Biodegradation of organochlorine pesticide endosulfan by bacterial strain Alcaligenes faecalis JBW4

The recently discovered endosulfan-degrading bacterial strain Alcaligenesfaecalis JBW4 was isolated from activated sludge. This strain is able to use endosulfan as a carbon and energy source. The optimal conditions for the growth of strain JBW4 and for biodegradation by this strain were identified, and the metabolic products of endosulfan degradation were studied in detail. The maximum level of endosulfan biodegradation by strain JBW4 was obtained using broth at an initial pH of 7.0, an incubation temperature of 40℃ and an endosulfan concentration of I00 mg/L. The concentration of endosulfan was determined by gas chromatography. Strain JBW4 was able to degrade 87.5% of α-endosulfan and 83.9% of β-endosulfan within 5 days. These degradation rates are much higher than the previously reported bacterial strains. Endosulfan diol and endosulfan lactone were the major metabolites detected by gas chromatography-mass spectrometry; endosulfan sulfate, which is a persistent and toxic metabolite, was not detected. These results suggested that A. faecalis JBW4 degrades endosulfan via a non-oxidative pathway. The biodegradation of endosulfan by A. faecalis is reported for the first time. Additionally, the present study indicates that strain JBW4 may have potential for the biodegradation of endosulfan residues.     

Molecular simulation and experimental studies on CO2 and N2 adsorption to bituminous coal

Environmental Science and Pollution Research - A coal fire is one of the most serious disasters in coal mining. To improve the efficiency of an inert gas for extinguishing the fire, the adsorption...     

Surfactant-assisted adsorption of uranyl ions in aqueous solution on TiO2/polythiophene nanocomposite

In this work, hexadecyltrimethylammonium-bromide (HTAB)-modified polythiophene (PTh)/TiO₂ nanocomposite (HTAB/PTh/TiO₂) was applied to remove uranyl ions (UO₂²⁺). FT-IR, XRD, ζ potential, TGA, SEM, and XPS were utilized to obtain the chemical and physical properties of HTAB/PTh/TiO₂. The effects of HTAB content, preparation temperature, and adsorption conditions on UO₂²⁺ removal were investigated comprehensively. And the UO₂²⁺ adsorption process on HTAB/PTh/TiO₂ was fitted to the Sips model with a saturated adsorption capacity of 234.74 mg/g, which was 6 times over TiO₂. The results suggested that the surfactant of HTAB can significantly improve the adsorption ability of TiO₂ for UO₂²⁺ ions. This work provides a strategy of surfactant modification for enhancing the separation and recovery ability of adsorbent toward UO₂²⁺ in the radioactive wastewater.

     

Association between ambient temperature and childhood respiratory hospital visits in Beijing,China: a time-series study (2013–2017)

Environmental Science and Pollution Research - Little is known on the potential impact of temperature on respiratory morbidity, especially for children whose respiratory system can be more...     

LncRNA NEAT1 contributes to the acquisition of a tumor like-phenotype induced by PM 2.5 in lung bronchial epithelial cells via HIF-1α activation

Environmental Science and Pollution Research - The hazards of particulate matter (PM2.5) on human respiratory health have been previously reported. However, the molecular mechanisms underlying...     

煤矿采掘废弃物对地下水的影响

对抚顺矿区西舍场地下水做了调查及水质分析，结果表明：舍场地下水水质极差，为高矿化度、高硬度、重盐碱的硫酸盐型水，已失去饮用和工农业生产使用价值，成为域内地下水运移有害成分的载体。     

高职高专英语教学改革阶段性分析

为适应我校高职高专英语教学改革的要求，根据课题“高职高专英语教学改革的研究与探索”的研究目标和研究任务，本文提出了具体的实施步骤，分析了考试结果，进行了经验总结。     

论安全文化建设的基础和推动力

结合工作实践 ,笔者在分析了安全文化的内涵和外延的基础上 ,通过论述安全宣传教育不同的层次而形成的覆盖面和宣传教育工作在改善人的意识、观念和行为模式中的作用机理 ,确认安全宣传教育的有效开展是安全文化建设的前提和基础。并根据市场经济活动的规律和特点 ,进一步提出行政指导和行政强制是推进企业安全文化建设的必要条件