本文關(guān)鍵詞： 諾氟沙星 臭氧氧化 中間產(chǎn)物 生態(tài)毒性 發(fā)光菌 斑馬魚(yú)　出處：《山東建筑大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：水環(huán)境中抗生素的殘留對(duì)生態(tài)環(huán)境以及人類(lèi)健康構(gòu)成的威脅日趨嚴(yán)重,而現(xiàn)有污水處理技術(shù)難以對(duì)其有效去除。臭氧作為一種氧化能力較強(qiáng)的氧化劑,能有效去除抗生素母體,然而有毒副產(chǎn)物的產(chǎn)生是困擾臭氧技術(shù)應(yīng)用的主要問(wèn)題。本課題以諾氟沙星為目標(biāo)抗生素,臭氧氧化為技術(shù)手段,主要研究了臭氧對(duì)諾氟沙星的降解能力及降解過(guò)程中產(chǎn)生的中間產(chǎn)物的可生物降解性能;以發(fā)光菌的發(fā)光率為毒性評(píng)價(jià)手段,通過(guò)研究諾氟沙星及臭氧氧化諾氟沙星中間產(chǎn)物對(duì)發(fā)光菌抑制作用探討了臭氧氧化前后諾氟沙星毒性變化,并推測(cè)了可能的中間產(chǎn)物;利用斑馬魚(yú)為受試生物,針對(duì)諾氟沙星及臭氧氧化諾氟沙星中間產(chǎn)物對(duì)斑馬魚(yú)死亡率及微核率進(jìn)行研究,考查了臭氧氧化諾氟沙星中間產(chǎn)物的毒理性。研究結(jié)果如下:臭氧氧化初始濃度為5mg/L的諾氟沙星溶液,去除率隨著臭氧投加量的增加而逐漸升高,通過(guò)研究pH對(duì)去除率的影響,可發(fā)現(xiàn),臭氧對(duì)諾氟沙星的氧化效果在pH11的環(huán)境下要比pH3的環(huán)境下好,但去除率也并非一直升高,當(dāng)臭氧投加量大于10 mg/L時(shí),去除率均趨于平緩。對(duì)臭氧氧化諾氟沙星過(guò)程中指標(biāo)變化測(cè)定顯示,當(dāng)pH3的氧化環(huán)境且臭氧投加量為20mg/L時(shí),臭氧氧化諾氟沙星溶液過(guò)程中對(duì)DOC的去除效果最佳,UV_(254)在不同的pH氧化條件下,基本都是逐漸降低的趨勢(shì),且pH 11條件下對(duì)UV_(254)的去除效果相較與另兩個(gè)條件而言效果略差;隨著臭氧投加量的增加,諾氟沙星中的N原子經(jīng)氧化逐漸脫離諾氟沙星游離出來(lái),以氨氮和NO3—形式存在。臭氧氧化諾氟沙星后的溶液生物降解性逐漸升高,說(shuō)明生成的中間產(chǎn)物易于生物降解。費(fèi)氏弧菌的發(fā)光抑制率與諾氟沙星濃度有較強(qiáng)的相關(guān)性,諾氟沙星初始濃度為500mg/L時(shí),諾氟沙星對(duì)費(fèi)氏弧菌的發(fā)光抑制率為65%左右。臭氧氧化諾氟沙星中間產(chǎn)物對(duì)發(fā)光菌發(fā)光抑制研究表明,pH11的氧化條件下,氧化后的溶液對(duì)費(fèi)氏弧菌的發(fā)光抑制率隨時(shí)間的遞增呈現(xiàn)一直升高的趨勢(shì),通臭氧時(shí)間相同的前提下發(fā)光抑制率均低于pH3和pH7的結(jié)果。對(duì)臭氧氧化諾氟沙星中間產(chǎn)物分析,中間產(chǎn)物HCHO的生成受氧化環(huán)境pH的影響,酸性條件下甲醛的生成要低于中性和堿性條件,從生物砂對(duì)甲醛的降解作用來(lái)看,雖不能完全降解但降解作用也較為穩(wěn)定,都能將HCHO降至0.7mg/L以下。斑馬魚(yú)微核率隨著諾氟沙星濃度的升高呈現(xiàn)上升趨勢(shì),說(shuō)明諾氟沙星濃度越大,致突變率越高,毒性就會(huì)越大。以250 mg/L的諾氟沙星溶液為原液,伴隨臭氧濃度的增加,諾氟沙星中間產(chǎn)物對(duì)斑馬魚(yú)紅細(xì)胞微核率的影響出現(xiàn)急劇下降,當(dāng)臭氧投加量為2.5mg/L時(shí),斑馬魚(yú)紅細(xì)胞微核率為2‰,并且隨著臭氧投加量的增多微核率逐漸升高,當(dāng)臭氧投加量達(dá)到10 mg/L時(shí)微核率基本穩(wěn)定在3‰左右。
[Abstract]:Antibiotic residues in water environment pose more and more serious threats to ecological environment and human health, but it is difficult to remove them effectively by existing wastewater treatment technology. Ozone, as an oxidant with strong oxidation ability, can effectively remove antibiotic parent body. However, the production of toxic by-products is the main problem that puzzles the application of ozone technology. In this paper, norfloxacin as the target antibiotic, ozone oxidation as the technical means, The biodegradation ability of ozone to norfloxacin and the biodegradability of intermediate products produced during the degradation were studied. By studying the inhibitory effect of norfloxacin and norfloxacin intermediate products on luminescent bacteria, the toxic changes of norfloxacin before and after ozonation were studied, and the possible intermediates were speculated. Zebrafish were used as tested organisms. The mortality and micronucleus rate