LAUSR

Abstract Solids suspended in industrial effluents possess a negative charge, hence it repels each other. This repulsion forbids the particles from agglomerating, causing them to remain suspension. An attempt has been made to use ionic liquids as a coagulant to treat turbid water. A synthetic turbid water was prepared by using kaolin. Three different ionic liquids such as 1-buthyl-3-methylimidazolium bis (triflouromethyl sulfonyl) imide {[BMIM][Ntf2]}, 1-ethyl-3-methylimidazolium bis (triflouromethyl sulfonyl) imide {[EMIM][Ntf2]} and 1-ethyl-3-methylimidazolium ethyl sulphate {[EMIM][EtSO4]} were chosen. Three different ratios of synthetic turbid water (STW) and ionic liquids (IL) (9:1 ratio, 8:2 and 6:4) were tested for the present coagulation experiments. From the results it has been observed that less volume of 1-ethyl-3-methylimidazolium ethyl sulphate (STW:IL = 9:1) renders 87% of turbidity removal suggesting that IL can also be used as a cost effective green coagulant. In addition, COSMO-RS model is used to represent the molecular interaction between [EMIM], [BMIM], [EtSO4], [Ntf2], [EMIM][EtSO4], [BMIM][Ntf2] and water through sigma profile. However, quantitative analysis of the ionic liquid content in the cleaned water phase and a toxicological evaluation of this level are needed before the method might be applied in vivo.