【作者】 董敏慧；

【导师】 胡曰利； 吴晓芙；

【作者基本信息】 中南林业科技大学 ， 环境科学， 2007， 硕士

【摘要】 论文探索了天然蛭石作为人工湿地填料的可行性,并针对城镇生活污水的污染控制,进行了模拟试验与机理研究。将蛭石吸附处理技术应用于人工湿地处理工艺是蛭石应用的新领域,同时,填料的生物再生也是近年来人工湿地污水处理技术的研究热点。本研究内容主要包括：(1)天然蛭石挂膜试验：(2)挂膜后的生物蛭石参数调节试验；(3)生物蛭石脱氮机理探究试验。(1)蛭石的挂膜运行试验表明：蛭石具有易挂膜性,2至3周内就能成功实现挂膜,由天然蛭石变为生物蛭石,形成蛭石与微生物之间的协同作用,一方面蛭石对氨氮具有离子交换吸附作用,另一方面微生物对吸附后的氨氮有生物转化作用,使得蛭石对氨氮的去除能力被大大增强。(2)挂膜好的生物蛭石柱运行试验表明：在pH=7.89、DO=5.40 mg/L的情况下,系统的运行效果相比之下最好。进水中氨氮和总氮的去除率达到了最大,分别为56%和45%。一般的城镇生活污水都可以达到pH=7.89、DO=5.40 mg/L的条件,所以在不需要额外改变废水溶解氧和碱度的条件下,生物蛭石柱就能达到较好的氮处理效果,处理后的出水,氨氮浓度达到二级污水处理厂的废水排放标准。生物蛭石柱在冬季对于污染物的去除,总的来看效果不及夏季。其中,受影响最大的是对进水中COD的去除,去除率由夏季的69.80%下降到44.18%,其次是T-N从夏季的45.00%降到了冬季的30.00%,氨氮也由夏季的55.00%下降到了44.00%,受季节温度影响最小的是蛭石柱对T-P的去除。(3)生物蛭石脱氮机理探究试验表明：在生物蛭石柱中,氮素的转化不符合单一的传统硝化—反硝化理论,也不符合单一的短程硝化理论。通过对试验现象的观察以及对试验数据进行的氮素平衡分析得出,厌氧氨氧化脱氮过程在生物蛭石柱内发生,蛭石表面的高氨氮环境为这一反应提供了可能。然而,传统意义上的硝化—反硝化过程也在生物蛭石柱内进行。挂膜后的生物蛭石柱内,氮素去除是依靠硝化—反硝化和厌氧氨氧化这两种作用共同来完成的。经测定,生物蛭石柱内,上层蛭石的硝化强度最大为4.38×1.0-3 mg/g.h,中部最小为0.63×10-3 mg/g.h,底层硝化速率为1.90×10-3 mg/g.h。反硝化强度则恰好相反,中部最大。所不同的是,厌氧氨氧化反应在生物蛭石柱上部、中部、底部的反应强度相当,平均大约为1.00×10-3 mg/g.h,这说明了厌氧氨氧化菌生长在蛭石生物膜的内层,且在蛭石柱内的分布没有受溶解氧和有机物浓度变化的影响。对生物蛭石柱中基质上生物膜有机质进行测定后,发现基质上生物膜的发育达到了较高的水平,上、中、下层基质生物膜的VSS均值可达到26.41 mg/g,说明蛭石上的生物膜生长良好,蛭石作为生物膜的载体发挥了很好的附着作用。对于特殊功能菌进行计数结果表明,本试验测定的硝化细菌个数与反硝化细菌个数都较少,其数量处于其他人研究结果的下限。以上的研究结果对蛭石填料人工湿地技术提供了理论支持。生物量、生物反应强度、微生物数量,这些测定指标因为其特有的特征和性能,可以作为衡量人工湿地发育程度的关键指标,本研究通过测定这些指标对于以后更加深入地阐明人工湿地的净化机理、建立人工湿地评价体系做了有益的探索性的工作。同时,本研究关于厌氧氨氧化脱氮反应在生物蛭石系统中的发现和验证,丰富了现阶段脱氮领域关于厌氧氨氧化反应的研究。更多还原

