Spent active carbon regeneration ­ by wetting with sodium hydroxide soln., extn. of organic load with methanol, methanol recovery and washing

The spent C is wetted with an alkaline 1 0% NaOH soln. for 1 0 min. The organic load is extd. with MeOH, at reflux, for 30 min. The MeOH, contg. organic substances and alkaline soln., is recovered by distn. and recycled to the regeneration process. After removing the residual MeOH with steam, the regenerated C is
washed with a soln. of 4% Na meta­bisulphite to pH 1 .5. Washing is continued with a soln. of 0.001 % Na meta­bisulphite, until the washing water reaches pH 4.5.