Reductive dechlorination of hexachlorobenzene by Cu/Fe bimetal in the presence of nonionic surfactant.
This study investigated the enhancement of nonionic surfactant (TritonX-100, TX-100) on the reductive dechlorination of hexachlorobenzene (HCB) by microscale Cu/Fe bimetal. HCB reduction by Cu/Fe without TX-100, in aqueous TX-100, adsorbed with TX-100 and prepared with TX-100 was compared. Results showed that HCB reduction by Cu/Fe in aqueous TX-100 increased with increasing TX-100 concentration, reached a maximum of 98.6% when aqueous TX-100 concentration attained its critical micelle concentration (CMC), and decreased with the further increase in TX-100 concentration. The mechanism was suggested as the increased HCB mass transport at low TX-100 concentration below CMC and the coverage of reactive sites at high TX-100 concentration above CMC. The greatest reduction was achieved by Cu/Fe in the presence of 0.2mM TX-100, followed by Cu/Fe adsorbed and prepared with 0.2 mM TX-100. Pentachlorobenzene and tetrachlorobenzene were found as the main dechlorination intermediates. Successive reduction by Cu/Fe in aqueous TX-100 solution could be maintained above 98% for four cycles. It is an alternative to use nonionic surfactants to enhance the reductive dechlorination of hydrophobic polychlorinated aromatic hydrocarbons (PCAH) by Cu/Fe bimetal.
Zheng
Zhonghua
Z
Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Yuan
Songhu
S
Liu
Yang
Y
Lu
Xiaohua
X
Wan
Jinzhong
J
Wu
Xiaohui
X
Chen
Jing
J
D000327:Adsorption; D002713:Chlorine / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006581:Hexachlorobenzene / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D017830:Octoxynol; D010084:Oxidation-Reduction; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D013500:Surface Tension; D013501:Surface-Active Agents; D014961:X-Ray Diffraction
D011084:Polycyclic Aromatic Hydrocarbons; D013501:Surface-Active Agents; D002713:Chlorine; D006581:Hexachlorobenzene; D003300:Copper; D017830:Octoxynol; D007501:Iron