针对内蒙古农村地区高腐殖酸地下水的处理问题,分别对(pH调节)-PAC强化混凝、高锰酸钾预氧化/混凝、活性炭吸附/混凝、Fenton氧化等技术处理的可行性进行了研究,同时利用三维荧光和高效体积排阻色谱分析处理前后水中有机物的组成变化特征。有机分析结果显示,水中的有机物为腐殖酸类物质,分子量分别为1600和3500,腐殖酸类物质为水中色度的主要贡献者。原水PAC强化混凝、高锰酸钾预氧化/PAC混凝对有机物的去除效果不佳,处理前后水样DOC浓度无明显变化,而pH调节.PAC强化混凝、微米活性炭吸附和Fenton氧化均能有效去除有机物。将原水pH调节至6.5,经300mg/LPAC混凝后出水DOC降至5.99mg/L。活性炭投加量为0.6g/L时,DOC降至7.6mg/L,然后采用60mg/LPAC混凝出去高度分散而不易沉降的小颗粒活性炭。此外,当反应初始pH值为3,过氧化氢投加量为0.5%(v/v),亚铁和双氧水摩尔比为0.05时,出水DOC降至5.6mg/L,氧化后有小分子有机物生成。
The feasibility of several technologies (pH adjustment-PAC enhanced coagulation, KMnO4 pre- oxidation/coagulation, coagulation/flocculation, activated carbon absorption/coagulation, Fenton oxidation) on the treatment of ground water with high content humic acid was investigated in this study. The effect of different processes on organic composition was characterized by three-dimensional excitation emission matrix (3-DEEM) spectra and high performance size-exclusion chromatography analysis. The results indicated that dissolved organic matters (DOMs) were mainly composed by two humic acids whose molecular weights (MWs) were 1 600 and 3 500, respectively. Yellow color in water was caused by humic-like organics. PAC enhanced coagulation, KM- nO4 pre-oxidation/coagulation had rather limited effect on DOC removal. However, organic matters could be ef- fectively removed by using pH adjustment-PAC enhanced coagulation, Fenton oxidation and activated carbon ab- sorption. DOC concentration decreased to 5.99 mg/L when the dosage of PAC and pH were 300 mg/L and 6.5, respectively. The content of DOC reduced to 8 mg/L by adding micro-size activated carbon at the dosage of 0.6 g/L, and then the highly dispersive powdered activated carbon could be rapidly removed through PAC coagula- tion followed by settling process. Again, effluent DOC concentration was 5.6 mg/L when the dosage of hydrogen peroxide, molar ratio of ferrous and hydrogen peroxide, pH were 0. 5% (v/v) , 0.05, 3, respectively. Some by- products with low MWs were observed after Fenton oxidation treatment.