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621.
Luo SL Chen L Chen JL Xiao X Xu TY Wan Y Rao C Liu CB Liu YT Lai C Zeng GM 《Chemosphere》2011,85(7):1130-1138
This study investigates the heavy metal-resistant bacterial endophytes of Cd-hyperaccumulator Solanum nigrum L. grown on a mine tailing by using cultivation-dependent technique. Thirty Cd-tolerant bacterial endophytes were isolated from roots, stems, and leaves of S. nigrum L. and classified by amplified ribosomal DNA-restriction analysis into 18 different types. Phylogenetic analysis based on 16S rDNA sequences showed that these isolates belonged to four groups: Actinobacteria (43%), Proteobacteria (23%), Bacteroidetes (27%) and Firmicutes (7%). All the isolates were then characterized for their plant growth promoting traits as well as their resistances to different heavy metals; and the actual plant growth promotion and colonization ability were also assessed. Four isolates were re-introduced into S. nigrum L. under Cd stress and resulted in Cd phytotoxicity decrease, as dry weights of roots increased from 55% to 143% and dry weights of above-ground from 64% to 100% compared to the uninoculated ones. The total Cd accumulation of inoculated plants increased from 66% to 135% (roots) and from 22% to 64% (above-ground) compared to the uninoculated ones. Our research suggests that bacterial endophytes are a most promising resource and may be the excellent candidates of bio-inoculants for enhancing the phytoremediation efficiency. 相似文献
622.
W Xi HT Wan YG Zhao MH Wong JP Giesy CK Wong 《Environmental science and pollution research international》2011,19(7):2515-2527
Purpose
In this study, we investigated the effects of maternal transfer of bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP) during gestational and weaning periods on gonadal development of male offspring.Methods
Pregnant CD-1 mice were administered by gavages in corn oil with 0.1, 1, or 10 mg/kg/day of BPA and DEHP from gestational days (GD1?C21) to the weaning period (postnatal days (PND) 1?C21).Results
Our data indicated that the exposure significantly reduced the male-to-female sex ratio and the sizes of the gonads of male pups as recorded at PND15. The testes of the perinatally exposed male pups were developed less and the expression levels of testicular anti-mullerian hormone, androgen receptor, cyclin A, and StAR were significantly lesser than the control male pups. The less developed testes were accompanied with significant reductions in the expression levels of Gnrh and Fsh at the hypothalamic?Cpituitary levels. The negative effects were found to be persistent in the sexually mature pups at PND42.Conclusion
Our data reveal that the maternal transfer of BPA and DEHP may impose negative influence on the development and functions of the reproductive system of male pups. 相似文献623.
要创建和谐生态工业园区应做到:坚持“环保优先”,强化环保基础设施建设;以“发展高科技、实现产业化”为根本目标;调整产业结构,改变经济增长方式,实现可持续发展;加大力度促进企业发展;大力加强环保宣传。 相似文献
624.
以淀粉废水水解酸化处理系统中的蛋白酶、淀粉酶、脱氢酶为研究对象,考察了在无机离子、营养元素、pH等条件作用下的酶比活变化规律.实验结果表明:Mg2+和Co2+对酶比活有显著影响,MgCl2·6H2O加入量为30 mg/L时蛋白酶、淀粉酶、脱氖酶的比活分别是空白的5.6倍、1.6倍、1.5倍,COD去除率提高17.6%;而CoCl2·6H2O加入量为10 mg/L时,蛋白酶和淀粉酶的比活较单独投加30 mg/L的MgCl2·6H2O时分别下降了80.6%和42.5%,脱氢酶比活却提高了13.2%;以NH4Cl与CO(NH2)2作为混合N源(m(NH4Cl):m(CO(NH2)2)=1:2)时蛋白酶、淀粉酶、脱氢酶的比活分别是单独以CO(NH2)2为N源时的3.0倍、1.4倍、1.8倍,COD去除率提高了11.8%;中性偏碱性条件较利于酶促反应的进行. 相似文献
625.
