A.M. Hatami; M.R. Sabour; A. Amiri
Abstract
Oil refining is an inevitable step in production of edible and industrial oil. Bleaching is the most important process among the refining processes. Bleaching adsorption is the most common method and clay is the most widely used adsorbent in this method. Disposal of bleaching clay, as a waste from re-refining ...
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Oil refining is an inevitable step in production of edible and industrial oil. Bleaching is the most important process among the refining processes. Bleaching adsorption is the most common method and clay is the most widely used adsorbent in this method. Disposal of bleaching clay, as a waste from re-refining plants, makes many environmental problems and economic losses. In the current study, the effects of possible factors such as solvent to clay ratio, temperature, time, aggregation size and rotation speed of the stirrer (degree of mixing) on the efficiency of extracted lubricating oil were investigated by solvent extraction method. By conducting experiments at different reaction times and rotation speeds, it was concluded that the most important factor in obtaining the appropriate output was solvent to clay ratio. The tests conducted to investigate the effect of grain size on the efficiency indicated that agglomerates size did not have a positive effect on efficiency. Finally, for the solvent to clay ratios ranging from 2.48-9.53 ml/g and a time period ranging from 5 to 40 minutes, the main tests designed by the response surface methodology. The best efficiency was obtained at the highest level of solvent to clay ratio (9.53 ml/g) and at the time of 22.5 minutes that led to 88.60% oil extraction from the clay. The accuracy of the model output was estimated to be 96%.
M.R. Sabour; A. Amiri
Abstract
Fenton process, as one of the most conventional advanced oxidation processes, is widely used in the treatment of specific wastewaters, especially landfill leachate. In current study, the main target was to evaluate some neglected aspects of Fenton process in operational applications. Thus, three novel ...
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Fenton process, as one of the most conventional advanced oxidation processes, is widely used in the treatment of specific wastewaters, especially landfill leachate. In current study, the main target was to evaluate some neglected aspects of Fenton process in operational applications. Thus, three novel responses were introduced. Mass removal efficiency evaluates overall recalcitrant destruction by establishing organics mass balance pre- and post-Fenton treatment. This differentiates it from conventional chemical oxygen demand removal, since mass removal efficiency basically considers the whole mixture and not only the supernatant. The mass content ratio response provides a measure to evaluate the remaining organics in the sludge. Therefore, a borderline mode considering these limitations leads to best feasible field operations. It was found that mass content ratio for effluent reacted conversely to the sludge in response to coagulation. By increasing the coagulant dosage, coagulation improved and the sludge ratio increased in result. For the mass removal efficiency response, it seemed that appropriate balance of the oxidation/coagulation had considerable role through Fe2+ dosage and [H2O2]/[Fe2+] ratio. Finally, by including further conventional parameters such as sludge quantity, the best operational conditions (X1 = 5.7, X2 = 16, X3 = 207 mM) were optimized by response surface methodology to 27.4% and 14.4% for sludge and effluent mass content ratio, respectively, and 58.1% for mass removal efficiency. The results were in good agreement with determination coefficient (R2) of 0.94–0.97, prediction R2 of 0.80–0.93 and coefficient of variation less than 10.
