Application of permanganate/bisulfite process for treatment of sulfamerazine contaminated water

The permanganate/bisulfite (PM/BS) process is highly efficient in the oxidation of refractory contaminants due to the generation of a large number of reactive manganese species and radicals. However, a lot of concerns need to be addressed for the application of the PM/BS process in real sulfamerazine (SMZ) contaminated water treatment. The factors affecting the degradation efficiency of SMZ by PM/BS and the influences of PM/BS pre-oxidation on the formation and toxicity of trihalomethanes (THMs) during the subsequent chlorination of simulated SMZ-contaminated waters were investigated in this study. The PM/BS process exhibited fast oxidation of SMZ at acidic/neutral pH and low SMZ concentration (5 μm) with more than 80% of SMZ removal within 15 s. The permanganate was efficiently activated by bisulfite and exhibited high efficiency in SMZ degradation when permanganate/bisulfite dosage was 50 μm:250 μm. The co-existing protein bovine serum albumin caused less than 10% inhibition of SMZ degradation in the PM/BS process at pH 6 and 7. However, humic acids and alginate inhibited the removal of SMZ by 18%–57%. PM/BS pre-oxidation of SMZ-contaminated waters achieved a 28%–64% reduction of THM formation in the subsequent chlorination, greatly decreasing the toxicity risk in chlorination.