基于腐蚀与盐堵塞问题的超临界水氧化研究进展

超临界水氧化(简称SCWO)以其特有的优点成为了引人注目的有机废水处理方法.在操作过程中,有机物与氧化剂呈现为快速的均相反应,在数分钟内便可完全氧化生成CO2和H20.尽管已建造了工业规模的SCWO装置并用于处理化学废水,但该技术所存在的设备腐蚀以及设备因盐沉积而堵塞的问题制约着该技术的推广应用.为解决上述问题,科技工作者对SCWO工艺进行了改进,并提出了多种新颖的SCWO反应器设计思想.综述了基于解决设备腐蚀与盐堵塞问题的SCWO研究进展,并对相关问题进行了讨论.     

Monitoring the genotoxicity of Lake Taihu, using two kinds of micronucleus tests

Mutagenicity of surface water in Lake Taihu was monitored by genotoxicological methods. The goal is to determine the situation concerning the contamination by mutagens, their distribution in the lake, and the potential effect on public health. In this study, the micronucleus test of Vicia faba root tip, a standard monitoring technique now in China, was carried out to make a preliminary screening of environmental mutagens in 39 representative sites of the lake. Highly significant differences in MCN permillage (average number of micronuclei per 1000 cells) and PI (pollution index) values were found among these sites. From the results, a rough distribution of the contamination could be obtained: mainly concentrated in the north-west area of the lake from several tributaries flowing into the lake. In order to provide further evidence, organic extracts from four entrances and one outlet of the five major tributaries were examined by the micronucleus test of human peripheral lymphocytes. The results were in accord with those of the micronucleus tests using Vicia faba. The tests also revealed that the intensity and mechanism of the pollutants were diverse in the different sources.     

The connection between urbanization and carbon emissions: a panel evidence from West Africa

Environment, Development and Sustainability - This study examined the nexus between urbanization and carbon emissions in West Africa. Second-generation econometric techniques that are robust to...     

Copper and zinc induction of lipid peroxidation and effects on antioxidant enzyme activities in the microalga Pavlova viridis (Prymnesiophyceae)

The metal-induced lipid peroxidation and response of antioxidative enzymes have been investigated in the marine microalga Pavlova viridis to understand the mechanisms of metal resistance in algal cells. We have analyzed superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) activities and glutathione (GSH) contents in microalgal cells grown at different concentrations of copper and zinc. In response to each metal, lipid peroxidation was enhanced with the increase of concentrations, as an indication of the oxidative damage caused by metal concentration assayed in the microalgae cells. Exposure of P. viridis to the two metals caused changes in enzyme activities in a different manner, depending on the metal assayed: after copper treatments, total SOD activity was enhanced, while it was reduced after zinc exposure. Copper and zinc stimulated the activities of CAT and GSH whereas GPX showed a remarkable increase in activity in response to copper treatments and decrease after zinc treatments. These results suggest that an activation of some antioxidant enzymes was enhanced to counteract the oxidative stress induced by the two metals.     

Postural evaluation in a poultry farm for broiler chickens

The goal of this study was to evaluate working postures in 9 operations of poultry farming for broiler chickens for 14 body segments with 4 categories, and for fingers with 14 categories. Overall, the farmers commonly bent almost all their body segments and used power grips. The operations of cleaning with water wand and inspecting chickens seemed light work because the farmers walked around most of their working time. The operations of detaching base from hanging feeder and attaching base to hanging feeder had the farmers continue squatting to handle the feeders close to the floor. The farmers also repeatedly bent their trunks in shoveling feces, unloading a box of chicks, and releasing chicks. A power grip was frequently observed due to using tools with round handles. Workplace design to raise working height would be necessary for a better working environment for broiler farmers.     

河北省应对水危机加快发展海水淡化的探讨

21世纪水危机严重威胁河北省经济社会发展。海水淡化是解决水危机问题的重要措施,具有良好的综合效益和发展前景。河北省海水淡化条件较好,基础比较雄厚,为此建议尽快编制河北省海水淡化规划,加快建设海水淡化工程,积极发展海水淡化装备制造业,并开展沿海热电厂非采暖季节利用气热淡化海水的实验研究。     

基于ZigBee技术的电力环境监测系统设计

为了解决电力环境监测中的数据传输问题,提出了基于ZigBee技术的电力环境监测系统设计方案。该系统通过ZigBee节点采集各种电力环境数据,并将ZigBee网络和GPRS相结合实现远程监测。方案采用TI公司CC2430芯片设计传感器节点电路,在ZigBee协议栈的基础上设计了协调控制器节点,提高了系统的可扩展性,确保了数据传输的实时性和可靠性。     

Cu2+对普通小球藻的光合毒性：初始藻密度的影响

为了研究Cu2+对普通小球藻的光合毒性以及初始藻密度对Cu2+光合毒性的影响,将初始密度为107mL-1的普通小球藻暴露于Cu2+的6个浓度(0、5、10、20、30和40μmol.L-1)中进行96 h的毒性暴露实验,在2、48和96 h分别利用叶绿素荧光仪(MAXI-Imaging-PAM)测定各项叶绿素荧光参数,同时,针对3个不同初始密度的普通小球藻(2×106、5×106和2×107mL-1),测定并比较了其暴露于0、20和40μmol.L-1的Cu2+12 h后,叶绿素荧光参数的变化。不同初始藻密度的毒性实验结果显示,初始藻密度为2×106mL-1时,20和40μmol.L-1Cu2+可完全抑制普通小球藻的光合作用;当初始藻密度增加到5×106和2×107mL-1时,40μmol.L-1Cu2+对普通小球藻的实际光合作用效率仅有约75%和25%的抑制。这表明初始藻密度越大,Cu2+的光合毒性越弱。但随着初始藻密度的增加,初始藻密度的变化对Cu2+光合毒性的影响减弱。初始藻密度为107mL-1时的毒性实验结果显示,暴露于20~40μmol.L-1Cu2+2 h后,普通小球藻的光合作用即受到抑制,且该抑制程度随Cu2+浓度的增加而增强,并随着暴露时间的延长有所缓解。随着Cu2+浓度的增加,最大量子产量(Fv/Fm)、实际量子产量(Yield)、相对电子传递速率(ETR)和光化学淬灭系数(qP)逐渐降低,非光化学淬灭系数(NPQ/4)逐渐上升。研究结果表明,Cu2+对普通小球藻的光合作用有一定的抑制作用,其机理可能为通过引起PSII系统反应中心的部分失活,导致PSII系统反应中心的开放比例减少,引起电子传递速率降低以及ATP和NADPH的合成减慢,从而使光合作用速率下降;初始藻密度对Cu2+的光合毒性大小有较大的影响,故在进行藻类的毒性实验时,也应关注初始藻密度的影响。