Aqueous photolysis of tetracycline and toxicity of photolytic products to luminescent bacteria
Aqueous photolysis of tetracycline and toxicity of photolytic products to luminescent bacteria
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四环素的水溶液光解及光解产物对发光细菌的毒性
DOI：
10.1016/j.chemosphere.2008.05.042
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发表时间：
2008-09-01
期刊：
影响因子：
8.8
通讯作者：
Chen, Liangyan
中科院分区：
文献类型：
--
作者：
Jiao, Shaojun;Zheng, Shourong;Chen, Liangyan
抗生素在药物治疗和农业生产中的广泛应用，导致了世界范围内的环境污染。研究了四环素的光解行为及其降解产物的毒性。结果表明，TC的光解符合一级动力学规律。发现光解速率依赖于TC的初始浓度，TC浓度从10增加到40 mg l（-1）导致光解速率常数从0.0045 min（-1）降低到0.0014 min（-1）。TC的光解具有很强的pH依赖性，在高pH值下，TC的光解强烈增强。在硝酸盐和溶解有机物的存在下，也观察到显着升高的TC光解。照射300 min后，总有机碳（TOC）仅减少15%，而TC的转化率高达73%，表明大部分TC转化为中间产物，但没有完全矿化。采用高效液相色谱-电喷雾-质谱联用技术（HPLC-ESI-MS）分析了TC光解的中间产物，提出了TC的主要光解产物。利用发光细菌对降解产物的毒性进行了评价，结果表明降解产物的毒性随光照强度的增加而增加，表明降解产物对细菌的逆境风险较高。(C)2008爱思唯尔有限公司保留所有权利。
The extensive utilization of antibiotics in the pharmaceutical therapies and agricultural husbandry has led to the worldwide pollution in environments. In this study the photolysis behaviors of tetracycline (TC) and toxicity of its degradation products were investigated. The results showed that TC photolysis followed first-order kinetics. The photolysis rate was found to be dependent on the initial TC concentration and increasing TC concentration from 10 to 40 mg l(-1) led to the decrease of the photolysis rate constant from 0.0045 min(-1) to 0.0014 min(-1). TC photolysis was highly pH-dependent and strongly enhanced at high pH value. Markedly elevated TC photolysis was also observed in the presence of nitrate and dissolved organic matter. Upon irradiation for 300 min, only 15% reduction of total organic carbon (TOC) occurred in spite of quick conversion of 73% of TC, suggesting that a majority of TC transformed into intermediate products without complete mineralization. The intermediate products from TC photolysis were analyzed using high-performance liquid chromatography-electrospray ionisation-mass spectrometry (HPLC-ESI-MS) and the main photolysis products of TC were proposed. The toxicity of the photolysis compounds was evaluated using luminescent bacterium, and the results revealed that the toxicity increased with irradiation, indicative of a higher adversity risk of the degradation products of TC on bacteria upon photolysis. (C) 2008 Elsevier Ltd. All rights reserved.