Harrison I, Leader R U, Higgo J J, Williams G M
Fluid Processes & Waste Management Group, Kingsley Dunham Centre, Keyworth, Nottingham, U.K.
Chemosphere. 1998 Mar;36(6):1211-32. doi: 10.1016/s0045-6535(97)10043-1.
The biodegradation of three phenoxyalkanoic acid herbicides, viz. MCPA, dichlorprop and mecoprop, under aerobic and anaerobic conditions was investigated using microcosm techniques. The field studies were conducted in a limestone aquifer that had suffered contamination from leaking landfill sites in which phenoxyalkanoic acid herbicides (mostly mecoprop) had undergone disposal. The results from in situ field and laboratory microcosms indicated that under microbially active aerobic conditions the biotransformation of all three herbicides was rapid and that lag phases were short. Under fully aerobic conditions the concentration of each of the three herbicides was reduced from 2,000 micrograms/l to below the detection limit (approx. 10 micrograms/l) of the HPLC system, used for their analysis, within 14 days. However, under microbially active anaerobic conditions no degradation of the herbicides could be discerned over the 100-200 day duration of the experiments. This finding has significant implications for the disposal of phenoxyalkanoic acid herbicides particularly in situations where any resulting leachate may find its way into underlying water resources.
采用微观世界技术研究了三种苯氧基链烷酸除草剂，即2甲4氯（MCPA）、二氯丙酸和甲羧除草醚在好氧和厌氧条件下的生物降解情况。现场研究在一个石灰岩含水层中进行，该含水层受到垃圾填埋场渗漏的污染，这些垃圾填埋场曾处置过苯氧基链烷酸除草剂（主要是甲羧除草醚）。现场原位和实验室微观世界的研究结果表明，在具有微生物活性的好氧条件下，所有三种除草剂的生物转化都很快，且滞后期很短。在完全好氧条件下，三种除草剂中的每一种的浓度在14天内从2000微克/升降至用于分析它们的高效液相色谱系统的检测限（约10微克/升）以下。然而，在具有微生物活性的厌氧条件下，在100 - 200天的实验期间未发现除草剂有降解现象。这一发现对于苯氧基链烷酸除草剂的处置具有重要意义，特别是在任何产生的渗滤液可能流入地下水资源的情况下。
