1. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. 1

2. 2  Activated sludge processes ◦ Fixed film and suspended processes  Aerobic/anoxic/anaerobic processes modifications.  Nutrient removal ◦ nitrification / denitrification, phosphorous removal  Water reuse and reclamation ◦ membrane bioreactors  Disinfection  Satellite and On-site Wastewater Treatment

3. 3  Bacteriological, ◦ Vibrio Cholerae, Campylobacter, Salmonella, Shigella,  Viruses ◦ Hepatitis A, Norovirus  Protozoan ◦ Giardia, Cryptosporidium, Entamoeba  Biological oxygen demand ◦ Organic matter causes algae to thrive and deplete dissolved oxygen  Nutrient removal to prevent eutrophication ◦ Nitrogen and phosphorus from waste, and agriculture

4. 4 What does wastewater look like? Source: Wastewater Engineering, Metcalf and Eddy- medium strength WW MeasurementValueUnits Total Suspended Solids (TSS)210mg/L BOD190mg/L TOC430mg/L COD140mg/L Organic Nitrogen15mg/L Free Ammonia25mg/L Nitrite/Nitrate0/0mg/L Phosphorous7mg/L Total coliform10 7 -10 9 colonies/100mL Fecal coliform10 4 -10 6 colonies/100mL Cryptospiridium oocysts0.1-10no./100mL Giardia Lamblia0.1-100no./100mL

5. 5 Testing for pathogens directly is expensive and hazardous Indicators from the family Enterobacteriacae are used (E. Coli, Citrobacter,Enterobacter, Klebsiella) Grow bacteria on a specified medai and count the number of colonies after incubation Other assays are used and are approved by the US EPA (Colilert shown)

6. 6 Suspended growth process Fixed film process Primary settling Screens Sludge drying Grit remova l Digeste r

7. 7 Treated Water Waste Water Facultative/Anaerobic Bed Media Aerobic  100µm ~1 mm Biofilm Fixed film biological processes

8. 8 Trickling filter Fixed film biological processes Uses biofilm to treat water to remove BOD

9. 9 Trickling filter effectiveness BOD 5 removal rates for trickling filters Filter TypeHydraulic loading m 3 /m 2 day BOD5 Removal (%) Low Rate1-480 - 90 Intermediate4-1050 - 70 High Rate10-4065 - 85 Roughing Filter 40 - 65 Source: Environmental Engineers Handbook, 1997.

10. 10 Suspended growth biological processes Anoxic – no dissolved oxygen Waste Water Aerobic Treated Water Activated Sludge Anoxic sludge Return activated sludge Coagulation Clarifier

11. 11 BOD and nutrient (nitrogen and phosphorous) removal Aerobic Conditions Anoxic Conditions BOD + O 2 CO 2 + increased cell mass NO 3 Organic N NH 4 NO 2 NO 3 N2N2 Aerobic Conditions P increased cell mass Anaerobic/Aerob ic Conditions Alum organic sludge inorgani c sludge

12. 12 Suspended growth activated sludge processes requires energy Use forced air suspension of biological sludge to reduce BOD Largest expense for this process is the electrical energy required

13. 13 Activated sludge process stages Anoxic Basin SedimentationFinal Clarification Aerobic Basin

14. 14 Anaerobic sludge digestion reduces solids - makes methane Anaerobic sludge digestors produce methane (65% CH 4 - 35% CO 2 ) On-site electricity is produced with the methane 50% of plant power (2.2MW)

15. 15 Aeration Sedimentation Solids Handling N org  NH 3 + NH 3 +  NO 2 NO 2  N 2 Mixing C 6 H 14  Biomass + CO 2

16. 16 Modified Ludzack- Ettinger (MLE Process) A2OA2OBardenpho RAS = Return Activated Sludge WAS = Waste Activated Sludge Exemplary process stages

17. 17 CH 4 + CO 2 C 6 H 14 + H 2 O Anaerobic Fermentation (30 days) Aeration Blowers 6.6 MW Disposal or Reuse (150 t/day) Diesel Generators Biosolids Centrifuges PNM

18. 18 NH 3 + Settling & Aeration Fermentation River Sewers CO 2 N2N2 CH 4 Microbes Composting CO 2 H2OH2OH 2 O+C+N+S O2O2 Humus Heat Power H2SH2S CO 2 HOCl - SO 2 (Biosolids)

19. 19 Water reuse often uses membrane bioreactor with submerged membranes Uses submerged hollow fiber membranes High Solids Retention Time membrane bioreactor Conventional activated sludge plant MBR membrane cassette

20. 20 Membrane bioreactors offer small size, high rate of reaction for satellite WW Screens AnoxicAerobicSubmerged Membrane

21. 21 Membrane separation spectrum Source: Zenon Membranes

22. 22 Screen before membrane bio reactor

23. 23 Kubota MBR pilot plant

24. 24 Raw feed and MBR product

25. 25 Reverse osmosis after MBR makes water suitable for groundwater recharge RO treated water is better than most surface water sources

26. 26 Hyperion Wastewater Plant Los Angeles 450 mgd 10% of discharge from this plant is sent to microfiltration plant to purify for groundwater injection

27. 27 West Basin Microfiltration Plant (35 mgd from Hyperion) Submerged microfiltration for treated wastewater effluent

28. 28 The final step is disinfection and discharge (no residual free chlorine) Chlorination to kill the remaining pathogens Cl 2  HOCl Dechlorination to remove chlorine SO 2 + HOCl + H 2 O  HCl + H 2 SO 4 SO 2 + NH 2 Cl + 2H 2 O  NH 4 Cl + H 2 SO 4 UV radiation reduces chemical needs and chlorinated products

29. 29 Effect of wastewater on disinfection ChlorineOzoneUV BOD,COD,TOCChlorine demandOzone demandLittle effect Oil and greaseChlorine demandOzone demandMay block light NitriteForms NDMAOxidizedNo effect NitrateForms chloraminesReduce O 3 effectiveness No effect Iron and ManganeseOxidized May block light Forms disinfection byproducts YesYes, but nonchlorinated No Source: Wastewater Engineering- Metcalf & Eddy

30. 30 Satellite and on-site waste disposal Satellite facilities are mid scale sewage treatment plants that treat waste near the point of generation Lagoons Aeration ditches Trickling filters Membrane bioreactor On-site waste disposal is septic tank system with drain field Provides low cost alternative Can be very effective Need little maintenance (but maintenance is important)