The performance of quaternized magnetic microspheres on control of disinfection by-products and toxicity in drinking water

•A novel quaternized magnetic resin NDMP was efficient for the reduction of DBPs FP.•The formation of THMs, HAAs and HANs were decreased with increasing ammonia levels.•Increasing bromide levels will enhance the formation of THMs, HAAs and HANs.•NDMP resin could greatly reduce the cytotoxicity of the raw water.•Bromide and ammonia will enhance the cytotoxicity to cells in raw water.

The aim of this study was to evaluate the performance of quaternized magnetic microspheres (NDMP) on control of disinfection by-products (DBPs) and toxicity in drinking water. High concentrations of dissolved organic carbon (6.7 mg/L) and bromide (185 μg/L) were present in the raw water. The NDMP showed good performance on removing dissolved organic matter, bromide and dissolved organic nitrogen. In the present study, we investigated the formation potential (FP) of DBPs as well as the human hepatoma cells cytotoxicity and genotoxicity before and after resin treatment. The results showed that the FP of trihalomethanes (THMs), haloacetic acids (HAAs) and haloacetonitriles (HANs) were greatly reduced by the NDMP treatment with maximum removal efficiency of 73%, 56% and 81%, respectively. Additionally, the NDMP resin greatly reduced the cytotoxicity and genotoxicity of the raw water during subsequent chlorination. With increasing bromide levels, the FP of THMs, HAAs and HANs were increased by 31%, 36% and 27%, respectively. On the contrary, the FP of THMs, HAAs and HANs were reduced by 85%, 77% and 69% when the ammonia concentration reached to 10.5 mg/L. The addition of bromide increased the toxicity after chlorination due to the formation of more toxic brominated DBPs. NDMP can efficiently control the DBPs formation and toxicity in treated water, which provide us a new kind of advanced drinking water treatment technology in the future.