【作者】 万杰；

【导师】 花日茂； 李学德；

【作者基本信息】 安徽农业大学 ， 环境工程， 2007， 硕士

【摘要】 壬基酚是环境激素中雌激素效应比较强,难生物治理的化合物,治理洗涤、日化废水的关键就是对壬基酚的有效治理。本文通过大量的实验研究工作,系统地对4-壬基酚降解菌分离与生长繁殖特性、高效降解菌对4-壬基酚降解性能、生物强化因子等进行了初步研究,为治理工业废水中4-壬基酚提供了理论依据。1.对采集的样品进行好氧驯化,从分离出的31株菌中筛选出了5株细菌,它们可以在固体培养基上良好生长,并对4—壬基酚有较好的降解效果。2.分离出的5株细菌,标记为菌株A、菌株B、菌株C、菌株D、菌株E、对它们的菌落形态特征进行了初步研究。3.通过对初筛菌株生长特性的研究,A、B、C、E四菌都是在48h后就进入稳定期,其中A、B两菌的生长情况比较接近,D菌则比其它四株菌较快的进入稳定期(24h),C菌相比其它四株菌在同一时间内细胞增殖的最快。4.环境因素对菌株生长的有一定的影响,在实验室条件下,五株菌在不同的pH下生长差异比较大,A菌株在pH5.0和pH9.0生长都比较差,在pH6.0-8.0生长都比较好。B菌在pH5.0时的生长受到了抑制,20℃和25℃时A和B菌的生长都差不多,25℃时两株菌的生长量要略高一点;C菌在中性偏碱性条件下生长都较好,最适温度为35℃;D菌反而在两个极端生长较好,在pH6.0-8.0时一般,E菌在pH5.0时生长受到了抑制,D和E菌的最适温度为20℃。5.采用人工诱变-紫外线照射诱变法,对分离筛选出的五株降解菌进行了诱变处理,经扩大培养,得到三株生长与降解效果较好的菌株X、Y、Z。菌株降解效果测定结果表明,菌株X和Y降解性能高于菌株Z。6.对诱变得到的高效降解菌株的特性进行了较为详细的研究,主要是在多种环境条件下,对菌株生长繁殖、降解4—壬基酚能力的变化进行了实验研究,摸索出了最适的菌株培养条件,在这些条件共同存在并作用下,菌株降解4—壬基酚的效率有很大的提高,最高壬基酚去除率可达76.4%。7.通过共代谢初级碳源和氮源对菌株降解性能比较,实验结果得出4—NP并不是X和Z菌株的唯一碳源,外碳源的加入在一定浓度上促进了菌株的降解,而葡萄糖浓度的改变反而降低了Y菌株的降解率,说明葡萄糖在一定程度上抑制了菌株对碳源的吸收。当培养液中硝酸铵的浓度为40mg/L时促进了X和Y菌株的降解,降解率分别为79.8%和78.6%。对Z菌株,随着培养液中硝酸铵浓度的增大,降解率逐渐降低,可见培养液中氮源浓度的增长抑制了Z菌株对4—NP碳源的利用。8.在菌株Y最佳生长温度,pH值条件下,进行实验室模拟实验。有诱变菌株的一组降解效果较对照组好,在100mg/L的4—壬基酚浓度下,1d后加诱变菌组在降解率可达到75.2%,而对照组仅达到5.1%;在300mg/L的4—壬基酚浓度下,1d后加诱变菌组在可降解67.5%,而对照组降解率仅达到3.9%。更多还原

【Abstract】 Nonylphenolp(NP)is a kind of compound which is hard to dispose under biology fathering,and has comparatively high toxicity to EEDs.The key point of washing waste water is the effective fathering of lignin.Through a large amount of experiment, such as the separation of high effect bacilli and its’ growth trait,the degradation capability of high effect to 4-NP,and experiment of biology strengthen gene,the thesis provides theory support of improving the disposal effect of 4-NP in the washing waste water.1.Screening out 5 bacilli from 31 kinds of bacilli,which can grow well in the solid culture medium,making elementary research of the degradating capability of these 5 bacilli to 4-NP.2.Separating the animalcule which can grow comparatively well in the culture medium which includes 4-NP after domesticating the gathered sample.Screening out 5 bacilli from 31 kinds of bacilli after separating them though flat score,and marking them as strain A、strain B、strain C、strain D、strain E,all of them can grow well in the culture medium which includes 4-NP.We also make research of its shape character.3.Through the research of the growth characteristic of these bacilli,we find out that A、B、C、E come into stabilization 48 hours later,among them,A grows close to B,D enters into stabilization quicker than the other four,C proliferate cells faster than the other four in the same time.4.The environment has some effect on the growth of the bacilli.Under the condition of the lab,there exists difference among the 5 bacilli with different pH.A grows bad under pH5.0 and pH 9.0,while grows well under pH 6.0-8.0.B restrains its growth under pH5.0.A grows close to B under 20℃and 25℃.These two grow a litter bit high under 25℃.C grows well under the condition of alkalescent,the proper temperature is 35℃.However,D grows well in the two extremes, commonly under pH6.0-8.0.D restrains its growth under pH5.0,and the proper temperature for D and E is 20℃.5.Adopting the method of mutation law-ultraviolet irradiation mutagenic law,and making a series of disposal to the 5 bacilli by use of the appropriate mutagen dosage,we can get 3 bacilli X、Y、Z which grows well,making favorable foundation of degradation.The result indicates that the degradating capability of X and Y is higher than Z. 6.We do detailed research on the characteristic of the high effect bacilli,particularly under various environment condition.By studying the propagation of bacilli and the change of the capability to degrade 4-NP,we can find out the suitable condition.We can improve the efficiency of the high effect bacilli under these condition,wiping off 4-NP 76.4%.The result indicates that the condition of temperature is 30℃.7.Through the medium of manifold cometabolism primary carbon source and nitrogen source efficiency comare,we found that 4-NP degradation can be increased with the concentration of external carbon source for straint X and straint Y,but not the straint of Y.8.Under the optimal combination of temperature,pH.some laboratorial simulation experiments were carried out.The experimental results show that the performance of the group containing mutated strain is better the performance of CK.When the density of 4-NP was 100mg/L,the removal rate of mutated group was 75.2%after 1d degradation and that of CK was 5.1%.When the density of 4-NP was 300mg/L, the removal rate of mutated group was 67.5%after 1d degradation and that of CK was 3.9%.更多还原