【作者】 苏妍彦；

【导师】 王竞；

【作者基本信息】 大连理工大学 ， 环境科学， 2008， 硕士

【摘要】 偶氮染料被广泛应用于纺织品、皮革、纸张、塑料、化妆品和食品染色。在染料的生产和使用中,约有10%～15%的染料随废水排入环境水体,加之偶氮染料的前体及其降解产物的致癌、致畸、致突变的“三致”作用,对全球的生态环境造成了影响,严重威胁生物多样性。在众多处理方法中,生物处理技术中的厌氧-好氧法应用最广,效果最好,但其中厌氧阶段的反应速度缓慢,是偶氮染料完全生物降解的瓶颈,而氧化还原介体强化是提高厌氧脱色效率的有效途径。常用的介体是苯醌、蒽醌、萘醌等醌类化合物,但这些化合物更难降解,通常会随出水流出而造成二次污染。本论文的研究目的是寻找新型氧化还原介体或技术以减少介体使用所引起的二次污染。研究内容包括醌还原菌群以可好氧降解的蒽醌染料中间体溴氨酸(1-氨基-4-溴蒽醌-2-磺酸,BAA)为氧化还原介体强化染料脱色;将菌群以海藻酸钙法包埋,在不补加BAA的条件下考察循环利用的情况;并将菌群与非水溶性蒽醌共固定化,考察其强化染料脱色及循环利用的情况。游离态菌群以BAA作为氧化还原介体可强化多种偶氮染料的生物脱色,其中对酸性大红3R脱色的适宜条件为pH6～9之间;温度30℃;外加葡萄糖浓度400～600mg/L;BAA浓度19～34.2mg/L,染料起始浓度≤900mg/L。在此条件下,最大脱色率约为95%、达到最大脱色率的时间＜7h。同时发现,投加氧化还原介体BAA浓度为38～57mg/L,最佳菌球投加量为120g/L时,固定化菌群降解酸性大红3R(180mg/L)的最大脱色率在14 h内达到93%;在不补加BAA的情况下,固定化菌球经7次循环使用后,脱色率仍保持在85%以上。同时考察了非水溶性的蒽醌与醌还原菌群共固定化后对偶氮染料生物脱色的强化作用。结果表明,共固定化后,菌球与氧化还原介体结合更紧密,可强化多种偶氮染料的生物脱色,其中对酸性大红3R脱色的适宜pH仍为6～9,温度30℃,葡萄糖浓度500mg/L,最佳菌球投加量为120g/L;达到最大脱色率的时间＜12h。经循环使用10次,酸性大红3R的脱色率仍然保持88%以上。更多还原

【Abstract】 Azo dyes are widespread environmental pollutants associated with the textile, cosmetic, food colorants, printing, and various other purposes. 10%-15% of these dyes are released into the environment during the process of producing or using. The release of these compounds into the environment is undesirable, not only because of their color but also because many azo dyes and their breakdown products are toxic and/or mutagenic to life. Among kinds of methods, anaerobic-aerobic biotreatment may present a relatively efficient way and be the most frequently applied methods to remove dyes from wastewater. Anaerobic process is a time-consuming process, reflected by the requirement of long reaction times. Enhancement by redox mediator is an effective method to increase the performance of anaerobic decolorization. Some quinones such as anthraquinone, naphthoquinone are powerful redox mediators, while they are also pollutant and more difficult to break down as the secondary pollutions.The purpose of this dissertation is to find new redox mediator or technology to reduce the secondary pollutions caused by redox mediators. Three aspects are included in this paper. Enhanced biodecolourization of azo dyes by the anthraquinone dyes intermedaitors bromoamine acid (BAA) were studied, and BAA can be easily degraded under aerobic condition. The bacterial cells were immobilized by entrapment in calcium alginate (CA), and the reusing without adding BAA was studied. The bacterial cells and anthnaquinone were co-immobilized, and then the decolourization and reusing were also investigated.The suspended bacterium community could enhance the biodecolourization of many kinds of azo dyes using bromoamine acid (BAA) as redox mediator, the optimum conditions for Acid Red 3R were as follows: pH 6-9, temperature 30℃, glucose, BAA and initial dye concentrations 400-600 mg/L, 19-34.2mg/L and≤900mg/L, respectively. Under these conditions, the maximal decolourzation rate was about 95%, which was reached within 7 h for suspended cells and 14 h for immobilized bacteria. However, the latter needed 38-57mg/L BAA as redox mediator and inoculation amount 120g/L. In addition, after 7 cycles without BAA addition, the decolourzation rate of Acid Red 3R by immobilized bacteria retained over 85%.Enhanced biodecolourization of azo dyes by co-immobilized quinone-reducing community and anthraquinone were also investigated. After the co-immobilization, the bacterium and the redox mediator get closer, which can enhance biodecolourization of different kinds of azo dyes. The optimum conditions for Acid Red 3R were: pH6~9, temperature 30℃, inoculation amount 120g/L, the maximal decolourization rate was reached within 12 h. After 10 cycles, the decolourization rate of Acid Red 3R by co-immobilized beads retained over 88%.更多还原