Green refined laterite soil as advanced high efficient natural coagulant for removal of cationic dye and anionic dye

Abstract

Application of green environment technology to treat industrial wastewater is an approaching contemporary phenomenon. In this study, silicon (Si), aluminum (Al) and iron (Fe)-rich laterite soil was applied as a natural coagulant to treat cationic dye (methylene blue), anionic dye (methyl orange) and their mixture (combination of methylene blue and methyl orange). Laterite soil showed the best performance at pH 2 and optimum dosages of coagulant used in the removal of colour were: methylene blue at 5.5 g/L with 99.61% removal, methyl orange at 31 g/L with 92.11 % removal, mixed dye at 17.5 g/L with 98.53% removal. The breakage of bond structures was monitored using Fourier Transform Infrared Spectrophotometry (FT-IR). Significant sludge yielded laid in the best range of standard sludge volume index (SVI) (methylene blue at 18.692 mL/g, methyl orange at 26.769 mL/g and mixed dye at 22.181 mL/g).