Disinfection is at the heart of drinking water treatment due to its importance in protecting public health. While the use of disinfectants has significantly reduced waterborne outbreaks due to the presence of pathogens, concerns regarding the formation of potentially carcinogenic disinfection by-products (DBPs) have dominated the development of regulations, the operation of treatment plants, and drinking water related research. The overarching objective of Program C of WINSSS is to evaluate technologies that will allow small water systems to meet water quality standards for DBPs in a sustainable way through the use of technologies that either:

(1) reduce the concentration of natural organic matter (NOM) precursors to the formation of DBPs, or

(2) reduce the concentration of DBPs formed following disinfection. The hypothesis driving the research is that treatment technologies that make the best sense for large water treatment systems do not necessarily make the best sense for small systems.

Program C projects will be undertaken by WINSSS investigators at the University of Texas and will focus on technologies for meeting DBP regulations that

(1) reduce DBP-precursor concentrations, and

(2) remove DBPs after their formation and will consider both chlorine and chloramine disinfection.

Technological, economic, and operational assessment will be conducted for conventional and non-conventional processes to meet water quality requirements. The first phase of research will include a review of classic and current literature to re-evaluate technological and economic feasibility and sustainability of treatment processes for precursor and DBP reductions for small systems. This work will be followed by preliminary economic and sustainability assessments focused on small-scale systems for each identified viable technology. In the second phase, bench-scale testing with a range of water compositions will be conducted for selected mature and novel technologies based on both economic and sustainability considerations. This second phase of testing will include two major tasks, one on removal of precursors and the second on DBP removal. The final phase of research will revisit and update the feasibility assessment based on the results obtained.

This research will develop several new technologies for removal of NOM from water, including novel ion exchange/membrane processes and innovative oxidative coupling/membrane processes that may be suitable for small drinking water systems. It will also provide a thorough evaluation and predictive model for a membrane air-stripping system that that utilizes cross-flow contacting. Comparison of these novel processes to more conventional approaches for DBP precursor and DBP removal will yield a set of guidelines for small water systems to identify appropriate technologies for their particular source water quality, flow requirements, and operational challenges.

Presentation from WINSSS March 2016 Center Meeting