment for some 14 years with considerable success in the removal of solids and BOD reduction. Scottish Water's newly formed Research and Innovation team will, during 2012, commence a strategic research program into filter media and the wider water treatment process in order to demonstrate the performance of the media across Scotland - ensuring that the results are captured and communicated across our asset base. We fully expect the results to be repeated - leading to a wider programme of engagement and adoption with of AFM.
Yours faithfully Mark Haffey R&D Technical Leader, Technology & InnovationScottish Water - Always Serving ScotlandScottish Water