【Abstract】 The thesis investigates the possibility of the natural vermiculite to be the constructed wetlands filling; moreover, simulation experiment and the mechanism research for control the pollution because of the living waste water were done. It is the new area for the vermiculite application that the treatment technique of the vermiculite adsorption was applied to constructed wetlands. Recently, bio-regeneration of the filling is the hot point in the technique research on the constructed wetlands. This research contents mainly include:(1) the bio-film growing experiment of the natural vermiculite; (2) the parameter adjusted experiment of the intake with bio-vermiculite pole; (3) the mechanism explored experiment of the N removal of the bio-vermiculite pole.(1) the bio-film growing experiment on the natural vermiculite is shown as follows: It is easy for the natural vermiculite to be the carrier of the bio-film, becoming the bio-vermiculite, which comes into being the assimilation and transformation between the vermiculite and bacteria in 2-3 weeks. On the one hand there is the ion exchange adsorption to the ammonia nitrogen owing to the vermiculite; on the other hand, the adsorbed NH4+ can be transformed by the microbe, thus the ability of removal of the NH4+ for vermiculite can be greatly strengthened。(2) the parameter adjusted experiment of the intake bio-vermiculite is shown:the best effect can be gained under the given condition of pH=7.89, DO=5.40 mg/L, which makes the removal rate of the ammonia nitrogen and the total nitrogen best, 56.00%,45.00%, respectively. The normal living waste water can conveniently attain the condition of pH=7.89, DO=5.40 mg/L. So bio-vermiculite pole has the better treatment effect of removal of nitrogen under unnecessary extra adjustment of the intake parameter. The outtake can attain theⅡrank standard of the national waste water integrated outflow standard. The treatment effect in the summer is better than in the winter. All of them, it causes the removal of COD most remarkably affected from summer of 69.80% to 44.18% in winter, secondly, that of T-N from 45.00% of the summer to the winter of 30.00%, and then that of ammonia nitrogen from 44.00% by 55.00% of the summer. Meanwhile, the effect rate of the T-P is also hardly affected.(3) the mechanism explored experiment of the N removal for the bio-vermiculite is also shown:in the bio-vermiculite pole, the transformation of nitrogen doesn’t agree with the traditional theory of the nitrification and the denitrification as well as the single and short process nitrification. According to the analyzing of the nitrogen balance and observing the experimental phenomena, the anaerobic ammonia oxidation, has happened in the pole. The condition of the high ammonia nitrogen at the vermiculite surface makes the reaction possible. However, the reaction of the traditional nitrification and denitrifi cation also happens in the pole. According to the results of determination, the most intensity of nitrification of the bio-vermiculite is 4.38×10-3 mg/g.h in the upper layer; that of the least in the middle is 0.63×10-3 mg/g.h, and 1.90×10-3 mg/g.h at the bottom. While the intensity of the denitrification in the pole is opposite against that of the nitrification, and the most intensity of denitrification is in the middle. Moreover the intensity of anaerobic ammonia oxidation is almost equal, average 1.00×10-3mg/g.h. This explains that the anaerobic ammonia oxidation bacteria grows in the bio-film endothecium, and the inner layer can not be affected by the organic substance and DO. According to the test results of VSS of the bio-film in the substance of the pole, the bio-film on the filling grows well, the average VSS 26.41 mg/g. Thus, as the carrier of the bio-vermiculite, the natural vermiculite plays a good adhering function. The results of counting the special function bacterium show that the amount of the denitrification and nitrification bacterium are little, at the floor level of the other investigation.The research results offer the theoretical support for the constructed wetlands used vermiculite as filling. At the same time, the indexes of biomass, the intensity reaction, the microorganism quantity, which can be the key index to measure the developmental degree of the constructed wetlands because of its special characteristic and function, are determined in this study, thus it is helpful to clarify the decontamination mechanism of the constructed wetlands and establish the evaluated the system. The discovery and validation concerning on verifications anaerobic ammonia oxidation reaction in the bio-vermiculite system make the field of current removal nitrogen on anaerobic ammonia oxidation reaction rich.更多还原