喹啉与葡萄糖共基质条件下生物降解的动力学分析

研究了在喹啉与葡萄糖共基质时皮氏伯克霍尔得氏菌 (Burkholderiapickettii)对二者的降解动力学 .结果表明 :在共基质条件下 ,喹啉与葡萄糖能同时被微生物降解 .葡萄糖的存在对喹啉的生物降解起到一定的促进作用 ,而喹啉的存在减慢了微生物对葡萄糖的降解作用 .5 0mg·L-1喹啉与 34、6 0、110mg·L-1葡萄糖共基质时 ,喹啉与葡萄糖的降解都遵循一级反应动力学 .30 0mg·L-1喹啉与 110、32 0、6 90mg·L-1葡萄糖共基质时 ,喹啉的降解已不遵循一级或零级反应 ,而葡萄糖在 110mg·L-1时仍为一级反应 ,增到 32 0、6 90mg·L-1时转变为零级反应动力学     

糖蜜酒精废液厌氧生物降解生物化学甲烷势分析

在中温条件下,对pH值和营养比例2个影响因素进行了糖蜜酒精废液的BMP分析,探讨酒精废液在厌氧消化过程中产甲烷量、COD浓度的变化情况,以及COD去除率与产气量、pH值之间的关系.研究结果表明,厌氧处理法能够使糖蜜酒精废液的有机负荷大大降低,COD去除率最高可达90.6%.在调节营养比例的条件下,pH=8.5时甲烷菌活性最佳,其中COD:P=300:1的产甲烷量最高.     

Removal of Microcystins by Phototrophic Biofilms. A Microcosm Study (6 pp)

Background, Aims and Scope Microcystins (MCs) are a family of natural toxins produced by cyanobacteria (blue-green algae). As a result of eutrophication, massive cyanobacterial blooms occur more frequently and MCs represent important contaminants of freshwater ecosystems. Bacterial biodegradation is considered a main mechanism for MC breakdown in environmental conditions. While existing studies were mostly focused on MC biodegradation by planktonic bacteria, our experiments examined the fate and kinetics of MC degradation in river-originated phototrophic biofilms and investigated factors influencing the rate of MC removal. Methods The fate of dissolved MCs was studied in laboratory microcosms with different composition (containing water only, water with phytoplankton and/or phototrophic biofilms). Biofilms originated from river ecosystem were pre-incubated under various conditions (with/without presence of cyanobacterial biomass or model organic substrates: glucose and protein - casein). Changes in MC concentration (0-14 days) in water columns were measured by HPLC DAD after external additions of purified MCs (160 μg L-1, MC-LR and MC YR), and halftimes (t1/2) of MC removal were estimated. Results and Discussion The slow degradation of MC was revealed in tap water (t1/2 ~ 14 days) and river water without cyanobacteria (t1/2 ~ 8 days). Enhanced removal occurred in the presence of natural planktonic cyanobacteria (t1/2 ~ 44 h), most probably due to microorganisms associated with the biomass of cyanobacterial bloom. More rapid MC elimination occurred in the variants containing phototrophic biofilms, and was particularly pronounced at those biofilms pre-cultivated in the presence of cyanobacterial blooms (t1/2 ~ 20 h). Much slower removal was observed in the variants simulating possible substrate-dependent induction of microorganism metabolism (biofilms pre-incubated with glucose: t1/2 ~ 35 h, and casein: t1/2 ~ 80 h). After termination of experiments, total amounts of MCs accumulated in the biofilms were below 5% of the initial toxin level revealing significant biodegradation processes. Conclusion The microcosm studies contributed to understanding of the environmental fate of MCs and revealed a rapid biodegradation by phototrophic biofilms. The rate of MC elimination depends on history of biofilm community, previous contact with cyanobacteria seems to be a selective factor improving the biodegradation potential. Recommendation and Outlook Our results experimentally showed a positive role of biofilms in MC elimination during water treatment processes such as bank filtration or slow sand filtration, and could eventually serve for further research of biofilm-based technological applications for MCs removal in small-scale drinking water treatment facilities.     

