铁锰微污染水的生物净化滤池工艺优化及其菌群结构研究

发布时间：2019-03-13 18:01

【摘要】：由于我国经济的快速发展所导致的水质污染以及地质结构等因素,微污染水中的铁锰含量日益超过我国《地表水环境质量标准》(GB3838-2002)中对生活饮用水所制定的标准要求。这不仅给人们的生产生活带来不便,也严重危害人们的身体健康。本研究参照我国微污染水中铁锰含量背景值作为试验用水的铁锰离子浓度,借助自主设计的将碳化稻壳作为滤池滤料,并接种铁锰氧化功能菌(Bacillus megaterium)的生物滤池,经过生物滤池的启动及运行参数逐个优化等过程最终实现对铁锰的高效去除。同时采用了傅里叶红外光谱、扫描电镜等分析方法对滤料的表面特性进行分析,并结合PCR-DGGE和高通量测序等现代分子生物技术对滤池内菌群的分布特征进行考察。本研究获得的成果主要有以下几个方面:在滤池的启动试验研究中,接触氧化法与生物氧化法对铁锰去除率分别达到89.70%、99.53%,说明生物氧化法对铁锰的处理效果明显提高。滤池运行第61 d时,扫描电子显微镜观察发现滤层深度20 cm与40 cm处的滤料样品中有接种微生物存在。借助PCR-DGGE技术进一步分析确定滤料表面所富集的微生物含有Bacillus sp.菌属微生物,初步说明接种微生物能够在滤料表面富集定殖。结合生物滤池对铁锰离子的去除效果,确定生物除铁除锰滤池在此阶段启动成功。本研究对生物滤池的进水流速、进水铁、锰离子浓度、反冲洗强度、反冲洗周期、反冲洗时间等参数分别进行了优化试验。试验结果表明:滤池在进水流速为3 m/h、进水铁含量8-10 mg/L、进水锰含量1-2 mg/L、反冲洗强度4 L/m2·s、反冲洗周期4 d、反冲洗时间5 min条件下,滤池稳定高效运行,出水平均铁锰离子浓度及浊度分别为0.002 mg/L、0.011 mg/L、0.137 NTU,去除率分别高达99%、95%、98.5%,出水上述指标均达到我国生活饮用水卫生标准。本研究在完成生物滤池运行参数优化基础上,进一步对滤层不同深度(20 cm、40 cm、100 cm)滤料的表面样貌与细菌群落结构进行研究。试验结果表明:随着滤池运行状态趋于稳定,各滤层深度的滤料表面均形成规则、致密如棉花团样的“锰球”。红外光谱分析及扫描电镜能谱分析结果表明:上述滤料表面物质组成含有铁锰氧化物及微生物成分,随着滤层深度的增加,锰球的粒径逐渐减小,且分布比较无规则。采用高通量测序技术对滤池内细菌群落在不同滤层深度的分布特征进行分析。从门分类水平分析结果表明,滤池内存在厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)、疣微菌门(Verrucomicrobia)。从菌落分布丰度热图分析结果表明:Bacillus sp.菌属微生物在所考察的三个滤层深度的丰度分别为91.19%、82.83%、87.28%,说明所接种的Bacillus sp.菌属微生物在生物滤池内为优势微生物。滤池内所构筑的微生物生态系统趋于稳定,从而实现对铁、锰的高效去除。
[Abstract]:Due to the pollution of water quality and geological structure caused by the rapid development of economy in China, the content of iron and manganese in the micro-polluted water is more and more higher than that in the Standard of Environmental quality of Surface Water (GB3838-2002) for drinking water in China. This not only brings inconvenience to people's production and life, but also seriously harms people's health. Referring to the background value of iron and manganese content in micro-polluted water of our country as the concentration of iron and manganese ion in the test water, the carbonized rice husk was used as filter material and inoculated with the bio-filter of Fe-mn oxidation functional bacterium (Bacillus megaterium), which was designed by ourselves. After the start-up and operation parameters optimization of the biofilter, the efficient removal of iron and manganese was finally realized. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze the surface characteristics of the filter media, and the distribution characteristics of microflora in the filter were investigated by means of modern molecular biotechnology such as PCR-DGGE and high-throughput sequencing. The main achievements of this study are as follows: in the start-up experiment of the filter, the removal rate of iron and manganese by contact oxidation and biological oxidation reached 89.70%, 99.53%, respectively. The results show that the treatment effect of bio-oxidation on iron and manganese is obviously improved. During the 61st day operation of the filter, scanning electron microscopy (SEM) showed that the inoculated microorganisms existed in the filter media samples at the depth of 20 cm and 40 cm. Further Analysis with PCR-DGGE Technology to determine that microorganisms enriched on the Surface of filter Media contain Bacillus sp. The results show that the inoculated microorganism can accumulate and colonize on the surface of the filter medium. Combined with the removal effect of iron and manganese ions by biological filter, it was confirmed that the biological iron removal and manganese removal filter was successfully started at this stage. In this study, the influent velocity, influent iron, manganese ion concentration, backwashing intensity, backwashing cycle and backwashing time of biological filter were optimized. The experimental results showed that the backwashing strength of the filter was 4 L / m ~ 2 路s, the backwashing time was 5 min and the influent iron content was 8? 10 mg/L, the backwashing strength was 4 L / m ~ 2 路s, the influent iron content was 8? 10 mg/L, and the backwashing time was 5 min. The filter operated stably and efficiently, and the average removal rates of iron and manganese ions and turbidity were as high as 99%, 95% and 98.5%, respectively, when the average concentration of iron and manganese ions and turbidity were 0.002 mg/L,0.011 mg/L,0.137 NTU,. The above indexes of effluent all meet the sanitary standard of drinking water in our country. On the basis of optimizing the operating parameters of biological filter, the surface appearance and bacterial community structure of filter media with different depth (20 cm,40 cm,100 cm) were further studied in this study. The experimental results show that with the steady operation of the filter, the surface of the filter media of each filter layer depth is regular and compact as the "manganese ball" of cotton pellets. The results of infrared spectrum analysis and SEM energy spectrum analysis show that the composition of the filter media surface material contains iron-manganese oxide and microbial composition. With the increase of filter depth, the particle size of manganese ball decreases gradually, and the distribution is irregular. The distribution characteristics of bacterial community in different depth of filter bed were analyzed by high flux sequencing technique. From the level of phylum classification, the results showed that there were thick wall fungi (Firmicutes), (Proteobacteria), (Acidobacteria), (Bacteroidetes), actinomycetes, (Actinobacteria), (Actinobacteria), and (Verrucomicrobia). The results of thermographic analysis of colony distribution abundance show that: Bacillus sp. The abundance of bacteria at the depth of the three filter layers was 91.19%, 82.83% and 87.28%, respectively, indicating that Bacillus sp. was inoculated. Bacteria are the dominant microorganisms in the biofilter. The microbial ecosystem constructed in the filter tends to be stable so as to achieve the efficient removal of iron and manganese.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.2;X172

【参考文献】