CIE4485 Wastewater Treatment

Transcription

1 CIE4485 Wastewater Treatment Maria Lousada Ferreira 4. Research on MBR sludge filterability at MBR Terneuzen 1

2 Research on MBR sludge filterability at MBR Terneuzen Maria Ferreira - Evides Table of contents 1. Introduction a) MBR Terneuzen 2. Filterability a. Temperature b. Substrate c. Sludge coagulants d. Influent composition e. Effluent addition f. Mechanical stress 3. Conclusions

3 Introduction- MBR Terneuzen DOW DECO plant Town of Terneuzen Location Braakman pumping station (drinking water production) WWTP Introduction- MBR Terneuzen DECO NaOH Demi water EGV < 15 µs/cm Effluent EGV 25 µs/cm E.W.R.O.: 2 units B.W.R.O. : 2 units tussenbuffer tussenbuffer A.S. Freshwater Braakman Effluentank NaOCl NH4Cl MBR Production capacity: 62 m³/hr

4 Introduction- MBR Terneuzen Introduction- MBR Terneuzen 1, 3,1 m 3 /h influent 8% effluent 2% Addition waste sludge Addition clarifier overflow MBR Industrial reuse 4 62 m 3 /h

5 Introduction- MBR Terneuzen MBR Terneuzen (The Netherlands) Population equivalent 15,5 Location of the membranes External (Side stream) Membrane supplier Pentair (X flow) Membrane pore size µm.45 (...) Total membrane area m 2 13,86 Volume biological tanks m (aerobic) 652 (anoxic) Flux (average operation) L/m 2.h 25 4 MLSS g/l 8 Sludge age d ± 2 Cleaning Mechanical and chemical /21 Introduction-MBR Terneuzen

6 Introduction- MBR terneuzen Introduction- MBR Terneuzen

7 Filterability 7 6 R 2 <.1 Filterability Good R 2 [*1 12 m -1 ] < R 2 <1 R 2 >1 Moderate Poor MBR CAS /21 Filterability Factors afecting filterability: a.temperature b.substrate c.sludge coagulants d.influent composition e.effluent addition f.mechanical stress /21

8 Filterability and temperature /21 Filterability and temperature Relation between filterability and temperature is overall accepted. Temperature has an indirect effect on filterability Temperature Flocculation, viscosity, Filterability and temperature in 7 full-scale MBRs (6 with submerged membranes, 1 with side-stream membranes) [Moreau, 211] Filterability /21

9 Filterability and substrate Batch tests (long term: 4 days) Air Flow Proportional to real MBR situation Flow Applied in the substrate batch tests F/M Applied in the substrate batch tests [g BOD 5 /gmlss.d] Day 1 Day 2 and Day 3 Glycerol.25 ml/d.25 L/d Kwalidrink 2 ml/d 2 L/d /21 Filterability and substrate Batch tests: long term (MBR Terneuzen) /21

10 Filterability and substrate 1 8 DR2 day 1 DR2 day 4 R 2 [*1 12 m -1 ] MBR+glycerol MBR+kwalidrink /21 Filterability and sludge coagulants Batch tests (short term: ½ hour) Commercial name Company Composition PAX 14 Kemwater TM Polyaluminium Chloride MPE 5 Nalco Polymers Date MLSS sludge [g/l] L Enhancer/kg MLSS PAX March March April MPE 5 14-March May May May /21

11 Filterability and sludge coagulants R 2 [*1 12 m -1 ] 3, 2,5 2, 1,5 1, DR2 original DR2 MBR+flux enhancer,5, MBR+PAX (,21) MBR+PAX (,7) MBR+PAX (,16) /21 Filterability and sludge coagulants R 2 [*1 12 m -1 ] 3, 2,5 2, 1,5 1,,5, DR2 original DR2 MBR+flux enhancer MBR+ MPE(,4) MBR+ MPE(,4) MBR+ MPE(,2) MBR+ MPE(,1) /21

12 Filterability and sludge coagulants /21 Filterability and influent composition 1. Koegors land fill 1. About 3 years; no longer in use. 2. Until the 8 s: domestic use 3. After the 8 s: non-toxic industrial waste 2. Indaver- Location Hoek 1. Dangerous waste Indaver Gevaarlijk Afval 2. Transfer location, wastewater treatment plant and cleaning installation for trucks and trains. 3. Started discharging: 23 january /21

13 Filterability and influent composition leachate flow leachate flow [m 3 /d] R 2 [*1 12 m -1 ] DR2 1 per. Mov. Avg. (leachate flow) /21 Filterability and effluent addition Hypothesis: Effluent addition leads to the accumulation of submicron particles in the MBR sludge 1,,8 1 8 DR2 day 1 DR2 day 4 MLSS day 1 MLSS day 4 R 2 [*1 12 m -1 ],6,4, MLSS[g/L], MBR+effluent MBR+influent MBR+influent+effluent /21

14 Filterability and effluent addition Day 1 [L] Day 2 [L] Supernatant Day 3 [L] Day 4 [L] Supernatant sludge influent effluent removed sludge influent effluent remove d Supernatant sludge influent effluentremoved sludge influent effluent MBR+influent MBR+ effluent MBR+ influent +effluent 2 2,5 2,5 2,5 2,5,5, /21 Filterability and mechanical stress /21

15 Filterability and mechanical stress T=26 o C Rotation speed [rpm] Low stress High stress R 2 [*1 12 m -1 ] Time [minutes] T=1 o C Rotation speed [rpm] R 2 [*1 12 m -1 ] Time [minutes] /21 Filterability and mechanical stress T=26 o C Rotation speed [rpm] Floc size [ m] Time [minutes] T=1 o C Rotation speed [rpm] Time [minutes] 35 Floc size [ m] /21

16 Filterability and mechanical stress Membranes Air Bioreactor /21 Conclusions The effect of different factors in filterability has to be evaluated by analyzing each factor separatly. The influence of temperature on filterability is always present. Excess of substrate can deteorate filterability; the substrate itselft is not toxic but the amount might be. Filterability can be improved with coagulants. Influent composition, effluent addition and mechanical stress are likely to influence filterability /21