Final Report: Development of a Cost-effective, Nutrient-removal, Onsite Household Wastewater Treatment System for Environmentally Fragile AreasEPA Contract Number: EPD14026
Title: Development of a Cost-effective, Nutrient-removal, Onsite Household Wastewater Treatment System for Environmentally Fragile Areas
Investigators: Cid, Clément A
Small Business: Caltech Lab for Energy and Water (CLEW)
EPA Contact: Richards, April
Project Period: May 1, 2014 through April 30, 2015
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2014) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Wastewater and Sustainable Infrastructure
The purpose of this EPA SBIR Phase 1 was to develop a cost-effective onsite nutrient removal system from household wastewaters in environmentally fragile areas. At the core of the CLEW Systems technology lies an electrochemical reactor with multilayer semiconducting anodes and stainless steel cathodes developed at the California Institute of Technology by Prof. Hoffmann and his team. This electrochemical treatment technology oxidizes chloride into active chlorine to disinfect the wastewater, and it reduces its chemical oxygen demand and removes its nitrogen content.
The main objective of Phase I was to address effectively the nitrogen and phosphorus removal from the systems effluents to comply with drastic TMDLs of 5 mg/L for nitrogen and 1 mg/L for phosphorous.
- Decanted toilet wastewater from the self-contained prototype installed at the California Institute of Technology (Pasadena, California) mixed with direct household effluent from Los Angeles County Wastewater Reclamation Plants (Whittier, California).
- Direct household effluent from Los Angeles County Wastewater Reclamation Plants (La Cañada, California and Whittier, California).
- Water and urine from one healthy individual (26-year-old male).
A system that electrochemically removes nitrogen at the source needs to be designed so that the electrode surface area to reactor volume ratio r is as low as possible. Obviously, the volume of liquid waste to treat and the size of the treatment system are limiting, but for a single toilet with four users the size of the system would not be bigger than 20 L (less than 8 × 4 × 4 box).