辽河口苇田水体污染的湿地植物—多孔介质联合净化技术研究

发布时间：2017-12-31 03:38

本文关键词：辽河口苇田水体污染的湿地植物—多孔介质联合净化技术研究　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：辽河河口地区具有丰富的湿地资源,为达到苇田湿地的多级利用,苇田养殖业近年来得到了快速发展。苇田养殖是在芦苇湿地中构建田间工程,同时进行鱼、蟹养殖和芦苇种植的一水多收的生态养殖经济模式。然而随着苇田养殖业整体上向着集约化、高密度、高产出的模式发展,常年过度放养使得苇田水体中氨氮、CODG含量超标,污染物质不断积累对苇田湿地生态系统及滨海环境带来一定影响。与传统养殖明显不同,苇田养殖以芦苇高产模式进行,总体上表现为需水量很大,但又随着季节变化对水量的要求有所不同,且间歇性排水,在鱼、蟹捕捞和芦苇收割后,苇田多呈现无水状态,传统处理技术对苇田养殖水体并不具有适用性。本文根据苇田养殖的自身特点以及污染特征,研制了煤渣—沸石复合多孔介质材料,研究了其吸附能力和热再生性能,以及生物挂膜特性,并将其作为硬质填料与芦苇湿地结合起来构建联合净化系统,以氨氮、CODG、TP为评价指标研究其对模拟苇田养殖水体的净化效果,为该技术在苇田水体中的应用进行先期性探索并提供一些可供参考的技术参数。研究结果如下：(1)确定了煤渣—沸石复合多孔介质材料的制备方法,以煤渣、沸石2：1的质量配比为原料,可以有效结合煤渣和沸石的优势,其对氨氮和CODG的最大去除效率可分别达到57.2%和51.2%。扫描电镜图片清晰地呈现出了该材料表面大量的孔道结构。(2)通过运用动力学方程、颗粒内扩散方程对实验数据进行拟合分析,煤潭—沸石复合多孔介质材料对水样中氨氮和CODG的吸附过程对准二级动力学方程具有更好的符合度,该吸附过程为化学吸附,且吸附过程均较为复杂,受到内扩散和边界扩散的影响；运用Freundlich等温方程和Langmuir等温方程对等温吸附过程进行分析,该过程符合Langmuir等温方程,氨氮和CODG在该材料表面主要发生的是单分子层吸附。由Langmuir等温方程拟合出的氨氮和CODG的最大吸附量分别为0.1798mg/g、0.9804mg/g;以标准再吸附实验法评价煤渣—沸石多孔介质材料的再生性能,确定了最佳的再生条件为170℃、4h,对氨氮和CODG的再生率分别为73.55%、50.42%,且在污染物浓度较低的情况下,依然具有一定的吸附能力。(3)以校园景观河水为水源、以河水中丰富的微生物菌群为微生物种源,在自然条件下进行生物膜培养。由于到河水中基质浓度较低,且在自然条件下进行,生物膜培养的时间较长,为30天,且材料表面的生物膜较薄。微生物镜检发现,生物膜中的优势后生动物有轮虫、钟虫、楣纤虫、肉足虫、指鳃尾盘蚓等,生物膜的扫描电镜图片显示菌类主要以杆菌和球菌为主。(4)将经生物膜培养的煤渣—沸石复合多孔介质材料与芦苇湿地结合起来构建的联合净化系统,10L/h时的氨氮、CODG、TP的平均去除效率最大,分别为50.4%、44.3%、31.9%。当污染物进水浓度较大时,该联合净化系统对氨氮、CODG、TP的去除率较大,但是受进水浓度波动的影响出水中污染物的浓度也呈现出较大的变化。在进水流量为10、20、40、80L/h条件下,芦苇湿地及多孔介质填料对进水中的污染物质均有一定的去除作用,但随着流量的增大各污染物质的平均去除效率呈下降的趋势。此外,通过8、9月份的两次实验,验证了该联合净化系统对微污染水体中的氨氮、CODG、TP去除具有一定的稳定性,但由于微污染水体中的有机物质含量较低,多孔介质填料的生物膜较薄,对有机物的去除率并不是太高。
[Abstract]:Liaohe estuary area has rich wetland resources, multi-level utilization reaches reed wetland, reed aquaculture industry has been developing rapidly in recent years. Reed breeding is to construct field works in reed wetland, and fish, a water crab breeding and reed planting overcharged ecological farming economy. But with the reed the whole industry towards intensive mode of development, high density, high-yield, perennial over stocking makes ammonia reed in water, CODG content exceed the standard, pollutant accumulation of a certain impact on the ecological system of wetland reed field and coastal environment. Different from the traditional culture, the culture of reed reed in the high yield model, overall on the performance of water demand, but also with the seasonal change of water is different, and intermittent drainage, in fish, crab fishing and reed harvesting, reed showed no water condition, the traditional office Science and technology is not applicable to reed aquaculture water. According to their own characteristics and pollution characteristics of reed breeding, development of cinder - zeolite composite porous material, studied its adsorption capacity and regeneration performance, and biofilm formation characteristics, and make it as hard filler and reed wetland combined construction joint purification system with ammonia nitrogen, CODG, TP in order to study the purification effect of simulated reed aquaculture water evaluation index, this technique is used in the reed field water in the early exploration and provide some reference for the technical parameters. The results are as follows: (1) to determine