RECLAMATION OF SITE USED FOR IMPOUNDMENT OF WASTE-WATER FROM A PESTICIDE INDUSTRY - A CASE-STUDY

Wastewater generated from a pesticide industry containing 15 to 20% HC l was neutralised and stored in three solar evaporation ponds (SEP)lin ed with Flexible Membrane Liner(FML). Characteristics of the pond wate r showed the presence of high concentration of dissolved solids which were mainly due to salts such as chloride and sulfate of calcium and s odium. High performance liquid chromatographic (HPLC) analysis of pond water did not indicate the presence of sevin. A variation in the chem ical composition of the sediment samples was observed from top to bott om layers. The study revealed that the salts and organics were retaine d mostly in the upper portion of the pond sediment thus indicating rem ote possibility of percolation. The possible treatment alternatives/re medial measures to be adopted for cleanup of the ponds are discussed.