Treatment of sludge contg. toxic heavy metals - comprises treating with excess hydrochloric acid, concentrating by thermal evapn. and distilling

摘要

Sludge contaminated with toxic heavy metals and toxic organic material is first treated with excess hydrochloric acid in respect to the heavy metals present in the sludge. The sludge is divided into a solid phase and a liq. phase contg. the heavy metal cpds. and the liq. phase is concentrated by thermal evapn. and then distilled to remove excess HCl acid which is recycled. Heat regenerated is used to warm up the extraction soln. The solid phase is neutralised and is decontaminated by biological treatment with white rot fungus in presence of a food source contg. cellulose, e.g. straw. The heavy metals may be recovered from the liq. phase by pptn.. USE/ADVANTAGE - The consumption of extractor is minimised, the heavy metals can be recovered and the solid phase may be used as compost or land improving material.