Publications (2)5.52 Total impact
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Article: Transformation of metals speciation in a combined landfill leachate treatment.
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ABSTRACT: Landfill leachate was treated by a combined sequential batch reactor (SBR), coagulation, Fenton oxidation and biological aerated filter (BAF) technology. The metals in treatment process were fractionated into three fractions: particulate and colloidal (size charge filtration), free ion/labile (cation exchange) and non-labile fractions. Fifty percent to 66% Cu, Ni, Zn, Mn, Pb and Cd were present as particulate/colloidal matter in raw leachate, whereas Cr was present 94.9% as non-labile complexes. The free ion/labile fractions of Ni, Zn, Mg, Mn, Pb and Cd increased significantly after treatment except Cr. Fifty-nine percent to 100% of Al was present mainly as particulate/colloidal matter >0.45 μm and the remaining portions were predicted as non-labile complexes except in coagulation effluent. The speciation of Fe varied significantly in various individual processes. Visual MINTEQ simulation showed that 95-100% colloidal species for Cu, Cd and Pb were present as metal-humic complexes even with the lower dissolved organic carbon. Optimum agreements for the free ion/labile species were within acidic solution, whereas under-estimated in alkaline effluents. Overestimated particulate/colloidal fraction consisted with the hypothesis that a portion of colloids in fraction <0.45 μm were considered as dissolved.Science of The Total Environment 02/2011; 409(9):1613-20. · 3.29 Impact Factor -
Article: Oxidation and coagulation removal of humic acid using Fenton process
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ABSTRACT: The treatment of humic acid (HA) in water with Fenton reagents was carried out and the roles of oxidation and coagulation in removing HA during treatment were investigated. The removal efficiencies of HA by oxidation and coagulation were tested under various operating conditions: reaction time, initial pH, dosages of Fenton reagents, [H2O2]/[Fe2+] molar ratio, initial HA concentration and reaction temperature. It is demonstrated that Fenton process can effectively remove HA. The values of 27.6% mineralization of HA and 78.9% reduction of UV absorbance at 254 nm (UV254) by oxidation after 120 min reaction time indicated that HA was not completely oxidized to carbon dioxide but rather transformed to some organic intermediates. Moreover, the oxidation occurred mainly at the first 60 min and predominated the HA removal efficiency. Under the most favorable conditions (initial pH 4.0, H2O2 160 mM, Fe2+ 40 mM, reaction time 120 min, reaction temperature 30 °C), 93.3% of UV254 was reduced, the reduction of UV254 by oxidation and coagulation were 78.9% and 14.4%, respectively. Results highlighted the synergistic roles of oxidation and coagulation in Fenton treatment of HA.Colloids and Surfaces A Physicochemical and Engineering Aspects 379:151-156. · 2.24 Impact Factor
