Emerging Technologies in Onsite Wastewater Treatment

Transcription

1 Emerging Technologies in Onsite Wastewater Treatment Gordon Balch Centre for Alternative Wastewater Treatment, Fleming College, Lindsay, Alberta Onsite Wastewater Management Association: Convention and Trade Show Friday, March 6 th, 2015, Edmonton, Alberta

2 Overview Opportunities for Rural Growth through Sustainable Service Framework (Building Code) Advanced Treatment Systems domestic Customized (alternative systems) CAWT Testing Future Trends / Needs 2

3 Ont. Building Code Part 8: Sewage Systems Building code regulates a number of different classes of onsite treatment systems Class 4 is most common and is intended to minimize pathogens released into the environment can include secondary and tertiary (advanced) treatment systems located between septic tank and leaching bed 3

4 Advanced Treatment Systems 4

5 Advanced Treatment Systems Advantages provide the opportunity to service sites not suited for conventional septic systems Better treatment may extend the life of an existing leaching bed take up less room in the yard require mandatory maintenance (ensures the unit is functioning properly) may reduce nutrient output (depending on type) Disadvantages may be more expensive to purchase and install more expensive to operate (e.g. yearly electrical costs, media replacement) mechanical parts that can break down or need replacement requires mandatory maintenance (increases costs) 5

6 Conventional Septic System Pre-treatment septic tank Final Distribution and Soil Treatment Absorption trench or filter bed pipe 30-50% treatment in septic tank 50-70% treatment in soil SepticSmart

7 Advanced Treatment System Pre-treatment Final Distribution and Soil Treatment Shallow Buried Trench advanced treatment unit gravity or pump flow Area Bed pre-treatment tank* stone sand pipe native soil saturated soil 90% treatment in septic tank 10% treatment in soil SepticSmart

8 Advanced Treatment Systems Intent of ATS: To mitigate site impediments to installation (e.g., heavy clays, shallow soils, limited space, high water table, etc.) To provide added protection (nutrient abatement) to at-risk sites (e.g., nutrient sensitive lakes, ground waters, etc.) 8

9 Approval Criteria for ATS Must meet performance criteria set out by building code testing and certification by the NSF International (U.S.-based) standard consideration of Ontario s environmental/climatic conditions evidence of in-field performance. 9

10 Evaluation of ATS Technologies Treatment unit technologies were evaluated by MMAH List of approved treatment units found in Supplementary Standard SB-5 to the Building Code All currently approved systems incorporate microbial treatment and or physical filtration 10

11 SB-5 (Ontario): Advanced Treatment Units Suspended Growth Aquarobic Canada Aqua Safe and Aqua Air Biocycle Aerated Wastewater System Clearstream Treatment Systems Norweco Singulair Treatment Systems Whitewater Treatment Systems WSB Clean Treatment Systems 11

12 SB-5 (Ontario): Advanced Treatment Units Attached Growth Bio-Microbics FAST Wastewater Treatment Systems Bionest Technologies Inc. Nayadic Wastewater Treatment Systems Rotordisk Wastewater Systems 12

13 SB-5 (Ontario): Advanced Treatment Units Synthetic Media Filter Orenco AdvanTex Wastewater Treatment System Waterloo Biofilter Treatment Systems Peat Filter Premier Tech Environment Ecoflo Biofilter Treatment Systems Puraflo Peat Fiber Biofilter Treatment Systems Sand Filter Orenco Treatment Systems 13

14 Alberta manufacturers/parent companies authorized to sell their NSF 40 Class 1 Sewage Treatment Plants. Treatment Plant AdvanTex Bionest Aero-Tech Singulair Singulair Mo-Dad AdvanTex Singulair Fast Ecopod Ecoflo Bioflo SludgeHammer Singulair Pro Flo Jet Bat Bionest Manufacturer/Parent Company Orenco Systems Inc. Bionest Technologies Inc. Aero-Tech Norweco Inc. Norweco Inc. Acquired Wastewater Technologies, LLC Orenco Systems Inc. Norweco Inc. Bio-Microbics Inc. Pentair (formerly Delta Environmental Products) Premier Tech Technologies Limited SludgeHammer Group Ltd. Norweco Inc. Pro Flo Aerobic Systems, LP Jet Inc. Bionest Technologies Inc. 14

