造纸中段废水的混凝—臭氧氧化深度处理研究

Tertiary treatment of biologically treated pulp and paper wastewater by combined coagulation-ozonation process

就混凝-臭氧氧化组合工艺对造纸中段废水生物处理出水的净化效果进行了研究。结果表明，Ca（OH）2对废水色度、TOC、COD和254nm的紫外吸收值（UV254）的去除效果均优于聚合氯化铝／聚丙烯酰胺（PAC／PAM）；Ca（OH）2O3组合工艺的处理效果也优于PAC／PAM—O2工艺。当Ca（OH）2投加量为1g／L、臭氧投加量为50mg／L时，废水色度降低至10倍以下，COD小于150mg／L。经Ca（OH）2混凝处理后，相对分子量在0．5～1．0ku和10．0ku以上的有机物显著减少；进一步臭氧氧化处理后，除0．5～1．0ku范围的有机物大幅度增加外，其余分子量有机物显著减少。由于对色度贡献很大的大分子量物质的去除，废水的色度显著下降直至无色。

Combined coagulation-ozonation process was used for tertiary treatment of biologically treated paper and pulp wastewater. It was showed that coagulation by Ca（OH）2 was better than PAC/PAM for COD, TOC and color removals. The efficiency of the combination of Ca（OH）2O3 process was also much better than that of PAC/ PAM Oa process. When the dosage of Ca（OH）2 was about lg/L, ozone was 50 mg/L, the color and COD were decreased to less than 10 and 150 mg/L, respectively. After coagulation of Ca（OH）2, organic compounds with molecular weight （MW） 0.5-1.0 ku and that larger than 10.0 ku were significantly removed from the wastewater. After further ozonation process, organic compounds with MW 0.5-1.0 ku greatly increased, however those with other MW obviously decreased. Due to the removal of the organic compounds with higher MW characterized by the color, the color of the wastewater greatly decreased.