Degradation of Metronidazole by carboxymethyl cellulose stabilized iron sulfide nanoparticles in water and soil phases

Abstract

The removal of Metronidazole (MNZ) from water and soil phases by iron sulfide (FeS) nanoparticles was investigated. From the results, for the batch test, 10 mg/L MNZ in the solution can be fully removed by the 350 mg/L FeS at pH = 7.5 in 2 hours then the FeS dosage effect, carboxymethyl cellulose (CMC) stabilization effect, pH effect, humic acid (HA) effect, CMC to FeS molar ratio were investigated to find out the best degradation conditions. The removal of MNZ by FeS followed a pseudo-first order kinetic model. The removal efficiency is increasing while the FeS concentration increasing, pH increasing, HA decreasing and a suitable CMC to FeS molar ratio from 0.0005 to 0.00225. The CMC stabilized FeS was compared with the bare FeS, CMC stabilized FeS showed faster removal rate and removal efficiency. In the soil phase experiment, adsorption, desorption, degradation and column tests were conducted, the result showed the MNZ can be adsorbed and degraded in the soil with lower removal efficiency, low removal rate and longer treatment time compared to the batch tests.