15 Waterloo Biofilter There are different configuration depending on the wastewater constituents and desired treatment level 15

16 CANWEST tanks & ecological systems Ltd. Surry, BC 16

17 1. Primary Clarification 2. Moving Bed Bioreactor 3. Aeration 4. Final Clarification 1 5. Sludge Return 6 6. Outlet WSB clean Septic System 17

18 CAN/BNQ CAN/BNQ , Onsite Residential Wastewater Treatment Technologies is the new national standard for testing wastewater residential treatment technologies. This standard will replace the current criteria for treatment units set out in the Ontario Building Code, and the list of treatment units found in Supplementary Standard SB-5 which are deemed to meet these Code requirements. [to be revoked Jan 1/17] 18

19 Treatment Options Domestic Conventional Septic Systems Advanced Wastewater Treatment Microbial (suspended or fixed) ± aeration Physical filtration ± aeration Alternative Constructed Wetlands Engineered Bio Reactors (e.g., S-reducing Bacteria for Arsenic) Sportive media for Phosphorus Moving Bed Bio Reactors for Oxidized N Ozone UV Hybridized nano-membranes with nanoparticles others 19

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21 Specialized (site-specific)treatment Needs Complexity of waste stream is increasing Greater need for site specific treatment options reduce treatment burden on existing systems (e.g., high BOD from brewery industry) Meet industry specific needs (aquaculture, mining, health care, etc.) Ozone, sulfur reducing bioreactors, hybridized constructed wetlands, etc., all showing promise 21

22 Enhanced Nitrogen Removal (stationary fixed film) Denitrification 2.3 g BOD per g NO 3 -N 3.02 g organic matter per g NO 3 -N Heterotrophic bacteria for generation of carbon source Significant portion of BOD generally consumed during nitrification, leaving little for denitrification Return unconsumed Carbon High in BOD & NH4 Anoxic Aerobic Clarifier Denitrification Nitrification + BOD removal 22

23 Moving Bed BioReactor (MBBR) Small foot print Very efficient Up to 5Xs biofilm Does require pumps and aeration 23

24 Phosphate Removal adsorption, precipitation H 2 PO Fe Fe O O Fe O Fe O Adsorption (Fe, Al, Mn oxides) Precipitation (Fe, Ca, Al phosphates) O P O H O H Variety of Sources and Manufactures Blast furnace steel slag Oxide rich natural clays Manufactured oxides (Al, Fe, mixtures) 24

25 Phosphorous adsorptive media for Stormwater runoff Adsorptive media can also be used in advanced treatment systems (residential) Work is proceeding in looking at ways to incorporate and regenerate media 25

26 Mining Sector Arsenic Removal from Tailings Waters Engineered wetland to complex dissolved Arsenic with Sulfur with the use of bacteria Use of sulfur reducing bacteria 26

27 Agriculture Sector CUI2I Agriculture Wastewaters Greenhouse wastewaters rich in Cl -, SO 4 2-, Na, + K +, Ca ++ High in Nitrates and Sulfates Employ salt hyper-accumulating plants, denitrification reactors (removing NO 3 and convert SO 4 to H 2 S) College-University idea to innovation Grants 27

28 Aquaculture Sector Land Based fish farm Solids Nutrients (N & P) Fish pathogens 28

29 Trickle Filters High removal rate of BOD, Nitrogen, TSS Aerobic and anaerobic zones Food wastes, aquaculture applications (e.g. winery wastes) Sewer by-laws 29

30 Advanced On-Site Treatment Ozone Pressure differentials Poly-filter Granulated activated carbon filter Nutrients (N & P) TSS BOD Pathogens PPCPs 30

31 Overview of System Off gas & destruct 31

32 Results: Selected PPCPs (ppt) Sulfamethoxazole Trimethoprim Carbamazepine Diclofenac Aspartame Medroxyprogesterone Progesterone Levonargestrel n.d. n.d. n.d. n.d. Influent Effluent n.d. n.d. n.d Concentration (ng L -1 ) Mean ± SD 32

