兼氧FMBR处理印染废水的实验研究及其机理分析

发布时间：2018-06-16 07:30

本文选题：兼氧 + 膜生物反应器　；参考：《江西理工大学》2016年硕士论文

【摘要】：印染废水,因其有机物含量高、成分复杂、色度深、水质变化大而成为国内外公认的难处理工业废水之一。目前,虽然已有多种处理印染废水的传统工艺和方法,但在实际运行中,或因占地面积大,或因处理成本高,或因工艺条件苛刻、操作复杂,或因出水水质难以稳定达标,仍然没有被环境工作者广为接受的工艺技术。随着新环保法的实施,传统工艺更是受到了严重挑战,为与大型工程项目相衔接,本研究采用了一套有效容积为65m3的兼氧膜生物反应器(兼氧FMBR),对江西某印染厂排放的实际废水进行处理。在实验第一阶段,水力停留时间(HRT)为30小时(h)时,系统对各种污染物表现出很好的去除效果,设备出水水质稳定达到国家《纺织染整工业水污染物排放标准》(GB 4287-2012)2015年修改后的要求。为优化实验工艺的参数,首先寻求系统的最佳HRT,使反应器HRT在20h、18h和15h下分别运行半个月,结果表明,只有当HRT为15h时,反应器出水COD和色度不能稳定达到国家直接排放要求。为进一步降低实验装置的能耗,在保证系统出水水质稳定达标(HRT为18h)的前提下,通过控制曝气量进行了反应器内溶解氧(DO)调整,膜区和兼性区DO分别由原来1.5-2.0mg/L和0.5-1.0mg/L调整为1.0-1.5mg/L和0.5mg/L以下。结果表明,在相同的HRT下,兼性区DO的降低有利于反应器对废水中COD和色度的去除,平均去除率分别提高1.0%和0.3%,而对NH3-N的去除效率大大降低,使出水NH3-N浓度高于国家直接排放要求,从而确定本实验最佳HRT为18h,膜区最佳DO为1.5-2.0mg/L、兼性区最佳DO为0.5-1.0mg/L,此时,出水COD平均值为67.7 mg/L,平均去除率为88.5%;出水NH3-N平均值为7.1mg/L,平均去除率为81.7%;出水色度平均为39倍,平均去除率为90.6%。研究了膜的截留对COD、NH3-N及色度去除作用的程度,结果表明,膜对COD和色度有较好的截留效果,对NH3-N几乎没有截留作用;兼氧FMBR对污染物的去除效果受HRT、DO、污泥负荷、温度、进水COD浓度、进水NH3-N浓度、p H值及污泥浓度等操作条件和因素的影响;分析了反应器运行过程中污泥的各方面变化。最后对兼氧FMBR的相关机理进行了分析探讨,并阐述了相关的理论基础。
[Abstract]:Printing and dyeing wastewater is recognized as one of the refractory industrial wastewater because of its high organic content, complex composition, deep chromaticity and great change of water quality. At present, although there are many traditional processes and methods for the treatment of printing and dyeing wastewater, in actual operation, either because of the large area, or because of the high treatment cost, or because of the harsh process conditions, the operation is complicated, or the effluent quality is difficult to reach the standard. There is still no technology widely accepted by environmental workers. With the implementation of the new environmental protection law, the traditional technology has been faced with serious challenges, in order to link up with large-scale projects, In this study, a set of facultative membrane bioreactor (FMBR) with effective volume of 65m3 was used to treat the actual wastewater discharged from a printing and dyeing factory in Jiangxi Province. In the first stage of the experiment, when HRT was 30 hours, the system showed a good effect on the removal of various pollutants. The effluent quality of the equipment meets the requirements of the National discharge Standard for Water pollutants in Textile dyeing and finishing Industry (GB 4287-2012) in 2015. In order to optimize the parameters of the experimental process, the optimal HRT of the system was first sought, and the HRT of the reactor was operated for half a month at 20 h or 15 h, respectively. The results showed that the effluent COD and chroma of the reactor could not meet the national direct discharge requirements when HRT was 15 h. In order to further reduce the energy consumption of the experimental equipment, under the premise that the effluent quality of the system is up to the standard of HRT (18 h), the dissolved oxygen (DOO) in the reactor is adjusted by controlling the aeration rate. The membrane region and facultative region do were adjusted from 1.5-2.0 mg / L and 0.5-1.0 mg / L to 1.0-1.5 mg / L and 0.5 mg / L respectively. The results showed that under the same HRT, the reduction of do in the facultative zone was beneficial to the removal of COD and chromaticity in the reactor, the average removal rate was increased by 1.0% and 0.3%, respectively, while the removal efficiency of NH3-N was greatly reduced. The effluent NH3-N concentration is higher than the national direct discharge requirement, and the best HRT is 18 h, the best do in the membrane region is 1.5-2.0 mg / L, the best do in the facultative zone is 0.5-1.0 mg / L, at this time, the best HRT is 18 h, and the best do in the facultative zone is 0.5-1.0 mg / L. The average COD of effluent is 67.7 mg / L, the average removal rate is 88.5, the average value of effluent NH3-N is 7.1 mg / L, the average removal rate is 81.7%, the average chroma of effluent is 39 times, the average removal rate is 90.6%. The effect of membrane retention on COD NH3-N and chromaticity removal was studied. The results showed that the membrane had a good retention effect on COD and chroma, and had little effect on NH3-N, and the removal effect of facultative FMBR on pollutants was affected by HRTDO, sludge load, temperature, etc. The influence of operating conditions and factors such as influent COD concentration, influent NH3-N concentration, sludge concentration and so on were analyzed. Finally, the related mechanism of facultative FMBR is analyzed and discussed, and the relevant theoretical basis is expounded.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X791

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