噬菌体MS2作为水中肠道病毒指示生物的特征及其影响因素

噬菌体MS2作为潜在的水中肠道病毒指示生物,已逐渐成为回用水微生物学安全评价指标的主要研究方向之一。在此,阐述噬菌体MS2作为水中肠道病毒指示生物的主要特征,并介绍噬菌体MS2作为水中肠道病毒指示生物应用的影响因素。     

Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom

After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs): methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS). Even in the untreated control without a methionine addition, methionine and its catabolites (VOSCs, mainly DMDS) were found in considerable amounts that were high enough to account for the water’s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.     

酸雨与镧对大豆幼苗生长的复合伤害效应研究

为探索酸雨与稀土镧对大豆幼苗生长的复合影响及其内在机制,以重要油粮作物大豆(Glycine max)为材料,研究在模拟酸雨pH分别为3.0、3.5、4.5与稀土镧La(Ⅲ)浓度分别为60、100和300mg·L-1处理下大豆幼苗生长及光合作用的变化.结果表明,相对单一酸雨与镧处理,酸雨与La(Ⅲ)复合处理组中大豆幼苗的生长受抑制程度增大,两者呈协同效应,且pH越低,La(Ⅲ)浓度越高,抑制效应越明显.光合参数的变化规律与生长指标近同,相同处理组各光合参数的降幅不一致,其中最大荧光(Fv/Fm)和叶绿素含量(Chl)的降幅范围分别为9.53%～22.75%和9.14%～24.53%,较净光合速率Pn(22.78%～84.7%)、希尔(Hill)反应速率(15.52%～73.38%)和Mg2+-ATPase活性(14.51%～71.54%)小,表明各光合参数对2个胁迫因子的敏感程度存在差异.进一步相关性分析发现,Pn变化主要受Hill反应速率与Mg2+-ATPase活性的影响,而Chl、Fv/Fm次之.表明酸雨与La(Ⅲ)对植物光合过程各环节的作用机制不同,光合作用受阻是影响植物生长的重要因素之一.     

辽河流域河流栖息地评价指标与评价方法研究

建立了由底质、栖息地复杂性、速度-深度结合特性、堤岸稳定性、河道变化、河水水量状况、植被多样性、水质状况、人类活动强度和河岸土地利用类型所构成的河流栖息地评价指标体系,确定了各指标的等级划分以及栖息地综合指数的计算方法.结合2005年辽河流域河流生态调查结果,对流域内所调查的28个河段的栖息地质量状况进行了具体评价,并进一步分析了河道栖息地综合指数与河流理化因子、底栖生物以及小流域土地利用状况的相关关系.结果表明:①辽河流域28个河段的栖息地质量状况差异显著,其中10个河段达到了较好等级以上,6个仅为中等水平,12个河段为较差等级以下;②栖息地质量与理化因子、底栖生物指标具有显著相关性,表明栖息地质量是影响水质与生物状况的重要因素;③小流域的人类未利用土地比例与栖息地质量显著相关,表明小流域土地利用程度对栖息地环境质量影响较大,是恢复与保护河流栖息地质量的重要条件.     

Long-term joint effect of nutrients and temperature increase on algal growth in Lake Taihu, China

To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature (AT), water temperature (WT), and their average temperature (ST), while substrate variables were calculated using annual mean total nitrogen (TN), total phosphorus (TP), and their weighted aggregate (R), respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0℃. Results also showed that the more eutrophic the lake, the greater the effect AT had on algal growth. Subsequently, the long-term joint effect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.     

东海赤潮及其监视监测

赤潮是一种海洋生态异常现象，是海洋生态系统受损与退化的表征与警示。近20a以来，东海赤潮频发，且影响范围不断扩大、持续时间增长，并呈逐年上升趋势，在一定程度上制约了东海区沿海省市海洋经济的发展。开展有害赤潮常规监测和应急监视监测是当前赤潮监控中最为有效手段。本文系统回顾和总结了近20a来东海区赤潮发生特点，以及在东海区开展的赤潮监视监测工作，并对21世纪东海赤潮监视监测进行了简要展望。     

土壤中微生物及其环境效益的浅析

关于土壤微生物活性,已经成为目前土壤方面研究的热点问题。有些学者曾经对微生物在土壤环境中的作用表示怀疑,他们过分强调物理化学作用在土壤形成和土壤环境效应中的作用,而忽视微生物的研究。随着土壤学研究的深入,关于土壤成因、土壤生产力和环境现象已经越来越复杂,单纯依靠物理和化学的知识已经无法解释某些复杂的实验现象,现在必须依靠微生物来解释某些现象。本文将对土壤微生物在土壤研究中的作用进行简述,同时分析土壤环境变化对微生物数量和活性的影响,并简述一些微生物研究的进展。     

城市污水处理工艺对噬菌体的去除效果

测定了北京市3座城市污水处理厂各处理单元出水中的SC噬菌体和F-RNA噬菌体浓度进水中SC噬菌体和F-RNA噬菌体浓度范围分别为6.25 ×103～1.34×104 PFU·mL-1和2.4×10～2.4×103 PFU·mL-1,经过处理,上述2类噬菌体的总去除率分别为72.45%～99.89%和57.84%～93.06%,低于对粪大肠菌的处理效果生物曝气工艺对噬菌体的去除效率最高,深度处理中的砂滤工艺对噬菌体的去除作用不明显.根据测定的F-RNA噬菌体浓度预测水中肠道病毒的浓度,结果显示生活污水经常规处理和深度处理后仍含有0.65～15.8 PFU·L-1的肠道病毒.     

松花江佳木斯江段水环境质量变化状况及趋势分析研究

根据近十年来的松花江佳木斯江段水环境质量监测数据,介绍了松花江佳木斯江段水质现状,探讨了松花江佳木斯江段水质的主要污染物,从理化指标对松花江佳木斯江段水环境质量变化趋势进行了评价分析,分析结果表明：主要污染指标高锰酸盐指数、化学需氧量、氨氮、生化需氧量浓度值均有不同幅度的下降,2005年水质状况为轻度污染,2013年已达到良好水平.水环境质量呈规律性的逐年提高和改善,确保了松花江更好地休养生息.     

中国主要城市土壤重金属累积特征与风险评价

我国快速城市化过程可能会导致重金属在城市土壤中累积,威胁居民健康.通过收集和整理最近15年间发表的文献数据,从整体上分析了我国52个主要城市土壤重金属含量特征及其健康风险.结果表明,我国城市土壤平均ω(Pb)、ω(Cd)、ω(Cu)和 ω(Zn)分别为:58.5、0.49、42.1 和 156.3 mg·kg-1,其I...