回用蒸煮黑液、实现达标排放

精制棉生产时产生的蒸煮黑液中含有大量的棉超短绒、果胶、油脂、棉蜡、木糖等，色度大于2000倍，CODCr质量浓度高达6000mg/L以上，生化性差，难处理。若将蒸煮黑液预处理，高浓度回收利用，低浓度与洗涤废水混合经厌氧、好氧、混凝处理后，不但出水水质达到GB8978-1996《污水综合排放标准》一级标准，而且大大降低了投资和运行费用。

Reuse Cooking Black Liquor to Meet Discharge Standard

The cooking black liquor from refined cotton production contains a lot of cotton linter, pectin, oil, cotton wax, xylose etc, which is difficult to treat because of the chroma over 2 000 times, CODCr over 6 000 mg/L and poor biodegradability. After pre-treatment, the high concentration black was recycled. And the low concentration black liquor mixing with washing wastewater was treated by the anaerobic-aerobic-coagulation process. The effluent can meet the first class Integrated Wastewater Discharge Standard （GB 8978--1996）, which greatly reduces the investment and operation cost.