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INTRODUCTION Regulation, handling and bioremediation of hazardous materials require an assessment of the risk to some living species other than human being, or assessment of hazard to the entire ecosystem. As- sessment endpoints are values of the ecosystem that are to be protected and are identified early in the analysis. Such endpoints may include life cycle stages of a species and reproductive or growth patterns. Ecosystem risk assessment is at its dawn with this area of environment sci… 相似文献
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MAHMOOD Qaisar 郑平 SIDDIQI M. Rehan ISLAM Ejaz ul AZIM M. Rashid HAYAT Yousaf 《Journal of Zhejiang University. Science. B》2005,6(10)
Water hyacinth (Eichhornia crassipes (Mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy of the plant were studied. Water hyacinth exhibits hydrophytic adaptations which include reduced epidermis cells lacking cuticle in most cases, presence of large air spaces (7～50 μm), reduced vascular tissue and absorbing structures. Textile waste significantly affected the size of root cells.The presence of raphide crystals was noted in parenchyma cells of various organs in treated plants. 相似文献
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CAI Jing ZHENG Ping MAHMOOD Qaisar ISLAM Ejazul HU Bao-lan WU Dong-lei 《浙江大学学报(A卷英文版)》2007,8(7):1149-1156
The optimal operation conditions in an anoxic sulfide oxidizing (ASO) bioreactor were investigated. The maximal removal rates for sulfide and nitrate were found to be 4.18 kg/(m3·d) and 1.73 kg/(m3·d), respectively. The volumetrical volumetric loading rates (LRs) observed through decreasing hydraulic retention time (HRT) at fixed substrate concentration are higher than those by increasing substrate concentration at fixed HRT. The sulfide oxidation in ASO reactor was partially producing both sulfate and sulfur; but the amount of sulfate produced was approximately one third that of sulfur. The process was able to tolerate high sulfide concentration, as the sulfide removal percentage always remained near 99% when influent concentration was up to 580 mg/L. It tolerated relatively lower nitrate concentration because the removal percentage dropped to 85% when influent con- centration was increased above 110 mg/L. The process can tolerate shorter HRT but careful operation is needed. Nitrate conversion was more sensitive to HRT than sulfide conversion since the process performance deteriorated abruptly when HRT was decreased from 3.12 h to 2.88 h. In order to avoid nitrite accumulation in the reactor, the influent sulfide and nitrate concentrations should be kept at 280 mg/L and 67.5 mg/L respectively. Present biotechnology is useful for removing sulfides from sewers and crude oil. 相似文献
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Dan LIU Song LI Ejazul ISLAM Jun-ren CHEN Jia-sen WU Zheng-qian YE Dan-li PENG Wen-bo YAN Kou-ping LU 《Journal of Zhejiang University. Science. B》2015,16(2):123-130
目的:探索毛竹在修复铅污染土壤的植物修复潜力。创新点:使用了毛竹作为一种全新的植物修复材料进行研究。得到了毛竹幼苗在铅胁迫下的生长与生理反应情况,不同植物组织对铅的吸收与积累情况,铅胁迫下毛竹幼苗表层与细胞超微结构的特征。方法:根系形态分析(图3)、植物重金属含量分析(表1)、扫描电镜分析(图4)和透射电镜分析(图5)。结论:各组织部位铅浓度的值揭示了,毛竹是一个很好的固定铅污染土壤的植物材料;但是由于毛竹茎的高生物量,也可以作为铅污染土壤的植物修复材料。在0~200μmol/L铅处理下,毛竹的生物量与根系形态没有显著性差异,生长正常未出现中毒症状。通过扫描电镜观察铅胁迫导致叶片的气孔减少,根与茎内含物增多。通过透射电镜观察高浓度的铅胁迫导致部分细胞内部叶绿体变形、内质网消失、细胞核与核仁缩小和类囊体膜消失。尽管超微结构观察到细胞内部的损害,但是未出现视觉的毒性症状。毛竹铅的高耐性与茎的高生物量,提供了毛竹作为材料修复土壤重金属铅更大的可能性。 相似文献
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