NALMS 2003 Protecting Our Lakes' Legacy

Transcription

1 NALMS 2003 Protecting Our Lakes' Legacy Performance of Nitrex for Nitrogen Removal and Phosphex and PhosRID for Phosphorus Removal From Wastewater November 6, 2003 Pio Lombardo, P.E. Lombardo Associates, Inc. Newton, MA

2 Need for N & P removal in decentralized wastewater systems Excess N and P implicated in declines of numerous lakes Septic systems: contribute 40 to 50% of all N to some watersheds may be the greatest single source of P to lakes

3 Nutrient criteria vs. technology limits Nutrient EPA Criteria Limit of Technology N mg/l lakes mg/l rivers 3 mg/l P mg/l lakes mg/l in rivers 0.03 mg/l

4 Nitrex for nitrogen removal Developed in mid 1990s at University of Waterloo Comprised of pretreatment + Nitrex filter: Septic Tank Pre- Treatment Nitrex Filter Tile Bed Nitrex filter contains organic by-product material that acts as long-term carbon source for denitrification

5 Nitrex Nitrogen removal mechanisms 1. Ammonification and Nitrification (sand filter or other aerobic treatment system): Organic Nitrogen NH 4 + NH O 2 2 H + + H 2 O + NO 2-2. Denitrification (Nitrex filter): 4NO CH 2 O 2N 2 + 5CO 2 + 3H 2 O + 4OH - Organic by-product

6 Nitrex Demonstration projects 1. LaPine Oregon National Decentralized Wastewater Treatment and Disposal Demonstration Project funded by EPA ( ) 2. Montana Department of Natural Resources evaluation of three on-site denitrification systems in Polson, MT ( ) 3. Massachusetts Septic System Test Center, Otis Air Force Base Cape Cod, MA ( ongoing) 4. Seven additional installations in Canada for individual and cluster wastewater systems, along with golf course and farmland runoff treatment systems (since 1997)

7 Nitrex LaPine, Oregon Results Best nitrogen removal system out of 17 technologies tested Table 1 LaPine, Oregon Nitrogen Removal technology Evaluation Technology Total Nitrogen Effluent Quality in mg/l Technology Average Effluent TN Std. Dev. 1 Nitrex TM Innovative Trench Design B AX RX Biokreisel EnviroServer Amphidrome FAST Pressure Nayadic Constructed Wetlands Innovative Trench Design A Bottomless Sand Filter Puraflo Niteless Standard IDEA BESTEP 75.3

8 Nitrex LaPine, Oregon Results TN (mg/l) Temperature (deg C) Septic Tank Effluent Nitrex Effluent Temperature /1/2000 1/9/2001 4/19/2001 7/28/ /5/2001 2/13/2002 Date 5/24/2002 9/1/ /10/2002 3/20/2003 6/28/2003

9 Nitrex Polson, Montana Results Septic Tank Effluent Nitrex Effluent Temperature TN (mg/l) Temperature (deg C) /28/99 12/6/99 3/15/00 6/23/00 10/1/00 1/9/01 4/19/01 7/28/01 Date

10 Nitrex

11 Nitrex

12 Nitrex Summary Numerous installations have shown Nitrex TM filter systems to achieve 3 to 4 mg N/l No maintenance required Temperatures above 40 to 48 F optimal - lower temp requires larger systems Only drawback: initial, temporarily high BOD Ongoing studies are focusing on methods to achieve TN < 1 mg/l

13 Phosphex for phosphorus removal Developed at University of Waterloo Comprised of pretreatment + Phosphex filter + ph neutralization, if needed: Septic Tank Pre- Treatment Phosphex Filter Soil Dispersal o o o o o o????? PHOSPHEX module in a septic system Phosphex reactive media is Basic Oxygen Furnace (BOF) slag, a steel production waste, & limestone ph neutralization accomplished with peat or CO 2

14 Phosphex Phosphorus removal mechanisms Phosphorus removal depends on: 1. High ph (phosphate PO 4 3- ) 2. Presence of aluminum, calcium, and iron in BOF to form: Hydroxyapatite Ca 5 (OH)(PO 4 ) 3 Strengite Variscite FePO 4?2H 2 O AlPO 4?2H 2 O

15 Phosphex Demonstration projects Installations Waterloo, ONT Wastewater Treatment Plant North Bay, ONT single-family home Many other small & medium individual systems Third Party Testing (ongoing) Septic System Test Center, MA Hall County, GA

16 Phosphex Waterloo Treatment Plant, Ontario 8 7 Phosphex Influent Phosphex Effluent Jun Jul Jul Aug-95 8-Sep Sep Oct-95 7-Nov Nov-95 Total Phosphorus (mg/l) Date

17 Phosphex North Bay, Ontario Phosphex Influent Phosphex Effluent Total Phosphorus (mg/l) Day from Project Start

18 Phosphex North Bay, Ontario

19 Phosphex North Bay, Ontario

20 Phosphex North Bay, Ontario

21 Phosphex Summary Achieves <0.1 mg P/l (97% removal or more) Also removes E. coli Materials are inexpensive, readily available Passive system with a life of years No sludge production Ongoing studies are focused on optimizing ph neutralization

22 PhosRID for phosphorus removal Developed at University of Waterloo PhosRID filter + oxygenation filter: Septic tank or primary clarifier PhosRID filter containing Fe(III)-hydroxide rich media PhosRID sand filter (or other aerobic process) Next treatment process or dispersal PhosRID media is amorphous ferric hydroxide-rich media

23 PhosRID Phosphorus removal mechanisms 1. Reductive iron dissolution with organic-rich septic tank effluent (in RID media) 2. Formation of dissolved Fe(II)-PO 4 complexes (in RID media) 3. Removal of PO 4 as Fe(III) precipitates or by adsorption to Fe oxides (in oxygenation filter)

24 PhosRID Demonstration projects Extensive University of Waterloo laboratory tests Pilot facilities operational at Septic System Test Center, MA: Summer 2002 to present Scheduled for test installation in Hall County, GA: Winter 2003

25 PhosRID Otis Test Center, Massachusetts Total P (mg P/l) Effluent Influent 0 Sep-02 Oct-02 Dec-02 Feb-03 Mar-03 May-03 Date

26 PhosRID Otis Test Center, Massachusetts Total N in Effluent Total N in Influent Total N (mg/l) Jan-03 Feb-03 Feb-03 Mar-03 Date Apr-03 Apr-03 May-03

27 PhosRID Otis Test Center, Massachusetts 300 BOD in Effluent 250 BOD in Influent 200 BOD (mg/l) Sep-02 Oct-02 Dec-02 Date Jan-03 Mar-03 May-03

28 Installation Options New construction Retrofit to conventional septic system Residential Commercial Institutional Cluster or Centralized System Flow

29 Questions / Answers