Presentation on theme: "Phosphate removal and phosphate recovery: Towards Sustainable Development Dees Lijmbach, President Technical Committee, Chris Thornton, co-ordinator,CEEP."— Presentation transcript:
Phosphate removal and phosphate recovery: Towards Sustainable Development Dees Lijmbach, President Technical Committee, Chris Thornton, co-ordinator,CEEP Centre Européen d’Etudes des Polyphosphates COPPERAS - November 2000
How did phosphorus recycling break down in Europe? The growth of cities (16th Century onwards) The introduction of sewage collection and treatment systems Decline in agricultural re-use of sewage biosolids
Modern society conducts phosphorus from the land and out to the rivers and sea
Why re-visit phosphorus recycling now? Phosphate rock reserves and costs Impurities in phosphate rock Increasingly, phosphate removal from waste water will be required by law Opportunity to improve waste water treatment economics/ sludge cycle Sewage and animal wastes are, potentially, a rich source of pure phosphate (45,000 and 200,000 tonnes of P per annum, respectively in UK)
Why re-visit phosphorus recycling now? Agricultural spreading is the BEST way to recycle phosphorus (and nitrogen values, biosolids, …) But this option is declining across Europe : - concentration of cities / storage - transport problems - competition from animal manures - legislative and social pressure re contaminants Also, the P:N ratio in sewage sludge is higher than agronomic requirements
% Depletion 0 20 40 60 80 100 Depletion of Phosphate Rock Reserves High growthMedium growthLow growthConservation scenario
Phosphoric acid analyses trace impurities Acid from Morocco phosphate rockppm Al 200 Cd 40 Cr 357 Fe 1600 Mg 5700 Na 1700 Ni 67 Ti 108 Zn 880 Mn 10 Cu 23 As 5 Organic C 50 Acid from Geestmerambacht recovered phosphatesppm Al 950 Cd <6 Cr 8 Fe 1260 Mg 4200 Na 360 Ni 8 Ti 8 Zn 310 Mn 560 Cu 17 As 2 Organic C >2000
Possible pathways for P-recovery - 1 Precipitation of a recyclable phosphate product from liquors in wwtp: - calcium phosphate -> P-industry - struvite (magnesium ammonium phosphate) -> fertiliser use - synergy with biological P-removal high-P side streams, P release in digesters, avoidance of struvite deposit problems) - other possible technologies may allow precipitation from wwtp main stream - ion exchangers, membranes...
Full scale phosphate recovery (as calcium phosphates) from sewage : DHV Crystalactor® at Geestmerambacht sewage works, near Edam, Holland (230,000 pe.)
Full scale struvite recovery plant, Shimane Prefecture, Japan. Capacity : 45.000 m 2 /day. Unitika Ltd / Japan Sewage Works Agency
Phosphorus Recovery: Remaining technical/economic concerns Chemistry of P-recovery by CaP or struvite precipitation looks simple but is poorly understood. Inadequate knowledge of reaction kinetics. Existing reactor designs are far from optimised. Further LCA, economic & logistic evaluation is needed.
Despite this: There are already about a dozen demonstration scale and full scale plants operating world-wide. Small amounts of recovered phosphate are already reaching industry.
Possible pathways for P-recovery - 2 Recovery of phosphates in combination with existing chemical P-stripping - chemical constraints: - no known recycling pathway to date for iron phosphates - aluminium phosphates can be recycled in Thermphos’ Vlissingen furnaces, Holland - physical constraints : - how to recover a low-water, recyclable product and not a “sludge”, - need to separate phosphate product from sludge biosolids
Possible pathways for P-recovery - 3 Recovery from sewage sludges or sludge incineration ashes - problems : - iron (from chemical P-stripping/flocculants used in sewage treatment) - copper (from diffuse sources : piping, diet...)
CEEP and P recovery The European detergent and technical phosphate industry is committed to “making it happen” and is leading research in the area. Contacts with water companies and regulators Promotion - communications : SCOPE Newsletter, P-recovery conference (Holland, 12th-14th March 2001) EU 5th Framework Proposal CYCLOPHOS addressing precipitation of calcium phosphate and struvite Possibilities for co-operation with INCOPA ?
Cyclophos Industrial Partners Water Industry: - CIWEM - Berlin Wasser - Lyonnaise des Eaux - Thames, Anglian, Yorkshire, Severn Trent - Canal Isabel II - STOWA - Polish water industry - Posch and Partners - WS Atkins National regulators: - UK Environment Agency - Spanish Environment Ministry - Swedish Environmental Protection Agency
Phosphorus Recovery: current CEEP research Scenarios for struvite recovery economics Imperial College, London Feasibility of P-recovery and recycling in Benelux STOWA/Thermphos/Haskoning Economics and sludge management implications Office Internationale de l’Eau Sludge production implications INSA Toulouse, France
Phosphorus Recovery: current CEEP research Precipitation reactor design parameters LAGEP/Uinversité Lyon II, France P-recovery potential in different areas of 3 bio-P wwtps CSIC Madrid/ Canal Isabel II Water Company Struvite formation in STW Imperial College (joint project with UK water industry). Testing of full-scale struvite precipitation reactor at Treviso bio-P sewage works, Italy (Ancona, Verona, Venice Universities)
Phosphorus Recovery: current CEEP research Testing of a pilot scale struvite reactor at Zarbze sewage works, Poland, Lodz Technical University Bielsko Biéla Crystallisation of calcium phosphates using calcite seed Karlsruhe Research Centre Precipitation of calcium phosphates - Centre for Ecology & Hydrology, UK and Natural history Museum, London Recovery of phosphates by reversible adsorption onto fly ash, Bath University, UK
Phosphorus Recovery: current CEEP research Biologically induced P precipitation in combination with biological P-removal from sewage Queens University, Belfast. Application of REM-NUT ion exchange for P recovery from sewage works main stream Bari Polytechnic, Italy Pathways for P recovery from sewage sludges Swedish Royal Institute of Technology Phosphorus separation and recovery in animal manures Institute of Grassland & Environmental Research, UK.
Recovery of P from iron compounds ? Results of an initial experiment using sulfate reducing bacteria to solubilise phosphates from iron phosphate sludge, Jan Suschka, Lodz Tech. Univ, Bielsko Biéla, Poland 9 2000