造纸废水危害很大，其中黑水是危害最大的，它所含的污染物占到了造纸工业污染排放总量的90％以上，由于黑水碱性大、颜色深、臭味重、泡沫多，并大量消耗水中溶解氧，严重地污染水源，给环境和人类健康带来危害。而中段水对环境污染最严重的是漂白过程中产生的含氯废水，例如氯化漂白废水，次氯酸盐漂白废水等。此外，漂白废液中含有毒性极强的致癌物质二恶英，也对生态环境和人体健康造成了严重威胁。 Great harm papermaking wastewater, which blackwater is one of the biggest dangers, it contains pollutants accounted for paper industry pollution emissions more than 90% of the total, because the blackwater alkaline big heavy, deep color, odor, foam, and a large number of consumption of dissolved oxygen in water, seriously polluted water, has a harmful effect on environment and human health. The most serious environmental pollution is chlorinated waste water, such as chlorinated bleaching wastewater and chlorate bleaching wastewater. In addition, the highly toxic carcinogenic dioxins in the bleaching waste water also pose a serious threat to the ecological environment and human health.