Treatment of Treatment of Slaughterhouse Slaughterhouse

WastewaterWastewater

Mike LawrenceMike Lawrence

NDSUNDSU

Fall 2006Fall 2006

OverviewOverview

Challenges Challenges Wastewater ParametersWastewater Parameters Treatment OptionsTreatment Options Process ModificationsProcess Modifications Typical On-site Treatment OptionsTypical On-site Treatment Options Design ProblemDesign Problem

Challenges of Slaughterhouse Challenges of Slaughterhouse WastewaterWastewater

Wastewater contains large amounts Wastewater contains large amounts of blood, fat, and hairof blood, fat, and hair

Wastewater is above municipal Wastewater is above municipal standards which leaves two options; standards which leaves two options; on site treatment or pay to be on site treatment or pay to be treated elsewheretreated elsewhere

On site treatment with low capital On site treatment with low capital and maintenance costs is desirableand maintenance costs is desirable

Wastewater ParametersWastewater Parameters

BOD approx. 1,000 to 4,000 mg/LBOD approx. 1,000 to 4,000 mg/L COD approx. 2,000 to 10,000 mg/LCOD approx. 2,000 to 10,000 mg/L SS approx. 200 to 1,500 mg/LSS approx. 200 to 1,500 mg/L High Oil and Grease contentHigh Oil and Grease content Possible high chloride content from Possible high chloride content from

salting skinssalting skins

Treatment OptionsTreatment Options Discharge to sewer to be treated by Discharge to sewer to be treated by

municipal treatment plantmunicipal treatment plant Land application of wastewater for Land application of wastewater for

irrigationirrigation Reduce amount of wastewater and/or Reduce amount of wastewater and/or

concentrations with the wastewater by concentrations with the wastewater by changing the processeschanging the processes

On site TreatmentOn site Treatment– Flow Equalization, Screening, Dissolved Air Flow Equalization, Screening, Dissolved Air

Flotation, Primary SedimentationFlotation, Primary Sedimentation– Aerobic TreatmentAerobic Treatment– Anaerobic TreatmentAnaerobic Treatment

In-Plant Modifications to Reduce In-Plant Modifications to Reduce PollutionPollution

Main goal should be to prevent product Main goal should be to prevent product from entering the waste stream and using from entering the waste stream and using the least amount of water possiblethe least amount of water possible

Reduce the amount of water used, saves Reduce the amount of water used, saves money in two waysmoney in two ways

Use high pressure and just enoughUse high pressure and just enough Proper detergentsProper detergents Lower volume of water helps equipmentLower volume of water helps equipment Reuse as much water as possibleReuse as much water as possible

Line SeparationLine Separation

Separating the various waste Separating the various waste streams as much as possiblestreams as much as possible

Sanitary lines should be discharged Sanitary lines should be discharged directly to the city sewerdirectly to the city sewer

Grease waste streams and non Grease waste streams and non grease waste streams can help grease waste streams can help reduce treatment costs reduce treatment costs

Separate Blood lineSeparate Blood line

Blood RecoveryBlood Recovery

Blood has ultimate BOD of 405,000 mg/LBlood has ultimate BOD of 405,000 mg/L One head of cattle contains 49 lbs. of One head of cattle contains 49 lbs. of

blood which equals 10 lbs. BOD, compared blood which equals 10 lbs. BOD, compared to 0.2 lbs. discharged per person per dayto 0.2 lbs. discharged per person per day

All blood should be recovered in a All blood should be recovered in a separate line draining to a tankseparate line draining to a tank

Blood is then dried, commonly a Blood is then dried, commonly a continuous drier is usedcontinuous drier is used

Profitable end productProfitable end product

Stockpen AreaStockpen Area

Stockpen waste and other manure Stockpen waste and other manure should be hauled away as a solidshould be hauled away as a solid

Cleaned periodically with as little Cleaned periodically with as little water as possiblewater as possible

