Al-Rajab Abdul Jabbar, Sabourin Lyne, Scott Andrew, Lapen David R, Topp Edward
Agriculture and Agri-Food Canada, London, Ontario, Canada.
Sci Total Environ. 2009 Nov 15;407(23):5978-85. doi: 10.1016/j.scitotenv.2009.08.003. Epub 2009 Sep 5.
The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC) are widely used in many personal care products. Knowledge concerning the fate of these two compounds in different environmental matrices is scarce. In this study, the fate of TCS and TCC in soil following direct addition, or when residues were applied via either liquid municipal biosolids (LMB) or dewatered municipal biosolids (DMB) was investigated in laboratory dissipation experiments and under outdoor conditions using radioisotope methods. In laboratory incubations, (14)C-TCC or (14)C-TCS was added to microcosms containing a loam soil and the rate of (14)CO(2) accumulation and loss of solvent-extractable (14)C were determined during incubation at 30 degrees C. Compared to when TCC or TCS was added directly to soil, both chemicals were mineralized more rapidly when applied in LMB, and both were mineralized more slowly when applied in DMB. The application matrix had no effect on the rate of removal of extractable residues. In field experiments, parent compounds were incorporated directly in soil, incorporated via LMB, or a single aggregate of amended DMB was applied to the soil surface. During the experiment soil temperatures ranged from 20 degrees C to 10 degrees C. Dissipation was much slower in the field than in the laboratory experiments. Removal of non-extractable residues was faster in the presence of LMB than the other treatments. Recovery of extractable and non-extractable residues suggested that there was little atmospheric loss of (14)C. Triclocarban readily formed non-extractable residues with DMB whereas TCS did not. Overall, this study has identified that both the pathways and the kinetics of TCS and TCC dissipation in soil are different when the chemicals are carried in biosolids compared to when these chemicals are added directly to the soil.
广谱抗菌剂三氯生（TCS）和三氯卡班（TCC）被广泛应用于许多个人护理产品中。关于这两种化合物在不同环境基质中的归宿的知识却很匮乏。在本研究中，通过实验室消解实验以及在户外条件下使用放射性同位素方法，研究了直接添加三氯生和三氯卡班后，或者当通过液态城市生物固体（LMB）或脱水城市生物固体（DMB）施加其残留物时，它们在土壤中的归宿。在实验室培养中，将¹⁴C-TCC或¹⁴C-TCS添加到含有壤土的微观世界中，并在30℃培养期间测定¹⁴CO₂的积累速率和可溶剂萃取的¹⁴C的损失。与直接将TCC或TCS添加到土壤中相比，当以LMB形式施用时，两种化学物质的矿化速度更快，而当以DMB形式施用时，两者的矿化速度更慢。施用基质对可萃取残留物的去除速率没有影响。在田间实验中，将母体化合物直接掺入土壤中，通过LMB掺入，或将单个改良DMB聚集体施用于土壤表面。在实验期间，土壤温度范围为20℃至10℃。田间的消解比实验室实验慢得多。在存在LMB的情况下，不可萃取残留物的去除比其他处理更快。可萃取和不可萃取残留物的回收率表明¹⁴C几乎没有大气损失。三氯卡班很容易与DMB形成不可萃取的残留物，而三氯生则不会。总体而言，本研究已经确定，与直接将这些化学物质添加到土壤中相比，当这些化学物质通过生物固体携带时，三氯生和三氯卡班在土壤中的消解途径和动力学是不同的。
