Onsite Wastewater Pretreatment Technologies

Transcription

1 Onsite Wastewater Pretreatment Technologies NDWRCDP Disclaimer This work was supported by the National Decentralized Water Resources Capacity Development Project (NDWRCDP) with funding provided by the U.S. Environmental Protection Agency through a Cooperative Agreement (EPA No. CR ) with Washington University in St. Louis. These materials have not been reviewed by the U.S. Environmental Protection Agency. These materials have been reviewed by representatives of the NDWRCDP. The contents of these materials do not necessarily reflect the views and policies of the NDWRCDP, Washington University, or the U.S. Environmental Protection Agency, nor does the mention of trade names or commercial products constitute their endorsement or recommendation for use. CIDWT/University Disclaimer These materials are the collective effort of individuals from academic, regulatory, and private sectors of the onsite/decentralized wastewater industry. These materials have been peer-reviewed and represent the current state of knowledge/science in this field. They were developed through a series of writing and review meetings with the goal of formulating a consensus on the materials presented. These materials do not necessarily reflect the views and policies of North Carolina State University, and/or the Consortium of Institutes for Decentralized Wastewater Treatment (CIDWT). The mention of trade names or commercial products does not constitute an endorsement or recommendation for use from these individuals or entities, nor does it constitute criticism for similar ones not mentioned. 1

2 Citation Lenning, D., T. Banathy, D. Gustafson, B.J. Lesikar, S. Wecker, D. Wright Technology Overview PowerPoint Presentation. in (D.L. Lindbo and N.E. Deal eds.) Model Decentralized Wastewater Practitioner Curriculum. National Decentralized Water Resources Capacity Development Project. North Carolina State University, Raleigh, NC. Pretreatment Options To evaluate the pretreatment option for a site, the following information must be known Hydraulic loading rate Daily and weekly peaks Organic loading rate Wastewater strength Contaminants of concern Pretreatment Options Wastewater Strength Organic loading rate BOD 5 TSS Fats, oils, and grease Temperature ph Nitrogen 2

3 Pretreatment Options Parameter Suspended solids Organic material (BOD 5 ) Pathogens Nitrogen Phosphorous Removal Processes Sedimentation, filtration Aerobic/anaerobic, sedimentation, filtration Filtration, predation, inactivation, disinfection Nitrification-denitrification, ion-exchange Adsorption in soil, physicalchemical, filtration, anoxicaerobic Adapted from USEPA, 2002 Pretreatment Approval Process Pretreatment Approval Process Pretreatment systems are approved by the Innovative and Experimental (I&E) Committee Committee is made up of people from both the public and private sector Requirements for approval listed in Rule

4 Pretreatment Approval Process Pretreatment can be approved as one of the three types Experimental Controlled Demonstration Innovative Main differences between the three are the number of systems that can be installed and the amount of sampling required Levels of Pretreatment Three levels of pretreatment in North Carolina NSF Std 40 Treatment Standard I Treatment Standard II Levels of Pretreatment NSF-40 CBOD < 25 mg/l TSS < 30 mg/l Treatment Standard I CBOD < 15 mg/l TSS < 15 mg/l NH4-N < 10 mg/l Fecal coliform <10,000 colonies/100 ml Treatment Standard II CBOD < 10 mg/l TSS < 10 mg/l NH4-N < 10 mg/l TN < 20 mg/l or > 60% Fecal coliform < 1,000 colonies/100 ml 4

5 Pretreatment and Rule.1970 If a pretreatment manufacturer can meet one of the three treatment standards, special siting and sizing requirements can be applied to the site Some of the special siting and sizing requirements include An increase in loading rate Reduced vertical separation distances Reduced horizontal separation distances NSF Standard 40 NSF Standard 40 that can meet the treatment level of NSF Standard 40 BOD < 25 mg/l TSS < 30 mg/l Must be certified by NSF or other accredited program that the unit can meet NSF Standard 40 Known as Residential Wastewater Treatment (RWTS) or Aerobic Treatment Units (ATUs) 5

6 NSF Standard 40 RWTS Manufacturers are approved by the On-Site Wastewater Branch and do not have to get approval from the I&E Committee NSF Standard 40 NSF Standard 40 A septic tank or settling tank prior to the unit is required Mechanical aeration of the wastewater occurs to provide aerobic treatment Aerobic treatment provides a better quality effluent High level of operation and maintenance required NSF Standard 40 Typical diagram of ATU Purdue University 6

7 NSF Standard 40 Approved NSF Standard 40 (RWTS) Aquarobic International Bio-Microbics Inc (FAST) Clearstream Wastewater, Inc Consolidated Wastewater Treatment Delta Environmental Products Inc Hoot Aerobic, Inc Hydro-Action Industries Jet Inc Norweco, Inc Treatment Standard I and II Treatment Standard I and II Bioclere (Aquapoint) Trickling filter system with plastic media Approved for both domestic strength and high strength waste Units can be up to 22 feet in height and 12 feet in diameter The smaller single family home units have not been approved for use 7

8 BIOCLERE SECTIONAL VIEW INTERNAL SCHEMATIC RANDOM PVC MEDIA LOCKABLE ACCESS COVER SAMPLING PORT NOZZLE ACCESS FROM OUTSIDE 1-1/2 SCHD 40 PVC RECYCLE LINE CENTRAL ACCESS SHAFT INSULATED FILTER DIAPHRAGM (MEDIA SUPPORT) 6 SCHD 40 PVC INLET 6 SCHD 40 PVC OUTLET CLARIFIER FAN HOUSING AND ELECTRICAL CONNECTIONS RECIRCULATING PUMP DOSING PUMP 3/13/

9 BIOCLERE INTERNAL VIEW 3/13/ Ecoflo Treatment Standard I and II Company is Premier Tech Product is a peat filter Some installations of the peat filter do not go to a separate drainfield Approved for TS-I only 9

10 10

11 Puraflo Treatment Standard I and II Company is Bord na Mona Product is a peat filter Peat filter is in a pod Approved for TS-I only 11

12 Treatment Standard I and II Sand Filters Intermittent and recirculating Generic sand filter approval and proprietary (Orenco, Inc and American Manufacturing) Can be either buried or open access For the generic sand filter, the containment structure can be either built on site or a premade structure 12

13 NSFC 13

14 Treatment Standard I and II AdvanTex Company is Orenco Inc Textile filter in a fiberglass basin Textile media is in sheets in basin Approved for TS-I and TS-II 14

15 FAST Treatment Standard I and II Company is Bio-Microbics, Inc Fixed activated sludge treatment process Combination of both suspended and attached growth processes Media in tank that bacteria can grow on Approved for TS-I and TS-II 15

16 Treatment Standard I and II SeptiTech Fixed film trickling filter using a polystrene media Polystrene media is held together with netting in the tank Approved for TS-I and TS-II 16

17 Treatment Standard I and II Earthtek Company is Wastewater Innovations, Inc Attached growth packed bed filter Textile chip media Approved for TS-I 17

18 Treatment Standard I and II E-Z Treat Company is E-Z Set Company Product is a filter using a polystrene bead media Approved for TS-I and TS-II 18