铁锰对Pseudomonas putida降解单苯环非甾体抗炎药的影响

发布时间：2018-08-01 10:36

【摘要】：环境中残留的对乙酰氨基酚(Acetaminophen,APAP)、水杨酸(Salicylic acid,SA)较难降解,污染环境且对水生动植物有毒性作用。恶臭假单胞菌(Pseudomonas putida)广泛存在于自然水体中,本文探讨了其通过氧化铁锰离子生成生物铁锰氧化物降解APAP与SA这两种单苯环非甾体抗炎药的可行性。研究了10-500 mg/L APAP的降解可行性,10 mg/L APAP可完全降解,随着APAP浓度增加去除率逐渐下降至零。后续主要研究10 mg/L APAP的降解特性。探究了APAP的降解条件,发现无铁锰时APAP不能被降解,仅有铁时APAP降解效果较差,铁锰共存时降解效果最好,且锰对APAP的降解作用更大。探究了APAP降解过程中Mn~(2+)的变化规律,发现APAP的降解速率和Mn~(2+)的氧化速率呈强烈正相关。Mn~(2+)为8.13 mg/L时APAP即可完全降解,此浓度后Mn~(2+)浓度越高APAP降解速度越慢,说明过量的Mn~(2+)对细菌有毒害作用。探究了APAP降解影响因素,发现细菌活性受到抑制时APAP降解率降至30%,其抑制产物中含有9.3 mg/L Mn~(2+),而细菌活性未被抑制的Mn~(2+)为0.5 mg/L,说明细菌活性可以通过抑制Mn~(2+)氧化进而影响APAP降解。研究了由不同浓度Mn~(2+)作用生成的不同量生物锰氧化物降解APAP的效果,发现生物锰氧化物量越多,APAP降解速度越快。解吸实验证明生物铁锰氧化物对APAP是降解作用而非吸附作用。通过测定降解过程中总有机碳的含量,发现其对APAP有一定的矿化度,TOC去除率达到48.05%。上述研究证实APAP的降解主要在Pseudomonas putida氧化溶解性铁锰离子为不溶态的生物铁锰氧化物这一过程中的。研究了0.5-10 mg/L SA的降解可行性,发现SA去除率随浓度增加而减少,0.5、1mg/L的SA可完全降解,5、10 mg/L的SA去除率分别为74.87%、61.98%。后续实验选取1 mg/L SA作为研究对象。探究了SA降解条件,发现无铁锰时SA不能被降解,仅有铁时SA去除率不足8%,说明铁对降解SA所起的作用较小。探究了SA浓度对Fe~(2+)及Mn~(2+)氧化的影响,SA为1、5、10 mg/L时Fe~(2+)在1 d的氧化率分别为98.15%、96.75%、23.33%,Mn~(2+)的氧化率分别为99.59%、98.82%、44.48%,说明高浓度的SA会抑制Fe~(2+)及Mn~(2+)的氧化速度。探究了SA降解影响因素,发现降解效果受到细菌活性、生物铁锰氧化物含量的影响,生物铁锰氧化物量越多,SA去除率越高。通过解析实验证明生物铁锰氧化物对SA是降解作用而非吸附作用。通过比较两种药物在降解过程中的差异性,发现APAP比SA更容易被生物铁锰氧化物降解,去除率较高且降解所需时间较短,可被降解的浓度限值较大。相较于APAP,SA存在的环境中Pseudomonas putida氧化溶解性铁锰离子的速度较慢。生物铁氧化物可降解部分APAP,而对SA的降解效果非常差。降解APAP所需生物铁锰氧化物的量较少,而SA的降解需要大量生物铁锰氧化物来维持,尤其需要大量的生物锰氧化物。
[Abstract]:The residues of acetaminophenol (AP) and salicylic acid (SA) in the environment are difficult to degrade, which pollute the environment and have toxicity to aquatic animals and plants. Pseudomonas malodor (Pseudomonas putida) is widely found in natural water. The feasibility of degrading APAP and SA, two monobenzene nonsteroidal anti-inflammatory drugs, by ferromanganese oxide (FeMn) ion was studied. The feasibility of degradation of 10-500 mg/L APAP was studied. The degradation rate of 10-500 mg/L APAP was reduced to zero with the increase of APAP concentration for 10 mg/L APAP. The degradation characteristics of 10 mg/L APAP were studied. The degradation conditions of APAP were investigated. It was found that APAP could not be degraded without iron and manganese, but the degradation effect of APAP was poor when iron was the only one. The degradation effect of APAP was the best when iron and manganese co-existed, and the degradation effect of mn on APAP was greater than that of mn. The changes of mn ~ (2) in the degradation of APAP were studied. It was found that the degradation rate of APAP and the oxidation rate of mn ~ (2) were positively correlated with the oxidation rate of mn ~ (2). When MNO ~ (2) was 8.13 mg/L, APAP could be completely degraded, and the higher the concentration of mn ~ (2) was, the slower the degradation rate of APAP was. It shows that excessive Mn2 has toxic effect on bacteria. The factors influencing the degradation of APAP were investigated. It was found that when the bacterial activity was inhibited, the degradation rate of APAP decreased to 30%, and the inhibiting product contained 9.3 mg/L Mn2, while the uninhibited Mn2 