皂素工业废水CODCr排放限值的研究

皂素工业是近几年来迅速发展的一个重要生物医药化工行业，我国皂素主产区位于南水北调中线工程水源汉江上游，其排放的大量高浓度含酸有机废水给水源保护带来严重威胁，急需制定我国的皂素工业水污染物排放标准.采用三段式两相厌氧为核心的二级生化组合工艺技术从实验室试验、现场工业性试验和示范工程三方面对皂素工业废水COD_Cr排放限值进行了研究，皂素废水二级生化处理出水中残留COD_Cr总量(以质量浓度计)约为400～500 mg/L，其中溶解性微生物代谢产物(SMP)质量浓度约为240～280 mg/L.综合考虑技术可达性和经济可行性，将现有企业COD_Cr排放限值规定为400 mg/L；为引导企业对废液综合利用，推进皂素行业清洁生产，规定新建企业和现有企业的第二时段的限值为300 mg/L.提出了丹江库区相应的COD_Cr总量指标及皂素规模限额.执行该标准后，全国每年可削减COD_Cr 71　400 t，其中南水北调中线工程水源汉江上游至少可削减60　690 t，可以满足中线调水水源区的环境保护要求. 

Study on Limited Value of CODCr Discharge from Sapogenin Industry Wastewater

Sapogenin industry is an important biological, medical and chemical industry which has been developing fast recently. Its main producing areas in China are in the upstream of the Hanjiang River of middle route of water transfer project from South to North. A large quantity of high-concentration organic wastewater containing acid seriously threatens water sources. Hence, it is urgent to establish discharge standard of water pollutants for sapogenin industry. Limited value of COD_Cr discharge from the industry is studied through adoption of bio-chemical combined craft technique based on two-phase anaerobic treatment with threestages, i.e. trial in lab, industrial trial and demonstration project. It is shown that the mass concentration of COD_Cr in the effluent after two stages of bio-chemical treatment varies between 400 and 500mg/L, containing soluble microbial products(SMP)about 240～280　mg/L. Considering technology availability and economy feasibility, the limit value of COD_Cr discharge on existing enterprises can be stated within 400 mg/L at present. In order to guide the enterprises' wastewater recycling and propel the cleaner production in sapogenin industry, the limits of the new enterprises and existing ones can be stated within 300mg/L at the second stage in the future. The limit of corresponding total discharge amount of CODCr and the scale of sapogenin in Danjiang Reservoir area is also proposed. If this standard is implemented, the total discharge amount of COD_Cr can be decreased by 71　400　t annually, among which the upstream of the Hanjiang River of middle routeof water transfer project from South to North can be eliminated by 60　690　t, and the water sources of the middle route of water transfer project can meet with the environmental protection requirement.