Agricultural residue anion exchanger for removal of dyestuff from wastewater using full factorial design

In this study, Remazol Black B dyestuff removal from wastewater by ion exchange was investigated with in a batch system and 23 full factorial design was applied. Anion exchanger resin was prepared from agricultural residue (straw) after reaction with epichlorohydrin and dimethylamine in the presence of pyridine and N,N-dimethylformamide (EDM method). The effect of individual variables and their interactional effects for dyestuff sorption were determined. From the statistical analysis, the most important parameter which is efficient in dyestuff removal can be obtained to be initial concentration of wastewater, which is followed by initial concentration–initial pH of wastewater. The interaction between initial pH and temperature was the least important factor for dyestuff removal from wastewater. A series of isotherm studies were undertaken, and the data evaluated for compliance with the Langmuir and Freundlich isotherm models.

Due to the large availability, low cost and biodegradability of agricultural residue (straw), the process of converting agricultural residue into ion exchanger has been investigated for dyestuff sorption from hydrolysed dye solution in this study. Sorption capacity of resin adsorbent was correlated to their mesopore surface area since mesopores (diameter between 20 and 500 Å) are more predominant in this material. From the statistical analysis, it can be concluded that sorption was favoured by increase in initial concentration and temperature and unfavoured by an increase initial pH. The sorption equilibrium data were analysed using Langmuir and Freundlich isotherm models and results have shown that sorption behaviour of Remazol Black B by resin adsorbent could be described by Freundlich model.