臭氧对化工园区废水厂二级出水的选择性氧化

以化工园区废水厂二级出水作为实验废水,采用臭氧氧化工艺对其进行处理,采用分子量分级、亲疏水性分离和傅里叶红外等手段对臭氧氧化前后水质进行了系统分析。结果表明,在进水COD为126 mg/L,臭氧氧化60 min的条件下,COD和UV254的去除率分别为37.9%和55%;臭氧氧化对水中疏水性物质去除效率高于亲水性物质,部分疏水性物质氧化成亲水性小分子有机物。臭氧氧化可以改变废水中有机物的分子结构,使水中分子量小于1×103 kDa的有机物比例从56.3%提高至71.2%,分子量大于1×105 kDa的有机物比例由原来的24.2%下降至9.6%。红外光谱分析表明,臭氧氧化具有一定的选择性,可显著去除水中含不饱和键、酚类、醇类等有机物,但对饱和烷烃基本无降解效果。

Selective oxidation of effluent in sewage plant of chemical industry park with ozonation

The effect of ozonation on a typical effluent in a sewage plant of a chemical industry park was studied. Molecular weight distribution(MWD), hydrophilicity and hydrophobic separation, fourier transform infrared spectrometry were used to analyze water quality before and after ozonation. The removal rates of COD and UV254 were 37.9% and 55%, respectively with an ozone duration of 60 min. Partially hydrophobic substances were oxidized the hydrophilic small organic molecules after the ozonation, and the removal efficiency of the hydrophobic substance in water was higher than the hydrophilic substance. Ozonation changed the MWD of the wastewater, increasing the percentage of small-molecular-weight organics(3 kDa) from 56.3% to 69.4%, and decreasing the percentage of big-molecular-weight organics(>1×105 kDa) from 24.2% to 9.6%.The results of the FT-IR spectra demonstrated that ozone oxidizes organic pollutants selectively. The ozonation can significantly remove the organic compounds containing unsaturated bond, phenols, alcohols, etc. in the water, but it almost has no degradation reacting with saturated alkanes.