COLOUR REMOVAL OF DYES WASTE BY SORPTION ON LIGNIN

Abstract

Dyes Wastes are frequently treated by biological treatment process such as aerated lagoon and activated sludge processes. These processes are effective in the reduction of BOD and SS but not suitable for colour removal. Coagulants like alum, lime and ferric salts have been proved to be expensive. In addition, they give rise to problems due to the production of large volume of sludges. Adsorbents like silica, wood, peat, Fuller's earth have also been tried with satisfactory results. Activated carbon gives very high efficiency of dye uptake but owing to its high manufacturing and regeneration cost, it has little field applicability. The object of ensuing study is to treat a waste by waste (a resource out of place). So that an industrialist is able to treat the waste produced by his own industry. Lignin was used as sorbent for basic dyes i.e.Basic Magneta and Amercylic Blue-5G. An attempt has been made to explore the possibility of using lignin precipitated form kraft mill black liquor, taken from waste stream. Experiments were conducted by varying the following factors:- i. Lignin dose - 0.5, 1, 2, 3, 4 and 5 gm/l. ii. Initial pH - 2, 4, 6, 10, 11 and natural pH of dyes. iii. Initial dye concentration - 30, 40 50, 60, 100 and 150 mg/l. A! colour removal of 84.33 % for Basic Magneta dye and 72.5 % for Amercylic Blue-5G has been observed at optimal lignin dose of 3 gm/l and initial dye concentration of 100 mg/1.