水解酸化+A/O工艺对石化废水不同分子量有机物去除效果评价

Treatment effect of hydrolysis-acidification + A/O process on organics with different molecular weight in petrochemical wastewater

对某典型石化企业综合污水处理厂'水解酸化+A/O'处理工艺各单元出水不同分子量区间的有机物含量及光谱特性进行了表征。研究表明,石化企业综合污水处理厂各处理单元出水DOC以分子量<1 kDa的有机物为主;处理工艺对废水COD、DOC和UV254的总去除率分别为84.58%、86.22%和72.92%,分子量<1 kDa、3~5 kDa、10~30 kDa、30~100 kDa的DOC去除率达90%左右,分子量5~10 kDa和>100 kDa的DOC增加了28.57%和43.90%;分子量<1 kDa的UV254的去除率为76.27%;水解酸化池对分子量30~100 kDa的有机物去除率达90.87%,缺氧段对分子量1~3 kDa的DOC去除率达92.86%,缺氧出水分子量3~10 kDa和30~100 kDa的DOC浓度较水解酸化出水有较大增加,好氧段对缺氧段出水中分子量30~100 kDa、5~10 kDa和3~5 kDa的有机物有很好的去除作用,去除率分别为80.85%、43.46%和72.32%,而分子量1~3 kDa的DOC浓度有所增加。各出水在260~270 nm有紫外吸收峰。各分子量区间DOC的SUVA值随处理工艺沿程增大,废水有机物芳香度提高,UV253/UV203呈减小趋势。

The DOC content and spectral characteristic of organics with different molecular weight( MW)were characterized,in the effluents collected from different treatment units of a typical petrochemical wastewater treatment plant with hydrolysis-acidification + A /O process. DOC of each effluent mainly consists of the fraction with MW < 1 kDa. The process gets a remarkable removal of COD,DOC and UV254with the removal efficiencies of84. 58%,86. 22% and 72. 92%,respectively. The removal efficiencies of DOC in the fractions with MW( < 1kDa,3 ~ 5 kDa,10 ~ 30 kDa and 30 ~ 100 kDa) are all around 90%,while the DOC of the fractions with MW in5 ~ 10 kDa and > 100 kDa increases by 28. 57% and 43. 90%,respectively after the treatment. The removal efficiency of UV254in the fraction with MW < 1 kDa reaches 76. 27%. In the hydrolytic-acidification pool,the DOC of the fraction with MW in 30 ~ 100 kDa decreases by 90. 87%. In the anoxic stage,the organic matters with MW in 1 ~ 3 kDa are decreased by 92. 86%,but those with MW in 3 ~ 10 kDa and 30 ~ 100 kDa greatly increase,compared with their DOC contents in the effluent of the hydrolytic-acidification pool. The aerobic pool has obvious DOC removal of the fractions with MW in 30 ~ 100 kDa,5 ~ 10 kDa,and 3 ~ 5 kDa( 80. 85%,43. 46% and72. 32%,respectively) generated in the anoxic stage,while the content of DOC with MW in 1 ~ 3 kDa increases.UV absorption peaks appear in each effluent in the wavelength range of 260 to 270 nm. The SUVA value of each fraction increases gradually along the treatment process,indicating that the aromaticity of the organic matters in the wastewater is enhanced. The rate of UV253/UV203exhibits a tendency of decrease along the treatment process.