鼠李糖脂对不同菌株降解柴油污染物的影响

通过一系列实验分析了鼠李糖脂对柴油污染物生物降解的影响。单菌株柴油降解实验结果表明,在添加生物表面活性剂鼠李糖脂后,各菌株细胞表面疏水性均发生不同程度的增加,并且对柴油的降解率均有所提高。在混合菌的柴油污染物降解实验中,发现当向土壤中添加了200 mg/L鼠李糖脂时,对柴油的降解才有较大的提高;而当添加100 mg/L的鼠李糖脂到水体中时,对柴油的降解就有较大的提高,而当鼠李糖脂浓度提高为200 mg/L时,柴油的降解率却没有进一步明显的提高。这说明鼠李糖脂对柴油降解的影响程度不仅与环境介质有关,还与添加的鼠李糖脂浓度有关。进一步分析表明,添加适当浓度的鼠李糖脂不仅可以提高对柴油的降解率,而且可加速其降解速度,缩短生物修复所需时间。     

重金属对海岸带沉积物中菊酯生物降解的影响

通过考察Cu2+、Cd2+对渤海海岸带沉积物中甲氰菊酯、氯氰菊酯和溴氰菊酯的缺氧生物降解的影响,发现:外加Cu2+和Cd2+均对渤海海岸带沉积物中甲氰菊酯、氯氰菊酯和溴氰菊酯的缺氧生物降解有抑制作用,且随着外加金属离子浓度的增大,抑制作用更为明显。与Cu2+相比较,Cd2+对渤海沉积物中拟除虫菊酯缺氧生物降解的抑制作用更大,这跟Cu、Cd在渤海海岸带沉积物中的存在形态和对生物的毒性不同有密切的关系。     

微囊藻毒素-LR降解菌的筛选及降解特性研究

从上海市淀山湖表层水体中筛选分离出了1株降解微囊藻毒素-LR(MC-LR)的细菌并研究了其降解特性。根据细胞形态结构、生理生化特征及其16S rDNA基因序列分析,鉴定分离菌株DHU-28(GenBank序列登录号为HM047512)属嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)。微囊藻毒素降解实验结果表明,该菌株能在以MC-LR为唯一碳源、氮源的无机盐培养基中生长,6 d内可将初始质量浓度为15 mg/L的MC-LR降解为8.12 mg/L,降解效率达到45.9%。菌株DHU-28的最适生长温度是30℃,最适生长pH为7.0。酵母粉、蛋白胨、葡萄糖等营养物质可以明显促进菌株对MC-LR的降解效率,尤其是加入50 mg/L酵母粉后,6 d降解率达到63.2%。     

表面活性剂对Bacillus pumilus strain Bap9降解苯并[a]芘的影响

研究了非离子型表面活性剂Triton X-100（TX-100）和Tween80（TW-80）对苯并[a]芘的增溶特性及对苯并[a]芘高效降解菌Bacillus pumilus strain Bap9生长的影响,结果表明,2种表面活性剂对苯并[a]芘均有良好的增溶效果,均能作为碳源和能源被菌株Bap9所利用,TX-100增溶能力和增殖能力相对更强;不同浓度的TX-100对菌株降解苯并[a]芘的影响不同,当浓度为1 000 mg/L时,对降解的促进作用最强,可将苯并[a]芘降解率提高20.8%;在苯并[a]芘降解过程中,TX-100亦能作为碳源被菌株Bap9利用,不产生二次污染,因此可用于苯并[a]芘污染环境的生物修复。     

膜生物反应器处理甲苯废气的降解特性及传质过程强化

设计了一种气相空间带方形扰流柱结构的平板膜生物反应器,进行了甲苯降解废气净化实验,并与未加入方形扰流柱结构的反应器进行了对比。实验研究了甲苯入口浓度和气体流量对甲苯降解效率和传质速率的影响,结果表明,随着甲苯入口浓度和气体流量的增加,膜生物反应器降解效率降低,甲苯的传质速率增大,气相空间加入方形扰流柱后,甲苯在反应器中的传输得到了强化,降解效率最大提高了8%。     

