PowerPoint Presentation

Salamonie Reservoir: Wastewater TreatmentPresentation by Chelsea SmithMarch 11, 2014

My BackgroundSouthern Wells (K-12)Graduated in 2010

Ball State University (2010-2014)BS in Environmental ManagementMinor in Criminal JusticeMinor in Music Theory

2013 Summer InternshipSalamonie Reservoir and Lake (DNR)Duties included:Assisting the Wastewater Treatment OperatorSampling drinking waterServing as a boat ramp attendantLawn mowing and weed whackingOther

Wastewater Treatment PlantOperations proceed 24/76 Stations Influent enters the plant (aka raw sewage)Main treatment (aka mixed liquor) Effluent exits the plant (aka final clear water)Lab tests occur at least once each week

How many of you live in the country? How is your wastewater treated? Septic system (draw on board) and give short overview.Septic system used because it is not feasible for our houses to patch into a municipal wastewater treatment facility. Every plant is different. This is a small operation due to small inflow and smaller population in that area. 4

1. Headworks/ Screen UnitRaw flows in Headworks: primary removal of large items before the water can be treatedScreen unit removes debris and trashLeaves, toys, rocks, towels, Grit channel removes sand and smaller particles

Purpose: To remove contaminants which improves later water treatment, making it more effective

2. Grease SeparatorRemoves grease and oils from raw influent

Purpose: To make water treatment more effectiveGrease may cause clogs It is difficult for microbes to digest grease = slow process

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www.americanbiofuelscorp.com3. Chemical Feed PumpTreats water based of flowFerric chloride (FeCl3)Highly corrosiveLow pH = Acidic Reddish-brown liquid (stains easily)

Purpose: To remove sewage particles out of suspension in the water by coagulationSuspended particles attach to ferric salts and clumpClumps become bigger and heavier; settle to bottom

Salamonie used Ferric chloride, but also can use Aluminum Sulfate (alum)- Al2(SO4)3Try to use the least amount of chemicals as possible, but still meet standards.12

4. Clarifier (Main Treatment)Wastewater enters Aeration TankSmall air bubbles break up solids and mix waterMicrobes need oxygen to digest organic matter (sewage)Water moves from aeration tank to ClarifierSolids settle to the bottom of the ClarifierSludge at bottom pumped to Sludge Holding TankClear water spills over Clarifier rings

Purpose: To separate solids from clear water AND to digest organic compounds via microbial processesAeration reduces and even prevents foul odors. Compounds associated with these foul smells are produces from anaerobic processes (= without oxygen).Ammonia and hydrogen sulfide are the two main compounds that cause this smell in wastewater treatment processes.By aerating the tanks (adding oxygen), we produce an aerobic environment, and microbes digest organic matter and produce different byproducts (ones that do not smell bad).Water pumped from bottom of aeration tank to clarifier

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Draw aerial view of tank (showing aeration 2/3 and holding tank 1/3)Draw aerial view to show clarifier portion18

5. UV DisinfectionClear water flows from clarifier into the UV basinMust move slowly = more retention timeUV lights used instead of chlorineCl harmful to aquatic lifeUV bulbs and basin must be kept clean

Purpose: To kill any residual microorganisms and microbial pathogens (especially E. coli)Ultraviolet radiation damages the DNA of microorganisms, thus killing them.

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6. Final Aeration BasinClear water moves through a flow meter and into the final basinWater cascades down many stepsDischarged into the stream which flows into the lake

Purpose: To improve oxygen content in the water, thus provided aquatic organisms with needed oxygenSalamonie filled their aeration basin with rocks. The goal was to improve agitation and introduce more oxygen, but the problem was that algae easily grew on these rocks.Flow meter used to show how much water flows through and is treated in the plant each day. 23

Wastewater Weekly TestspH Dissolved Oxygen (DO)Carbonaceous Biological Oxygen Demand (BOD)Total Suspended Solids (TSS)Percent Settleable Solids in 30 minutesAmmoniaTotal PhosphorusE. coli

pHpH probe inserted into 100 mL sampleStir rod helps give an accurate sample throughoutMeasures: amount of hydrogen ions in solution

Importance: Aquatic organisms need pH 6-9 to surviveSolution: Control amount of ferric acid addedpreparatorychemistry.com

Aeration tank water usually has lower pH due to ferric acid added at this stageFinal clear water pH must be between 6-9 to support aquatic lifeRead pH twice each weekScale of 1-14, 7 is nuetralMore hydrogen ions = acidic, less hydrogen ions = basic/ alkaline

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Dissolved Oxygen (DO)DO probe inserted into 100 mL sampleSensors must be fully submergedMeasures: amount of oxygen molecules in water

Importance: Aquatic organisms need DO levels above 5.0 mg/L to survive easily

Solution: Increase aeration rate or allow sewage to have more retention time in aeration tanksTested 4 times each weekPermeable membrane at bottom of probe measures DOTemp sensor also on probeTemp. affects DO levels (higher temp, lower DO)

