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 pseudo-first-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

In this work, treatment of poultry slaughterhouse wastewater by electrocoagulation method with aluminum plate electrodes has been investigated. System was operated in batch and galvonostatic mode. Effect of initial pH of the wastewater was predominantly investigated on chemical oxygen demand (COD) removal efficiency but turbidity and oil–grease removal efficiencies were also evaluated. Operational parameters were kept constant at 150 rpm of stirring speed, 1 mA/cm² of current density, and 293 K of solution temperature. On the other hand, initial pH of the wastewater was in the range of 2–8. Initial pH of the wastewater was an effective parameter on COD removal efficiency as it is expected. When initial pH of the wastewater was in the range from 3 to 4, it was possible to obtain higher COD removal rates. In this study, when the initial pH of wastewater equals to 3 and current density is 1 mA/cm², system gives COD removal efficiency of 85% in 20 min. Meanwhile, system consumes 2.14 kWh/m³ of energy under above conditions.