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A radio frequency (RF) plasma system has been used to decompose 1,2-dichloroethane (DCE). Final products were identified by a Fourier transform infrared (FTIR) spectrometer. The main products of DCE decomposition in O 2 /Ar plasma were CO 2 , CO, and HCl. Other minor chlorinated products were CCl 4 , C 2 HCl 3 , C 2 H 3 Cl, C 2 Cl 4 , CHCl 3 , C 2 HCl 5 , and COCl 2 . Nonchlorinated products were C 2 H 2 , C 2 H 4 , C 2 H 6 , and HCOOH. The plasma reactor with a brass electrode had a higher decomposition fraction of DCE [η C 2 H 4 Cl 2 , (C in − C out )/C in × 100%] than that obtained with other materials (Au, Ni, and Cr). Different electrode configurations (inner and outer) were also evaluated for the decomposition of DCE. Argon plus oxygen was found to be the most suitable carrier/auxiliary gas for DCE decomposition. In addition, operational parameters for DCE decomposition in RF plasma including concentration, operational pressure, and total gas flow rate were evaluated.

This study assessed the feasibility of combining the water washing and electrokinetic (EK) treatments for the removal of Pb, Cd, Cr, and Cu from two municipal solid waste incineration (MSWI) fly ashes. Two approaches were compared: a direct electrokinetic (DEK) treatment and a combined method using water washing before the electrokinetic (WEK) treatment. The following experimental EK parameters were evaluated: electric current, pH, and treatment time (168 h). The analytical results from a toxicity characteristic leaching procedure (TCLP) showed that one fly ash sample was within the regulatory limits after either approach. However, the second fly ash sample was only within the limits following the WEK technique because the WEK technique was able to decrease the high Pb level of 58.6% in the exchangeable and carbonates fractions to 9.5% in this sample. The water washing step first extracted the soluble salts KCl, NaCl, SiCl4, and CaClOH and decreased the interference from the large chloride concentration, thereby promoting the ability of the subsequent EK treatment to stabilize heavy metals as less reactive complexes. Therefore, the WEK technique is recommended over the DEK technique for treating fly ash. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1235–1241, 2014

This research is the first to investigate acid leaching treatment of municipal solid waste incineration (MSWI) fly ash and handling of the fresh leachate using the electrodeposition (ED) technique. The purpose of this research was to evaluate the feasibility of acid leaching to extract Pb and Cu from fly ash and the recovery of Pb and Cu from the fresh leachate. Acid leaching fly ash at a fixed liquid–solid (L/S) ratio of 20/1 with a 0.5 N HNO3 solution has a loss mass of ∼68.6%, and the leaching percentages of Cl, Pb, and Cu are 87.6, 59.4, and 77.0%, respectively. As for the sequential extraction analyses, acid leaching can yield Pb and Cu from fly ash transformed into a comparatively steady fraction. Electrodeposition at an electric current of 10 A can recover 25.7% Pb and 59.8% Cu. This article also presents a solution for combining acid leaching treatment and the ED technique to handle MSWI fly ash. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1074–1081, 2013

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