Osterreicher-Cunha Patricia, Langenbach Tomaz, Torres João P M, Lima Ana L C, de Campos Tácio M P, Vargas Júnior Eurípedes do A, Wagener Angela R
Programa de Pós-Graduação em Biotecnologia Vegetal, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Environ Res. 2003 Nov;93(3):316-27. doi: 10.1016/s0013-9351(03)00091-4.
The closing down of a lindane factory near Rio de Janeiro, over 45 years ago, left an area heavily contaminated with hexachlorocyclohexane (HCH). Remediation by soil liming was applied by government authorities in 1995. This study aims to evaluate the HCH distribution and impact on soil microbiota due to contamination and liming. Microcosm experiments with uncontaminated soil mixed with HCH and lime indicated that lime-promoted dechlorination of HCH molecules led to leaching and volatilization of metabolites. The treatment applied transformed but did not solve the problem as most of the HCH remains in the soil. Reduced microbial respiratory activity was measured in contaminated field samples. Higher respiration rates in uncontaminated soil were reduced by HCH and lime addition; the sole addition of HCH caused a temporary increase in soil respiration, and stimulation occurred with oxygen and/or nutrient addition. A heterotrophic bacterial population around 10(9)CFU/g was found in polluted field soil, some well-known degraders having been isolated. Native soil microbiota showed resistance to high amounts of HCH and alkaline pH. The results allow considering bioremediation rather than chemical treatments to clean up the area.
45多年前，里约热内卢附近的一家林丹工厂关闭，导致该地区被六氯环己烷（HCH）严重污染。1995年，政府当局采用了土壤加石灰改良法进行修复。本研究旨在评估六氯环己烷的分布情况以及污染和加石灰处理对土壤微生物群的影响。用未受污染的土壤与六氯环己烷和石灰混合进行的微观实验表明，石灰促进的六氯环己烷分子脱氯导致代谢产物的淋溶和挥发。所采用的处理方法虽有改变，但并未解决问题，因为大部分六氯环己烷仍残留在土壤中。在受污染的田间样本中测得微生物呼吸活性降低。未受污染土壤中较高的呼吸速率因添加六氯环己烷和石灰而降低；单独添加六氯环己烷会使土壤呼吸暂时增加，添加氧气和/或养分则会刺激呼吸。在受污染的田间土壤中发现了约10（9）CFU/g的异养细菌种群，并且分离出了一些知名的降解菌。原生土壤微生物群对高含量的六氯环己烷和碱性pH具有抗性。研究结果表明可以考虑采用生物修复而非化学处理来清理该区域。
