Insights into multidimensional transport flux from vertical observation and numerical simulation in two cities in North China

This study represents the first quantitative evaluation of pollution transport budget within the boundary layer of typical cities in the Beijing-Tianjin-Hebei (BTH) region from the perspective of horizontal and vertical exchanges and further discusses the impact of the atmospheric boundary layer (ABL)-free troposphere (FT) exchange on concentration of fine particulate matter (PM_2.5) within the ABL during heavy pollution. From the perspective of the transport flux balance relationship, differences in pollution transport characteristics between the two cities is mainly reflected in the ABL-FT exchange effect. The FT mainly flowed into the ABL in BJ, while in SJZ, the outflow from the ABL to the FT was more intense. Combined with an analysis of vertical wind profile distribution, BJ was found to be more susceptible to the influence of northwest cold high prevailing in winter, while sinking of strong cold air allowed the FT flowing into the ABL influence the vertical exchange over BJ. In addition, we selected a typical pollution event for targeted analysis to understand mechanistic details of the influence of ABL-FT exchange on the pollution event. These results showed that ABL-FT interaction played an important role in PM_2.5 concentration within the ABL during heavy pollution. Especially in the early stage of heavy pollution, FT transport contributed as much as 82.74% of PM_2.5 within the ABL. These findings are significant for improving our understanding of pollution transport characteristics within the boundary layer and the effect of ABL-FT exchange on air quality.     

沸石在水处理中的应用

本文介绍了中国沸石的种类及其分布概况，以产自甘肃省白银市的斜发沸石为研究对象，对其化学组成及分子晶格形式作了较为详尽的阐述，经实验室检测出其化学组成及物化指标，且对沸石作为吸附剂、离子交换剂、催化剂处理废水的作用机理进行了深入的探讨，对于天然沸石改性进行了实验研究，得出采用氯化钠溶液对天然沸石改性的效果比较理想，改性溶液的最佳浓度为0．9mol/L。研究沸石在沸水处理领域中的应用，分析了沸石处理各类废水的机理，并对沸石处理废水的前景进行了展望。     

离子交换膜的制备及发展趋势研究

总结当前离子交换膜制备技术的发展状况.从膜的分类及膜性能出发,讨论均相膜及异相膜的差异和今后各自的发展前景,并就提升膜单方面性能(如:选择透过性、离子交换容量、膜电阻、抗氧化性等)的方式进行归纳总结.离子交换膜的改进制备大多从结构上入手,提出今后膜制备的主要研究方向为:深化均相膜制备技术、结合国内成熟的离子交换树脂制备工艺改进异相膜的制备技术.     

树脂基纳米零价铁复合材料的制备及其去除重金属铅Pb(Ⅱ)的性能研究

凭借着优越的还原活性,纳米零价铁在环境污染治理和修复领域应用广泛。通过将纳米零价铁(n ZVI)颗粒负载到大孔阴离子和阳离子交换树脂上,成功制备出2种树脂基纳米零价铁复合材料。研究了2种复合材料及其载体对水溶液中Pb(Ⅱ)的去除性能,考察了不同载体功能基团对复合材料去除Pb(Ⅱ)性能的影响。结果表明:以大孔阴离子交换树脂为载体的D001-Fe0复合材料因具有离子交换和化学还原双重作用,对Pb(Ⅱ)的去除效率高、速率快。     

Abusive supervision and work behaviors: The mediating role of LMX

We investigated the mediating role of the leader–member exchange (LMX) in the association of abusive supervision and employee work behaviors (task performance and organizational citizenship behaviors toward the organization and individuals). Using data collected from 366 supervisor–subordinate dyads, we found that LMX fully mediated the negative effects of abusive supervision on all three work behaviors. In addition, we conducted a supplementary study on the basis of the data collected from 54 supervisor–subordinate dyads from a garment company, and we found that LMX mediated the relationship between abusive supervision and employee objective future performance with interactional justice controlled. Copyright © 2011 John Wiley & Sons, Ltd.     

水铝钙石类阴离子黏土在水污染处理领域应用的研究现状

水铝钙石(Hydrocalumite)是一种阴离子黏土,又称"弗里德尔盐"(Friedel’s Salt),属于层状双金属氢氧化物(LDHs),可通过多种低成本方法人工合成.水铝钙石的层间阴离子具有可交换性,且在一定温度范围内焙烧时所获产物在水溶液中具有层状结构可恢复性,因此在水污染和固体废物处理领域有很大应用价值,已被用于水中B(OH)4-、SeO24-、CrO24-、MoO24-、Zn2+等无机组分和十二烷基硫酸钠(SDS)、烷基苯磺酸钠(SDBS)、甲基橙(MO)、酸性大红(GR)等有机组分的去除实验研究,以及粉煤灰等典型固体废物在填埋前的预处理研究.水铝钙石类阴离子黏土对水中有害组分的去除效果受到离子种类和性质、溶液pH、去除产物溶度积常数等多种因素的影响,所涉及去除机理包括离子交换、溶解-沉淀、表面吸附等.当前利用水铝钙石去除水污染的研究基本局限于实验室研究阶段,并在严格控制的实验条件下进行,因而今后应加强其处理实际受污染水体和原生劣质水的实验研究,并尝试作为填充材料在可渗透性反应墙(PRB)等水污染原位处理装置中加以应用.     

