超滤深度处理对水质及管道腐蚀影响

发布时间：2019-03-06 12:16

【摘要】：饮用水的水质与居民用水安全有着直接的密切联系,以往人们只关注出厂水的各项水质指标,而对管网二次污染带来的水质恶化重视不足。目前我国90%以上的给水管道采用的铸铁管内壁粗糙,非常利于微生物的附着和繁殖,影响水质和管网供水的稳定性,其中藏匿的致病菌更是直接威胁饮用水安全。以超滤技术为核心的新一代净水工艺安全性强,水质可靠,得到广泛关注。其出水中几乎不含细菌和大多数微生物可利用的有机物。对于改善出水的安全性和稳定性效果良好。本实验建立中试级别实验平台,对超滤膜的日常维护方式进行摸索,确定以反冲洗60s+表面冲洗30s,清洗频率为60min一次为日常清洗方式,以表面冲洗,使用NaClO+草酸的组合为离线化学清洗的方式。研究发现超滤系统对于水中浊度、藻类、大肠杆菌有很好的去除效果,超滤出水在管道中更加稳定,而对于UV254、遗传毒性类物质的去除能力较弱。在管道腐蚀实验中发现未经超滤处理的管道出水在硫酸根下降、总铁上升、铝离子沉积、硝酸根下降、pH下降的幅度比经过超滤处理的水幅度更大,可知经过超滤处理后的水对管道腐蚀有很好的改善作用,利用分子克隆技术对两套系统的管道内壁所附着的生物膜进行细菌多样性分析,无超滤无内衬管道管壁生物膜中包括了Brevundimonas菌属(7.14%)、Hydrogenophaga菌属(59.52%)、Bosea菌属(2.38%)、Sphingopyxis菌属(14.29%)、Sediminibacterium菌属(11.90%)。无超滤有内衬管道管壁生物膜中包括了Aquabacterium菌属(15.91%)、Hydrogenophaga菌属(66.77%)、Flavobacterium菌属(4.26%)、Sphingomonas菌属(4.26%)、Sediminibacterium菌属(2.27%)。经过超滤处理的管道系统,其中不含铁细菌;而未经超滤处理的管道系统,有铁细菌生长,基因鉴定发现属于Sediminibacterium菌属。管道连接处所沉积污泥中超滤处理的管道系统,不含硫酸盐还原菌,而未经超滤处理的管道系统,发现有硫酸盐还原菌生长,基因鉴定发现为属于Desulfovibrio菌属。
[Abstract]:The quality of drinking water is closely related to the water safety of residents. In the past, people only paid attention to the water quality indexes of the factory water, but paid less attention to the deterioration of the water quality caused by the secondary pollution of the pipe network. At present, the inner wall of cast iron pipe used in more than 90% of water supply pipelines in China is rough, which is very conducive to the attachment and reproduction of microorganisms, and affects the stability of water quality and water supply of the pipe network. Among them, the hidden pathogenic bacteria directly threaten the safety of drinking water. The new generation water purification process with ultrafiltration technology as the core has strong safety and reliable water quality, which has been paid more and more attention. The effluent contains almost no bacteria and most of the organic matter that can be used by microorganisms. It has a good effect on improving the safety and stability of the effluent. In this experiment, a pilot-scale experimental platform was set up to explore the daily maintenance mode of ultrafiltration membrane. It was determined that the surface washing was carried out by backwashing for 60s, the cleaning frequency was 60min for one time, and the surface washing was carried out with the method of surface washing. The combination of NaClO oxalic acid is used for off-line chemical cleaning. It was found that the ultrafiltration system had good removal effect on turbidity algae and Escherichia coli in water. The ultrafiltration system was more stable in the pipeline but weak in the removal of UV254, genotoxic substances. In the corrosion test of pipeline, it was found that the effluent of the pipeline without ultrafiltration treatment decreased in sulfate radical, total iron increased, aluminum ion deposition, nitrate decreased, and the decrease of pH was greater than that of water treated by ultrafiltration. It can be seen that the water treated by ultrafiltration has a good effect on the corrosion of pipeline. The bacterial diversity of biofilm attached to the inner wall of two systems was analyzed by molecular cloning technique. Brevundimonas (7.14%), Hydrogenophaga) (59.52%), Bosea) (2.38%), Sphingopyxis) (14.29%), Sediminibacterium (11.90%) were included in the biofilm of pipe wall without ultrafiltration. The biofilm without ultrafiltration included Aquabacterium (15.91%), Hydrogenophaga) (66.77%), Flavobacterium) (4.26%), Sphingomonas (2.27%). In the ultrafiltration-treated pipeline system, no iron-containing bacteria were found, while in the non-ultrafiltration-treated pipeline system, iron bacteria grew, and genetic identification revealed that they belonged to the genus Sediminibacterium. There are no sulfate reducing bacteria in the pipeline system of ultrafiltration treatment in the deposited sludge, but there is no sulfate reducing bacteria in the pipeline system without ultrafiltration treatment. The growth of sulfate reducing bacteria is found in the pipeline system, and the gene identification is found to belong to the genus Desulfovibrio.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU991.2

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