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Biological Oxygen Demand (BOD)9 different bottles prepared and incubated for 5 daysDO measured before and after incubationMeasures: amount of oxygen needed for microbes to decompose the organic (carbonaceous) matter available in waterRelates to DO levels (inverse reactions)Importance: Too much BOD can deplete DO levelsSolution: Increase aeration rate and allow microbes to digest more organic matterIn essence, it shows how much carbon is present in waterThe higher the BOD level, the lower the DO level Ideal range for final DO is 2-10 mg/LUse electric micropipette to measure samples into bottles32

Total Suspended Solids (TSS)Filter water sample through glass fiber filter and dryWeigh filters before and after sample is addedMeasures: amount of suspended solids in waterImportance: Lower amount of suspended solids = lower turbidity of final clear waterSolution: Increase retention time in aeration tank and increase amount of ferric acid added

Must handle filters with tweezers to prevent contaminants (oils, dirt, etc.) from getting on the filter. Contaminants will change the mass of the filter, thus giving a false amount of solids in water sample.Turbidity = murkinessTSS found by taking difference in weights, performing a conversion, and dividing answer by amount of sample added (giving mg/L)36

Settleable Solids in 30 minutesLet a 1000 mL mixed liquor sample settle solids for 30 minutesLevel of solids at the bottom = % solids in waterMeasures: amount of larger solids in water that will settle to the bottomImportance: Microbes in the aeration tank need 15-25% solids for efficient and effective treatmentSolution: Alter amount of solids (organic matter) in the aeration tank

Too much sludge in aeration tank= microbes will digest carbon continuously until oxygen levels become too lowToo little sludge in aeration tank= not enough food for all of the microbes, and some will die off41

AmmoniaAdd water sample to prepared vialsUse spectrophotometer to read ammonia levels after reaction completedMeasures: amount of ammonia (NH3) molecules in the waterImportance: Too much nitrogen in water can cause algae growth, which will deplete DOSolution: Increase aeration rates and retention time of mixed liquor in aeration basin

www.uh.eduIf algae grows in water bodies, it can use up dissolved oxygen in the water, thus depriving aquatic organisms of oxygen.43

Use micropipette to measure water sample into vial

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Darker the green, the more ammonia presentRaw should always be darker (higher amounts) due to no treatment or alteration45Total PhosphorusAdd water sample to prepared vialsUse spectrophotometer to read phosphorus levels after reaction completedMeasures: amount of phosphorus molecules in waterImportance: High amounts can cause depletion of dissolved oxygen and lead to algae growthSolution: Increase addition of ferric acid to remove phosphorus by coagulation

www.advancedaquarist.comPhosphorus tends to attract to soil particles (this is why it can be removed during coagulation)46

Darker the blue, the more phosphorus is present47www.keison.co.uk

SpectrophotometerHach DR 3900 SpectrophotometerBeam of light is directed at the sample. The amount of light that is absorbed by the sample is proportional to the amount of compound (in this case phosphorus) that is in the sample.48Escherichia coliSample is poured into a tray with many wellsAfter 24 hour incubation, number of luminescent wells correlates to amount of E. coliMeasures: number of colony forming units (CFU) that are present in a 100 mL water sampleImportance: E. coli is a disease-causing human pathogenSolution: Increase retention time in the UV basin and clean UV bulbs

No single sample can test over 235 CFU (Colony forming units)/ 100 mLGastrointestinal complications can occur if exposed to high amounts of E. coli.Salamonie lake is a recreational area, therefore E. coli levels must be low for the safety of swimmers and boaters.

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www.etsnclab.comHazardous Materials TrainingCertified in HazMatUseful when dealing with chemicals (i.e. ferric acid)Weapons of Mass Destruction (WMDs) ClassInternational and Domestic Terrorism Class

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Level A PPE

Level DPPE

Any Questions?

Referenceshttp://www.ovivowater.com/en/Headworkshttp://www.cwtozone.com/uploads/SalesDocs/Markets/Air%20Treatment/Papers/Technical%20Papers/Municipal-Odor-Control-Italy%20TP.pdfhttp://water.usgs.gov/edu/wwvisit.htmlhttp://www.cleanwaterservices.org/AboutUs/WastewaterAndStormwater/TreatmentProcess.aspxhttp://water.usgs.gov/edu/dissolvedoxygen.htmlhttp://water.epa.gov/type/rsl/monitoring/vms52.cfmhttp://www.waterworld.com/articles/print/volume-26/issue-3/editorial-features/addressing-the-challenge.htmlhttp://www.water.siemens.com/en/applications/wastewater_treatment/bod-cod-reduction/Pages/default.aspxhttp://water.usgs.gov/edu/nitrogen.htmlhttps://engineering.purdue.edu/SafeWater/watershed/ecoli.html#levels