碳纤维表面性能与好氧生物膜关联性研究

发布时间：2018-09-10 11:36

【摘要】：目前我国水资源短缺与水污染问题并存,地表水污染情况依旧严峻,保护水资源、改善水环境,提高水处理效率刻不容缓。市政污水多处于微污染状态,为贫营养环境,致使许多工程上常用的生物膜载体出现微生物活性降低、水处理能力下降的问题。因此,急需探寻、研制一种高效稳定的生物膜载体材料。碳纤维具有生物相容性及柔韧性,具备作为生物膜载体的条件,但碳纤维表面光滑、亲水性差,不利于生物膜的挂膜。为使碳纤维成为具有高效性、稳定性的优良生物膜载体材料,可对碳纤维进行表面改性。本论文主要通过XPS、静态接触角等测试手段,分析了碳纤维表面元素种类、亲水性等对好氧生物膜的影响,以及碳纤维生物膜载体在贫营养水体中的水质净化能力,探索了碳纤维生物膜挂膜机理。为碳纤维生物膜载体材料的改性方向提供理论依据,并验证了其应用于市政污染水中的可能性。本论文还首次利用有机铁对碳纤维进行表面改性,制备出性能优良的碳纤维生物膜载体材料。研究表明：以工程中常用的聚丙烯纤维(PPF)为对比,碳纤维载体生物膜系统的COD、氨氮去除率高达97.3%、92.0%,较PPF载体分别提高1.4%、6.6%。在贫营养水体中,PPF生物膜系统出现COD、氨氮去除率下降的现象,而碳纤维载体的COD、氨氮去除率不降反升,较PPF载体分别提高11.9%、5.6%。碳纤维还具有较好的抗微生物损耗能力,重复使用率高,可应用于市政污水处理中。碳纤维表面含氮量对生物膜有一定影响,表面含氮量高的碳纤维载体生物膜系统的COD、氨氮去除率较高,稳定性好,特别对脱氮性能有明显的促进作用；碳纤维表面氮含量的不同对生物膜系统的除磷性能影响不大。采用草酸亚铁、柠檬酸铁对碳纤维进行表面改性,有机铁改性后碳纤维表面的粗糙程度显著提高,亲水性得到极大改善,载体生物膜量大大提高,分别是未改性碳纤维载体的3.3倍、3.2倍,COD、氨氮、TP的平均去除率显著提高,分别为97%、96%、97%,94%、93%、95%；在贫营养水体中,出水COD值分别在11mg/L、12mg/L左右,远低于国标GB 18918-2002一级A排放标准,均符合地表水环境质量标准GB3838-2002中的Ⅰ类。其中草酸亚铁改性碳纤维载体表现出优异的脱氮性能,柠檬酸铁改性碳纤维载体具有较好的除磷性能。
[Abstract]:At present, water shortage and water pollution coexist in our country, and surface water pollution is still serious. It is urgent to protect water resources, improve water environment and improve water treatment efficiency. The municipal sewage is mostly in the condition of micro-pollution, which is poor nutrition environment, which leads to the problem that the microbial activity and the water treatment ability of many commonly used biofilm carriers are decreased. Therefore, it is urgent to explore and develop an efficient and stable biofilm carrier material. Carbon fiber has biocompatibility and flexibility, and is suitable for biofilm carrier, but the surface of carbon fiber is smooth and hydrophilicity is poor, which is not good for biofilm suspension. In order to make carbon fiber become an excellent biofilm carrier material with high efficiency and stability, the surface of carbon fiber can be modified. In this paper, the effects of surface elements and hydrophilicity of carbon fiber on aerobic biofilm were analyzed by means of XPS, static contact angle, and the water quality purification ability of carbon fiber biofilm carrier in poor nutrient water was also analyzed. The mechanism of carbon fiber biofilm suspension was explored. It provides a theoretical basis for the modification of carbon fiber biofilm carrier and verifies the possibility of its application in municipal polluted water. In this paper, carbon fiber surface was modified by organic iron for the first time, and carbon fiber biofilm carrier material with excellent properties was prepared. The results show that the removal rate of COD, ammonia nitrogen in the biofilm system of carbon fiber carrier is as high as 97.32.0, which is 1.4% higher than that of PPF carrier. The COD, ammonia nitrogen removal rate decreased in the biofilm system of poor nutrient water, while the COD, ammonia nitrogen removal rate of carbon fiber carrier increased by 11.5% and 5.6% as compared with that of PPF carrier. Carbon fiber can also be used in municipal wastewater treatment because of its good resistance to microbial wastage and high reuse rate. Carbon fiber surface nitrogen content has a certain effect on the biofilm. The carbon fiber carrier biofilm system with high surface nitrogen content has higher removal rate of COD, ammonia nitrogen and good stability, especially has obvious promoting effect on denitrification performance. Nitrogen content on carbon fiber surface has little effect on phosphorus removal performance of biofilm system. Carbon fiber surface was modified by ferrous oxalate and ferric citrate. The surface roughness, hydrophilicity and biofilm of carbon fiber modified by organic iron were greatly improved. The average removal rate of NH3-N TP was significantly higher than that of unmodified carbon fiber carrier, which was 9395%. In the poor nutrient water, the effluent COD value was about 11 mg / L ~ (12 mg / L), which was far lower than the national standard GB 18918-2002 first class A discharge standard. All accord with class I of surface water environmental quality standard GB3838-2002. Ferrous oxalate modified carbon fiber carrier showed excellent denitrification performance, and ferric citrate modified carbon fiber carrier had better phosphorus removal performance.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ342.742;X703

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