生物表面活性剂及其在环境修复中的研究进展

生物表面活性剂是由微生物分泌的天然产物，由于其物理性质和化学结构与许多人工合成的表面活性剂相似，并且对土壤、淡水、海洋等生态系统毒性较低，因而在环境污染治理方面，特别是在重金属和石油等有机溶剂污染的原位和异位生物修复方面具有极大的应用潜力。主要综述了近年国内外生物表面活性剂在廉价制备、作用机理、环境修复中的研究进展。     

富含腐殖酸还原混合菌的污泥厌氧降解对乙酰氨基酚的机制

以杭州市四堡污水处理厂的厌氧污泥为接种污泥,驯化富集了厌氧腐殖酸还原混合菌,加入不同的腐殖酸和碳源以优化驯化条件.结果表明,利用驯化厌氧污泥降解对乙酰氨基酚,1周降解时间内,驯化1个月的含腐殖酸还原混合菌群污泥比普通厌氧污泥降解率高34%,驯化半年的成熟厌氧污泥降解效果更好,降解率达90%以上.驯化厌氧污泥的最佳pH为7.0,Fe3 与腐殖酸同时存在时能进一步提高对乙酰氨基酚的厌氧生物降解效果.     

低温微生物环境污染修复技术研究进展

生物修复技术由于成本低、效果好、对环境负面影响小,且无二次污染等优点,受到普遍的关注,已成为环境治理的重要方法和技术.目前微生物修复技术多以常温微生物为主,而在自然环境中,占地表绝大部分的极地、海洋、湖泊以及高山和高纬地区的土壤等,其全年平均温度大多在15℃或以下,恰恰是低温微生物的最适生长温度.因此,以低温微生物为主的生物修复技术,在常年低温的极地、海洋、高山或高纬区域以及若干地区冬季进行污染物的生物降解方面有独到的优势.目前,以低温微生物为主体的低温生物修复技术已成了生物修复技术研究领域的热点.从4个方面讨论目前利用低温微生物所开展的低温生物修复技术的最新发展动态.     

一株有机浮选药剂——黄原酸盐降解菌的特性研究

从矿山废水中经富集分离到一株能以黄原酸盐为惟一碳源的黄原酸盐降解菌，初步鉴定为铜绿假单胞菌属。菌株降解黄原酸盐的最佳条件为：pH为8，温度30℃，振荡速率120r／min。当黄原酸盐浓度达到1500mg／L时，24h后浓度降解率为95．7％，COD去除率为84．7％。黄原酸盐浓度越高，COD去除率越高。当加入0．2g／L的葡萄糖时可大大提高菌对黄原酸盐的降解率。     

厌氧折流板反应器处理化纤厂棉浆粕综合废水的实验研究

对新型厌氧反应器(ABR)处理化纤厂棉浆粕综合废水进行了研究。试验结果表明:采用ABR厌氧处理该废水,可以有效去除其中的有机物,在HRT为1d、进水COD为3360mg/L、有机负荷(OLR)为3.36kgCOD/(m3·d)的条件下,COD去除率为71.5%,出水COD降至958mg/L;利用浆粕黑液和纺丝废水混合调节pH,可以减少碱的用量,降低运行成本。     

有机污染物湿地生物降解实验规律研究

本文以苯、甲苯和萘为对象 ,通过实验研究 ,测定有机污染物的土壤 水吸附平衡过程、在水溶液中生物降解过程以及在湿地系统 (即土壤 水 微生物系统 )中生物降解过程 ,并以质量守恒定律为基础 ,建立有机污染物湿地生物降解过程综合数学模型 ;数学模型通过实验验证。利用模型 ,定量预测了污染物生物降解所需的时间和程度 ,并提出动力学因子FK,判断污染物湿地生物降解速度的控制因素 ,定量预测了污染物在土壤固相的浓度分布规律     

二噁口英及类似有毒有害物的处理技术

二(口恶、口英)、多氯联苯、多环芳香烃及化学武器等有毒有害物的处理技术已取得长足进展.这些有毒有害物的处理技术可概括为物理方法、化学方法、物理化学方法和生物降解法.本文从概念、应用场合、分解效率以及操作条件等方面对这些方法分别进行了介绍,重点介绍和评述了吸附和催化法,以及应用前景很好的生物降解技术.