Tailor-made treatment concepts for wastewater re-use - experiences gained by pilot trials covering 7 water treatment technologies Benjamin Simstich, Dieter Pauly
Pilot Trials at Three Paper Mills 2 You are here 3 paper mills Newsprint Board Pulp LCA, Micro-biology
Comprehensive Pilot Trials at a Board Mill 3 Hamburger Rieger GmbH & Co. KG in Germany Board mill producing on 2 machines >150,000 t/a Folded box board & white top testliner (coated/uncoated) Raw material is 100 % recovered paper Involved companies: 7 different technologies in parallel pilot operation March 2011 September 2011 -> 182 days
The Technologies 4 Application and further development of technologies: 1. Anaerobic reactor Biomar ASB-x with a new type of sedimentation (EnviroChemie GmbH) 2. Innovative pre-filtration system (Flexible Fiber Filtration 3FM) (Veolia Environment) 3. Membrane bioreactor (MBR) technology (PTS) 4. Multiflo Softening TM with a precipitation/crystallisation technology (Veolia Environment) 5. Ozone treatment (Xylem Water Solutions (WEDECO) ) 6. Nanofiltration (EnviroChemie GmbH) 7. Evapoconcentration (2 pilot plants) (Veolia Environment Research & Innovation)
The Objectives 5 Demonstration in pilot scale under real process conditions Study effects of interconnection of the plants with recirculations Individual aims: Further development of each technology and individual research tasks Anaerobic: handling of calcium, improved reactor design Solid-filtration (3FM) & Softening: first trials in paper industry and further development MBR and NF: strategies to overcome calcium scaling. General aims: Overall concepts: comparison & evaluation of costs, reliability and sustainability Develop modular based design of water concepts Tertiary treatment: ozone or NF? NF-concentrates: recirculate or evaporate? LCA, footprints & sustainability
The Trial Concept: 2 Studied Treatment Lines 1 st : physical-chemical technologies for tertiary treatment 2 nd : biological & tertiary treatment with internal concentrate recirculation 6 final effluent of paper mill COD 100 mg/l BOD 5 7 mg/l Cond. 2.5 ms/cm Ca 2+ Cl - 300 mg/l 170 mg/l Color 1.9 m -1 ph 8.0 3FM Soft. Ozone NF Evapo. Ozone = water quality for reuse raw effluent of paper mill COD 3,100 mg/l BOD 5 1,600 mg/l Cond. 2.2 ms/cm Ca 2+ Cl - 360 mg/l 190 mg/l Color 5.3 m -1 ph 5.8 Ozone Anaer. Soft. MBR NF Evapo. Ozone
Individual Results: MBR 7 Treatment of effluent of anaerobic reactor Challenge: Calcium inflow concentration 260 mg/l Very low elimination of Calcium observed. Anyhow occurred scaling problems -> necessitate frequent acidic cleaning Trials with ph control and study effects of softening Stable Flux of 8-12 L/m 2 /h COD and BOD 5 removal (74 %, 97 %) 2nd trial period with pre-softening of feed Conclusion: softening necessary for reliable operation SEM of membrane surface Results of membrane cleaning tests
Evaluated Treatment Line 1: Upgrade existing mill 8 Evaluation in terms of: Technical feasibilty & reliability Costs LCA & sustainability Existing wwtp Additional technologies Reclaim water: improved quality (solid-free, softened) Reclaim water: high quality Anaerobic reactor Conventional activated sludge process Softening Prefiltration (e.g. 3FM, UF ) NF Effluent to receiving waters Solid waste Evapoconcentration
Evaluated Treatment Line 2: New installation 9 Reclaim water: improved quality (solid-free, softened) Reclaim water: high quality Anaerobic reactor Softening MBR (AS+UF)* NF Effluent to receiving waters Solid waste Evapoconcentration
Main Results and Highlights 10 It s possible to achieve tailor-made water qualities according to individual reuse requirements. Two treatment lines have been evaluated in-depth. Water softening has been proven as an essential pre-treatment whenever membrane processes are to be used. Process showed good results downstream of aerobic treatment as well as anaerobic treatment. Better performance of the pilot anaerobic reactor in comparison to the full scale plant. Recirculation of NF concentrates in the anaerobic reactor after pre-treatment by ozone oxidation could not be evaluated reliably in this particular case. Using evapo-concentration for NF concentrate disposal has been evaluated as an alternative treatment technology. MBR: direct comparison of ph control and upstream softening was investigated. Public reports will be available soon: www.aquafit4use.eu
Acknowledgements 11 Results were obtained in the project AquaFit4use (EU-FP7-ENV-211534) funded by the European Commission. Further information: www.aquafit4use.eu Dr. Benjamin Simstich benjamin.simstich@ptspaper.de +49 (0) 89 121 46 388 www.ptspaper.com Special thanks to Hamburger Rieger, project partners, on-site staff, students, colleagues.