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1.
生物强化和生物刺激对土壤中PAHs降解的影响 总被引：6，自引：2，他引：6
采用生物强化(农田土中添加PAHs污染土或污泥)和生物刺激(PAHs污染土中添加(NH4)2HPO4)2种措施,研究了土壤中13种PAHs的降解及CO2的释放量.结果显示,农田土壤中的微生物对2~5环的PAHs都有较强的降解能力,添加污染土显著增强了对5环PAHs的降解,表明污染土中的微生物对高环PAHs的降解能力更强;添加污泥对促进PAHs降解的作用不明显,可能是好氧培养条件不适合厌氧菌的生长.添加N、P营养盐可显著提高污染土中3~4环PAHs的降解,但5环PAHs在添加和未添加N、P中的降解率始终较低,均小于10%.CO2的释放呈现先增加再降低,再略微增加直至平稳的过程,且与PAHs的降解高度响应,说明PAHs的降解与微生物活性密切相关. 相似文献
2.
F. Olcay Topac Sagban 《环境科学学报(英文版)》2011,23(4):616-623
The possible impacts on nitrogen-cycle in a p-nitrophenol (PNP) polluted soil and the e ectiveness of wastewater sludge amendmentsin restoring nitrification potential and urease activity were evaluated by an incubation study. The results indicated that PNP at 250 mg/kgsoil inhibited urease activity, nitrification potential, arginine ammonification rate and heterotrophic bacteria counts to some extents.After exposure to PNP, the nitrification potential of the tested soil was dramatically reduced to zero over a period of 30 days. Basedon the findings, nitrification potential was postulated as a simple biochemical indicator for PNP pollution in soils. Nitrogen-cyclingprocesses in soils responded positively to the applications of wastewater sludges. A sludge application rate of 200 tons/ha was su cientfor successful biostimulation of these nitrogen processes. The microbial activities in sludge-amended, heavy PNP-polluted soils seemedto recover after 30–45 days, indicating the e ectiveness of sludge as a useful soil amendment. 相似文献
3.
向污染土壤中加入外源氮进行生物刺激修复是目前广为采用的土壤有机污染修复技术.然而,目前对于修复过程中土壤微生物类群对组分烃的代谢特征尚不清楚.本文以13C标记的十六烷污染土壤为研究对象,利用稳定同位素标记-磷脂脂肪酸技术(stableisotopelabeling-phospholipidfattyacid technology,13C-SIP-PLFA)研究了加入硝酸钾和有机肥对石油污染土壤进行修复时,不同微生物类群对十六烷的利用特征.结果表明,与自然降解（CC）相比,加入KNO3（CN）和施入有机肥（CY）的处理均可提高土壤中十六烷的去除效率.修复30 d时,土壤中十六烷的去除率由6.14%（CC）提高至13.6%（CN）和15.0%（CY）.加入硝酸钾修复使得土壤微生物总量略有降低(总PLFAs由82.8 nmol·g-1（CC）降低至79.7 nmol·g-1（CN）),但被微生物同化为细胞组分的十六烷含量（13C-PLFA）由81.12 ng·g-1（CC）增加至92.84 ng·g-1（CN）,硝酸钾生物刺激修复提高了革兰氏阳性菌和真菌对十六烷的同化代谢作用.加入有机肥修复的土壤中,微生物总量(总PLFAs为99.3 nmol·g-1)和微生物同化代谢十六烷的含量均明显增加(13C-PLFA为142.67 ng·g-1),土壤中革兰氏阳性菌和放线菌对十六烷的同化代谢作用明显增强.在不同修复处理的土壤中,可利用十六烷的主要微生物有G+菌i15:0和a15:0、G-菌16:1ω5c和16:1ω7c、真菌18:1ω9c、放线菌16:0（10Me）和Unspecific菌16:00.结果表明,革兰氏阳性菌是不同修复处理中最主要的十六烷降解菌,两种修复剂对土壤不同微生物类群的代谢激活作用存在差异. 相似文献
4.
