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-In this study, color removal by absorption from synthetically prepared wastewater was investigated using montmorillonite clay by adsorption. As dyestuff Astrazon Red Violet 3RN (Basic Violet 16) was used. Experimental parameters selected were pH, temperature, agitation speed, initial dyestuff concentration, adsorbent dosage and ionic strength. It was established that adsorption rate increased with increasing pH, temperature, dye concentration and agitation speed, but decreased with increased ionic strength and adsorbent dosage. Adsorption equilibrium data obtained by a series of experiments carried out in a water bath were employed with common isotherm equations such as Langmuir, Freundlich, Temkin, Elovich and Dubinin-Radushkevich. It was found that the Langmuir equation appears to fit the equilibrium data better than the other models. Furthermore, the fit of the kinetic data to common kinetic models such as the pseudofirst-order, second-order, Elovich and intraparticle diffusion models was tested to elucidate the adsorption mechanism. Kinetic data conformed to the pseudo-second-order model, indicating chemisorptions. In addition, the thermodynamic parameters activation energy, Ea, enthalpy ΔH*, entropy, ΔS*, and free energy change, ΔG*, were calculated. The values of the calculated parameters indicated that physical adsorption of ARV on the clay was dominant and that the adsorption process was endothermic.

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In the present study, removal of chemical oxygen demand (COD), total organic carbon (TOC), and total phenols (TP) from pistachio processing industry wastewater was investigated using electro‐oxidation. COD, TOC, and TP removal efficiencies were compared considering stirring speed, support electrolyte types, support electrolyte concentrations, wastewater initial pH, and current density by using stainless steel cathodes and graphite anodes. Results showed that optimum values of operating variables, i.e., processing time, stirring speed, wastewater pH, current density, and support electrolyte (NaCl), were 5 h, 400 rpm, 3, 30 mA/cm2, and 1.25 M, respectively. Removal efficiencies of 99.79, 76.55, and 100% were obtained with these values for COD, TOC, and TP, respectively. Removal of COD, TOC, and TP increased with increased chloride concentration and current density at acidic pH.

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