UV-C/H202, microfiltration and reverse osmosis applied to remove emerging contaminants considering the potable reuse treatment ofwater

The United Nations Environment Program and the World Health Organization classifies as essential and urgent knowledge of the sources, transformations and fate of emerging contaminants in the environment due unequivocal evidence about numerous observed effects to wild populations, as well as possible damages observed in humans. These are thousands of chemicals that are present in the environment and may cause risks to the intended uses of water. The prioritization of these substances is essential to the beginning of the regulatory process, whether for prevention or contrai of input. ln addition, potable reuse of wastewater is becoming more common as populations increase and freshwater resources become more scarce. Producing safe drinking water from treated wastewater is challenging due to the presence of contaminants that are not completely removed in conventional wastewater treatment and due to transformation products that can be formed with advanced oxidation technologies (AOTs) that are used in potable reuse treatments. These contaminants can be harmful for human and ecological health. ln 2013, two Science Advisory paneis determined two lists of priority emerging contaminants to be monitored in aquatic ecosystems and human potable water reuse. These compounds were determined based on toxicity, persistence through wastewater treatment, and environmental water concentrations. This project have investigated the removal and/or transformation of 21 of these priority emerging contaminants from US through UV-C/H20 2, microfiltration and reverse osmosis in three samplings from Full-Scale Advanced Wastewater Treatment Plant (Orange County GWRS) in arder to make indirect potable reuse of wastewater safer. Ultra performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS) was used to quantify bisphenol A, p-nonylphenol, bis (2- ethylhexylphthlate), butylbenzyl phthlate, perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), diclofenac, ibuprofen, erythromycin, triclosan, 17a-ethinylestradiol, 1 7~-estradiol , estrone and chlorpyrifos. Gas chromatography mass spectrometry (GC-MS/MS) was used to quantify permethrin, galaxolide (HCCB), polybrominated diphenyl ether (PBDE)-47, polybrominated diphenyl ether (PBDE)-99, bifenthrin and Nnitrosodimethyl- amine (NDMA). Transformation products, disinfection by-products (DBPs), and unknown compounds are being identified via high resolution-time-of-flight GC(TOF)MS/MS and UPLC(Q-TOF)MS/MS. Some compounds were not removed even after UV treatment. The results brings a criticai conclusion about the efficiency of treatment of water considering the risks involving the presence of many different contaminants in the environment even in the trace leveis.