2,4,6-三硝基甲苯(TNT)是1种硝基芳香族污染物,对人类和生态环境造成严重危害.全面了解微生物对TNT胁迫的细胞反应,对于开发合理的TNT修复技术是必要的.本研究以蜡样芽孢杆菌T4为研究对象,筛选细菌最适的生物刺激因子,分析外源营养物质刺激对细菌生长及TNT转化的影响.利用转录组和代谢组学技术,揭示微生物对TNT的降解和耐受机制.结果显示,该细菌的最适碳氮源分别为葡萄糖、酵母粉.当TNT浓度为100 mg·L-1时,培养基中葡萄糖和酵母粉浓度分别为9.08 g·L-1和0.94 g·L-1.在泥浆反应体系中接种TNT降解菌,TNT的降解率达到96.91％～97.73％.此外,共鉴定到892个差异表达基因和139个差异代谢物.组学联合分析表明,氨基酸代谢、碳水化合物代谢、能量代谢和膜转运途径参与了细菌对TNT的降解及耐受过程. 相似文献
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介绍了生物修复石油污染海滩时常用的修复剂类型及其特点.当实验室环境条件能较好控制时,生物强化剂一般是有效的;然而污染现场得出的证据不能表明其对生物降解有促进作用.实验室和现场的研究均表明营养型生物促进剂能有效促进石油的生物降解.水溶性营养易被波浪和潮汐冲刷掉;缓释型营养盐面临的主要挑战是如何控制其释放速率,以保证孔隙水中能较长时间维持理想的营养浓度;亲油型肥料中含有有机碳,有可能在微生物降解石油之前被优先降解.建议根据污染环境的特点选用适合的生物促进剂. 相似文献
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通过室内实验,探究了低浓度过硫酸盐预氧化耦合生物强化或生物刺激技术处理下土壤中菲的降解率和修复效应。结果表明,浓度为0.1 mmol·g−1、温度为50 ℃热活化的过硫酸钠对土壤中菲7 d的降解率为22.7%。预氧化后,加入高效降解菌和营养物质,强化微生物对菲的降解,继续培育21 d,最终降解率较第7天可提高8.08%~18.59%。同时添加高效降解菌和营养物质N,对土壤中菲的降解促进作用最强,最终降解率可达41.29%,较仅进行化学氧化的对照组和仅进行微生物降解的对照组分别提高17.44%和22.86%,较预氧化后不进行微生物强化的对照组提高12.9%。降解期间,土壤微生物数量和pH呈先下降,后上升趋势,最终维持在相对稳定水平。相关性分析结果表明,土壤中菲的降解率与氧化剂和营养物质N的添加呈显著正相关,土壤微生物数量与pH呈正相关,与氧化剂呈负相关,土壤pH与氧化剂及营养物质P呈负相关。研究结果证实了化学预氧化耦合生物强化和生物刺激技术能有效促进微生物对菲污染土壤的修复。 相似文献
7.
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that are mutagenic, carcinogenic, and toxic to living organisms. Here, the ability and effectiveness of selected bacteria isolated from an oil‐contaminated area in biodegrading PAHs were evaluated, and the optimal conditions conducive to bacterial PAH biodegradation were determined. Of six bacterial isolates identified based on their 16S rRNA sequences, Planomicrobium alkanoclasticum could subsist on and consume nearly all hydrocarbons according to the 2,6‐dichlorophenolindophenol assay. The efficacy of this isolate at PAH biodegradation was then empirically confirmed. After 30 days of incubation, P. alkanoclasticum degraded 90.8% of the 16 PAH compounds analyzed and fully degraded eight of them. The optimum P. alkanoclasticum growth conditions were 35°C, pH 7.5, and NaNO3 as the nitrogen source. Under these biostimulant conditions, P. alkanoclasticum degraded 91.4% of the total PAH concentration and completely decomposed seven PAHs after 15 days incubation. Hence, P. alkanoclasticum is an apt candidate for the biodegradation of PAHs and the bioremediation of sites contaminated by them. 相似文献
8.
1,2-Dichloroethane (DCA), a potential mutagen and carcinogen, is commonly introduced into the environment through its industrial and agricultural use. In this study, the impact of lead and mercury on DCA degradation in soil was investigated, owing to the complex co-contamination problem frequently encountered in most sites. 1,2-Dichloroethane was degraded readily in both contaminated loam and clay soils with the degradation rate constants ranging between 0.370-0.536 week1 and 0.309-0.417 week1, respectively... 相似文献
9.
Multiple biostimulation treatments were applied to enhance the removal of heavy crude oil pollutants in the saline soil of Yellow River Delta. Changes of the soil bacterial community were monitored using the terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses. The 140-day microcosm experiments showed that low C:N:P ratio, high availability of surfactant and addition of bulking agent significantly enhanced the performance, leading to the highest total petroleum hydrocarbon removal. Meanwhile, the bacterial community was remarkably changed by the multiple biostimulation treatments, with the Deltaproteobacteria, Firmicutes, Actinobacteria, Acidobacteria and Planctomycetes being inhibited and the Alpha- and Beta-proteobacteria and some unknown Gammaproteobacteria bacteria being enriched. In addition, different hydrocarbon-degraders came to power in the following turn. At the first stage, the Alcanivorax-veldXed Gammaproteobacteria bacteria dominated in the biostimulated soil and contributed mainly to the biodegradation of easily degradable portion of the heavy crude oil. Then the bacteria belonging to Alphaproteobacteria, followed by bacteria belonging to Candidate division OD1, became the dominant oil-degraders to degrade the remaining recalcitrant constituents of the heavy crude oil. 相似文献
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