本实验采用内循环好氧三相流化床处理造纸中段废水，经过一段时间的驯化，获得了稳定的出水。COD去除率保持在65%以上，系统对进水污染负荷的变化具有较大的承受能力。出水Cl^-的浓度有所增加，说明驯化后的微生物可能对有机氯化物具有一定的降解作用。水气比在1/120至1/140之间可获得最好的COD去除效果。后续进行絮凝处理后，出水COD降为60～80mg/L，BOD为50～60mg/L，色度为100～150CU，挥发性酚的质量浓度小于0.0265mg/L。

The treatment of middle-stage effluent in paper mills with inter loopaerobic three-phrase fluidized bedis carried out.After aperiod of domestication,the character sofdis charged water are stable.The COD removal rate keeps higher than65%,which in dicates that the system could sustain the variation of input load.The increase of[Cl^-]ineffluentimpliedthe biofilm could biodegrad echloroa romatic component sincert a indegree after domestication.The best ratioof liquid-gas should be controlled betweent/120and1/140.Theout flow off luidizedbed is treated by flocculation,and the final drains COD is60~80mg/L,BODis50~60mg/L,chroma is 100~150CU,volatility-hydro xybenzene is less than 0.0265mg/L.