Sun Xin, Zhang Yi, Shi Lu-Xiao, Chen Xiao-Han, Tang Xiao
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Xi'an Jumping Water Environment Technology Co., Ltd., Xi'an 710075.
Huan Jing Ke Xue. 2018 Apr 8;39(4):1654-1660. doi: 10.13227/j.hjkx.201707208.
For the effective removal of two typical odorants found in drinking water, 2-methylisoborneol (2-MIB) and geosmin (GSM), which cannot be effectively removed by the conventional water treatment processes, the advanced oxidation process of vacuum ultraviolet combined with chlorine (VUV/chlorine) was studied. The efficiency of this technology in the removal of these typical odorants was investigated; the effects of ultraviolet intensity, chlorine concentration, pH, bicarbonate concentration, and humic acid concentration on the degradation of these typical odorants were examined, and the role of hydroxyl radicals (·OH) in the degradation of these typical odorants was analyzed. The purge and trap method coupled with gas chromatography and mass spectrometry (GC/MS) was used to determine the concentrations of the typical odorants. The results showed that the VUV/chlorine technology removed typical odorants effectively, and the removal rates of 2-MIB and GSM increased by 15% and 8%, respectively, in 30 minutes, compared with that by the UV/chlorine technology. With the increase in chlorine concentration and ultraviolet intensity, the degradation rates of the typical odorants was accelerated. The removal of the typical odorants was obvious under weak acid condition, and the removal rates of 2-MIB and GSM reached 95% and 96%, respectively, in 10 minutes under the condition of pH 5. Bicarbonate and humic acid competed with free radicals in the reaction system to inhibit the degradation of the typical odorants. The removal rates of 2-MIB and GSM decreased appreciably by 40% and 31%, respectively, when 1 mmol·L-butanol was added to the reaction mixture, which indicated that hydroxyl radicals (·OH) played a major role in the removal of these typical odorants.
为有效去除饮用水中两种常规水处理工艺无法有效去除的典型气味物质，即2-甲基异莰醇（2-MIB）和土臭素（GSM），研究了真空紫外光联合氯（VUV/氯）的高级氧化工艺。考察了该技术对这些典型气味物质的去除效率；研究了紫外光强度、氯浓度、pH值、碳酸氢盐浓度和腐殖酸浓度对这些典型气味物质降解的影响，并分析了羟基自由基（·OH）在这些典型气味物质降解中的作用。采用吹扫捕集法结合气相色谱-质谱联用仪（GC/MS）测定典型气味物质的浓度。结果表明，VUV/氯技术能有效去除典型气味物质，与UV/氯技术相比，30分钟内2-MIB和GSM的去除率分别提高了15%和8%。随着氯浓度和紫外光强度的增加，典型气味物质的降解速率加快。在弱酸条件下对典型气味物质的去除效果明显，pH值为5时，10分钟内2-MIB和GSM的去除率分别达到95%和96%。碳酸氢盐和腐殖酸与反应体系中的自由基发生竞争，抑制典型气味物质的降解。向反应混合物中加入1 mmol·L⁻¹丁醇时，2-MIB和GSM的去除率分别显著下降了40%和31%，这表明羟基自由基（·OH）在这些典型气味物质的去除中起主要作用。
