Study on the Treatment and Resource Reuse of Lipoic Acid Wastewater

The best resin which is used to recovery lipoic acid in lipoic acid wastewater is NG-16 macroporous adsorption resin. The result is determined by dynamic adsorption experiments. The optimal operation conditions are as follows: pH value of 5-5.5, at room temperature, adsorption flux of 3BV/h, double-column series disposing volume is 25BV/batch; at 303K, the resin is desorbed by 3BV methanol+2BV water, at 1BV/h flux; the pH of high-concentration desorption solution is adjusted to 7.2-7.8, and lipoic acid and methanol are recoveried by distillation; low-concentration desorption liquid is applied for next batch. Per tonne of waste can be recoveried 1.1kg lipoic acid about 80% purity. The lipoic acid content in treated wastewater is reduced from 1300-1500mg/L to 0, the total sulfur content is reduced from 400-450mg/L to 0.05mg/L, B/C increased from 0.30 to 0.65.