Benzene and MTBE removal by Fenton’s process using stabilized Nano Zero-Valent Iron particles

Abstract

A bench-scale study was designed for removal of Methyl Tertio Butyl Ether (MTBE) and benzene from south of Tehran groundwater. The experiments were implemented on a one-dimensional soil column with similar chemical and physical conditions of the region. Fenton's chemical oxidation with stabilized nano zero-valent iron particles (S-NZVI) as catalyst was used. For treatment of groundwater polluted with 2 mg L-1 MTBE and 1 mg L-1 benzene, optimum concentrations of H2O2 and S-NZVI were 1500 and 300 mg L-1, respectively. The optimum concentrations led to 78 % elimination of MTBE and 87 % of benzene. Hazardous by-products (acetone and tertio-butyl alcohol) concentrations were less than 0.1 mg L-1, which were considered to be negligible. The soil permeability was reduced to 30 % after removal process. To increase the system efficiency and reduce the consumption of iron, the reaction environment was acidified down to pH = 3.2 led to removal efficiency of 90 % and 96 % for MTBE and benzene, respectively. The scavengers (ions) reduced the system efficiency up to 15 %. This study indicates that theoretically the MTBE and benzene could be removed from groundwater using Fenton's chemical oxidation with S-NZVI.