As technological advances allow the development of new products, the number of synthetic chemical compounds released into the soil, surface water and groundwater increases, posing a threat to the environment. Therefore, treatability studies to improve bioremediation strategies (biostimulation and bioaugmentation) were applied to samples of soil containing nitro and chlorinated aromatic compounds from a former chemical manufacturing site in Brazil. Native microorganisms were stimulated to degrade compounds including dichloroanilines, dichloronitrobenzenes, 2-chloronitrobenzene, and 1,2-chlorobenzene, through oxygen exposure and pH (6.0-8.4) and moisture content (13-23%) adjustments. For the inoculation of soil samples, a culture enriched from site groundwater was developed. The aeration alone stimulated the indigenous microbes to degrade some of the compounds. However, reinoculation with an enriched culture and moisture content adjustment increased the attenuation rates by 3.6 and 1.4 times, respectively. The pH values in the range of 7.6 and 8.4 seem not to harm microbes' activity and moisture content higher than 16% is recommended to enhance biodegradation. Based on the findings, it is likely that natural attenuation is happening in aerobic zones at the site. Results indicate both bioremediation strategies (biostimulation and bioaugmentation through reinoculation with enriched culture mainly composed of organisms from the Diaphorobacter genus) are promising strategies to enhance bioremediation. However, considering the applicability of the strategies on a field scale, further experiments will broaden the understanding of biodegradability of compounds, such as their inhibitory effects when in higher concentration (>150 mg/kg), individually or combined.

中文翻译：

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暴露于氯化和硝基芳香族化合物的工业场地土壤的生物修复策略

随着技术进步允许新产品的开发，释放到土壤、地表水和地下水中的合成化合物的数量增加，对环境构成威胁。因此，对来自巴西前化学制造厂的含有硝基和氯化芳香族化合物的土壤样品进行了可处理性研究，以改进生物修复策略（生物刺激和生物强化）。通过氧气暴露和 pH (6.0-8.4) 和水分含量 (13-23%) 调整，刺激原生微生物降解包括二氯苯胺、二氯硝基苯、2-氯硝基苯和 1,2-氯苯在内的化合物。为了接种土壤样品，开发了一种从现场地下水中富集的培养物。仅曝气就刺激了本地微生物降解一些化合物。然而，通过富集培养物重新接种和水分含量调整使减毒率分别增加了 3.6 倍和 1.4 倍。pH值在7.6和8.4范围内似乎不会损害微生物的活性，建议水分含量高于16%以增强生物降解。根据这些发现，自然衰减很可能发生在该地点的有氧区域。结果表明两种生物修复策略（通过重新接种主要由来自生物体的富集培养物进行生物刺激和生物增强）6和8.4似乎不会损害微生物的活性，建议水分含量高于16%以增强生物降解。根据这些发现，自然衰减很可能发生在该地点的有氧区域。结果表明两种生物修复策略（通过重新接种主要由来自生物体的富集培养物进行生物刺激和生物增强）6和8.4似乎不会损害微生物的活性，建议水分含量高于16%以增强生物降解。根据这些发现，自然衰减很可能发生在该地点的有氧区域。结果表明两种生物修复策略（通过重新接种主要由来自生物体的富集培养物进行生物刺激和生物增强）Diaphorobacter genus）是增强生物修复的有前途的策略。然而，考虑到这些策略在现场规模的适用性，进一步的实验将拓宽对化合物生物降解性的理解，例如它们在较高浓度（> 150 mg/kg）时的单独或组合的抑制作用。