Water Resources Research Act Program

Details for Project ID 2016PR172B

Hybrid multimedia-filter prototype (HMP) for the degradation of trihalomethanes precursors and pathogens control from raw waters

Institute: Puerto Rico
Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $43,474

Principal Investigators: Pedro Tarafa, OMarcelo Suarez

Abstract: Trihalomethanes (THM’s) are disinfection by-products (DBP) that results from the reaction of chlorine with the natural organic matter (NOM) present in raw waters. THM’s are of concern because they have been identified as human carcinogens and the US Environmental Protection Agency (EPA) have set maximum contaminant levels (MCL) of 80 ppb for drinking waters. A reasonable strategy to minimize the THM’s formation potential is to reduce NOM concentration, which has been referred as THM’s precursors, in raw water before chlorination. One of the biggest challenges in water treatment facilities reside in controlling and limiting the risks from pathogens while simultaneously minimizing health risks from THM’s. The present proposal aims to develop and evaluate a hybrid multimedia-filter prototype (HMP) combining glass/TiO2 composite with an intermittent biosand filter (IBSF) to simultaneously treat both NOM and pathogens by photocatalytic and biological processes, respectively. Currently, our research group has been evaluating a filter-like composite made out of sintered crushed glass bearing TiO2 particles to promote a photocatalytic reaction under the influence of UV light for the destruction of humic acid (HA), the main component in the NOM. So far, the data have shown low degradation of HA, which is most likely due to the poor penetration of the UV light to reach and photoactivate the TiO2 particles embedded through the glass substrate. To accomplish the objectives for this endeavor, it is proposed a one-year project encompassed by: 1. Optimizing the protocol for the controlled incorporation/adhesion of TiO2 particles onto the glass matrix in such a way to increase the exposure of the TiO2 particles to the UV light; 2. Validating the protocol effectiveness by monitoring the glass/TiO2 composite capacity in degrading HA by means of total organic carbon (TOC) levels present in water before and after treatment; 3. Designing and constructing a lab-scale biosand filter; and 4. Proof-of-concept and testing. Pathogens population will be evaluated by monitoring two fecal pollution indicators: Escherichia coli and Enterococcus. Dissolved organic carbon will be accounted by a TOC analyzer to determine the organic levels in the treated and untreated samples. The realization of the project will provide essential data to set the foundations for the development and establishment of a novel, accessible treatment process for the degradation of THM’s precursors and pathogens elimination.