一株芽孢杆菌产生物絮凝剂去除赤潮微藻的研究

以赤潮微藻米氏凯伦藻(Karenia mikimotoi)和塔玛亚历山大藻(Alexandrium tamarense)为受试对象,对一株芽孢杆菌WZ01所产的生物絮凝剂去除赤潮微藻的性能进行了研究。结果表明:芽孢杆菌WZ01所产生物絮凝剂对人工培养的米氏凯伦藻和塔玛亚历山大藻藻液均有去除能力,适宜的絮凝剂质量浓度为40.0~60.0 mg/L,絮凝时间为90~120 min,pH=7.5~8.5,在20~40℃范围内生物絮凝剂对2种微藻的絮凝率无显著区别;Ca~(2+)和Mg~(2+)浓度对生物絮凝剂去除2种微藻有一定影响,适宜浓度为4.0~6.0 mmol/L;适宜条件下生物絮凝剂对人工培养的米氏凯伦藻和塔玛亚历山大藻藻液的絮凝率均超过80.0%。研究表明,芽孢杆菌WZ01所产的生物絮凝剂在去除赤潮微藻方面有应用潜力。     

水体中几种无机离子对硝酸根敏化甲芬那酸光降解影响研究

以中压汞灯为光源,研究环境浓度范围内硝酸根对甲芬那酸(MEF)光降解的影响机制.结果表明,甲芬那酸在不同浓度硝酸根溶液中的光解反应符合准一级动力学规律,其降解速率常数随硝酸根离子浓度增大而增大,当硝酸根离子浓度由0增至1 mmol·L-1时其速率常数由0.00627 min-1增至0.0232 min-1;以异丙醇为分子探针检测到羟基自由基存在于MEF光解过程中;光解过程中产生亚硝酸根,其浓度随着反应的进行而不断增大;碱性水环境对硝酸根敏化甲芬那酸的光解反应有利;碳酸盐、氯离子、三价铁对硝酸根敏化甲芬那酸光解产生抑制作用.采用UPLC/MS/MS对硝酸根敏化MEF光降解产物进行鉴定,并提出3条可能的光解路径.毒性研究表明,在硝酸根敏化甲芬那酸光降解过程中,生成了具有较甲芬那酸而言更高风险的中间产物.     

Plot-scale spatiotemporal variations of CO2 concentration and flux across water–air interfaces at aquaculture shrimp ponds in a subtropical estuary

Human activities have increased anthropogenic CO₂ emissions, which are believed to play important roles in global warming. The spatiotemporal variations of CO₂ concentration and flux at fine spatial scales in aquaculture ponds remain unclear, particularly in China, the country with the largest aquaculture. In this study, the plot-scale spatiotemporal variations of water CO₂ concentration and flux, both within and among ponds, were researched in shrimp ponds in Shanyutan Wetland, Min River Estuary, Southeast China. The average water CO₂ concentration and flux across the water–air interface in the shrimp ponds over the shrimp farming period varied from 22.79?±?0.54 to 186.66?±?8.71 μmol L^?1 and from ??0.50?±?0.04 to 2.87?±?0.78 mol m^?2 day^?1, respectively. There was no remarkable difference in CO₂ concentration and flux within the ponds, but significantly spatiotemporal differences in CO₂ flux were observed between shrimp ponds. Chlorophyll a, pH, salinity, air temperature, and morphometry were the important factors driving the spatiotemporal patterns of CO₂ flux in the shrimp ponds. Our findings highlighted the importance and spatiotemporal variations of CO₂ flux in the important coastal ecosystems.

     

Phenanthrene adsorption on soils from the Yangtze River Delta region under different pH and temperature conditions

Environmental Geochemistry and Health - The phenanthrene (PHE) adsorption on soils from the Yangtze River Delta region under different pH and temperature conditions was studied in the laboratory....     

Total and settling velocity-fractionated pollution potential of sewer sediments in Jiaxing,China

Environmental Science and Pollution Research - Sewer sediments and their associated contaminant released along with wet-weather discharges pose potential pollution risks to environment. This paper...     

倒计时表对黄灯启亮后的驾驶行为影响

为检验倒计时表对交叉口安全性的影响,选择黄灯启亮后的驾驶员决策类型和车辆通过停车线时间两个指标,研究倒计时表对驾驶行为的影响.选择道路和交通条件相近的6个交叉口(有无倒计时各3个)对直行车流进行数据采集,经处理获取相关驾驶行为数据.应用二元Logistics回归方法建立了黄灯启亮后的驾驶员决策类型选择模型.结果表明:黄灯启亮后,在相同位置、速度条件下,倒计时交叉口的驾驶员选择停车的优势比(Odd ratio)仅为无倒计时交叉口的0.282.采用非参数检验的Mann-Whitney方法,对黄灯启亮后车辆通过停车线的时间分布(TVC)进行检验.结果表明:安装倒计时表后,车辆通过停车线时间的平均值由1.52 s增大到2.92s;在5%显著性水平下,倒计时交叉口的TVC中位数与无倒计时的差异较大,车辆通过停车线时间跨度延长,对交叉口安全性造成不利影响.     

基于生命周期评价法的条斑紫菜养殖加工产业碳足迹分析

应用生命周期评价法（LCA）对条斑紫菜养殖加工行业进行了全周期的碳足迹分析，明确了各环节中碳排放源的种类和数量。结果表明，100亩条斑紫菜养殖加工过程中碳排放总量为1.25×10⁵~2.47×10⁵ kg CO₂，远高于条斑紫菜100亩养殖形成的可移出碳汇量（9.43×10³ kg CO₂）。基于全产业链的分析，条斑紫菜产业尚不是一个碳汇产业。养殖阶段碳排放量最大，排放源主要来自石油化工材料的大量使用。二次加工阶段碳排放量仅次于养殖阶段，排放源主要来自纸壳包装和塑料包装的大量使用。在一次加工阶段，热源的使用是影响该阶段碳排放的主要影响因素，生物质燃料是碳排放量最低的热源形式。     

起重机械作业人员职业适性检测指标研究

采用Ｄｅｌｐｈｉ法对起重机械作业人员职业适性指标进行了研究。咨询专家就各备择指标对工作重要性及发生事故的关系进行了评估。结果表明：专家积极程度与意见集中程度良好；事故重要性与工作重要性排序一致性良好，两者呈高度正相关。依据专家对“重要性”的排序，再通过专家会议与现场考证等方法，最终确定了起重机械作业人员职业适性检测指标体系。     

Rice straw for energy and value-added products in China: a review

Environmental Chemistry Letters - The rise of global waste and the decline of fossil fuels are calling for recycling waste into energy and materials. For example, rice straw, a by-product of rice...     

系统论视角下的防震减灾工作

进行防震减灾工作的研究．既要运用系统论和系统工程的观点，分别研究各个子系统的发展．又要综合研究各子系统间的相互关系和有机联系。而不能仅仅着眼于某一个方面、某一个层次或者某一个视角．应该从系统的整体性、相关性、适应性、层次性以及目的性等特征来展开。