Estimates of species- and ecosystem-level respiration of woody stems along an elevational gradient in the Luquillo Mountains, Puerto Rico

We measured CO₂ efflux from stems of seven subtropical tree species situated along an elevational gradient in the Luquillo Mountains, Puerto Rico and scaled these measurements up to the landscape level based on modeled and empirical relations. The most important determinants of ecosystem stem respiration were species composition and stem temperature. At a species scale, measured CO₂ efflux per unit bole surface area at a given temperature was highest in the early successional species Cecropia schreberiana and lowest in species that inhabit high elevations such as Micropholis garciniifolia and Tabebuia rigida. Carbon dioxide efflux rates followed a diel pattern that lagged approximately 6 h behind changes in sapwood temperatures. At an ecosystem scale, our simulation model indicates a decreasing trend of stem respiration rates with increasing elevation due to shifts in species composition, lower temperatures and reductions in branch surface area. The highest estimated stem respiration rates were present in the lowland tabonuco forest type and the lowest rates were present in the elfin forest type (mean 7.4 and 2.1 Mg C ha⁻¹ yr⁻¹, respectively). There was slight temperature-induced seasonal variation in simulated stem respiration rates at low elevations, with a maximum difference of 19% between the months of February and July. Our results coincide well with those of Odum and Jordan [Odum, H.T., Jordan, C.F., 1970. Metabolism and evapotranspiration of the lower forest in a giant plastic cylinder. In: Odum, H.T., Pigeon, R.F. (Eds.), A Tropical Rain Forest: A Study of Irradiation and Ecology at El Verde, Puerto Rico. U.S. Atomic Energy Commission, Oak Ridge, TN, pp. I165–I189] for the tabonuco forest type and extend their work by presenting estimates and spatial patterns of woody tissue respiration for the entire mountain rather than for a single forested plot.     

San copolymer membranes with ion exchangers for Cu(II) removal from synthetic wastewater by electrodialysis

Heterogeneous membranes were obtained by using styrene-acrylonitrile copolymer (SAN) blends with low content of ion-exchanger particles (5 wt.%). The membranes obtained by phase inversion were used for the removal of copper ions from synthetic wastewater solutions by electrodialytic separation. The electrodialysis was conducted in a three cell unit, without electrolyte recirculation. The process, under potentiostatic or galvanostatic control, was followed by pH and conductivity measurements in the solution. The electrodialytic performance, evaluated in terms of extraction removal degree (rd) of copper ions, was better under potentiostatic control then by the galvanostatic one and the highest (over 70%) was attained at 8 V. The membrane efficiency at small ion-exchanger load was explained by the migration of resin particles toward the pores surface during the phase inversion. The prepared membranes were characterized by various techniques i.e. optical microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis and contact angle measurements.     

基于博弈论的非点源污染控制模型探讨

随着对工业和城市生活污水等点源污染治理能力的不断增强,农业非点源污染对水质环境的影响日益凸现.相对于点源污染,非点源污染发生的不确定时间、不确定途径、不确定量等特点给治理政策的制定带来很大难度.本文从著名的公地悲剧现象出发,着力从市场博弈及政府监督博弈两个模型分析非点源污染制造者之间的博弈格局,并提出以“集体表现”的形式对非点源污染进行管理和控制.市场博弈模型中以一定的排污削减目标为前提,确定以成本最优的原则进行点源-非点源排污权交易是可行且有效率的;而政府监督博弈模型的结果显示:合理的环境补贴和惩罚机制、政府对自身声誉及公众形象的重视及维护对非点源污染治理起正向促进作用.     

离子交换法选择性回收污泥厌氧消化液中的磷

为探讨高效选择性回收污泥厌氧消化液中磷的离子交换方法,采用静态实验和动态实验研究了4种阴离子交换树脂（D213、D202、D301和DSQ）的磷回收性能,筛选了适合富磷污泥厌氧消化液选择性磷回收的高交换容量树脂。实验结果表明,D213、D202、D301和DSQ 4种树脂对正磷浓度为70 mg/L的厌氧消化液进行动态处理时,其最大穿透体积分别为3、7、17和90 BV;DSQ树脂磷交换容量远高于其他3种树脂,达到6 860 mg P/L湿树脂,是目前报道的高磷交换容量树脂的3~4倍;DSQ树脂能有效地抵抗厌氧消化液中有机质和硫酸根等阴离子的干扰;用NaOH溶液再生DSQ树脂并回收磷,磷洗脱率超过96%,洗脱液是高浓度含磷液,可作为磷矿石的优质替代品。研究表明,DSQ树脂是一种高效选择性分离磷的树脂,适用于污泥厌氧消化液的磷回收。