Ideally this water would go to a Ideally this water would go to a separate tankseparate tank

From the tank it would be emptied From the tank it would be emptied into a truck and land appliedinto a truck and land applied

On-Site TreatmentOn-Site Treatment

Costs of treating on site or letting the Costs of treating on site or letting the municipality treat the waste should municipality treat the waste should calculatedcalculated

Maintenance and operation should Maintenance and operation should be also put into cost analysisbe also put into cost analysis

Flow equalization is usually a very Flow equalization is usually a very good first step in on-site treatmentgood first step in on-site treatment

HydrasieveHydrasieve

BOD Removal 5-20%BOD Removal 5-20% TSS Removal 5-30%TSS Removal 5-30%

HydrasieveHydrasieveWidth

(ft)Height

(ft)Capacity

(gpm)Estimated

Price

2 5 75 $5,200

3.5 5 150 $6,400

4.5 7 300 $8,000

5.5 7 400 $10,000

6.5 7 500 $12,000

7 7.3 1000 $20,000

14 7.3 2000 $40,000

21 7.3 3000 $60,000

28 7.3 4000 $80,000

35 7.3 5000 $100,000

SS and Grease RemovalSS and Grease Removal

Grease removal could be very Grease removal could be very profitableprofitable

Skimming operationsSkimming operations– 20 to 30 % BOD removal20 to 30 % BOD removal– 40 to 50 % SS removal40 to 50 % SS removal– 50 to 60 % grease removal50 to 60 % grease removal

Dissolved Air Flotation, DAFDissolved Air Flotation, DAF– 30 to 35 % BOD removal30 to 35 % BOD removal– 60 % SS removal60 % SS removal– 80 % grease removal80 % grease removal

Skimming Operation (Primary Skimming Operation (Primary Sedimentation)Sedimentation)

Detention time 1.5 to 2.5 hrDetention time 1.5 to 2.5 hr Overflow Rate 800 to 1200 gal/ftOverflow Rate 800 to 1200 gal/ft22*d*d

Dissolved Air Flotation (DAF)Dissolved Air Flotation (DAF)

Hydraulic Loading RateHydraulic Loading Rate– 1.5 to 5.0 gpm/ sq. ft.1.5 to 5.0 gpm/ sq. ft.

Solids Removal RateSolids Removal Rate– 1.0 to 2.0 lbs/hr/sq. ft.1.0 to 2.0 lbs/hr/sq. ft.

Anaerobic LagoonsAnaerobic Lagoons Ideally the lagoon would be covered, odor & Ideally the lagoon would be covered, odor &

gas production contained, heat retentiongas production contained, heat retention Not well suited for colder climatesNot well suited for colder climates Detention time 20 to 50 daysDetention time 20 to 50 days BOD5 loading= 200 to 500 lb/ac.-dBOD5 loading= 200 to 500 lb/ac.-d

Anaerobic Contact Reactor (ACR)Anaerobic Contact Reactor (ACR)

Hydraulic Retention time 0.5-5 daysHydraulic Retention time 0.5-5 days Organic Loading rate of 1.0-8.0 kg Organic Loading rate of 1.0-8.0 kg

COD/mCOD/m33-d-d

Flocculator or

Anaerobic Sequencing Batch Anaerobic Sequencing Batch Reactor (ASBR)Reactor (ASBR)

HRT 6 to 24 hoursHRT 6 to 24 hours SRT 50 to 200 daysSRT 50 to 200 days 98% removal with 98% removal with

1.2kgCOD/m1.2kgCOD/m33-d-d 92% removal with 92% removal with

2.4kgCOD/m2.4kgCOD/m33-d-d Possibly rates to 5 Possibly rates to 5

kgCOD/mkgCOD/m33-d-d Effluent SS range Effluent SS range

between 50 – 100mg/L between 50 – 100mg/L depending on HRTdepending on HRT

Upflow Anaerobic Sludge Blanket Upflow Anaerobic Sludge Blanket (UASB)(UASB)

Proteins and fats Proteins and fats may cause problems may cause problems in formation of in formation of granules.granules.

