化学钝化和水生植物技术原位修复水体污染的研究

发布时间：2018-03-14 06:20

本文选题：新型复合钝化剂　切入点：原位修复　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：水体污染是目前较为突出的环境问题,而底泥污染物的防治是水体污染治理的关键,底泥中积累的大量有毒有害物质经过一定的交换作用会再次释放到上覆水体,导致上覆水体的二次污染,因此选择经济、生态、有效的底泥修复技术是水体污染治理的重点和难点。本研究采用原位修复技术,分别以南淝河底泥中的污染物为目标,在模拟河道反应器上研究化学钝化剂对底泥的修复效果,同时,利用水生植物综合治理斛兵塘的黑臭水体,并研究采用水生植物、生物操纵、护岸生态改造等生态综合治理技术在治理校园湖泊中的净化效果。通过大量的室内实验和工程实验,得出以下结论:(1)投加复合钝化剂对上覆水体中TN、NH4+-N和TP均有不同程度的净化效果,且净化效果随药剂量的增加而增强,最高去除率分别达到23.52%、21.79%和81.5%,上覆水体COD去除率随药剂投加量增多呈先升后降的趋势,最高(投加量为600mg/L)达到57.6%,投加复合钝化剂增大了底泥TP含量并促进底泥不稳态磷向稳定态磷转化,且投加复合钝化剂使不稳态锌向稳定态锌转化,且主要转化为残渣态,1#-5#锌的残渣态分别增加了41.3%,52.7%,49.8%,54.7%,54.2%,但不同处理间差异不显著。因此,从经济成本和修复效果方面综合分析,以投加量为600mg/L对底泥污染原位修复较为合适。(2)采用新型复合钝化剂、硫酸铝、硝酸钙和零价铁4种钝化剂研究对南淝河底泥污染物释放特征的影响中,底泥中投加Fe0和Ca(NO3)2后上覆水体pH由6.7增大至8.5左右,Eh则呈下降趋势,投加复合钝化剂后上覆水体pH稳定在7.5左右,Eh缓慢下降。投加Fe0后对上覆水体COD影响较硝酸钙小,但实验前期都会对上覆水体水质造成较大影响,投加复合钝化剂对底泥有机质的抑制效果最显著,上覆水COD稳定在5mg/L左右,铝盐的抑制效果仅次于复合钝化剂。底泥中投加4种钝化剂对底泥TP均有抑制效果,其中新型复合钝化剂硝酸钙硫酸铝零价铁。复合钝化剂的投加对底泥TN、NH4+-N有一定抑制效果,而投加硝酸钙则会增大上覆水体TN、NH4+-N含量,新型复合钝化剂对底泥污染物的抑制效果优于其他单一钝化剂。(3)通过对斛兵塘近三个月的水质分析,可知采用水生植物、生物操纵、护岸生态改造等生态综合治理技术对斛兵塘有很好的修复效果,水质得到极大改善。实验结束时,TN、TP、NH4+-N、COD平均去除率分别达到76.7%、85%、83.6%、67.5%。(4)斛兵塘的生态治理增强了水体的自净能力,水体的透明度达到0.5米,最好时能达到1米左右,水体的颜色恢复正常,水面清洁无杂物、无藻类等漂浮物,黑臭消除,景观效果增强。
[Abstract]:Water pollution is a prominent environmental problem at present, and the prevention and control of sediment pollutants is the key to the control of water pollution. A large number of toxic and harmful substances accumulated in the sediment will be released to the overlying water again after a certain exchange action. As a result of the secondary pollution of the overlying water, the selection of economic, ecological and effective sediment remediation technology is the key and difficult point of water pollution control. The effect of chemical passivating agent on the restoration of sediment was studied in a simulated river reactor. At the same time, the black and smelly water in the pond of Dendrobium was comprehensively treated with aquatic plants, and the biological manipulation was studied. The purification effect of ecological comprehensive management technology such as revetment ecological transformation in the treatment of campus lakes. Through a large number of indoor and engineering experiments, The following conclusions are drawn: (1) addition of compound passivator has different degree of purifying effect on TNN NH _ 4-N and TP in overlying water, and the purification effect increases with the increase of the dosage of the compound passivator. The highest removal rates were 23.52% 21.79% and 81.5%, respectively. The COD removal rate of overlying water increased first and then decreased with the increase of dosage. The highest (dosage of 600 mg / L) reached 57.6%. Adding compound passivator increased the TP content of sediment and promoted the conversion of unstable phosphorus to stable phosphorus, and the addition of compound passivator made unstable zinc to stable zinc. And the residue state which was mainly transformed into residual form, #-zinc, increased by 41.3% and 49.8% respectively, but the difference between different treatments was not significant. Therefore, the comprehensive analysis was made from the aspects of economic cost and effect of restoration. The effect of new compound passivator, aluminum sulfate, calcium nitrate and zero-valent iron on the release characteristics of pollutants from the sediment of Nanfeihe River was studied by using 600 mg / L in situ remediation of sediment pollution. After adding Fe0 and Ca(NO3)2 to the sediment, the pH value of the overlying water increased from 6.7 to about 8.5.The pH value of the overlying water decreased slowly after adding the compound passivator, and the effect of adding Fe0 on the COD of the overlying water was less than that of calcium nitrate. However, in the early stage of the experiment, the water quality of overlying water will be greatly affected. The inhibition effect of adding compound passivating agent on organic matter in sediment is the most significant. The COD of overlying water is stable at about 5 mg / L, The inhibitive effect of aluminum salt is second only to that of compound passivating agent. The addition of four passivating agents into the sediment has an inhibitory effect on TP in the sediment, among which a new compound passivating agent, calcium nitrate, aluminum sulfate, zero valence iron, and the addition of the compound passivating agent have certain inhibitory effects on TNNH _ 4-N in the sediment. The addition of calcium nitrate increased the content of TNN NH _ 4-N in the overlying water, and the inhibition effect of the new compound passivating agent on sediment pollutants was better than that of other single passivating agent. (3) by analyzing the water quality of Dendrobibibing pond in the last three months, we can know that aquatic plants are used and biological manipulation is used. At the end of the experiment, the average removal rate of NH _ 4 -NN _ (4) COD of TNT _ (TPN) was 76.7% and 83.6% respectively) the ecological treatment of Dendrobibibing pond enhanced the self-purification ability of the water body, and the ecological comprehensive treatment technology such as revetment ecological transformation had a good effect on the restoration of Dendrobibibing Pond, and the water quality was greatly improved. The transparency of water reaches 0.5 meters, and the best time is about 1 meter, the color of the water returns to normal, the water surface is clean and free of debris, there is no algae and other floating objects, the black smell is eliminated, and the landscape effect is enhanced.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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