阻尼式脉动气流分选装置处理电子废弃物的基础研究

采用机械物理回收方法对电子废弃物进行资源化利用具有巨大的经济效益和社会效益。针对电子废弃物的特点,作者采用阻尼式脉动气流分选装置对电子废弃物中有价组分的分选进行了研究。研究表明,与传统气流分选装置相比,阻尼式脉动气流分选装置可获得更高的分选效率和更宽范围的操作条件。     

PROTECTING BEIJLNG'S MUNICIPAL WATER SUPPLY THROUGH WATERSHED MANAGEMEN AN ECONOMIC ASSESSMENT1

ABSTRACT: Watersheds above the Miyun reservoir, a principal source of surface water for Beijing, are designated to be managed for water production, but under the principle of multiple use. Because of the scarcity of arable land, these watersheds cannot be managed only for drinking water. Efforts are under way to reduce sediment delivery, improve the quality of water entering Miyun reservoir, and improve the welfare of watershed inhabitants. An economic appraisal of a watershed management project for the 3,298‐ha Shixia watershed above the Miyun reservoir, indicates a 24 percent economic rate of return on the investment made in the project. The net present value (NPV) of the project, calculated at a discount rate of 10 percent, is approximately US$3.49 million. Sensitivity analyses indicate that a doubling of labor costs lowers the NPV to US$2.07 million and a 10 percent decrease in benefits lowered the NPV to US$2.87. It is concluded that the implementation of conservation practices on the Shixia Demonstration Watershed represent an economically efficient use of resources.     

高效无泄漏环保型磁力泵研究探讨

在流体输送过程中一直存在着泄漏问题,到目前为止所有的机械密封都没有很好地解决这一问题。磁力泵取消了泵的机械密封,完全消除了离心泵机械密封不可避免跑、冒、滴、漏的弊病,是实现无泄漏、零污染输送的较好选择,特别适用于易燃、易爆、易挥发及有毒介质的输送。分析了磁力泵特点及其在我国工业方面的应用前景,提出磁力泵的发展方向。     

阳江市第一净水厂SBR池的自动控制过程

介绍了SBR池按时序自动控制过程,阐述了在一个运行周期的5个阶段中,所有相关设备的运行状态。     

水质管理规划中BOD5响应矩阵的一种改型模式

本文推导对水质管理规划中经典BOD5响应矩阵的一种改型模式,并对数值例加以阐述.该模式以BOD5总量为控制对象,任一河流断面的BOD5输入量在此响应矩阵中仅出现一次,从而使响应关系由下三角矩阵改变为每一行均含三个变量的稀疏矩阵。这一改型不仅提高了计算速度,更重要的是,由于改型模式具有运输问题类型良好的特殊结构,可以方便地判断一个水质管理规划问题是否可行和给出可行的充分必要条件,这一特性具有较大的实际经济意义.改型模式与经典模式所需数据完全相同。      

Antibiotic and metal resistance of Stenotrophomonas maltophilia isolates from Eboling permafrost of the Tibetan Plateau

Environmental Science and Pollution Research - Whole-genome sequencing of pathogenic bacteria Stenotrophomonas maltophilia from a less polluted environment of permafrost can help understand the...     

Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

● A higher sulfur content reduced the curing rate of Cr in glass. ● Depolymerization increased the amounts of heavy metals in the carbonate bound state. ● Reducing the CaO/SiO₂ ratio increased the proportion of stable heavy metals. This work designed a new CaO-Al₂O₃-SiO₂-SO₃ glass for the immobilization of multiple heavy metals found in dechlorinated fly ash having high amounts of calcium and sulfur. Increasing the (CaO + SO₃)/SiO₂ mass ratio (M(CS/S)) from 0.28 to 0.85 was found to lower the proportions of Mn, Ni and Zn in an unstable state, while an M(CS/S) ratio of 0.51 gave the lowest proportions of unstable Cr and Pb. Decreasing the degree of polymerization of the glassy network increased the proportions of Mn, Cr, Ni, Pb and Zn in the carbonate bound state. The leaching out of metals in this state was the primary cause of degradation of Q³ structural units in the glassy network. The amount of Mn in the iron-manganese oxide bound state was increased by increasing the number of Q² units in the silicate network. Decreasing the CaO/SiO₂ mass ratio (M(C/S)) raised the proportions of Mn, Ni and Zn in the unstable state. An M(C/S) value of 0.43 lowered the proportions of unstable Cr and Pb. A principal components analysis determined that the leaching of toxic heavy metals from the glass was primarily related to the proportions of these metals in the unstable state while there were no evident correlations between leaching and the proportions in stable states.     

用声强法对油田注水泵房设备声源声功率的测量分析

通过对注水泵房设备声源声功率的测量和分析,确定每个噪声源重要性的排队次序,并识别其主要频率成分,作为噪声优化控制的基础。     

SO2排放造成的森林损失计算:以湖南省为例

SO₂排放对我国的森林生态系统造成了严重的损害,因而损失计算对于SO₂控制具有重要意义,但是目前仍缺乏有效的方法计算不同排放水平下的森林损失.本研究以硫沉降超临界负荷作为计算森林损失的参数,推导了适用于我国硫沉降导致森林损失的剂量-响应函数,并以湖南省为例,以1995为基准年,计算了2000年～2020年高中低3种SO₂排放方案下的森林损失.研究结果表明,随着今后湖南省经济和能源消费的增长,森林损失将继续增加.高排放方案下2020年SO₂排放将增长1.2倍,但森林损失增长4.3倍,边际损失高于6000元/t.在当前排放水平下对SO₂排放进行削减,边际效益达到1500元/t,因此控制SO₂具有显著的经济效益.对湖南案例的不确定性分析显示,计算方法有较高的可靠性.研究结果为区域SO₂控制策略的优化提供了支持.     

Effect of pipe materials on disinfection by-products and bacterial communities during sulfamethazine chlorination in a pilot-scale water distribution system

Environmental Chemistry Letters - Water research is usually done using simplified devices, e.g., beakers, in laboratory glassware, and thus may yield results that are not representative of real...