Pre se ntation Outline. Goalsof th e Study. Op e rating Ph ase s

Transcription

1 Se ssion : BiologicalPh osp h orusre m oval Pre se ntation Outline Effe ct of Proce ssconfigurationsand Alum Addition on EBPR in Me m b rane Biore actors 79 th Annual WEFTEC Dallas, TX October, Erik Johannessen Randal W. Samstag H. David Stensel Goals of the study Materials and methods Results and discussion P removal efficiency Alum addition Microbiological observations Simulations Membrane performance Conclusions 1 Goalsof th e Study Op e rating Ph ase s 1) Evaluate alternate process configurations for enhanced biological phosphorus removal (EBPR) and biological nitrogen removal (BNR) using a membrane bioreactor (MBR) ) Investigate effect of alum precipitation on EBPR Operating Phase Phase 1& Phase 3 Phase Conditions Comparison of the UCT and SmBNR process configurations Comparison of the UCT and UW-MBNR process configuration Alum addition in an EBPR-MBR 3 1

2 Ex p e rim e ntalconditions Ex p e rim e ntalse tup Two laboratory scale reactors in parallel operation Flat sheet membrane Temperature-controlled room ( C) SRT = 1 days Synthetic Feed % rbcod for Phases 1-3, 9% for Phase COD:P ratio 7 for Phases 1-3, 1-3 for Phase (Excess P) rbcod:p ratio - 11 for Phases 1-3, 1- for Phase (Excess P) Water #1 # N RAS IR N Anaerobic Anoxic #3 Air Permeate Aerobic Membrane RAS Synthetic feed tanks Diffuser Ex p e rim e ntalap p aratus Proce ssconfiguration - UCT W A S (Q W A S) A noxic recycle (Q ) Influ ent(q ) (3Q ) (Q ) A noxic A naerobic A erobic E fflu ent(q -Q W A S ) RA S (Q ) 7

3 Proce ssconfiguration - Sm BNR Proce sse shad th e Sam e Th e ore ticalhrt UC T S mb NR W A S (Q W A S) Influ ent(q ) A noxic (Q ) (Q ) A erobic A naerobic RA S (Q ) E fflu ent(q -Q W A S) HRT (Hours) Anae rob ic Anox ic Anox ic Anae rob ic Firs ts tage S ec ond S tage A erobic 9 1 But UCT h aslowe ranae rob ic MLVSS Conce ntration Ph ase Ove rallre sults: P Re m oval MLVSS (m g/l) 7,,,, 3,, 1, UC T S mb NR Anox ic Anox ic Anae rob ic Anae rob ic Firs ts tage S ec ond S tage A erobic P (m g/l) Operational upsets Tim e (day s) P -removaluc T P -removals mb NR Influ entp

4 Ph ase P Re m ovalre sults: UCT ve rsussm BNR Ph ase Re sults: Com p arison of P Re le ase and Up take UCT had lower effluent PO -P P Up take and Re le ase UCT had lower bcod used /P removed Ratio UC T S mb NR Efflu entp O-P (mg/l ) bc OD /P Ratio Influ ent UC T S mb NR Ave rage P Re m oval(m g/l) Anae rob ic Anox ic Anox ic Anae rob ic Firs ts tage S ec ond S tage A erobic 13 1 Ph ase 3 P Re m ovalre sults- Additional Proce ssconfiguration: UW -MBNR Ph ase 3 P Re m ovalre sults: UCT ve rsusuw -MBNR Modified SmBNR with influent feed to the second zone Run parallel to UCT UCT had lower PO-P UCT had lower bcod used /P removed ratio Anoxic Influent (Q) (Q) Anaerobic (Q) RAS (Q) Aerobic WAS (Q WAS) Effluent (Q-Q WAS) Ph ase 3 Efflu entp O -P (mg/l ) bc O D /P Ratio Influ ent UC T UW -M B NR 1

