Efficiency comparison of alum and ferric chloride coagulants in removal of dye and organic material from industrial wastewater - A case study

Coagulation and flocculation are most widely methods used for dye and pollution removal from various wastewaters. The aim of this study is efficiency comparison of inorganic coagulant (Alum and Ferric Cchloride) for treatment of textile factory wastewater. The appropriate coagulant was selected at optimum condition for treatment of textile's factory wastewater by measuring of dye, COD, BOD5 and TSS parameters. The different pH (4, 5, 6, 7, 8 and 9) was used for determine the optimum pH. Totally, 240 samples were collected and exanimated according the standard methods of wastewater and water tests. Results showed that the ferric chloride has more removal efficiency than alum in removal of COD, TSS and dye. The most removal of COD, TSS and dye using alum was obtained 36, 19 and 68.8 while for ferric chloride was obtained 72, 60 and 98 respectively. The optimum pH 7 and 5 were obtained for alum and ferric chloride respectively. Based on the results, it can be concluded that COD, TSS and dye removal using ferric chloride has higher efficiency than alum. Therefore, application of ferric chloride in the same conditions is preferred than alum. © 2015 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria