The objective of this work was to study the sorption behavior of the strongly basic and macroporous commercial resin IRA 958-Cl for the removal of natural organic matter (NOM) from groundwater in the Melenci settlement located near Zrenjanin (Northern Serbia). The investigation was performed in a pilot plant using native groundwater and the same water after chlorination with sodium hypochlorite. More efficient removal of NOM and arsenic was achieved without the addition of an oxidant under a wide range of working conditions. NOM removal was more efficient with the addition of the oxidizing agent compared with the overall efficiency for 2,900 bed volumes (BV) of treated water only during the initial phase of operation. Arsenic removal from chlorinated water was more efficient up to approximately 700 BV. At higher BV values, arsenic removal was up to two times more efficient with non-chlorinated water. The results obtained for the NOM sorption affinity to the resin indicated that it is possible to achieve a sorption capacity that exceeds the performance quoted by the resin manufacturer on several occasions.
Keywords: arsenic, groundwater, natural organic matter (NOM), sorption characteristics, strongly basic macroporous resin