放射通道碟管式反渗透（RCDTRO）系统处理垃圾渗滤液的性能研究

发布时间：2018-09-12 11:57

【摘要】：垃圾渗滤液是卫生填埋过程中产生的一种高浓度有机废水,如果对其处理不当会对土壤,地下水和地表水,大气等造成严重污染。然而由于垃圾渗滤液污染物浓度较高,水质和水量波动性大,成分较为复杂,因此目前垃圾渗滤液的处理依然是个世界性难题。垃圾渗滤液的组成成分复杂,是一种高强度的废水,拥有很高的化学需氧量(COD)和氨氮(NH3-N)含量,但是碳氮比和BOD5/COD(B/C)很低,因此目前的研究主要集中于物理化学方法,尤其是用反渗透膜处理垃圾渗滤液。本研究以醴陵垃圾填埋场的垃圾渗滤液作为研究对象,用创新型的放射通道碟管式反渗透(RCDTRO)系统渗滤液,测试其性能,包括处理效率和对膜污染的抵抗力两方面;其次,还通过试验确定其最佳的操作条件;最后,对污染膜片进行扫描电镜和超声波清洗,分析引起膜污染的主要成分和原因,对RCDTRO系统稳定持续地运行提供科学依据。本文研究了碟管式反渗透(RCDTRO)系统在垃圾渗滤液处理中的应用,从主要污染物的处理效果和对膜污染的抵抗力,对RCDTRO的性能进行了评估。研究表明,在不进行预处理和后置处理的情况下,一级RCDTRO系统对COD的去除率为98.89±0.26%、NH3-N的去除率为96.04±0.21%、脱盐率为97.53±0.18%。此外,更长的清洗周期说明该系统具有很强的抗膜污染力。实验室研究得出最佳的操作条件为操作压力42-50bar,加压泵频率35Hz,处理水回收率65%-75%。本研究表明RCDTRO系统处理垃圾渗滤液在技术上和经济上都是可行的,并且能够在相对较低的压力下维持较高的处理效率。通过扫描电镜确定反渗透膜表面污染物质的成分;其次,在检测之前,用有机溶剂丙酮浸泡,并测定在不同浸泡时间内膜表面污染物质的变化;再次,通过对污染膜片的超声波清洗,对比前后膜表面物质的变化;最后,用AFM-原子力显微镜检测污染前后膜表面的粗糙程度,进一步确定清洗前后反渗透膜表面污染物质的变化。可以得出以下结论:(1)反渗透膜污染后表面聚集大量有机物和重金属元素,非金属元素中主要包含硅和硫元素。(2)在金属元素中,汞、铜、铁占大多数,这些金属元素在水中能形成胶体物质,粘附在膜表面。(3)膜污染的形成过程可能是由于重金属元素或者硅等物质在水中形成胶体状物质,并粘附在膜表面,然后不断吸附有机物,最后有机物与胶体螯合,造成膜污染。(4)反渗透膜污染后在有机溶剂丙酮浸泡后可以降低膜污染表面物质的浓度,尤其是有机物方面。(5)反渗透膜污染后,对其进行超声波清洗,能有效降低有机污染、减小膜表面的粗糙程度,增加其光滑度。
[Abstract]:Landfill leachate is a kind of high concentration organic wastewater produced in the process of sanitary landfill. If it is not treated properly, it will cause serious pollution to soil, groundwater and surface water, atmosphere and so on. However, the treatment of landfill leachate is still a worldwide problem because of its high concentration of pollutants, high volatility of water quality and quantity, and complex composition. The composition of landfill leachate is complex, it is a kind of high intensity wastewater, it has high chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) content, but carbon nitrogen ratio and BOD5/COD (B / C) are very low, so the current research is mainly focused on physical and chemical methods. In particular, reverse osmosis membrane is used to treat landfill leachate. In this study, the landfill leachate of Liling Landfill was used as the research object, and the performance of the leachate of the Liling landfill leachate was tested by using the innovative radioactive channel, disc tube reverse osmosis (RCDTRO) system leachate, including the treatment efficiency and resistance to membrane fouling. Secondly, The optimal operating conditions were determined by experiments. Finally, the main components and causes of membrane fouling were analyzed by scanning electron microscope and ultrasonic cleaning, which provided scientific basis for the stable and continuous operation of RCDTRO system. In this paper, the application of disc tube reverse osmosis (RCDTRO) system in landfill leachate treatment is studied. The performance of RCDTRO is evaluated from the treatment effect of main pollutants and resistance to membrane fouling. The results showed that the removal rate of COD was 98.89 卤0.26 and the removal rate of NH _ 3-N was 96.04 卤0.21 and 97.53 卤0.18 in the first RCDTRO system without pretreatment and post-treatment. In addition, the longer cleaning period shows that the system has a strong resistance to membrane fouling. The experimental results show that the optimal operating conditions are operating pressure 42-50 bar. pressure pump frequency 35Hz, water recovery 65-75. This study shows that the RCDTRO system is technically and economically feasible to treat landfill leachate and can maintain a higher treatment efficiency under relatively low pressure. The composition of surface contaminants of reverse osmosis membrane was determined by scanning electron microscope. Secondly, the organic solvent acetone was used to soak in the membrane before detection, and the changes of the surface pollutants of the membrane in different immersion time were measured. Again, Through ultrasonic cleaning of contaminated membrane, the changes of membrane surface material were compared. Finally, AFM- atomic force microscope was used to detect the roughness of membrane surface before and after pollution, and to further determine the change of fouling material of reverse osmosis membrane before and after cleaning. The following conclusions can be drawn: (1) the surface of the reverse osmosis membrane is contaminated with a large amount of organic and heavy metal elements, and the non-metallic elements mainly contain silicon and sulfur elements. (2) among the metal elements, mercury, copper and iron are the majority. These metal elements can form colloids in water and adhere to the membrane surface. (3) the formation process of membrane fouling may be due to the formation of colloidal substances in water by heavy metal elements or silicon and adhesion to the membrane surface, and then to the continuous adsorption of organic matter. Finally, organic matter chelates with colloid, resulting in membrane fouling. (4) the concentration of surface substances contaminated by reverse osmosis can be reduced after soaking in organic solvent acetone, especially in organic matter. (5) after fouling of reverse osmosis membrane, ultrasonic cleaning is carried out. It can effectively reduce organic pollution, reduce the roughness of membrane surface and increase its smoothness.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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