【作者】 孙亮；

【导师】 季民；

【作者基本信息】 天津大学 ， 环境工程， 2012， 博士

【摘要】 本文以典型化工制药废水为研究对象,考察了内电解技术对废水可生化性和生物毒性的影响规律,进一步探讨了内电解反应的降解途径及其机理;在此基础上,系统考察了多种内电解联合工艺的处理效果;深入分析了内电解过程中填料板结问题的机理,为解决内电解技术在工程应用的问题提供了理论支持。采用烧杯间歇试验和自行开发的多级鼓泡塔内电解反应器的连续试验,系统考察了内电解技术处理制药废水的效果及其影响因素。试验结果表明,内电解技术对废水COD的去除率为20%,B/C提高率为60%,生物毒性削减率为40%。内电解填料的铁炭质量比为2,在进水低pH值条件下有较好的处理效果。整理试验数据,得到内电解反应对制药废水COD的降解动力学符合一级反应动力学,得出最佳进水pH为2.5,铁炭质量比为2.125。内电解反应对有机物的去除过程包括氧化还原反应和吸附-混凝作用。内电解过程中生成的铁的氢氧化物可以吸附废水中的小分子有机物,过程中发生了酯类水解反应和氧化还原反应,将废水中的大分子有机物分解为小分子物质,增加了给电子的有机官能团。试验对比了3种内电解技术与其他方法的联合处理工艺。内电解-Fenton技术对废水COD的去除率最大为为61.5%;三种联合工艺都能使废水的可生化性得到明显改善,B/C的提高率约为50%。;内电解-超声和内电解-Fenton联合工艺具有很好的去毒效果,经综合对比三种联合工艺的处理效果和处理成本,推荐内电解-Fenton联合工艺为难降解化工废水预处理的首选工艺。采用中试规模的内电解-Fenton处理装置,在天津某化工园区废水处理厂进行了现场试验。2个月的连续运行结果表明,该处理技术对综合化工废水有着比较好的预处理效果,COD的平均去除率可以达到30%,B/C提高率平均达到60%,生物毒性削减率可以达到50%以上。通过SEM观察发现板结后的内电解填料表面沉积了大量的颗粒状物质,采用EDX、XPS和XRD分析推断出这些物质主要为氢氧化铁,通过FTIR分析推断氢氧化铁可以吸附废水中含有给电子官能团的有机物。吸附有机物时,有机物作为路易斯碱,氢氧化铁作为接受电子的路易斯酸,吸附过程中电子从有机物向氢氧化铁中的氧转移,内电解过程产生的氢氧化铁吸附有机物并沉积在填料表面是引起内电解技术填料板结问题的主要原因。更多还原

【Abstract】 In this paper, a typical chemical pharmaceutical wastewater was selected as the target water and the internal electrolysis (IE) and combined technologies were chosen as the main treatment technologies. The biotoxicity removal of the IE process on the typical pharmaceutical wastewater was investigated, Moreover, the changes of the biodegradability and the the degradation products after IE treatment were analyzed and the removal mechanisms of the main pollutants in the pharmaceutical wastewater were discussed, further, the combined technologies composed of IE and other physical chemical technologies were studied, simultaneously .to understand the mechanism of fillings agglomeration, various techniques were implemented to characterize in order to provide the basic basis to the rational application of the internal electrolysis in the treatment of the toxic chemical wastewater.Long operation results showed that the internal electrolysis was an effective pre-treatment technology, the COD removal efficiency was 20%, the B/C enhancement efficiency was 60% and the acute biotoxicity removal efficiency was 40%. The iron carbon mass ratio was 2; low initial pH was favorable to the treatment. A new kinetics model was established, according to the model, the best reaction factors were obtained under initial pH value of 2.5 and the iron carbon mass ratio of 2.125.The process of the organics removal was complicated; the internal electrolysis reactions were the main effect. Some compounds with cyclic or long carbon chain could be decomposed into small molecule substance; in addition, suspended particles and colloidal matters of wastewater could be adsorbed by the newborn iron oxide hydroxide which was good flocculants with high activity of adsorption and flocculation.The comparisons of the results by there internal electrolysis combined technologies were studied. The COD removal efficiency for IE-Fenton technology was 61.5%, the B/C enhancement efficiency of these three technologies was 50%; the acute biotoxicity of IE-ultrasonic irradiation technology was 88% and it was 80% for the IE-Fenton technology. Accoding to the comparison of the effects and the cost, the internal electrolysis-Fenton technology was chosn to treat the chemical wastewater.Actual mixed chemical wastewater was treated using the internal electrolysis-Fenton technology, with long operation times (more than 2 months), the COD removal efficiency was 30%, the B/C enhancement efficiency was 60% and the acute biotoxicity was 50%. To understand the mechanism of agglomeration, various techniques were implemented to characterize. Scanning electron microscopy (SEM) indicated that there were granular matters on the surface of agglomerate fillings to arouse the agglomeration. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicated that the granular matters were ferric hydroxide and the crystal structure was amorphous. XPS and Fourier transform infrared (FTIR) indicated that adsorption of the internal electrolysis was chemical adsorption and ferric hydroxide could easily adsorb the organics which contained the donating electron groups. The deposition on the surface of fillings by ferric hydroxide which adsorbed the organics was the main reason of agglomeration of the internal electrolysis technology.更多还原