the composite porous material - zeolite cinder the preparation methods of coal cinder, the mass ratio of 2:1 zeolite as raw material, can effectively combine the advantages of cinder and zeolite, the removal efficiency of ammonia and CODG can reach 57.2% and 51.2 respectively. The scanning electron Mirror images clearly show the pore structure of the material surface a lot. (2) by using the kinetic equations, the equation to fit the experimental data of particle diffusion in coal, Tan - adsorption process of zeolite composite porous material of ammonia and CODG in water samples at the two level dynamic equation with the better. The adsorption process of chemical adsorption, and the adsorption process is complex, affected by internal diffusion and boundary diffusion; using Freundlich isotherm equation and Langmuir isotherm equation to analyze the adsorption isothermal process, the process accords with Langmuir isothermal equation, ammonia nitrogen and CODG in the surface of the material is mainly composed of single molecular layer adsorption. The maximum adsorption of Langmuir isothermal equation fitting out ammonia and CODG were 0.1798mg/g, 0.9804mg/g; standard re adsorption regeneration experiment method to evaluate coal - zeolite porous material The performance, to determine the optimum conditions of regeneration is 170 DEG C, 4h, regeneration of ammonia and CODG rates were 73.55%, 50.42%, and the pollutant concentration is low, still has certain adsorption capacity. (3) to the campus landscape river as a water source, the microbial bacteria rich microbial group the source of water, biofilm cultivation under natural conditions. Due to the low substrate concentration, and under natural conditions, the biofilm culturing time longer, for 30 days, and the biofilm surface is thin. The biological microscopy found in biological membranes have advantages of metazoan rotifers, bell worm, Mei pellionella, amoebae, gill refers to the late earthworm, SEM images of the biofilm display fungus mainly bacillus and coccus. (4) the biofilm cultivation of cinder - zeolite composite porous materials and combined joint reed wetland purification system to build, 1 0L/h CODG, ammonia nitrogen, average TP removal efficiency were 50.4%, 44.3%, 31.9%., when the influent concentration of pollutants is large, the purification system of ammonia, CODG, TP removal rate is larger, but affected by fluctuations in the concentration of the influent concentration of pollutants is also showing great changes in the water. Flow rate is 10,20,40,80L/h under the condition of reed wetland and porous medium filling a certain effect on the removal of pollutants in the influent were, but along with the increase of flow rate of each pollutant removal efficiency decreased. In addition, through two experiments 8,9 month, the validation of the combined purification system CODG of ammonia nitrogen in water micro pollution, TP removal has certain stability, but due to the micro organic pollutants in water is low, porous biofilm packing is thinner, the removal rate of organic matter is not too high.

【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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