Towards a self-sustained wastewater treatment plant

Transcription

1 Towards a self-sustained wastewater treatment plant Siegfried Egner Head of Department Fraunhofer IGB

2 TOWARDS A SELF-SUSTAINED WASTEWATER TREATMENT PLANT Concept for a direct recovery of nutrients as fertilizers combined with a advanced recovery of energy to enable a self-sustained wastewater treatment plant. Siegfried Egner, Dr. Iosif Mariakakis, Dr. Ursula Schließmann Fraunhofer IGB

3 OUTLINE: Mass-flow and waste treatment by today Valuable content of municipal waste water Our Mission and Vision: Valorization by recovery with innovative recovery technologies Carbon to Fuel Nutrient-salts to direct applicable fertilizers A new Concept for municipal WWTPs Achievements

4 Mass flow and waste treatment by today CO 2 (synthetic) fertilizers harvesting Manufacture Food/Feed industry Solid and liquid waste Consumption Soil SoA WWTP loss by destruction or disposal Task Waste water Carbon (COD, BOD) Nutrients Waste sludge SoA-Objective Removal Reduction by degradation Removal (as a unpleasant load) Removal by disposal or destruction

5 Valuable content of municipal waste water Carbon dissolved or suspended as biomass-matrices. Nutrients Phosphorus Ammonium

6 Our Mission and Vision: Valorization Development of new Strategies and Technologies to recycle mineral Nutrients and organic Matrices from waste water and organic residuals to form closed loops of material flow in agriculture. CO 2 harvesting Manufacture Food/Feed industry Consumption Compensation of Nutrients by specific Fertilizers WWTP Solid and liquid waste Energy Soil Recovered Nutrients and Treated Solids Partial loss of nutrients by disposal Valorization by cost-effective recovery with innovative technologies

7 Valorization by recovery with innovative technologies Carbon to Fuel Anaerobic process performed as High Load Digestion, achieving: shorter retention time (e.g. 5 days instead of days), smaller digestion space (8-10kg TVS/m³*d instead of 1-2 kg TVS/m³*d), enhanced degradation rate, higher biogas yield (about 1/3 higher) without foaming, enhanced dewatering performance due to higher mineralization rate. Enhanced P and N re-solubilization due to higher degradation efficiency of organic matrices. Reference: WWTP Edenkoben/Germany

8 Valorization by recovery with innovative technologies Nutrient-salts to direct applicable fertilizers The electrochemical ephos -process Anode (Oxidation) Cathode (Reduction) => No dosage of base to adjust ph Mg 2+ + NH PO H 2 O MgNH 4 PO 4 6H 2 O Struvite

9 A new Concept for municipal WWTPs Basic principle of a State-of-Art WWTP (small to medium size):

10 A new Concept for municipal WWTPs Advanced WWTPs do transform organic carbon source into a fuel by anaerobic digestion, while innovative HLD enables advanced AD-efficiency even for smaller plants, and perform Bio-P- / BNR-process to enable high nutrient recovery rates. Bio-P- / BNR-process (preferred) HLD High-load digestion with microfiltration at a sewage plant with 10,000 PE in Wutöschingen(DE).

11 A new Concept for municipal WWTPs Our first approach: Integration of the ephos -technology into a standard WWTP (best case with Bio-P / BNR) ANAER ANOX AEROB SEDIMENT. P-RICH SLUDGE P-& N- RECOVERY BY ephos SLUDGE DEWATERING DIGESTION Waste sludge as side stream Low volumes for treatment BNR-plants are preferred High potential for phosphorus recovery P & N AS Struvite FERTILIZER DEWATERED SLUDGE

12 A new Concept for municipal WWTPs Improve of energy and nutrients recovery by (Thermal) Hydrolysis ANAER ANOX AEROB SEDIMENT. P-RICH SLUDGE P-& N- RECOVERY BY ephos SLUDGE DEWATERING DIGESTION Typical option for (THP) hydrolysis to disintegrate bio-matrices P & N AS Struvite FERTILIZER Increased content of nutrients in the filtrate/centrate water DEWATERED SLUDGE

13 A new Concept for municipal WWTPs Formation od a advanced sink for nutrients by a additional electrochemical increase of ph by ephos and remove of Ammonia and recover as Ammonium-sulfate-fertilizer. No re-load of nutrients ANAER ANOX AEROB SEDIMENT. Remove and recovery of volatile Ammonia P-& N- RECOVERY BY ephos SLUDGE DEWATERING DIGESTION P-RICH SLUDGE Electrolytic adjust of ph to >9 P & N AS Struvite FERTILIZER DEWATERED SLUDGE

14 A new Concept for municipal WWTPs Our concept with a destruction of organic matrix by THP to enable quick availability for the anaerobic process and consequently an advanced release of nutrients for recovery.

15 A new Concept for municipal WWTPs Our concept with a destruction of organic matrix by THP to enable quick availability for the anaerobic process and consequently an advanced release of nutrients for recovery.

16 Achievements HLD-process in combination with THP for disintegration enables a high transformation of organic carbon sources into biogas. Significant mass-reduction for sludge disposal. Remaining sludge has a high mineral-content and a good dewatering performance. Better operation stability of the WWTP due to elimination of the P and N return loads Potential to recover >65% of the phosphate-inflow and 20% of the Nitrogen-inflow into a WWTP. Easy remove and recover of ammonium as ammonium-sulfate. ephos for Struvite and AMORE for Ammonium are modular and flexible adjustable systems enabling process operation on demand.

17 Summary A municipal WWTP can be energetically self-sustained or even deliver surplus energy by transforming more organic carbon into biogas. saving energy and efforts to remove nitrogen due to controlled, minimized re-load. Nutrients could be recovered as applicable fertilizers and directly returned to the agricultural fields. Remaining sludge is significantly reduced in mass-flow has a high mineral-content a good dewatering performance enabling smaller devices for final mineralization e.g. by gasification.

18 Contact Siegfried Egner, Dipl.-Ing. Head of Department Physical Process Technologies Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB Nobelstrasse 12, Stuttgart, Germany Phone Fax