No abstract

Publication informationChemosphere, 72 (4): 673-677Publisher Elsevier

A huge amount of water is consumed in the textile industry, and the result is the production of a large amount of wastewater. The treatment of such wastewater significantly reduces the pollution load. Oxidation by nano-Fenton reactions (Fe 3+ / H 2 O 2) is a reasonable and cost-efficient process for the remediation of harmful pollutants in wastewater. In the present study, nano-hematite was applied as a source of iron in Fenton's reagent for methylene blue dye removal from wastewater. The effects of different parameters, presence of nano-hematite, hydrogen peroxide concentrations and pH, were optimized using the response surface methodology technique. A Box-Behnken design was applied, and the response (dye removal) was maximized. A maximal dye removal (81.6%) was attained when wastewater was treated at pH 2.5 in the presence of nanohematite and hydrogen peroxide in the amounts of 41 and 388 mg/L, respectively. The model is well fitted and described using the second-order polynomial equation. Moreover, the model validation showed a 97% fit between the theoretical and experimental ones.

In spite of the less efficiency in CST reduction of Fenton's reagent in alum sludge conditioning compared with that of polymer conditioning, is less than that of polymer conditioning. This study provided an example of proactive treatment engineering which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.

The objective of this study is to develop a mathematical model which would confidently predict the rate of substrate degradation of an oil-water emulsion in a laboratory-scale completely-mixed continuous flow reactor using the photo-Fenton treatment process. Two models are developed from first principles and the predicted substrate removal rates for both models are compared with experimental data. The principal conclusions of the study are that both models produce good correlations with the experimental data at moderate to long hydraulic retention times, but, at short hydraulic retention times, there is some divergence between the predicted and measured data. This disparity may be attributable to a greater degree of short-circuiting through the reactor at short hydraulic retention times.