【作者】 翁娜娜；

【导师】 刘志强；

【作者基本信息】 青岛理工大学 ， 环境工程， 2008， 硕士

【摘要】 生活污水可利用率大,排入水体后会造成很大危害,为减轻污水厂负担和沿途污染,生活污水的分散处理尤为重要。用膜代替二沉池出水具有很多优点,但价格昂贵且污染严重。用价格低廉、便于清洗的材料制作过滤组件以提高出水水质,是污水处理技术的发展趋势之。试验利用两种不同孔径的尼龙网,包裹在已加工成型的塑料管骨架外,形成类似平板膜的过滤空腔,以水头压差为动力进行过滤。把尼龙空腔与中空纤维膜同时放置于A/O反应器中运行,在完全相同的条件下,对比其对生活污水的处理效果,为开发廉价的过滤材料做些基础研究。试验结果表明,在A/O反应器中,中空纤维膜和尼龙网对浊度、SS、COD_cr、氨氮均达到了满意的去除效果,膜出水平均浊度为0.15NTU,对SS的截留可达100%,COD_cr平均去除率为93.7%,氨氮平均去除率为92.4%;尼龙网出水平均浊度均小于3NTU,SS在绝大多数时间未检出,COD_cr平均去除率均大于91.0%,氨氮平均去除率均大于92.0%。受搅拌速度偏低、进水总氮浓度较高及系统不排泥的影响,出水对总氮、总磷的去除并不理想,膜出水总氮平均去除率为49.0%,总磷平均去除率为41.6%;尼龙网出水总氮平均去除率均大于48.0%,总磷平均去除率均大于42.0%。可以看出,尼龙网孔径虽大,但其表面形成的自生动态膜层可以强化截留性能,弥补孔径的不足,其出水水质几乎可以和膜出水相当。试验结果表明,出水COD_cr去除率随HRT增长而增加,但当HRT大于6h后,COD_cr去除率渐渐趋向平稳;随着曝气量增加,生物处理效果变好,但曝气量过大,尼龙网表面的自生动态膜层很难形成或者遭到冲刷破坏,导致其自身截留效果变差;进水浓度冲击后,出水COD_cr浓度明显增高,但仍然小于50mg/L,出水抗浓度冲击负荷较好。根据膜和尼龙网各自的污染程度和状况,确定膜的清洗方式为自来水清洗—碱洗—酸洗,尼龙网的清洗方式为定时大强度空曝气,其中空曝强度为2m³/h,空曝时间为3分钟/次,空曝频率为1次/天。通过对微生物相进行监测,了解系统中活性污泥状况。污泥尚未培育良好时,出现了变形虫、表壳虫、鞭毛虫等微生物,当菌胶团培育成熟时,出现了钟虫、吸管虫等,系统稳定运行后,出现了轮虫,标志水质处理优良。更多还原

【Abstract】 Domestic wastewater was very available,but often brought huge pollution.As the separate treatment of domestic wastewater decreased the load of sewage plant and the pollution of environment,it became very important.Making use of the filtration of hollow-fiber membrane instead of the gravity deposition of secondary settling tank had lots of advantages,but the membrane was dear and the pollution of membrane was serious.To improve effluent quality by filtration cube which was made of inexpensive material became one of the popular wastewater treatment techniques in future.The experiment made use of two different aperture cubes which were made of big aperture,inexpensive nylon-netting and general plastic-pipe.The cubes looked like flat membrane and effused by hydraulic pressure.To contrast removal effect on domestic wastewater in the identic condition,two nylon-netting cubes and hollow-fiber membrane were placed in the A/O reactor and ran at the same time.The experiment made for exploitation of inexpensive filtration material.The results of experiment indicated that,the effluent of hollow-fiber membrane and nylon-netting took on good removal effect on turbidity、SS、COD_cr and NH₃-N.The average turbidity of membrane effluent was0.15NTU,the removal ratio of SS was 100%,the average removal ratio of COD_cr was 93.7%,and the average removal ratio of NH₃-N was 92.4%.The average turbidity of two nylon-netting effluent both were under3NTU, SS both were zero for the most of time,the average removal ratio of COD_cr both exceeded 91.0%,and the average removal ratio of NH₃-N both exceeded 92.0%.At the same time,the effluent of hollow-fiber membrane and two nylon-netting took on low removal effect on TN and TP because of low mixed rate and high nitrogen of wastewater.The average removal ratio of TN of membrane effluent was 49.0%,and the average removal ratio of TP was 41.6%.At the same time,the average removal ratio of TN of two nylon- netting effluent both exceeded 48.0%,and the average removal ratio of TP both exceeded 42.0%.Although the aperture of nylon-netting was wide,the self-forming dynamic membrane which was formed on the surface enhanced removal ratio and made up the deficiency of wide aperture.The effluent of nylon- netting took on good removal effect which was comparable with the effluent of hollow-fiber membrane.The results of experiment indicated that,the COD_cr removal ratio risen when HRT increased,but when HRT exceeded 6h,the COD_cr removal kept calm.The COD_cr removal ratio in the reactor risen when aeration intensity increased.But when aeration intensity was excess,the self-forming dynamic membrane which was formed on the surface was hard to form or easy to be destroyed,and the removal ratio of nylon-netting itself decreased.The COD_cr of effluent risen after high consistence impact,but effluent consistence was under 50mg/L all the same.The resistance to high consistence impact load of system was well.According to the degree of fouling,there were three steps of membrane cleaning: by water-by NaC1O-by HC1.The cleaning means of nylon-netting was high intensity and timing aeration.The intensity of aeration was 2m³/h,the time of aeration was 3min once time,and the frequency of aeration was once everyday.According to the results of espial,the status of microorganism were found out.In the cultivation period,the main types of microorganism appeared in activated sludge were amoeba、flagellate and so on.When the zoogloea was well cultivated,the main species were vorticella and so on.And the appearance of rotifera indicated that the system was run well,and the quality of effluence was steadily and well.更多还原