K.W. Pi L.X. Gao M.X. Fan W.Q. Gong D.J. Wan 《Process Safety and Environmental Protection》2009,87(5):336-342
The municipal landfill leachate was treated in a hydrolysis–acidification reactor (HAR)/aerobic bio-contact oxidation reactor (ABOR) following a pretreatment with ultrafiltration (UF) membrane. Experiments were conducted continuously for 44 days at a constant flow rate of 20 l d−1 and organic loading rates (OLRs) from 0.75 to 1.5 kgCOD m−3 per day. The results showed that COD of the leachate steadily decreased from 20,015 mg l−1 to less than 3000 mg l−1, and NH4-N decreased from 368.6 mg l−1 to 259.3 mg l−1 in the UF process. The COD and NH4-N removal efficiency of HAR was 56.7% and 27.7%, and that of ABOR was 94.6% and 86.7%, respectively. The total COD and NH4-N removal efficiency reached 99.6% and 93.2%, respectively. UF and HAR played a critical role in raising the biodegradability of the landfill leachate, while ABOR had an important function on removing the dissolved NH4-N in leachate. 相似文献
626.
627.
根据粤港政府<珠江三角洲地区空气质素管理计划>关于清洁生产的要求,在总结清洁生产技术支援试验项目经验的基础上,香港特区政府推出了清洁生产伙伴计划(CP3),旨在通过激励机制协助珠江三角洲地区的港资企业自愿参与节能减排行动.CP3主要包括认知推广、实地评估、清洁生产技术及作业方式的示范项目以及核证改善项目的成效等内容.印刷行业VOC减排成效案例及一般性厂房节能方案评估结果表明,CP3将有助于改善珠江三角洲区域空气质量. 相似文献
628.
Stelyus L. Mkoma Willy Maenhaut Xuguang Chi Wan Wang Nico Raes 《Atmospheric environment (Oxford, England : 1994)》2009,43(3):631-639
Ambient daily PM10 aerosol samples were collected at two sites in Tanzania in May and June 2005 (during the wet season), and their chemical characteristics were studied. The sites were a rural site in Morogoro and an urban kerbside site in Dar es Salaam. A Gent PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters, providing fine and coarse size fractions, and a PM10 sampler with quartz fibre filters were deployed. Parallel collections of 24 h were made with the two samplers and the number of these collections was 13 in Morogoro and 16 in Dar es Salaam. The average mass concentration of PM10 was 27 ± 11 μg/m3 in Morogoro and 51 ± 21 μg/m3 in Dar es Salaam. In Morogoro, the mean concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were 6.8, 0.51, and 2.8 μg/m3, respectively. In contrast, higher mean concentrations (11.9, 4.6, and 3.3 μg/m3, respectively) were obtained for Dar es Salaam. At both sites, species and elements, such as black carbon, NH4+, non-sea-salt SO42?, K, and Ni (and at Dar es Salaam also V, As, Br, and Pb) were mainly present in the fine size fraction. The common crustal and sea-salt elements, including Na, Mg, Al, Si, Cl, Ca, Ti, Mn, Fe, and Sr, and also NO3? and P (and to a lesser extent Cu and Zn) were concentrated in the coarse particles. Aerosol chemical mass closure indicated that the PM10 mass in Morogoro consisted, on average, of 48% organic matter (OM), 44% crustal matter, 4% sea salt, and 2% EC, while in Dar es Salaam OM, crustal matter, sea salt, and EC represented 37%, 32%, 9%, and 9% of the PM10 mass. The contributions of the secondary inorganic aerosol (non-sea-salt sulphate, nitrate, and ammonium) were small, i.e., only 5% in total at each site. Carbonaceous materials and crustal matter were thus the most important components of the PM10 mass. It is suggested that biomass burning is a major contributor to the OM; at Dar es Salaam there is also a very substantial contribution from traffic. A source apportionment calculation indicated that 68% of the OC at this site originated from traffic exhaust versus 32% from charcoal burning. The crustal matter at Morogoro is likely mainly attributable to soil dust resuspension, whereas in Dar es Salaam it is likely mostly resuspended road dust. 相似文献
629.
不同遮光方式的抑藻效果比较研究 总被引:3,自引:1,他引:2
藻类的生长繁殖与其自身通过光照进行光合作用有着密不可分的关系。研究了遮光面积、遮光周期、遮光率与水体叶绿素a含量和藻类密度之间的关系,探讨不同遮光方式对藻类生长的抑制作用;以及不同遮光方式下水体中氮磷浓度的变化情况。实验结果显示:遮光50%以上的实验桶内的叶绿素a含量和藻类密度相对于不遮光减少50%以上;从上午9:00至下午3:00遮光,12 d可以使绿素a浓度和藻类数量相对于不遮光减少70%以上;遮光率达到67%以上时,抑藻效果才较为明显,第12 d时,叶绿素a含量和藻类密度相对于不遮光减少50%以上。遮光是抑制藻类暴发的有效措施之一,不同水体可以根据具体情况选择不同的遮光方式。 相似文献
630.