Cationized starch-based material as a new ion-exchanger adsorbent for the removal of C.I. Acid Blue 25 from aqueous solutions.
ABSTRACT This article describes the use of a cationized starch-based material as new ion-exchanger adsorbent for the removal of C.I. Acid Blue 25 (AB 25) from aqueous solutions. Batch adsorption studies concerning the effects of contact time, pH and temperature are presented and discussed. Adsorption experimental data showed that: (i) the process was uniform and rapid: adsorption of dye reached equilibrium in 50 min in the wide pH range of dye solutions; (ii) adsorption kinetics followed the pseudo-second order model; (iii) the Langmuir model yielded a much better fit than the Freundlich model for the dye concentration range under study; (iv) this adsorbent exhibited interesting adsorption capacities: on the basis of the Langmuir analysis, the maximum adsorption capacity was determined to be 322 mg of dye per gram of material at 25 degrees C; (v) the adsorption capacity decreased with increasing temperature; and (vi) the negative value of free energy change indicated the spontaneous nature of adsorption.
- SourceAvailable from: Monika WawrzkiewiczIndustrial & Engineering Chemistry Research 07/2014; 53:11838. · 2.24 Impact Factor
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ABSTRACT: Among organic pollutants, four families have been listed as priority substances by the European Agency, namely polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), chlorophenols (CPs) and alkylphenols (APs). In this study, sorption onto a non-conventional cyclodextrin-based material alone as well as in combination with advanced oxidation using a UV-ozone process as pre-treatment was applied for the removal of PAHs, VOCs, CPs and APs from industrial effluents. After the various treatments proposed, we present the abatements obtained in the levels of chemical pollution monitored by a complete chemical analysis, and total organic carbon (TOC) and chemical oxygen demand (COD) measurements. High levels of pollutant removal were attained with the combined use of oxidation and sorption. The treatment led to the almost total elimination of organics such as chloroform, 1,2-dichlorobenzene, 2,4,6-trichlorophenol, nonylphenol and phenanthrene. The treatment also lowered TOC and COD by more than 84% and 93%, respectively. This combined lab-scale process using a non-conventional material could constitute an advantageous technology for removing organic pollutants when scaled up to treat polycontaminated industrial effluent.Journal of the Taiwan Institute of Chemical Engineers 03/2014; 45(2):603–608. · 2.64 Impact Factor
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ABSTRACT: Over a period of 24 months of operation, we optimised a physicochemical plant for the decontamination of surface treatment industrial wastewater. This article presents the abatements obtained in the levels of chemical pollution after the various optimisations validated in the laboratory and then transposed to the industrial site. The optimisation of the plant reduced the effluent organic load, nitrite and zinc levels by about 70%, 85% and 80%, respectively. To evaluate the utility of each optimisation proposal, standard bioassays based on lettuce seed germination were carried out on the final effluent. Decreasing concentrations of pollutants in the effluent led to a reduction of its impact on seed germination. The bioassays confirmed the environmental benefits obtained from the optimisation of the treatment plant. The biological tests proposed seem to be good indicators of the contaminant concentrations present in wastewater.The Canadian Journal of Chemical Engineering 03/2014; 92(3). · 1.31 Impact Factor