【作者】 刘菲；

【导师】 何江涛；

【作者基本信息】 中国地质大学(北京) ， 环境科学与工程， 2014， 硕士

【摘要】 碳源选择是地下水硝酸盐原位修复过程中的一个瓶颈问题。本文选择乳化油作为研究碳源,研究了乳化油配比、乳化油注入对介质渗透性影响及通过室内柱实验模拟原位修复过程中乳化油作为碳源去除硝酸盐的效果,对乳化油进行反硝化效果评估。论文取得的成果可以为实际场地的工程设计提供一定的依据。论文取得主要结论如下：乳化油配比实验表明,当油的体积分数在55%-60%,同时乳化剂的体积分数在13%-15%之间时,乳化油的稳定性较好。制备样品的粒径均为微米级,且样品的粘性与水相似,有利于乳化油注入及在含水层中均匀分布：样品的COD释放量基本在105～106 mg/L之间,能够满足作为反硝化反应碳源的要求；渗透性模拟柱实验表明,乳化油注入初始阶段,各土柱的渗透系数突然降低,基本降到初始值的20%左右；随着出水体积的增加,土柱渗透系数逐渐恢复到初始值的30%～50%,此时出水COD累积释放量基本达到注入的乳化油的COD释放量的80%以上。由于加入乳化油后会对介质的渗透性有影响,需要在实际工程中加以注意。乳化油去除硝酸盐模拟柱实验表明,在试验的116天内,进水浓度硝酸盐氮分别为20 mg/L和50 mg/L,出水硝酸盐氮浓度最低可以达到0.32 mg/L和0.45mg/L,最高去除率能达到99%左右,硝酸盐氮总去除率在73%和70%左右,总去除量分别为437.2 mg和1117.0mg。乳化油作为原位修复硝酸盐污染的碳源对硝酸盐具有一定的去除效果。乳化油评估计算结果表明,两次注入的乳化油的使用寿命可以达到116天左右,单位体积乳化油去除硝酸盐氮的量分别为5.5 g/L和14.0 g/L。在反硝化反应过程中,COD/N比分别为30.9和12.8。反硝化反应的COD利用率为35.13%和37.27%。流失碳源所能够去除硝氮质量为268.76 mg和584.74 mg。乳化油去除硝酸盐的半衰期能够达到13天和24天左右。更多还原

【Abstract】 Carbon source selection is a bottleneck problem in the process of groundwater nitrate in-situ remediation. This paper chose the emulsified soybean oil as the carbon source in the study. It studied the ratio of emulsified soybean oil, the impact of emulsified soybean oil injection on permeability of medium and through the indoor column simulated experiment in-situ remediation of emulsified soybean oil as carbon source in the process of removing the effect of nitrate, and evaluate the emulsified soybean oil denitrification effect. In the paper, the conclusions could provide a basis for the practical engineering. The main conclusions were as follows:The ratio experiment of emulsified soybean oil showed, the volume fraction of oil between 55% and 60%, at the same time the volume fraction of emulsifier between 13% and 15%, the stability of emulsified soybean oil was good. The grain size of the samples were micron grade, and the viscosity of the samples were similar to water. The properties of the samples were beneficial to the emulsified soybean oil injection and uniformly distributed in the aquifer sands. The COD cumulative released quantity of the samples were between 105-106 mg/L. The properties of emulsified soybean oil were able to meet the requirements as carbon source of denitrification reaction.The permeability of column simulated experiment showed, at the initial stage when the emulsified soybean oil injected into the column, the hydraulic conductivity of each column suddenly dropped, the hydraulic conductivity fell to about 20% of the initial value. With the increasing of the volume, the hydraulic conductivity of column gradually recovered to the 30% to 50% of the initial hydraulic conductivity, at the same time, the column effluent cumulative release quantity of COD had achieved more than 80% of COD emission of emulsified soybean oil. After adding emulsified soybean oil would have an effect on the permeability of medium, so it need pay attention to the change of hydraulic conductivity in the practical engineering.The simulated column experiment that used emulsified soybean oil to remove nitrate showed, in the experiment of 116 days, the nitrite nitrogen (NO3-N) concentrations of the inffluent were 20 mg/L and 50 mg/L.The lowest nitrite nitrogen (NO3-N) concentrations in the effluent could reach 0.32 mg/L and 0.45 mg/L. The highest nitrate nitrogen removal rate could reach 99%. The total removal efficiency were about 73% and 70%. The amounts of total removal of nitrate nitrogen were 437.2 mg and 1117.0 mg respectively. Emulsified soybean oil as the carbon source of in-situ nitrate remediation had an good effect on nitrate removal.The calculation results of emulsified oil evaluation showed that, the longevity of the emulsified vetetable oil that were injected could reach 116 days or so. The amount of unit volume emulsified soybean oil to remove nitrate nitrogen were 5.5 g/L and 14.0 g/L. In the denitrification reaction, the ratios of COD/N were 30.9 and 12.8. The utilization rates of COD were 35.13% and 35.13%. According to the calculation of COD/N ratio, the loss of carbon source in the experiment could remove nitrate nitrogen quality were 268.76 mg and 584.74 mg. The half-life of emulsified soybean oil removing nitrate could reach 13 and 24 days or so.更多还原