【作者】 张永静；

【导师】 马剑敏；

【作者基本信息】 河南师范大学 ， 生态学， 2010， 硕士

【摘要】 本论文中以复合垂直流人工湿地(IVCW)和水平潜流人工湿地(HSCW)为研究对象,主要开展了以下研究:通过监测两种湿地的进、出水指标,对其不同季节运行时的最佳水力停留时间(HRT)及污水净化效果进行了研究和对比;通过监测两种湿地进水、湿地侧面不同高度出水的水质指标,初步研究了不同月份时两种人工湿地中不同填料层对污水的净化效果及曝气对两种湿地的污水净化效果的影响。实验中所监测的水质指标有:温度(T)、溶解氧(DO)、pH、总氮(TN)、总磷(TP)、CODCr、铵态氮(NH4+-N)、硝态氮(NO3--N)。主要结论如下:(1)两种人工湿地的HRT参数分别为:在IVCW中,最佳HRT在春、秋季为8～10小时;夏季为6小时;冬季为12小时。在HSCW中,最佳HRT在春、秋季为10～12小时;夏季为6～8小时;冬季为24～36小时。可见不同季节下IVCW需要的最佳HRT参数小于HSCW。(2)两种人工湿地对CODCr为100～300mg/L、TN为0.50～16.00 mg/L、TP为0.10～4.00 mg/L的生活污水具有相似的去除效果,不同污染物的去除率存在明显的季节性差异。不同季节下两种湿地对CODCr的去除率无显著差异;在不同季节下IVCW对TN的去除效果均高于HSCW;湿地进水中铵态氮占总氮含量的比重影响湿地脱氮效果,比值越大,整个湿地的总氮去除率越低。两种湿地对TP的去除率受到季节性磷负荷、HRT参数及温度变化的影响,在去除率上表现出的规律性较差。两种湿地对NH4+-N的去除效果除冬季较好外,其余季节都较差。(3)两种湿地中水温的季节性变化与TN去除率的变化存在一定的正相关;在IVCW中与TP去除率的变化存在正相关性,而在HSCW中与TP去除率的变化存在负相关性。在IVCW中N、P的去除率变化受水温变化的影响比HSCW中明显。(4)在两种人工湿地中,对污水中CODCr的去除不随填料层高度的变化而发生显著变化。两种人工湿地的填料表层对TN的平均去除率较高且稳定;不同月份下两种湿地填料的中层和底层对TN的去除率产生较大波动,可见中层和底层填料的TN去除率变化决定了整个湿地的TN去除效果。IVCW中,对NH4+-N的去除主要发生在填料的底层,其表层、中层填料的NH4+-N去除效果略差于底层;填料表层对NH4+-N的去除率波动较大。HSCW中,对NH4+-N去除主要发生在填料表层和底层,中层的去除效果最差。(5)IVCW的表层、中层填料除磷效果稳定;不同月份下表层填料的去除率存在显著差异。HSCW中,除磷主要发生在填料的底层;受温度、HRT、磷污染负荷条件的共同影响,其表层和中层填料容易出现明显的基质磷释放现象。(6)水环境温度对IVCW中TN、NH4+-N、TP的去除具有显著影响;对HSCW中各种污染物的去除影响不显著。湿地填料间隙水中DO含量与IVCW中的TN、TP、CODCr的去除率间均显著正相关,与HSCW中的TP、NH4+-N的去除率间也显著正相关。(7)IVCW以气水比为2进行曝气时,对污水的净化效果最好,上行池出水的CODCr、TN、NH4+-N、NO3--N平均去除率比不曝气时分别提高了16.47%、5.15%、13.84%、96.91%;气水比为6时对CODCr去除效果比2稍好,在处理更高负荷污水时可采用此气水比进行曝气。曝气对TP的去除率影响不明显。(8)曝气对HSCW的CODCr去除率较不曝气时有显著提高,气水比为6时效果最好,增加30%;TN、NH4+-N平均去除率在气水比为2时较对照无明显改变,NO3--N去除率有大幅提高;气水比继续增大时,脱氮效果有不同程度的降低;对TP的去除率无显著影响。更多还原

