Z khan f khan and s sabir environmental research

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Unformatted text preview: 1 effluent COD and DCP concentrations were 95 mg L and 2.5 mg L with corresponding removal efficiencies of 96 % and 95 % were achieved. Degradation profile shows a high initial removal rate which decreases later. There was a good agreement between COD and DCP removal profile. Degradation rate is directly proportional to the substrate concentration and the removal rate of DCP was found to be -1 - 1 -1 15.35 mg DCP L h at 60 mg L . Specific degradation rate of DCP and specific cell growth rate was 6.54 -1 -1 -1 mg DCP g VSS h and 0.042 ±0.005 d respectively. A parallel decrease in COD and DCP concentration confirms the complete mineralization of DCP. High O.D.600 of SBR shows effective biomass retention, which is the main advantage of this technique. ENV-O28 REMOVAL OF 2,4-DICHLOROPHENOXYACETIC ACID HERBICIDE VIA IMMOBILIZED TIO2 PHOTOCATALYTIC SYSTEM Lelifajri and Mohd Asri Nawi School of Chemical Sciences, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia E-mail:masri@usm.my Removal of 2,4- dichlorophenoxyacetic acid (2,4-D) herbicide was investigated by photocatalytic process under visible light irradiation using immobilized titanium oxide (TiO 2). A simple dip coating method using the dip-coating formulation containing TiO2 powder and PVC-ENR blend as adhesive was applied for the immobilization of P -25 TiO2 powder on glass plate. The effects of experimental parameters such as catalyst loading and pH were investigated. The removal process was evaluated by monitoring the decrease of the concentration of 2,4-D via high performance liquid chromatography (HPLC). The mineralization process was observed by monitoring of the formed intermediate products and chemical oxygen demand values of the treated solutions. The 2,4 -D adsorption by immobilized TiO2 in the dark -1 exhibited a low pseudo-first-order rate constant of 0.0040 min . The enhanced pseudo -first-order rate -1 constant of 0.0479 min was achieved when photocatalytic process via immobilized TiO2 under fluorescent lamp irradiation was used whereby up to 99 % of 2,4-D was degraded in 90 minutes of irradiation. 101 23rd-25th June 2010 3rd ICYC 201...
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