Applicability of a Septic Tank/Engineered Wetland Coupled System in the Treatment and Recycling of Wastewater from a Small Community

A septic tank (ST)/engineered wetland coupled system used to treat and recycle wastewater from a small community in Dar es Salaam, Tanzania was monitored to assess its performance. The engineered wetland system (EWS) had two parallel units each with two serial beds packed with different sizes of media and vegetated differently. The larger-sized medium bed was upstream and was planted with Phragmites (reeds) and the smaller-sized medium bed was downstream and was planted with Typha (cattails). The ST/EWS coupled system was able to remove ammonia by an average of 60%, nitrate by 71%, sulfate by 55%, chemical oxygen demand by 91%, and fecal coliform as well as total coliform by almost 100%. The effluent from the ST/EWS coupled system is used for irrigation. Notably, users of the recycled irrigation water do not harbor any negative feelings about it. This study demonstrates that it is possible to treat and recycle domestic wastewater using ST/EWS coupled systems. The study also brings attention to the fact that an ST/EWS coupled system has operation and maintenance (O&M) needs that must be fulfilled for its effectiveness and acceptability. These include removal of unwanted weeds, harvesting of wetland plants when the EWS becomes unappealingly bushy, and routine repair.     

HSE绿卡管理模式在HSE管理体系中的应用

结合健康、安全与环境(HSE)管理体系的实施,提出了HSE绿卡管理模式。利用该模式可以在不同阶段对不同岗位、不同专业的人员进行科学的及系统的HSE培训教育工作,对员工进行规范的HSE培训、考核与管理,从而有效地消除生产过程中人工操作的不安全行为。实际验证结果表明: HSE绿卡管理模式是实施HSE管理体系的有效措施,它为成功地实施健康、安全与环境管理体系提供了充足的人力“资源”基础,从而实现“以人为本”的现代管理体制。     

Mineral wealth and the economic transition: Kazakstan

The exploitation of mineral wealth can amplify the problems of the transition economies in three basic ways. First, the rebound of the real exchange rate that characterises a successful transition may be augmented by the capital inflow required to expand mineral production. This can cause both recession in the short-run and lower growth in the medium-term. Second, when the mineral revenues expand, the Dutch Disease effects may intensify the transition-related shrinkage of the non-mining tradeable sector, thereby retarding economic diversification and rendering the economy vulnerable to external shocks. Third, a mineral boom tends to concentrate revenue on the government, which may use it to postpone difficult decisions on economic reform and/or dissipate the revenue due to weak financial markets and inadequate public accountability. Kazakstan, like oil-rich Azerbaijan, is a late reformer and displays evidence of a faster transition rebound than other less resource-rich countries in the CIS do. However, Kazakstan has two advantages over Azerbaijan. First, Kazakstan has a more diversified mineral endowment with which to counter any trend towards single commodity specialization. Second, Kazakstan is making a later start on oil expansion so that it can learn from the experience of Azerbaijan. Priorities for Kazakstan are the continuation of prudent economic policies, the creation of institutions to enhance the transparency of the revenue flows, and the use of environmental accounting to provide a rationale for the deployment of the oil rents.     

绿色饲料添加剂的研究与应用

本文对几种新型的绿色饲料添加剂的作用、在畜禽生产中的实际应用及存在的问题进行了综述。     

EFFECTS OF WOODY VEGETATION ON SANDY LEVEE INTEGRITY1

he influence of woody vegetation on the reliability of a sandy levee was investigated using field data in seepage and slope stability analyses. Field data were collected from selected sites within a 10-km segment of a channel levee on the Sacramento River near Elkhorn, California. Root architecture and distribution were determined using the profile-wall method in which root cross sections were exposed in the vertical wall of an excavated trench. Transects running both parallel and perpendicular to the crest of the levee were excavated at six sites. Each site was dominated by different plant species: five sites were adjacent to trees or woody shrubs, while one supported only herbaceous growth. Lateral plant roots were primarily restricted to, and modified, the near-surface soil horizons to a depth of approximately 1 meter. Root area ratios (RARs) did not exceed 2.02 percent and generally decreased exponentially with depth. At depths greater than 20 cm, mean RARs for sites dominated by wood species were not significantly different from the mean RAB for the herbaceous site. No open voids clearly attributable to plant roots were observed. Roots reinforced the levee soil and increased shear resistance in a measurable manner. Infinite slope and circular arc stability analyses were performed on the landward and riverward slopes under different hydraulic loading conditions. Infinite slope analyses indicated increasing root area ratio from 0.01 percent to 1 percent increased the factor of safety from less than one to more than seven. Circular arc analyses indicated that even the lower measured root concentrations sufficed to increase safety factors for arcs with maximum depths of about 1 m from less than one to about 1.2. Our findings suggest that allowing woody shrubs and small trees on levees would provide environmental benefits and would enhance structural integrity without the hazards associated with large trees such as wind-throwing.     

《绿色食品产地环境质量现状评价纲要（试行）》刍议

绿色食品产地生态环境质量评价中优化监测方案和评价标准与方法的合理确定尤为重要。现行的《评价纲要》中监测布点偏多、所选取的某些评价标准与方法欠佳，需加以修订和改进，以提高我国绿色食品产地生态环境质量评价的科学性与实用性。     

吸烟烟气对鼠肺细胞膜的损伤和茶多酚的保护作用

本文以香烟气相物质作用鼠肺细胞膜为模型,用脂肪酸自旋标记物5-DOXYL和16DOXYL分别研究膜浅层和深层的动态性质受气相烟的影响,并用紫外可见分光光度法研究气相烟对膜脂的作用。结果发现,在实验的气相烟流量下,香烟气相物质能引发鼠肺细胞膜的脂质过氧化,并且使膜浅层的流动性增大。但对膜深层的动态性质没有明显的改变,如果在鼠肺细胞中预先加入粗晶态或粉态茶多酚。则肺细胞的过氧化和膜的动态性质改变受到抑制,而且这种抑制作用与茶多酚浓度呈量效关系,而茶多酚本身对膜浅层无明显作用,但对膜深层的流动性有一定影响,而且两种茶多酚的作用相似。     

部分绿色植物对环境的保护作用

绿色植物对环境有着重要的保护作用．概括而言，绿色植物可以吸收CO2、二氧化硫、氟化氢及其它一些有害气体，同时绿色植物还吸收空气中的灰尘、杀灭细菌以及净化水源．本文详细探讨了绿色植物的环保作用，旨在提高人们对于绿色植物认识和保护意识．     

CVM中的抗议性响应:动机与影响——以胶州湾浒苔治理支付意愿为例

抗议性响应是意愿调查法应用中受访者表现出的典型策略性行为,可能导致对资源环境物品或服务的估值出现偏差。识别抗议性响应影响因素并降低其对支付意愿的影响,有助于提高CVM估值效度。以胶州湾海域居民浒苔治理支付意愿为例,以抗议性信念作为受访者抗议性响应的度量指标,筛选抗议性信念的驱动因素,量化各驱动因素对支付意愿的影响方向及程度。研究结果表明:（1）愿意支付的受访者仍然具有抗议性信念,且在个别测量题项中,其抗议性信念甚至高于拒绝支付群体。（2）环境关注、搭便车顾虑、暖光效应等变量均对受访者抗议性信念存在影响。（3）抗议性信念水平对受访者参与决策与支付意愿金额均存在显著负向影响,抗议性信念变量对参与和支付决策的影响方向与程度存在差异,进一步证明参与和支付决策是不同的机制。研究结论将对优化CVM问卷设计、规范操作流程、减少评估偏差具有指导意义。