INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY, cilt.103, sa.9, ss.2107-2125, 2023 (SCI-Expanded)
In the article, the treatment of pre-treated laundry wastewater by adsorption method was studied through the experimental design. The composites of the polyaniline-supported activated carbons produced from sunflower seed hulls (PAn/SH) were used as adsorbents. Characteristics of the adsorbents were determined with the help of scanning electron microscopy, Fourier-transform infrared spectroscopy and elemental analysis. Experimental design was used to determine the effects of pH (4-12), reaction time (5-150 min), adsorbent amount (0.3-1.5 g) and mixing rate (50-200 rpm) on the process efficiency. Monitoring of the efficiency was held in terms of detergent and chemical oxygen demand removals. Response surface methodology based on the four-variable-three-level Box-Behnken design was used to interpret the adsorption properties of laundry wastewater on COD and detergent removal efficiencies. The removal efficiencies of the adsorption process were evaluated regarding to the experimental design and also Pareto analysis was applied for profiling the percentage effect of the independent variable on the response for the study. Accordingly, the most effective factors were computed as the amount of adsorbent (82%) in detergent removal and the mixing rate (31%) in COD removal, where pH was the second effective factor for both. The highest efficiencies of the MBAS and COD removals were achieved as 95% and 74% in the 24th run, respectively. In the treatment of laundry wastewater by adsorption method, using PAn/SH produced from the sunflower seed hulls as an adsorbent will be an alternative method.