河流水体黑臭演化过程及恶臭硫化物的产生机制

Study on Evolution and Mechanism of River Water Black-odor and Malodorous Sulfide

水体黑臭是河道水环境污染极其严重的表现,认识水体黑臭演化过程对开展水污染防治至关重要。该研究在实验室模拟条件下,结合滨海河流水质特点,重点研究了总有机碳(TOC)、总氮(TN)及Fe^(2+)浓度等3个水质因子对水体黑臭形成的影响,同时分析了不同水质条件下甲硫醇(MT)和H_2S等挥发性硫化物的产生机制。通过采用河流原水进行接种制备人工黑臭水,设定不同的TOC,TN、Fe^(2+)浓度和水体盐度梯度进行模拟实验,分析了单一水质因素对水体黑臭形成的影响;为了进一步认识各种水质因素之间的相互作用及其对黑臭水体形成的综合影响,该文同时开展了多因素正交试验。单因子实验结果表明,当TOC浓度>100 mg/L、TN浓度>50 mg/L且Fe^(2+)浓度>5 mg/L时,水体在第7天开始变黑,试验结束时(12 d),水中H_2S及MT浓度增长显著(MT浓度>6μg/L,H_2S浓度>250μg/L);正交试验结果表明,TOC对黑臭水形成的影响极其显著(显著值<0.01)。该研究可为水体黑臭的有效防控提供有力的技术支撑。

Black and malodorous river reflects water-body being heavily polluted. This paper described a laboratory simulation experiment to probe into the mechanism of evolution of black-odorous river, taking into consideration of the characteristics of a stream in the coastal and estuary zone. Influences of three important water quality factors including TOC, total nitrogen（TN） and Fe^2＋on the formation of black-odor in water body were studied; at the same time, the mechanisms of volatile odorous sulfides produced, i.e. methyl mercaptan（MT） and H2 S were analyzed under different water quality conditions. In the experimental water, different concentrations of TOC, TN and Fe^2＋being prepared were added, and inoculated with mixed bacteria of river-water, thereby the effects of different factors on the formation of black odor were respectively studied. Additionally, a multi-factor orthogonal test was designed for further understanding of the comprehensive influences of different water quality factors on the formation of black-odorous water. The single factor experiment indicated that when TOC100 mg/L, TN50 mg/L and Fe^2＋5 mg/L,the water turned black after seven days, and at the end of the experiment（12 days later）, the concentrations of H2 S and MT in the water increased to over 250 μg/L and 6 μg/L, respectively.Furthermore, the orthogonal test showed that TOC had highly significant correlation with the formation of black-odor in water（sig〈 0.01）. Hopefully, the study can provide an effective technical support for prevention and remediation of black and odorous waters.