本文關(guān)鍵詞：納米零價(jià)鐵降解污染物碘造影劑的過程和機(jī)理研究　出處：《中國科學(xué)技術(shù)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 納米零價(jià)鐵 碘造影劑 泛影酸鈉 脫鹵反應(yīng) 高級氧化 好氧生物降解

【摘要】：碘造影劑(Iodinatedcontrastmedia,ICM)被廣泛用于在診斷檢查期間內(nèi)部身體結(jié)構(gòu)如器官,血管和軟組織的成像,一般會通過人體排泄尿液進(jìn)入污水系統(tǒng)。傳統(tǒng)的污水處理方法無法有效去除碘造影劑,導(dǎo)致其在環(huán)境中的積累和同化到生物系統(tǒng)中,會對環(huán)境及人體造成長期的不利影響。另一方面,納米零價(jià)鐵(Nano zero-valent iron,nZVI)獨(dú)特的性能被廣泛應(yīng)用于各類污染物的去除。本文以典型的碘造影劑泛影酸鈉(Diatrizoatesodium,DTA)為研究對象,分別研究了厭氧以及好氧條件下納米零價(jià)鐵(nZVI)對其的降解過程和機(jī)理,研究結(jié)果將為污染物碘造影劑的強(qiáng)化去除提供技術(shù)支持并推動(dòng)納米零價(jià)鐵的應(yīng)用。本文的研究內(nèi)容和主要結(jié)論如下:1、厭氧條件下研究了 nZVI對DTA的還原脫鹵作用的可行性,考察并探究了 DTA脫鹵后產(chǎn)物的可生化性。研究發(fā)現(xiàn),厭氧條件下nZVI可以有效的進(jìn)行DTA的脫鹵去除。DTA的降解效效率隨著nZVI劑量的增加而增加,隨著溶液pH值升高而降低,nZVI陳化時(shí)間對DTA脫鹵有負(fù)面影響;低濃度的天然有機(jī)質(zhì)可以提高DTA降解效果,而在高濃度下則有負(fù)面影響:與硫酸鹽不同,硝酸鹽和磷酸鹽的存在強(qiáng)烈抑制DTA去除。另外,相比于DTA本身,還原產(chǎn)物DAB A可以通過好氧生物處理降解,說明利用nZVI對DTA脫鹵后其產(chǎn)物的可生化性得到了較為顯著的提高。2、好氧條件下研究了 nZVI對DTA降解的可行性,考察了 nZVI劑量、溶液pH、競爭性陰離子等對DTA降解的影響,并探究DTA的降解機(jī)理。研究發(fā)現(xiàn)好氧條件下利用nZVI也可以實(shí)現(xiàn)DTA的降解。DTA降解效率隨著nZVI劑量的增加而增加,隨著溶液pH值升高而降低,硝酸鹽的存在強(qiáng)烈抑制DTA去除,而磷酸鹽的存在卻沒有明顯的影響。然而,DTA降解過程中總有機(jī)碳去除效果不佳,表明好氧條件下利用nZVI無法有效實(shí)現(xiàn)DTA的礦化。機(jī)理研究結(jié)果表明,好氧條件下nZVI降解DTA既有脫鹵反應(yīng),也存在高級氧化過程。
[Abstract]:Iodine contrast media (ICM) is widely used in imaging internal body structures such as organs, blood vessels and soft tissue during diagnostic examinations. The traditional sewage treatment method can not effectively remove iodine contrast agent, resulting in its accumulation and assimilation into the biological system in the environment. On the other hand, the nanocrystalline zero-valent iron Nano zero-valent iron can cause long-term adverse effects on the environment and human body. The unique properties of nZVI have been widely used in the removal of various pollutants. In this paper, the typical iodine contrast agent Diatrizoatesodium DTAs was used as the research object. The degradation process and mechanism of NZVI were studied under anaerobic and aerobic conditions. The results will provide technical support for the enhanced removal of iodine contrast agent and promote the application of nanometer zero-valent iron. The research contents and main conclusions of this paper are as follows: 1. The feasibility of dehalogenation of nZVI on DTA was studied under anaerobic conditions. The biodegradability of the dehalogenated products of DTA was investigated. Under anaerobic conditions, nZVI could effectively dehalogenate DTA. The degradation efficiency of DTA increased with the increase of nZVI dose, and decreased with the increase of pH value of the solution. The aging time of nZVI has a negative effect on DTA dehalogenation. Low concentrations of natural organic matter can improve the degradation of DTA, but at high concentrations, there is a negative effect: unlike sulfate, the presence of nitrate and phosphate strongly inhibit DTA removal. Compared with DTA itself, the reduction product DAB A can be degraded by aerobic biotreatment, which indicates that the biodegradability of DTA dehalogenated by nZVI is improved by 2.2. The feasibility of DTA degradation by nZVI was studied under aerobic conditions. The effects of nZVI dosage, pH of solution and competitive anion on DTA degradation were investigated. The degradation mechanism of DTA was investigated. It was found that the degradation efficiency of DTA could also be achieved by using nZVI under aerobic conditions with the increase of nZVI dosage. With the increase of pH value of the solution, the presence of nitrate strongly inhibited the removal of DTA, but the presence of phosphate had no obvious effect. However, the removal of total organic carbon was not good during the degradation process. The results show that the mineralization of DTA can not be realized effectively by using nZVI under aerobic conditions. The results of mechanism study show that the degradation of DTA by nZVI under aerobic conditions has both dehalogenation reaction and advanced oxidation process.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X703;TQ421.7

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本文編號：1423275