Electrocoagulation for the removal of phenol and aldehyde contaminants from resin effluent.

This paper is a report on a study which aimed to investigate the effect of different current density, pH, temperature, and cathode-anode combination on the removal of phenol and aldehyde in two samples of actual resin effluent through the process of electrocoagulation using solar energy. Current density 60 A/m(2) and pH 6 proved to be the best levels for both contaminants. As for the effect of temperature, although the highest degree of phenol and aldehyde removal was achieved at 15 °C, 25 °C was taken to be the optimum temperature for economic reasons. The Fe-Fe combination of electrodes was found to be the best as it led to nearly 93% of phenol removal and approximately 95% of aldehyde removal. Also, the effect of electrode combination on energy consumption was studied. It was observed that the Fe-Fe combination consumed the least amount of energy (0.7-4.3 kWh/m(3) of wastewater in the case of phenol and 0.8-4 kWh/m(3) of wastewater in the case aldehyde). Moreover, the Fe-Fe combination brought about the best results in terms of chemical oxygen demand removal: 93% in both cases. Finally, an economic analysis was performed for the electrocoagulation process.

Treatment of colored and real industrial effluents through electrocoagulation using solar energy.

This study was undertaken to investigate the removal of Acid Orange 2 (sodium 4-[(2E)-2-(2-oxonaphthalen-1-ylidene) hydrazinyl] benzenesulfonate) and Reactive Blue 19 (2-Anthracenesulfonicacid,1-amino-9,10-dihydro-9,10-dioxo-4-[[3-[[2-(sulfooxy) ethyl] sulfonyl] phenyl] amino]-,sodium salt (1:2)) from synthesized and real effluents through electrocoagulation using solar cells for the purpose of improving economic efficiency of the process. The impact of a number of key operating parameters was explored including current density, anode type, temperature, pH, and electrolyte concentration. The current density of 45 Am(-2) proved to be the optimum level for both dyes. The same optimum alternatives were found for the other parameters in both cases: iron anode, a temperature level of 25°C, a pH of 7, and an electrolyte concentration of 15 mg L(-1). Both effluent samples were subjected to COD (chemical oxygen demand) and TOC (total organic carbon) tests. Cost analysis was performed for the treatment process.

Photoelectrocatalytic degradation of acid dye using Ni-TiO2 with the energy supplied by solar cell: mechanism and economical studies.

This paper reports an investigation into the effect of a number of operating factors on the removal of Acid Red 88 from an aqueous solution through photoelectrocatalysis: photocatalyst dose, dye concentration, pH, bias potential, and electrolyte concentration. The photocatalyst was Ni-TiO2 applied in suspension to the solution to achieve a larger catalyst surface area. The optimum values for photocatalyst dose, dye concentration, and electrolyte concentration turned out to be 0.6 mg L(-1), 50 mg L(-1), and 5 mg L(-1), respectively. Also, the best pH was found to be 7, and bias potential proved to be best at 1.6 V. The aqueous solution was characterized for its COD and TOC. Photocatalyst efficiency was evaluated using SEM and XRD techniques. The characterization of the post-treatment product using FT-IR, HPLC, and GC-MS studies revealed intermediate compounds. A pathway was proposed for the degradation of the dye. The energy required by the experiment was supplied by solar cells, meaning the money that would have otherwise been spent on electricity was saved. Cost analysis was also done for the treatment process.

Adsorption of an azo dye in an aqueous solution using hydroxyl-terminated polybutadiene (HTPB).

This paper reports an investigation into the effect of a number of operating factors on the removal of Acid Blue 92 (AB92) from an aqueous solution using hydroxyl-terminated polybutadiene (HTPB) as an adsorbent. The optimum values of adsorbent dose and pH were found to be 35mgL(-1) and 6, respectively. Temperature showed a significant effect, with maximum dye removal being observed at 45°C. Stirring the solution during the treatment process resulted in significant removal improvement. The Langmuir adsorption model was used to quantify the amount of AB92 adsorbed on the surface of HTPB. FT-IR spectrometry results for HTPB, AB92, and HTPB-AB92 verified the efficiency of the treatment. Further, the adsorbent was characterized using SEM and H NMR techniques.