5 Efflue nt P Re m ovalre sults: Com p arison of AllTh re e Proce sse sat End of Ph ase Sum m ary of Re sultsab out P Re m oval: W h y wasuct Be tte r? P(mg/L) UC T. S m B N R UW -M B R. Sm BNR UW -MBNR UCT Tim e (days) More rbcod for PAO than SmBNR or UW- MBNR -> less competition with denitrifiers Longer effective HRT for P uptake ->More P Uptake Shorter effective anaerobic HRT than SmBNR -> Less Secondary P Release 17 1 Ph ase : Alum Addition Ph ase : UCT Proce ssw ith and W ith out Ch e m icalpre cip itation Compared UCT configuration with and without Alum Alum Dose 1. mole Alum / 1. mole P removed Target. mg/l P removed Alum Dose - 1. mg Al (SO ) 3. 1(H O) / L Day Test Period 1 Day SRT MLSS,, mg/l Acetate 9% of feed COD P(mg/L). 9. E ff. -P (m g/l )-C ontrol. E ff. -P (m g/l )-A lu m mgp/l mgp/l Alum addition mgp/l Tim e (day s) 19

6 Up take Re sults Ph ase : P Re m ovaland COD Up take Ratio Lower P uptake rates at lower mixed liquor P concentrations 3 3 An Ae P sc OD 3 3 Lower effluent P with Alum Both with and without alum feed had a very low bcod used /P removed ratio P (m g / L ) Time (min) sc O D (m g / L ) Ph ase Efflu entp O -P (mg/l ) bc O D /P Ratio Influ ent No A lu m W itha lu m 1 Sum m ary of Re sultswith Ch e m ical Tre atm e nt Microb iologicalre sults: High Conce ntration of PAO in Se e d Sludge forph ase Initially the expected. mg/l difference between the systems was seen Subsequently the P removal difference decreased to 1-1. mg/l In alum reactor from release/uptake tests, lower P concentrations led to lower P uptake rate 3

7 Microb iologicalre sults: GAO Dom inate d MLSS at End of Ph ase Microb iologicalre sults: Filam e ntousfloc in Ph ase BioW in Sim ulations Sim ulation Re sults: Calib ration of Lab and Mode lfor% rb COD fe e d (UCT Configuration) W AS UCT Influe nt Anae rob ic Anox ic Ae rob ic Me m b rane s Efflue nt Model over-predicted P removal % rb COD Fe e d W AS L ab M od el SmBNR UW-MBNR Influe nt Influe nt Anox ic Anox ic Anae rob ic Anae rob ic Ae rob ic Ae rob ic Me m b rane s Efflue nt W AS Me m b rane s Efflue nt Efflue nt PO-P (m g/l) 1 1 UC T S mb NR UW -M B NR 7 7

8 Calib ration Re sultsfor19% rb COD (UCT Configuration) Me m b rane Pe rform ance : Sum m ary of Effe ctson Me m b rane Fouling Predicted effluent P more similar to lab Efflue nt PO-P (m g/l) % rb COD Fe e d L ab M od el UC T S mb NR UW -M B NR M embrane Fou lingrate Fac tor H IGH M ED IUM L O W S tarc h X X X N o filaments X X X P olymer X Filam ents X X A lu m X X 9 3 Conclusions Acknowle dge m e nts EBPR Confirmed for ALL MBR Configurations! UCT performed more efficiently for EBPR than either SmMBR and UW-MBNR Alum did not reduce EBPR efficiency for high effluent P; For lower effluent P alum reduced effectiveness of EBPR Uptake more critical than release: Staged reactors recommended BioWin over-predicted P removal. Because GAO not modeled? Polymer, alum, and filaments reduced membrane fouling Carollo Engineers, P.C. Valle Scholarship and Scandinavian Exchange Program 31 3

9 M embrane Fou lingrate Fac tor H IGH M ED IUM L O W S tarc h X X X No filaments X X X P olymer X Filaments X X A lu m X X Que stions? P (m g / L ) An Ae P 3 sc OD Time (min) sc O D ( m g / L ) 3 Operational upsets P -removaluc T P -removals mb N R Influ entp P (m g/l) Tim e (day s) P(mg/L). 9. E ff. -P (m g/l )-C ontrol. E ff. -P (m g/l )-A lu m mgp/l mgp/l Alum addition mgp/l T im e (day s) 9