Activated Sludge Design, Startup, Operation, Monitoring ...

1 Activated Sludge design , startup , Operation, Monitoring and troubleshooting Ohio Water Environment Association Plant operations Workshop Columbus, Ohio September 1, 2010 Phil Anderson operations SpecialistDesign - Activated Sludge design Team Treatment Goals Activated Sludge Processes Engineering Standards Preliminary Treatment Tertiary TreatmentTreatment Goals BOD Removal Dissolved wastes are consumed as food by the Activated Sludge microbes and converted to biomass, water, carbon dioxide, and other gases Nitrification The process through which ammonia is oxidized to nitrite and nitrate Denitrification A process by which nitrates and nitrites are converted to gaseous end products, primarily nitrogen Sludge ProcessesConventional CBOD Removal Plug or Step FeedSingle-Stage NitrificationOxidation Ditch - Vertical Loop ReactorExtended AerationMBRBNRA dditional Processes Preliminary Treatment Screening Grit Removal Tertiary Treatment Filters Solids Handling Recycle FlowsDesign Engineering Standards design of municipal wastewater Treatment Plants WEF Manual of Practice No.

2 8 wastewater Engineering, Treatment , Disposal, ReuseMetcalf & EddyDesign Engineering Standards Recommended Standards for wastewater Facilities Policies for the design , Review, and Approval of Plans and Specifications for wastewater Collection and Treatment FacilitiesMEMBER STATES AND PROVINCE IllinoisIndianaIowaMichiganMinnesotaMiss ouri New YorkOhioOntarioPennsylvaniaWisconsin Ten States StandardsProcess design Physical Aeration Tank Capacity - lbs. CBOD/1000 CF of Aeration Temperature Summer/Winter Final Settling Circular Center Feed or Peripheral Feed Process design Chemical Ammonia Loading - Nitrification Phosphorous Loading & Removal pH & AlkalinityProcess design Biological CBOD Loading 15lbs 40 lbs in Aeration - CBOD NH3 MLSS, MLVSS, RAS F/M Ratio - MCRT DaysNitrificationNH3NO2-NO3- Nitrosomonas, Nitrobacter Aerobic process (in the presence of DO)

3 Lbs O2required per lb ammonia-nitrogen lb alkalinity is consumed per pound of ammonia nitrogen pH sensitive with optimal range between and N2 Anoxic process (not in the presence of DO) Nitrification can decrease pH Denitrification recovers lb alkalinity per lb of nitrogen removed DO is consumed by nitrification and denitrification recovers lb per lb of nitrogen removedPlant startup Contractor Wants to push to startup What are Ohio EPA expectations? Manufacturer Checkout Operator Training Are You Ready What additional processes are available Do you and your Engineer have a Process Control Plan Are you seeding the aeration tanks?

4 Plant Operation Summer/Winter Dry Weather/Wet Weather DO Control RAS Rate - % 0f Influent Flow Chemical Feed Wasting Sludge Biological & ChemicalSummer Verses WinterSummer MCRT- days F/M Ratio- BOD Loading Rate- ,000 cf Required MCRT days DT for BOD hours DT for NH3 hours Aeration Tanks MLSS-3,000 mg/l MLVSS-2,100 mg/l Winter days F/M BOD Loading ,000 Required MCRT days DT for BOD hours DT for NH3 Oxidation= hours Aeration Tanks MLSS-4,800 mg/l MLVSS-3,360 mg/l Plant Operation Summer/Winter Dry Weather/Wet Weather DO Control RAS Rate - % 0f Influent Flow Chemical Feed Wasting Sludge Biological & ChemicalPlant Monitoring Regular Rounds Visual Aeration Tanks & FST Blowers/Aerators RAS Pumps Clarity of the EffluentPlant Monitoring SCADA Trending Flow, DO, ORP, pH Regular Rounds Visual Trending Instruments - Flow, DO, ORP, pH Lab Data MLSS, RAS, Settling MicrobiologyTroubleshooting Foaming Bulking Solids Loss Turbid Effluent Odor No CBOD or Ammonia RemovalHoly Crap!

5 !Observation of Settlometer TestCharacteristic Sludge Settling 020040060080010000306090120150180 Time (minutes)SSVFastNormalSlowLength of Settleometer Test Normal - 30 minutes to 2 hours - until complete compaction Extended - until the Sludge begins to riseLook Under the Microscope The Bugs -Good/Bad/UglyNocardiaMicrothrix parvicellaFilaments 1851 and 0041 Filament Type 0092 Filament type 0092 WWTP:WWTPBy:Phil Anderson -ARCADIS SummaryOperation: Activated Sludge Date:Summer 20093,000 MLSS, CF/M CELL RESIDENCE TIME (MCRT) Loading ,000 AerationRequired MCRT Ammonia Required MCRT DATA:6 Aeration Tanks On LineDT for BOD (MG) - Aeration tank volume (total) Tank MG EachDT for NH3 ,250 (mg/l) - Mixed liquor VOLATILE suspended solids (MLVSS)Aeration Tank Vol (MGD) - Daily flowrate of waste Activated Sludge (WAS) [See below]Aeration Tanks ,000 (mg/l) - WAS suspended solidsAeration Tanks On (MGD) - Plant flowMLSS3,000mg/lf10 (mg/l) - Effluent suspended solidsMLVSS2,250 mg/lNitrifiers (8% of MLVSS)180 mg/lSUPPLEMENTAL CALCULATIONS (MLVSS).