【Abstract】 In this paper, there are two kinds of constructed wetlands to be of the research objects, which are integrated vertical flow constructed wetland and horizontal subsurface flow constructed wetland, to be carried out the following studies, respectively.The main research contents include: studied the better parameter of seasonal hydraulic retention time and the sewage purification effect of the two kinds of constructed wetlands when they were working in the four seasons of a year, by monitoring the water samples from the import and export of the two kinds of constructed wetlands respectively; researched the purifying effect of pollutants in the different substrate layers in the two kinds of artificial wetlands in the different months and the effects of aeration on sewage purification in two kinds of constructed wetlands, by monitoring the effluent sampled from the side different heights and the inflow of the two kinds of artificial wetlands respectively. In the paper, the water quality indicators monitored: temperature (T), dissolved oxygen (DO), potential of hydrogen (pH), total nitrogen (TN), total phosphorus (TP), chemical oxygen demand(COD), ammonium nitrogen (NH4+-N), nitrate (NO3--N). The main conclusions of this thesis are as follows:(1) The optimum parameter of seasonal hydraulic retention time of the two kinds of artificial wetlands are as follows:The optimum parameter of seasonal hydraulic retention time of integrated vertical flow constructed wetland are in between eight and ten hours in spring and autumn, six hours in summer, twelve hours in winter.The optimum parameter of seasonal hydraulic retention time of horizontal subsurface flow constructed wetland are in between ten and twelve hours in spring and autumn, in between six and eight hours in summer, in between twenty-four and thirty-six hours in winter.It can clearly be seen that the optimum parameter of seasonal hydraulic retention time of integrated vertical flow constructed wetland are less than the horizontal subsurface flow constructed wetland.(2) The two kinds of constructed wetlands has a similar purification effect to the domestic sewage which contain thetotal nitrogen concentration between 0.50 and 16.0 milligrams per liter, the total phosphorus concentration between 0.10 and 4.00 milligrams per liter and the organic compound concentration between 100 and 300 milligrams per liter. There exists an obvious seasonal variations about the different pollutants removal in the two kinds of constructed wetlands.The chemical oxygen demand removal in different seasons is no significant differences between the two kinds of constructed wetlands; The total nitrogen average removal in each of the different seasons is higher in integrated vertical flow constructed wetland than in horizontal subsurface flow constructed wetland. The ratio of ammonium nitrogen content in the proportion of total nitrogen affects the nitrogen removal efficiency in the two kinds of constructed wetlands. The greater the ratio is, the lower the nitrogen removal efficiency is.The total phosphorus removal in the two kinds of constructed wetlands shows a poor regularity because of the seasonal effects of phosphorus load, hydraulic retention time parameter and the temperature change. About the removal efficiency of ammonium nitrogen, only in winter is better, the other seasons are lower. (3) The seasonal variations of water temperature in the two kinds of constructed wetlands is significantly correlated with the removal change of total nitrogen, and is not significant with the removal change of total phosphorus. The N, P removal affected by water temperature in integrated vertical flow constructed wetland was significantly more than in horizontal subsurface flow constructed wetland. (4) There is no significant difference about the COD removal in the different substrate layers of the two kinds of constructed wetlands.The TN average removal in the fill material surface of two kinds of constructed wetlands is high and stable; in the different months the TN removal efficiency have a greater volatility in the middle and bottom substrate layers of the two kinds of constructed wetlands, which can be seen filling the TN removal rate changes for the whole wetland TN removal.In integrated vertical flow constructed wetland, the ammonium nitrogen removal occurred mainly in the bottom of filler, in its surface and middle filler layers the ammonium nitrogen removal efficiency is slightly worse than the bottom filler; in the surface substrate layer of the two kinds of constructed wetlands there exist the ammonium nitrogen removal wider fluctuation margin phenomenon.In horizontal subsurface flow constructed wetland, the ammonium nitrogen removal occurred mainly in the surface and bottom filler, and in the middle substrate layer it is worst. (5) In integrated vertical flow constructed wetland, the surface and middle filler have stable phosphorus removal; removal; in different months the phosphorus removal of surface layer there are significant differences. In horizontal subsurface flow constructed wetland, the phosphorus removal occurre mainly in the bottom of filler; because of the combined effect of the temperature, HRT, phosphorus pollution load there exists a serious phenomenon of phosphorus releasing from the matrix in horizontal subsurface flow constructed wetland.(6) In integrated vertical flow constructed wetland there is significant impact on the removal of TN, NH4+-N and TP with the change of water environment temperature within constructed wetland; while the removal impact of various pollutants in horizontal subsurface flow constructed wetland is not significant. DO concentration in the interstitial water, has a significant positive correlation with the removal of TN, TP and COD of integrated vertical flow constructed wetland; with the NH4+-N removal of horizontal subsurface flow constructed wetland.(7) The results show that using the gas-water ratio of 2 to do aeration experiment in integrated vertical flow constructed wetland can get the best effects of sewage purification. The average removal rate of chemical oxygen demand、total nitrogen、ammonia nitrogen and nitrate nitrogen of the effluence of upstream pond respectively increase 16.47%, 5.15%, 13.84% and 96.91% than non-aerated experiment. The results indicate that the effect of removal COD at the gas-water ratio of 6 is better than 2, In dealing with domestic higher load can use this gas-water ratio to aerate.(8) In horizontal subsurface flow constructed wetland, aeration can make the treating effect of COD improve more obviously than non-aerated experiment, especially when gas-water ratio is 6 the increase can be up to 30%; the average removal rate of TN and NH4+-N is not obvious change when the gas-water ratio is 2, and there is a substantial increase in the removal rate of NO3--N; when gas-water ratio continues to increase, nitrogen removal have varying degrees of reduction. In the two kinds of constructed wetlands, the removal rate of total phosphorus is no significant change in the two conditions of aeration and non-aeration.更多还原