was 0.5 mg / L, which indicated that the bacteriological activity could affect the degradation of APAP by inhibiting Mn2 oxidation. The degradation of APAP by different amounts of biological manganese oxides with different concentrations of Mn2 was studied. It was found that the more the amount of mn oxides, the faster the degradation rate of APAP was. The desorption experiment showed that the biodegradation of APAP by biological ferromanganese oxides was not adsorption. By measuring the content of total organic carbon in the degradation process, it was found that it had a certain degree of mineralization and the removal rate of APAP reached 48.05%. These results indicate that the degradation of APAP is mainly due to the fact that the oxidized dissolved iron and manganese ions of Pseudomonas putida are insoluble biological ferromanganese oxides. The feasibility of SA degradation of 0.5-10 mg/L was studied. It was found that the removal rate of SA decreased by 0.5 mg / L of SA with the increase of concentration. The total removal rate of SA for 10 mg/L was 74.87% and 61.98%, respectively. 1 mg/L SA was selected as the research object in the follow-up experiment. It was found that SA could not be degraded without iron and manganese, but the removal rate of SA was less than 8 when iron was the only one, which indicated that iron had little effect on the degradation of SA. The effect of SA concentration on the oxidation of Fe ~ (2) and mn ~ (2) was investigated. The oxidation rate of Fe ~ (2) was 98.15 ~ (5) and 96.75 ~ (53) ~ (23) mn ~ (2) at one day when SA was 1 ~ 5 ~ 5 ~ 10 mg/L, respectively. The oxidation rates of Fe ~ (2) and mn ~ (2) were 99.59 ~ (2) and 98.82 ~ (2), respectively, indicating that high concentration of SA could inhibit the oxidation rate of Fe ~ (2) and mn ~ (2). The influencing factors of SA degradation were investigated. It was found that the degradation effect was affected by the activity of bacteria and the content of biological ferromanganese oxides, and the higher the amount of biological ferromanganese oxides was, the higher the removal rate of SA was. It is proved by analytical experiments that the degradation of SA by biological ferromanganese oxides is not adsorption. By comparing the differences between the two drugs in the process of degradation, it was found that APAP was more easily degraded by biological ferromanganese oxides than SA, the removal rate was higher, the time required for degradation was shorter, and the concentration limit for degradation was higher. The oxidation rate of iron and manganese ions in the presence of Pseudomonas putida was slower than that in the presence of Pseudomonas putida SA. Biological iron oxides can degrade part of APAPs, but the degradation effect of SA is very poor. The amount of biological ferromanganese oxides needed to degrade APAP is relatively small, but the degradation of SA requires a large number of biological ferromanganese oxides to maintain, especially a large number of biological manganese oxides.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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