of zebrafish were studied by using norfloxacin and norfloxacin intermediate products. The toxicity of the intermediate product of norfloxacin by ozone oxidation was investigated. The results are as follows: the removal rate of norfloxacin solution with the initial ozone oxidation concentration of 5 mg / L increases with the increase of ozone dosage, and the effect of pH on the removal rate is studied. It was found that the oxidation effect of ozone on norfloxacin was better in pH11 than in pH3, but the removal rate did not always increase. When the amount of ozone added was more than 10 mg/L, The determination of the index changes in the process of ozone oxidation of norfloxacin showed that when the oxidation environment of pH3 and the dosage of ozone was 20 mg / L, In the process of ozonation of norfloxacin solution, the removal efficiency of DOC was the best. Under different pH oxidation conditions, the DOC removal effect was decreased gradually, and the removal effect of DOC was slightly worse at pH 11 than that under the other two conditions. With the increase of ozone dosage, the N atom in norfloxacin was oxidized and dissociated from norfloxacin and existed in the form of ammonia nitrogen and no _ 3-. The biodegradability of the solution of norfloxacin was gradually increased after ozonation of norfloxacin. The results showed that the intermediate product was easy to biodegrade, and the luminescence inhibition rate of Vibrio ferryi was strongly correlated with the concentration of norfloxacin, when the initial concentration of norfloxacin was 500 mg / L, The luminescence inhibition rate of norfloxacin against Vibrio flexneri is about 65%. The luminescence inhibition rate of the oxidized solution against Vibrio ferrovirii has been increasing with the increase of time, and the luminescence inhibition rate of the oxidized solution under the same ozone time is lower than that of pH3 and pH7. The intermediate products of norfloxacin ozonation were analyzed. The formation of intermediate product HCHO was influenced by the pH of oxidation environment, and the formation of formaldehyde in acidic condition was lower than that in neutral and alkaline condition. From the degradation of formaldehyde by biological sand, although it could not be completely degraded, the degradation effect was relatively stable. The micronucleus rate of zebrafish increased with the increase of norfloxacin concentration, indicating that the higher the concentration of norfloxacin, the higher the mutagenicity, the greater the toxicity. With the increase of ozone concentration, the effect of norfloxacin intermediate product on erythrocyte micronucleus rate of zebrafish decreased sharply. When ozone dosage was 2.5 mg / L, the micronucleus rate of zebrafish erythrocyte was 2 鈥，

本文編號(hào)：1494048