33 Constructed Wetlands Man-made with specific design specifications Intended to treat domestic waste using natural processes Filtration / sedimentation Microbial oxidation / transformation Chemical processes Adsorption / absorption 33

34 Hybridized Constructed Wetlands Flow = 40 m 3 /d; Inlet COD = 1000 mg/l & NH3 = 1000 mg /L Each line consists of: 1. SFS-v (e.g.,vssf) stage with a superficial peat layer to ensure odor remove, leachate preoxidation and metals precipitation; 2. Two stage SFS-v in series for nitrification (add O 2 ) and organic load removal (e.g., BOD); 3. Two stage SFS-h (e.g., HSSF) in series for denitrification (remove O 2 ) and removal of persistent organic compounds; 4. A stage FWS to complete the denitrification and the organic compounds removal and to enhance the evapotranspiration; 5. A final detention pond to accumulate the effluent and enhance the evapotranspiration. The system is designed to ensure high removal rates (>90-95% COD and NH 3 ), and a good reduction of the effluent due to evapotranspiration. 34

35 Future Trends (???) 35

36 North America Wastewater Infrastructure Deficit Great Lakes Commission 2007 report Wastewater infrastructure deficit in 2 Provinces and 8 US states is $10 billion $90 billion needed in next 10 y (2007) to replace and upgrade Canada wide 36

37 Aging municipal infrastructure When Bigger Isn t Better: Decentralized Wastewater Treatment Systems (On. Environ. Commissioner 2009) Small or rural communities in Ontario faced with: Increasing population Climate change Stricter environmental regulations A call for decentralized systems 37

38 Waste Generation from DWWT Septic system leachate represents the largest unregulated source of wastewater 1980 USA census 3.8 trillion L per year to vadose zone (US EPA 1987) 25-30% of households in USA are served by septic systems (Bremer & Harter 2012) 22% of Canadians utilize on-site systems (Richardson & Fulton 2009) 38

39 Global Water Supply 1 st everything (1,385 km diameter) 2 nd groundwater, fresh surface water (272.8 km diameter) Source: Scientific American 3 rd fresh water in lakes and rivers (56.2 km diameter)

40 Cluster Systems Cluster systems are generally used to collect wastewater from a small cluster of homes Waste is transported to the site of treatment via alternative sewers The transported wastewater is treated at either a conventional treatment system or receives pre-treatment prior to soil absorption of the pretreated effluent 40

41 Final disposal to Wetland and Drainfield 41

42 Application of Cluster Systems There can be many reasons to install a cluster systems Most often installed because the land size of individual properties is not large enough to accommodate an on-site system OR Because the financial cost for construction of a conventional treatment plant is not feasible Small rural areas 42

43 Human Health Concerns Methaemoglobinaemia Cancers (increased risk) Thyroid disruption 2013 May see a greater emphasis on removal of Nitrates 43

44 Phosphorus??? Phosphorous not strongly linked to human health Most issues are impacts to surface waters Cyanobacteria? Present concerns are focused on agriculture, stormwater, etc. 44

45 Concluding Remarks Demand for decentralized treatment likely to increase Demand for specialized treatment to off-load burden to centralized systems may increase May see greater need for advanced treatment systems for Nitrate and Phosphorous in relationship to source water protection 45

46 Questions You cannot get through a single day without having an impact on the world around you. What you do makes a difference, and you have to decide what kind of difference you want to make. Jane Goodall 46

47 Advanced Treatment System Pre-treatment Final Distribution and Soil Treatment Shallow Buried Trench pre-treatment tank* advanced treatment unit pump chamber pressure flow pressure pipe and chamber native soil Advanced treatment units use oxygen to enhance treatment. saturated soil 90% treatment in septic tank 10% treatment in soil SepticSmart

48 Smaller foot print of advanced treatment systems conventional advanced WSB Clean 48

49 Disposal Challenges Regulatory oversight / requirements increasing post Walkerton Ont. Environ Protection Act, Ont. Clean Water Act, etc. Complexity of wastewater increasing Pharmaceuticals and personal care products Increasing number of wastewater sources Petroleum, agra-farms, aquaculture, etc. Treatment Costs Increasing 49