粉煤灰去除竹浆造纸废水中挥发酚的应用研究

The Application of Fly Ash to Remove Volatile Phenol in Wastewater of Bamboo Pulp and Paper Mill

关键词:  粉煤灰  挥发酚  造纸废水  以废治废

Key Words:fly ash  volatile phenol  polluted-condensate water  ash-water  wastewater treatment by using waste

摘要:实验采用污冷凝水和部分中段废水组成的碱性造纸废水直接作为水膜除尘系统的冲灰水，利用锅炉烟气中的粉煤灰对污冷凝水进行预处理，同时又利用废水的碱度对锅炉烟气进行脱硫处理。结果表明，废水pH值由9.8下降至8.6，COD_Cr去除率达75.8%，SS去除率达27.9%，挥发酚去除率达到76.5%，预处理后的废水进入生化处理系统进一步处理。锅炉的烟尘去除率达到95%以上，SO₂去除率达到80%以上，均能达到GB13271—2001二类Ⅱ时段规定的排放限值。吸附了挥发酚的粉煤灰用于焙烧制砖，挥发酚在高温下转化为二氧化碳和水，避免了二次污染。

Abstract:The primary goal of the study is to remove the volatile phenol which is the key precursor of aromatic halides, and reduce the productions of POPs and AOX in pulp and paper production by using bamboo as fiber raw material. The alkaline papermaking wastewater was directly used as ash-washing water in a water film scrubber. The composition of alkaline papermaking wastewater was polluted-condensate water and concentrated washing and bleaching water. The polluted-condensate water was pretreated by using fly ash of boiler flue gas, and the alkaline water was used as desulfurization at the same time. It achieved the purpose of wastewater treatment by using waste and reduced treatment cost. The results showed that, pH of wastewater decreased from an average of 9.8 to 8.6, COD_Cr removal rate of 75.8%, SS removal rate of 27.9%, volatile phenol removal rate of 76.5%. Volatile phenols in wastewater discharge could meet the standard A of “Integrated Wastewater Discharge Standard” (GB-8978—1996) when the pretreated waste water was further treated by the biological treatment system. Boiler fly ash removal rate of 95%, SO₂ removal rate of 80%, which reached (GB13271—2001) Type II slot Ⅱ emission limits. The fly ash adsorbed volatile phenol was used for bricks making, volatile phenol turned into carbon dioxide and vapor at high temperatures to avoid secondary pollution. The investment of industrial application of the process was about ￥0.6 million. The industrial application achieved a comprehensive utilization of the waste and wastewater treatment by using waste, and also effectively reduced the investment and operating costs.