Fate of Dissolved Organic Matter (DOM) during Groundwater Recharge Using Reclaimed Wastewater

Groundwater recharge using reclaimed wastewater has emerged as an integral part of water and wastewater management in arid regions of the world. This study investigated the fate of dissolved organic matter (DOM) through laboratory-scale soil aquifer treatment (SAT) for a year. During maturation period, reductions in dissolved organic carbon (DOC), absorbance of ultraviolet light at 254 nm (UV254) averaged 39.7% and 17.9% after SAT respectively. Reductions in haloacetic acids formation potential (HAAFP) averaged 33.4%, although the specific HAAFP increased by 11.6%. In the three main DOM fractions, hydrophobic acid (HPOA) had the highest HAAFP and specific HAAFP; hydrophilic fraction (HPI) had the lowest specific HAAFP but a high HAAFP which can be accounted for by its large fraction; transphilic acid (TPIA) had the lowest HAAFP. HPOA, TPIA and HPI were removed by 61.06%, 54.86% and 74.95% respectively.