制药废水的可生物降解性与生物毒性研究

Study on Biodegradability and Biotoxicity of Pharmaceutical Wastewater

制药废水有机物含量高,难生物降解成分多,有些成分可抑制污泥活性或具有生物毒性。以某制药企业维生素生产的7个工段（W1~W7）的排放废水为研究对象,用摇瓶试验评价了各工段废水的可生物降解性能,用瓦勃氏呼吸仪测试了各工段废水对污泥活性的抑制作用,用发光菌急性毒性试验评价了各工段废水经好氧生物处理前后的生物毒性变化。研究结果表明,各生产工段废水的可生物降解性和生物毒性差别显著。各废水中难降解有机碳（TOC）占总TOC的比例最高超过90%（W5和W6）,最低则小于10%（W4和W7）。各工段废水发光菌急性毒性EC50的最大值（W4）与最小值（W3）之间相差500倍以上。经过好氧生物处理,W2、W4和W7工段废水中的有机污染物和毒性都得到高效去除;W5工段废水中TOC未减少但是毒性得到削减;而W1和W3工段废水的TOC虽得到削减但是毒性未减小;W6工段废水不仅TOC未减少,且毒性上升,对污泥呼吸活性产生了抑制作用。因此,建议W6工段废水不直接进入好氧生物处理系统,W1和W3工段废水应在好氧生物处理前后采取必要的脱毒措施。

Pharmaceutical wastewaters contain high content of organic pollutants,most of which are refractory,and some of which are inhibitory to the activity of activated sludge respiration or toxic to bio-organisms.Using wastewater from seven processing units（denoted as W1-W7） in a vitamin synthesis manufacturer as the study object,a flask test was carried out to determine the biodegradability of wastewater,a Warburg respirometer was used to determine the inhibition to the sludge respiration activity induced by wastewater,and a luminescent bacteria test was carried out to determine the acute biotoxicity of wastewater before and after aerobic biological treatment.Results revealed that the biodegradability and biotoxicity of wastewater from seven processing units greatly differed among each other.The ratio of non-biodegradable organic carbon to total organic carbon（TOC） varied from over 90%（W5 and W6） to below 10%（W4 and W7）.Median effect concentration（EC50） to the luminescent bacteria differed 500 times between wastewater from W4（maximum value） and W3（minimum value）.Aerobic biological treatment was effective to remove both TOC and biotoxicity in wastewater from three units（W2,W4 and W7）,only effective to reduce toxicity but not TOC at one unit（W5）,effective to remove TOC but ineffective to reduce biotoxicity at two units（W1 and W3）,and effective to remove neither TOC nor biotoxicity at one unit（W6）.Biotoxicity of wastewater from W6 even increased after the aerobic biological treatment and started to show inhibition to sludge respiration activity.It is proposed that wastewater from W6 should not be discharged directly into biological treatment systems,and wastewater from W1 and W3 should be detoxified before or after the biological treatment.