Özet:

Reverse osmosis (RO) has been proven to be effective for removing precursors of disinfection by-products (DBPs) from different water sources in conventional water treatment processes. However, polymeric membranes have the potential to leach DBP precursors, which can introduce a bias in true performance evaluation of these membranes in bench, pilot, and full-scale operations. Therefore, this study first examined the NDMA precursor leaching potential of one of the commercially available virgin reverse osmosis (RO) membranes. Following a cleaning procedure, the efficiency of the RO membrane was tested for the rejection of N-nitrosodimethylamine (NDMA), trihalomethane (THM), and halonitromethane (HNM) precursors from surface water and wastewater treatment plant effluents. The results indicated that the leaching potentials of RO membranes for NDMA precursors were up to 370 ng/L, while the membrane's leaching potential decreased as the filtered volume of water increased. In the tested water samples, the RO rejection efficiencies ranged from 78 to 91%, 81 to 97%, and 63 to 78% for NDMA, THM, and HNM precursors, respectively. The results also showed that the background water quality did not have a considerable influence on the rejection of NDMA, HNMs, and THM precursors by the RO membrane. While the correlation between NDMAFP, HNMFP and THMFP, and TDN removals were weak (r2 ranged from 0.02 to 0.3), the removals of DBPFP were correlated well with DOC removals (r2 ranged from 0.6 to 0.89).

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