火山岩人工湿地处理三种类型污水的实验研究

发布时间：2018-11-24 13:48

【摘要】：当前,水资源短缺以及水污染问题已经成为世界性的水环境问题,在发展中国家该问题尤为突出。水体污染问题严重威胁着我国经济、社会和人文等多方面可持续性发展。尽管国家对水污染治理投入了大量的人力物力,但是,水环境并没有完全得到有效的改善。人工湿地作为近年来兴起的一种新型污水处理技术,在水污染控制方面正发挥着越来越重要的作用。人工湿地污水处理技术具有缓冲容量大、处理效果好、工艺简单、投资省、运行费用低等特点,非常适合中、小城镇的污水处理。本实验通过针对污水中COD、NH4+-N、NO2--N、NO3--N、PO43--P等指标,考察火山岩填料的人工湿地处理生活污水、低污染物浓度废水和高硝态氮浓度污水的实际效果。实验期间,针对不同的影响因子,控制调配其变化,研究DO、HRT和C/N对于污染物去除效果的影响。在课题研究期间,取得如下结果:1)在处理生活污水,采用人工曝气,逐步提高曝气量可以提高人工湿地对于污染物的去除效率,尤其是对于COD、NH4+-N。但对于总磷来说,区别不大,说明磷的去除主要是依靠基质的吸附作用。当水中溶解氧为3mg/L左右时,污染物的去除效果最好,COD、NH4+-N的去除率均能达到90%以上,出水水质良好。磷酸盐的去除率由于进水含量较低所以去除率不高,只有50%左右。实验认为,DO的值取5mg/L,可以得到较好的氨氮去除效果。2)在处理低污染物浓度废水,水力停留时间的增加能提高COD和氨氮的去除率。当HRT分别为1.5、2.5、4.0天时,CODcr的平均去除率分别为57.1%、72.6%、78.1%,氨氮的平均去除率为53.8%、98%、99%,明显提高。水力停留时间较低时,COD和氨氮去除率波动变化大,生化反应不充分。而且较长的停留时间使得反硝化作用减弱,氨氮全部转化为NO3--N排出。水力停留时间可以影响磷酸盐的去除率,但是效果不大,污水中磷的去除主要依靠基质吸附和离子交换作用。水力停留时间取2.5天,可以得到较好的去除效果。3)在处理高硝态氮污水,外加碳源的种类影响着和硝化和反硝化作用的进行。本试验主要针对高硝态氮浓度的废水,所以选取乙酸钠作为外加有机碳源,发现随着碳氮比的增加硝态氮的去除率都大幅度增加,从C/N为1:1时的不去除,到C/N为5:1时,NO3--N和PO43--P的去除率分别增加到85%和65%。碳氮比的增加对于有机物的去除影响不大。C/N比取5:1,可以得到较好的去除效果。4)以火山岩填料作为人工湿地基质,生物膜培养状态良好,有机物、氮的去除率均处于较高水平,磷的去除效果不明显。5)人工湿地作为一种生态污水处理工艺,具有良好的环境功能和生态价值,值得推广与应用。
[Abstract]:At present, water shortage and water pollution have become a worldwide water environmental problem, especially in developing countries. Water pollution seriously threatens the sustainable development of economy, society and humanities in China. Although the state has invested a lot of manpower and material resources in water pollution control, the water environment has not been completely improved effectively. As a new sewage treatment technology, constructed wetland is playing a more and more important role in water pollution control. Constructed wetland wastewater treatment technology has the characteristics of large buffer capacity, good treatment effect, simple process, low investment and low operating cost, etc. It is very suitable for sewage treatment in medium and small towns. In this experiment, the actual effect of treating domestic sewage, low pollutant concentration wastewater and high nitrate nitrogen concentration wastewater by using constructed wetland filled with volcanic rock to treat domestic sewage was investigated according to the indexes such as COD,NH4-Nno _ 2--N _ (10) -no _ (3) -N _ (3) O _ (43) -P in sewage. During the experiment, the effects of DO,HRT and C / N on the removal efficiency of pollutants were studied by controlling the changes of different influencing factors. During the study period, the following results were obtained: 1) in the treatment of domestic sewage, the use of artificial aeration, gradually increasing the amount of aeration can improve the removal efficiency of pollutants in constructed wetlands, especially for COD,NH4-N. However, for total phosphorus, the difference is not significant, indicating that phosphorus removal mainly depends on the adsorption of matrix. When the dissolved oxygen in water is about 3mg/L, the removal efficiency of pollutants is the best, the removal rate of COD,NH4-N can reach more than 90%, and the quality of effluent is good. The removal rate of phosphate is only about 50% because of the low influent content. The experimental results show that the removal efficiency of ammonia nitrogen can be obtained by using 5 mg / L of DO. 2) in the treatment of wastewater with low concentration of pollutants, the increase of HRT can improve the removal rate of COD and ammonia nitrogen. The average removal rate of CODcr was 57.1 and the average removal rate of ammonia nitrogen was 53.8% and 72.6%, respectively, and the average removal rate of ammonia nitrogen was 53.8% and 989.99%, respectively, when HRT was 1.5 ~ 2.5 ~ 4.0 days, and the average removal rate of CODcr was 57.1and the average removal rate of ammonia nitrogen was 53.8%. When the HRT is low, the removal rate of COD and ammonia nitrogen fluctuates greatly, and the biochemical reaction is not sufficient. Moreover, the denitrification was weakened with a long residence time, and all ammonia nitrogen was converted to NO3--N emission. HRT can affect the removal rate of phosphate, but the effect is not so good. The removal of phosphorus in wastewater mainly depends on matrix adsorption and ion exchange. When the HRT is 2.5 days, the removal efficiency can be better. 3) in the treatment of wastewater with high nitrate nitrogen, the addition of carbon sources affects the nitrification and denitrification. This experiment mainly aimed at the wastewater with high nitrate nitrogen concentration, so sodium acetate was selected as the added organic carbon source. It was found that the removal rate of nitrate nitrogen increased greatly with the increase of C / N ratio, and the removal rate was not removed from C / N at 1:1. At 5:1, the removal rates of NO3--N and PO43--P increased to 85% and 65%, respectively. C / N ratio of 5: 1 can get better removal effect. 4) with volcanic rock filler as the substrate of constructed wetland, the biofilm culture condition is good, organic matter, The removal rate of nitrogen is at a higher level, and the removal efficiency of phosphorus is not obvious. 5) as an ecological wastewater treatment process, constructed wetland has good environmental function and ecological value, which is worth popularizing and applying.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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