Potential Application of Biopolymer Chitosan and Cationic/Anionic Polymers in Textile Wastewater Treatment

Abstract

Biopolymer chitosan have been investigated for color removal in textile wastewater by using coagulation process of biopolymers and synthetic polymers. After the wastewater samples were treated with 0.1% chitosan for chitosan coagulation process, coagulation process of cationic or anionic polymer were performed by using chitosan and cationic polymer (CSC) or chitosan and anionic polymer (CSA) polymer concentrations of 0.1, 0.2 and 0.4 g/l at pH 6-8, respectively. The color removal efficiency of textile wastewater samples before and after treatment with chitosan followed by cationic/anionic polymers has been evaluated. The color removal by chitosan was dependent on pH and the maximum percent removal 31.4 ± 3.3% has been observed at pH 7. The optimum parameters for polymer-biopolymer coagulation process in this study was CSC at dosage of 0.2 g/l, pH 8 and CSA at dosage of 0.1 g/l, pH 7. Besides, its chemical analyses including Chemical Oxygen Demand (COD), dissolved solid, and suspended solid were analyzed in order to consider the potential application of chitosan in textile wastewater treatment. The results showed that the COD, dissolved solid and suspended solid of pre-treated textile wastewater were 290, 3998.7 and 280.7 mg/l, respectively, however, both dissolved solid and suspended solid were higher than the regulatory standard for wastewater. As the optimum condition, the COD, dissolved solid and suspended solid of textile wastewater after treatment with CSC (0.2 g/l at pH 8) were 260.7, 1939.8 and 103.6 mg/l, respectively, while the COD, dissolved solid and suspended solid of textile wastewater after treatment with CSA (0.1 g/l at pH 7) were 190.6, 3002.2and 106.8 mg/l, respectively. All of the results after treatments were within the regulatory standard. Therefore, the combination of chitosan and cationic/anionic polymers could be utilized in textile wastewater treatment.