Contaminant Removal Using Membrane Distillation for Sustainable Drinking Water TreatmentEPA Grant Number: R835333
Title: Contaminant Removal Using Membrane Distillation for Sustainable Drinking Water Treatment
Investigators: Childress, Amy E , Kolodziej, Edward P. , Park, Chanwoo
Institution: University of Southern California
EPA Project Officer: Hiscock, Michael
Project Period: September 1, 2013 through February 15, 2017
Project Amount: $499,743
RFA: Research and Demonstration of Innovative Drinking Water Treatment Technologies in Small Systems (2011) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
Over 94 percent of the nation’s public water treatment systems serve less than 3,300 people. Limited access of these small systems to the technology and resources to remove many dangerous and emerging contaminants is causing the EPA and researchers to target the most problematic of these pollutants. Membrane distillation (MD) is one technology that has the potential to assist small systems in reducing Safe Drinking Water Act violations and public health risks.
The main objectives of the proposed investigation are to quantify the range of drinking water contaminants and contaminant classes that can be removed by MD and to develop and test a small-scale pilot MD system that operates using waste heat to perform field testing at small water treatment systems. The steps toward achieving the goals of the proposed research are to perform bench-scale testing of MD to evaluate membrane performance for spiked feed waters and to determine waste heat requirements (temperature, thermal power, constancy, and period of supply); to evaluate a range of potential small system test sites and to select at least two sites co-located or in proximity with identified waste heat sources; to design and construct a modular small pilot-scale MD system with heat exchanger; and to test the small pilot system on existing source water as well as a side-stream of the source water spiked with contaminants. Two hypotheses that will be addressed include: the assertion that MD removal performance for volatile contaminants is an equilibrium process directly predictable by Henry’s Law and that MD membrane pore flooding will mirror the pore size distribution of the membrane.
In satisfying the objectives, it is expected that the proposed MD system will result in high removal of both traditional and emerging pollutants and that MD will be found to be an ideal technology to simplify the treatment train necessary for small systems to comply with multiple and competing drinking water regulations. For geographically isolated systems, MD systems driven by waste heat or renewable energy are ideal for providing affordable, efficient, and user-friendly water treatment. In terms of sustainability, MD driven by waste heat has a low carbon footprint, minimal operation and maintenance requirements, and reduced concentrate disposal requirements.