滇池流域人工生态潭对农田污染物截留及削减能力的研究

发布时间：2018-06-06 21:27

本文选题：滇池流域 + 农田水潭　；参考：《云南大学》2015年硕士论文

【摘要】：农业面源污染是造成滇池湖泊富营养化的重要原因,而农田污水是我国农业面源污染的主要污染源之一,对农田污水的削减成为了本研究的研究重点。本研究基于对滇池流域柴河子流域安乐村农田水潭的调查后,需要对现有的农田水潭进行适当的生态化工程改造,以提高其对污染物的削减效率,为实现这一目标,在实验室内构建小型生态潭,研究了不同污水浓度、水力停留时间、渗滤墙填料类型和渗滤墙厚度组合下,实验室小型生态潭对水体污染物的去除效果,择优挑选最佳去除水体污染物的组合,应用于户外农田水潭的生态化改造,构建人工生态潭,并研究生态潭对污染物的削减效果。获得的主要结果如下： (1)改造前不同农田水潭在不同月份,对总磷、总氮、硝氮、铵氮、COD和SS的截留量范围分别为每次4.75g-766.43g、0.13kg-6.19kg、0.12kg-2.84kg、0.68g-542.17g、0.64kg-10.57kg和13.13kg-157.75kg；农田水潭对污染物有一定的自净能力(即去除污染物的能力,HRT=2d),对总磷、总氮、硝氮、铵氮、COD和SS的平均自净率分别为15.02%、11.66%、11.75%、11.51%、10.60%和12.02%。 (2)室内设置4种组合(A, B, C, D),各模拟组合对污染物的削减能力为,削减总磷最好的组合为A组合,最高削减率为40.29%；削减总氮最好的组合为A组合,最高削减率为85.89%；削减硝氮最好的组合为D组合,最高削减率为67.89%；削减铵氮最好的组合为A组合,最高削减率为85.77%；削减COD最好的组合为B组合,最高削减率为66.92%。综合来看,削减各污染物最好的填料配比为碎石：石英砂：轻质陶粒：木屑；渗滤墙厚度80cm与50cm相比,尽管80cm稍占优势,但考虑到厚度为50cmm能够节约大量成本的同时,还可节省水潭空间,储存更多的灌溉用水和截留更多的污染物,故选择厚度为50cm的渗滤墙作为野外人工生态潭的实际参数。 (3)人工构建的生态潭对污染物削减情况(HRT=2d)为,总磷、总氮、硝氮、铵氮、COD和SS的平均削减率分别为35.19%、36.91%、35.01%、40.61%、30.25%和32.17%；其中,生态潭中渗滤墙对污染物削减具有明显的作用,对总磷、总氮、硝氮、铵氮、COD和SS的平均削减率分别为13.72%、18.88%、17.63%、18.66%、15.91%和16.40%。 (4)生态潭对总磷、总氮、铵氮、COD和SS的削减率随着时间的延长在缓慢下降,硝氮的削减率随着时间的延长保持相对稳定。
[Abstract]:Agricultural non-point source pollution is an important cause of eutrophication in Dianchi Lake, and farmland sewage is one of the main sources of agricultural non-point pollution in China. Based on the investigation of farmland pool in Anle Village of Chaihezi Basin in Dianchi Lake Basin, it is necessary to carry out proper ecological engineering transformation of the existing farmland pool in order to improve the efficiency of pollutant reduction, in order to achieve this goal. A small ecological pool was constructed in the laboratory. The removal effect of pollutants in the laboratory was studied under the conditions of different wastewater concentration, hydraulic retention time, the type of fill and the thickness of the leachate wall. The best combination of removing water pollutants was selected and applied to the ecological transformation of outdoor farmland pool, the artificial ecological pool was constructed, and the effect of the ecological pool on the reduction of pollutants was studied. The main results obtained are as follows: 1) before transformation, different farmland pools in different months, total phosphorus, total nitrogen, nitrate nitrogen, The rejection ranges of COD and SS were 4.75g-766.43g / d 0.13kg-6.19kg / time 0.12kg-2.84kg / kg (0.68g-542.17g / kg) 0.64kg-10.57kg and 13.13kg-157.75kg / kg respectively. The average self-purification rates of COD and SS were 15.02 and 11.66, respectively, and 11.51U 10.60% and 12.02%, respectively.) four combinations (A, B, C, DU) were set up indoors. The ability of reducing pollutants in each simulated combination was as follows: the best combination for reducing total phosphorus was combination A, The highest cutting rate is 40.29; the best combination of reducing total nitrogen is combination A, the highest cutting rate is 85.89; the best combination of reducing nitrate nitrogen is combination D, the highest cutting reduction rate is 67.89; the best combination of reducing ammonium nitrogen is combination A, The highest reduction rate of COD was 85.77, the best combination of COD reduction was combination B, and the highest cutting rate was 66.92%. Overall, the best proportion of fillers to reduce pollutants is gravel: quartz sand: lightweight ceramsite: sawdust; percolation wall thickness 80cm is slightly superior to 50cm, although 80cm is slightly superior, but considering that thickness of 50cmm can save a lot of cost, It can also save the pool space, store more irrigation water and retain more pollutants, so the percolation wall with thickness of 50cm is chosen as the actual parameter of artificial ecological pool in the field. The average reduction rates of COD and SS for total nitrogen, nitrate and ammonium nitrogen were 35.1919 / 36.91and 35.01% respectively, and 30.25% and 32.17% for COD and SS respectively, among which, the leachate wall in the ecological pool had obvious effect on the reduction of pollutants, and on the total phosphorus, total nitrogen, nitrate nitrogen, total phosphorus, total nitrogen, nitrate nitrogen, The average reduction rates of COD and SS were 13.72% and 18.8817.63% and 16.40%, respectively.) the reduction rates of total phosphorus, total nitrogen, ammonium nitrogen COD and SS decreased slowly with the prolongation of time, and the reduction rate of nitrate nitrogen remained relatively stable with the prolongation of time.
【学位授予单位】：云南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;X71

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