State Water Resources Research Institute Program

Project ID: 2007MO70B
Title: Development of Membrane Aerated Reactor Processes for Nitrogen and Phosphorus Removal from Wastewater
Project Type: Research
Start Date: 3/01/2007
End Date: 2/28/2008
Congressional District: 9
Focus Categories: Water Quantity, Nitrate Contamination, Treatment
Keywords: Membrane Aerated Processes, Nitrogen, Phosphorus, Wastewater, Nutrient Contamination, Eutrophication, anaerobic
Principal Investigator: Hu, Zhiqiang
Federal Funds: $ 22,000
Non-Federal Matching Funds: $ 48,036
Abstract: Eutrophication, a process where water bodies receive excess nutrients that stimulate excessive plant and algae growth, continues to seriously impact water bodies in the state of Missouri and the whole nation, resulting in symptoms like low dissolved oxygen (hypoxia), loss of submerged aquatic vegetation, and the occurrence of toxic algal blooms. Particularly, nutrient contamination of large, recreationally and economically important reservoirs such as Lake of the Ozarks and Table Rock Lake continues to be a concern as a result of heavy residential development around the lakes. Because such water quality issues are mainly related to nutrient discharges from wastewater treatment plants (WWTPs), septic tanks, and agricultural production, it is urgent to develop effective and efficient technologies to remove nutrients (N and P) from point sources such as WWTPs and on-site smaller wastewater treatment systems. Unfortunately, many wastewater treatment facilities are experiencing intermittent and extended periods of higher levels of nutrient in their discharges than the mandatory permits.

This project addresses research area (a): Aspects of Water Quantity in Missouri, which will build on investigator's previous experience and success in nitrification and nutrient removal processes. The objective of this research is to develop an anaerobic /membrane aerated reactor (ANMBR) system for efficient nitrogen and phosphorus removal from domestic wastewater. In the proposed research, a gas-permeable hollow fiber membrane will be applied as a carrier for aeration and nitrifying biofilm formation, and further, metallic iron (steel wool) materials will be introduced in anoxic basins to promote abiotic denitrification and chemical phosphorus precipitation. Through anaerobic/anoxic/aerobic cycling, denitrifying phosphate-accumulating organisms (DNPAO) will be enriched for biological N and P removal. Collectively, it is anticipated that efficient and effective nutrient removal (effluent TN <5 mg/L, TP <0.5 mg/L) can be achieved using this approach. With the support from the USGS water resources research program, we will be able to define stable operational regime (after 3 solids retention times) and control parameters (e.g., airflow rate) in the ANMBR systems to explore the limits of technology (LOT) for nutrient removal; we will further develop and validate a mechanistic model for metallic iron-assisted biological nutrient removal.

The results of this project will be valuable for future research and design of pilot and full-scale wastewater treatment systems that could be funded by EPA and USDA, which will greatly help water and wastewater treatment professionals to better understand the nutrient removal mechanisms and take corrective action to retrofit existing wastewater treatment systems. The development of the ANMBR process can be extended to nutrient removal of concentrated animal feeding operations in the state of Missouri. Hence, this research will have substantial impact on Missouri?s water quality improvement and economic development. With the support from Missouri Water Resources Research Center, the investigator will be able to train one graduate student and two undergraduate students, leading them to acquire significant research experience in water and wastewater engineering.

Progress/Completion Report, PDF