免水生物降解型生态厕所专用菌剂

针对免水生物降解型生态厕所专用的进口菌种成本偏高、不能长期高效运行等现状,从土壤中分离筛选得到6株降解菌并将其培养成1组复合菌,然后分别进行降解实验。结果表明,7组实验菌对人体排泄物降解效果良好,其中复合菌种更好,COD降解率达到59%。对实验菌种进行初步鉴定,显示6株菌分别是粪肠球菌、木糖葡萄球菌、蜡状芽孢杆菌、产氨棒杆菌、地衣芽孢杆菌和活动肉杆菌。优选的专用菌剂的制备及保存方法效果良好,保存半年后菌剂仍有较高活性。     

辛基酚的好氧生物降解及微生物群落特征

利用典型的活性污泥实验了辛基酚(octylphenol,OP)的生物降解性能。研究了水力停留时间、OP浓度和碳氮比对OP处理效率的影响,通过实时PCR和PCR-DGGE方法分别分析了微生物群落的总体密度和多样性变化。通过30d的启动,OP在序批式活性污泥典型好氧条件下出现有效生物降解。在OP浓度50～150μg/L整个实验过程中,OP去除率(84%～99%)基本保持稳定。在实验范围内,较长的水力停留时间(12 h)和碳氮比(2∶1)有利于OP生物降解。通过实时PCR方法测定得到系统微生物平均密度约为1.22 g/L,但富碳状态下生物密度增长上升。通过DGGE分离到17种优势基因型,包括了α-proteobacteria(6种)、β-proteobacteria(5种)、γ-proteobacteria(2种)、Actinobacteria(2种)和δ-proteobacteria(1种)群落。α-proteobacteria和δ-proteobacteria菌群密度呈现增长,β-proteobacteria和Actinobacteria菌群中的部分种类密度出现减少,OP在活性污泥中的好氧生物降解可能与α-proteobacteria中的特定类别相关。     

外加碳源对选矿废水浮选药剂生物降解效果的影响

研究了外加葡萄糖、淀粉、乙酸钠3种碳源对SBR法降解模拟选矿废水浮选药剂的影响.实验结果表明:在停留时间为2h、苯胺黑药(二苯胺基二硫代磷酸)、黄药(丁基黄原酸钠)、乙硫氮(三水合二乙基二硫代氨基甲酸钠)初始质量浓度分别为120,6,3 mg/L的条件下,以淀粉为外加碳源时,3种浮选药剂的降解效果最好,苯胺黑药、黄药、...     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

Dynamic changes in microbial activity and community structure during biodegradation of petroleum compounds： A laboratory experiment

With 110-d incubation experiment in laboratory,the responses of microbial quantity,soil enzymatic activity,and bacterial community structure to different amounts of diesel fuel amendments were studied to reveal whether certain biological and biochemical characteristics could serve as reliable indicators of petroleum hydrocarbon contamination in meadow-brown soil,and use these indicators to evaluate the actual ecological impacts of 50-year petroleum-refining wastewater irrigation on soil function in Sbenfu irrigation area.Results showed that amendments of≤1000 mg/kg diesel fuel stimulated the growth of aerobic beterotrophic bacteria,and increased the activity of soil dehydrogenase,hydrogenperoxidase,polypbenol oxidase and substrate-induced respiration.Soil bacterial diversity decreased slightly during the first 15 d of incubation and recovered to the control level on day 30.The significant decrease of the colony forming units of soil actinomyces and filamentous fungi can be taken as the sensitive biological indicators of petroleum contamination when soil was amended with≥5000 mg/kg diesel fuel.The sharp decrease in urease activity was recommended as the most sensitive biochemical indicator of heavy diesel fuel contamination.The shifts in community structure to a community documented by Sphingomonadaceae withinα-subgroup of Proteobacteria could be served as a sensitive and precise indicator of diesel fuel contamination.Based on the results described in this paper,the soil function in Shenfu irrigation area was disturbed to some extent.