Loading rates of 4-Loading rates of 4-12 kg sCOD/m12 kg sCOD/m33-d-d

Retention times of Retention times of 7-14 hours7-14 hours

Design ProblemDesign Problem

Flowrate:120,000 gpd, 83 gpm, Max Flowrate:120,000 gpd, 83 gpm, Max 300 gpm300 gpm

TSS=1500 mg/LTSS=1500 mg/L COD=5000 mg/LCOD=5000 mg/L sCOD=3000 mg/LsCOD=3000 mg/L BODBOD55=2,000 mg/L=2,000 mg/L Reduce levels to municipal levels and Reduce levels to municipal levels and

discharge into sewerdischarge into sewer

ScreeningScreening

HydrasieveHydrasieve Use prior to flow equalization to save Use prior to flow equalization to save

on pumps and buildup in the tankson pumps and buildup in the tanks Design for max flow of 300 gpmDesign for max flow of 300 gpm 4.5 by 7 foot model will handle flow4.5 by 7 foot model will handle flow Approximate cost of $8,000Approximate cost of $8,000

PrimaryPrimary

Loading Rate of 600 gal/ftLoading Rate of 600 gal/ft22-d-d Final DesignFinal Design

– 8 ft. wide, 25 ft. long, 10 ft. deep8 ft. wide, 25 ft. long, 10 ft. deep– 8 ft. of weir w/ loading rate of 15,000 8 ft. of weir w/ loading rate of 15,000

gpd/ftgpd/ft– HRT = 3 hoursHRT = 3 hours

25 ft

10 ft

8 ft

Anaerobic LagoonAnaerobic Lagoon Covered for heat retentionCovered for heat retention Side depth = 8 feetSide depth = 8 feet Final Design 540 lb BODFinal Design 540 lb BOD55/ac-d/ac-d HRT=80 daysHRT=80 days Plan View

400 ft

400 ft

Anaerobic Contact ReactorAnaerobic Contact Reactor

Final Design HRT=5 daysFinal Design HRT=5 days Loading Rate 1.0 kg COD/mLoading Rate 1.0 kg COD/m33-d-d Clarifier design based on 24m/d Clarifier design based on 24m/d

settling velocitysettling velocity

30 ft

56 ft

10 ft

16ft

ClarifierAnaerobic Contact Reactor, Completely Mixed

Flocculator, Deglassifier

Aerated Sequencing Batch ReactorAerated Sequencing Batch Reactor Two reactors of same sizeTwo reactors of same size Feed 8 hr, react 37.5 hr, settle 2 hr, drain Feed 8 hr, react 37.5 hr, settle 2 hr, drain

.5 hr.5 hr Feed 8 hr, react 13.5 hr, settle 2 hr, drain Feed 8 hr, react 13.5 hr, settle 2 hr, drain

.5 hr.5 hr

46 ft

24 ft

Sludge waste at bottom

Supernatant Drain 11.5 ft above bottom

Upflow Aerated Sludge Blanket Upflow Aerated Sludge Blanket ReactorReactor

Loading Rate of 10 kg sCOD/mLoading Rate of 10 kg sCOD/m33-d-d Two tanks, operated in parallelTwo tanks, operated in parallel Diameter = 4.5 m, Height= 7 m, Diameter = 4.5 m, Height= 7 m,

2.5 m for gas 2.5 m for gas storagestorage

7 m

4.5 m

Final DesignFinal Design

Include Hydrasieve: effectiveness and Include Hydrasieve: effectiveness and low capital, O & M costslow capital, O & M costs

Upflow Anaerobic Sludge Blanket Upflow Anaerobic Sludge Blanket ReactorReactor

Tank is smaller than most of the others Tank is smaller than most of the others due to high organic loading ratedue to high organic loading rate

Provides constant source of methane Provides constant source of methane gasgas