6 A3,000 (mg/l) Assumed mixed liquor suspended solids (MLSS)EFF (%) - Assumed percent volatileCBOD Weekly 15 mg/l2,250 (mg/l) - MLVSS TSS Weekly 18 mg/lWASTE Sludge VOLUME:Fecal Weekly 2,000 (S Only) Assumed Sludge yield (lb. SS generated/lb. BOD removed)Ammonia WK mg/l (S Only) (MGD) - Plant flowAmmonia Winter WK NAc200 (mg/l) - BOD concentration entering aeration tanksP Weekly mg/ld10 (mg/l) - BOD concentration following settlinge8,430 lbs. biological (mg/l) - chemical sludges producedh634 lbs. chemical (Fe/AL) Sludge generated/dayi9,064 Total lbs. WAS/dayj10,000 (mg/l) - Assumed WAS concentration (Note: 10,000 mg/l = ) (MGD) - Waste Activated Sludge quantity daysF/M Ratio = BOD Loading Rate = ,000 :WWTPBy:Phil Anderson - ARCADIS SummaryOperation: Activated Sludge Date:Winter4,500 MLSS, CF/M CELL RESIDENCE TIME (MCRT) Loading ,000 AerationRequired MCRT Ammonia Required MCRT DATA.

7 6 Aeration Tanks On LineDT for BOD (MG) - Aeration tank volume (total) Tank MG EachDT for NH3 ,375 (mg/l) - Mixed liquor VOLATILE suspended solids (MLVSS)Aeration Tank Vol (MGD) - Daily flowrate of waste Activated Sludge (WAS) [See below]Aeration Tanks ,000 (mg/l) - WAS suspended solidsAeration Tanks On (MGD) - Plant flowMLSS4,500mg/lf10 (mg/l) - Effluent suspended solidsMLVSS3,375 mg/lNitrifiers (8% of MLVSS)270 mg/lSUPPLEMENTAL CALCULATIONS (MLVSS):a4,500 (mg/l) Assumed mixed liquor suspended solids (MLSS)EFFLUENT (%) - Assumed percent volatileCBOD Weekly 15 mg/l3,375 (mg/l) - MLVSS TSS Weekly 18 mg/lFecal Weekly 2,000 (S Only)WASTE Sludge VOLUME:Ammonia WK mg/l (S Only) Assumed Sludge yield (lb.)

8 SS generated/lb. BOD removed)Ammonia Winter WK (MGD) - Plant flowP Weekly mg/lc200 (mg/l) - BOD concentration entering aeration tanksd10 (mg/l) - BOD concentration following settlinge8,430 lbs. biological (mg/l) - chemical sludges producedh634 lbs. chemical (Fe/AL) Sludge generated/dayi9,064 Total lbs. WAS/dayj10,000 (mg/l) - Assumed WAS concentration (Note: 10,000 mg/l = ) (MGD) - Waste Activated Sludge quantity daysF/M Ratio = BOD Loading Rate = ,000 (%)MCRT (Days)Figure 1 Effect of MCRT On NitrificationNitrification Efficiency % RatioMCRT, DaysFigure 2 Relationship Between MCRT and F/M RatioRatio024681012141618201234567891011 12131415 Ammonnia, mg/lTime (in 1/4 Hours)Figure 3 Ammonia Removal vs TimeAmmonia01020304050607080901001234567 8910111213141516171819202122232425262728 2930 Percent (%)Temperature (C)

9 Figure 4 Effect of Temperature On NitrificationRemoval Rate % MLSS/DayDissolved OxygenFigure 5 Effect of on NitrificationNH3 Oxidation Rate010203040506070809010012345678910 Precent (%) pHFigure 6 Effect of pH on NitrificationMaximum Nitrification Rate (%)05010015020025030035040012345 Alkalinity mg/lInfluent Ammonia (mg/l x 10)Figure 7 Alkalinity Used in NitrificationAlkalinity Required mg/lMaumee River WWTPDO ProbeSingle Stage BlowerCenter Feed FSTC enter Feed FSTP eripheral Feed FSTP eripheral Feed FSTC enter Feed