浅谈水体中硫化物保存、分离和测定方法的选择

水体中的硫化物是环境监测和工厂验收监测的一个重要参数.由于水中硫化物的不稳定性和水体中的干扰物质较多,保存常用技术为醋酸锌-氢氧化钠保存技术,但由于测定的手段不同,可根据不同的测定方法选用不同的保存和分离技术.比色法和碘量法时选用锌盐保存技术,分离技术有吹气分离、负压抽气分离或酸性溶液加锌产生氢气分离,选用不同的吸收液后测量;用间接测定技术时,可选用不同的金属盐进行沉淀后测定金属离子;选用电化学方法测定时,可选用使用于电化学的保存技术.为了准确地测定水体中的硫化物,宜选择最好的保存技术、分离技术和测定方法,并且必须使保存技术和测定方法相匹配,获得完善的监测技术和准确的监测结果.     

Current status and research on E-waste issues in Asia

Rapid economic growth in Asia and the increasing transboundary movement of secondary resources will increasingly require both 3R endeavors (reduce, reuse, recycle) in each country and appropriate control of international material cycles. Recently, managing electrical and electronic waste (E-waste) has become an important target for domestic and international material cycles from the viewpoints of environmental preservation and resource utilization efficiency. To understand the current status of E-waste issues in the context of international material cycles and to discuss the future tasks related to achieving 3R in the region, we organized the National Institute for Environmental Studies (NIES) E-waste Workshop in December 2004. This article reviews past studies on E-waste and briefly describes the topics presented and discussions held at the workshop. The topics at the workshop included E-waste generation, recycling systems, international trade, and environmental impacts. In addition, we discussed various issues such as terminology, current environmental concerns, and possible solutions. Transboundary shipments of E-waste should be conducted taking into consideration the concept of sustainable development. The direction of future research and possible collaborations are also discussed.     

木材防腐剂使用与环境安全性

笔者概述了国内外木材防腐剂研究与环境安全性状况 ,讨论了一些常用木材防腐剂的毒性与防腐剂对环境的安全性影响的主要途径 ,分析了木材防腐剂在制备生产中、使用过程中、废弃防腐木材处理以及通过生物体富集和食物链循环产生毒性对环境的污染。介绍了美国木材保护者协会AWPA有关木材防腐处理安全性规范和AWPA木材防腐处理标准 ,并简要论述了低毒和环境无害木材防腐、防蓝药剂的研究进展 ,对国内木材防腐剂研制开发提出了建议。     

长江口-浙闽沿岸沉积色素的分布特征及其指示意义

利用高效液相色谱法分析了长江口-浙闽沿岸表层沉积物中的色素组成和含量,探讨了海洋初级生产力、浮游植物功能类群和浮游植物色素保存效率的空间分布特征及其影响因素.结果表明,沉积物中的色素类型主要为沉积绿素(chloropigments,Chlorins)[包括叶绿素a(chlorophyll-a,Chl-a)及其降解产物(pheopigments,Pheo-a),如脱镁叶绿素a(pheophytin-a,PHtin-a)、脱镁叶绿酸a(pheophorbide-a,PHide-a)、焦脱镁叶绿素a(p Pheophytin-a,p PHtin-a)、甾醇绿素酯(sterol chlorin esters,SCEs)和胡萝卜醇绿素酯(carotenol chlorin esters,CCEs)].Chlorins高值区呈南北两大斑块状分布,可能主要是受到长江冲淡水及浙闽沿岸泥质区上升流输运的营养盐的影响.研究区域内类胡萝卜素整体上无明显趋势性变化,在长江口以及浙闽沿岸各呈现一个高值区.基于沉积物中特征类胡萝卜素比例估算得到的浮游植物功能类群中硅藻、甲藻、定鞭藻、青绿藻、隐藻和蓝藻的相对贡献分别为48.8%±17.4%、10.7%±11.5%、8.1%±7.2%、18.6%±8.2%、9.4%±6.4%和4.3%±3.2%.对营养盐水平、水体盐度等外界环境的偏好导致硅藻和甲藻比例离岸降低,青绿藻、隐藻和蓝藻比例离岸增加.Chl-a/Pheo-a比值的分布表明,较高的沉积速率以及季节性的底层水体缺氧事件导致了近岸海域(长江口最大浑浊带外缘、杭州湾湾口以及浙闽沿岸上升流区)具有较高的沉积色素保存效率,这些沉积色素保存效率较高的区域可能是进行海洋生态环境历史重建的理想区域,而杭州湾水体通过舟山群岛与外部海水进行水体交换时造成的较差沉积环境可能是导致杭州湾外海具有较低沉积色素含量和较低保存效率的主要原因.     

间歇性饥饿对厌氧氨氧化菌混培物保藏特性的影响

厌氧条件下,采用4℃、4℃并每隔10 d换1次NO-2-N/NH+4-N浓度比为1.32的基质、4℃并每隔10 d换1次NO-2-N/NH+4-N浓度比为1.63的基质3种方法保藏厌氧氨氧化菌混培物,研究间歇性饥饿对厌氧氨氧化菌混培物保藏特性的影响.结果表明,间歇性饥饿对厌氧氨氧化菌混培物的危害大于长期性饥饿,且亚硝态氮浓度越高危害越大;另厌氧氨氧化菌混培物活性还与血红素c含量有直接相关性,无外界颜色干扰时厌氧氨氧化菌混培物颜色还可直观反映其活性和血红素c含量,且厌氧氨氧化菌混培物的颗粒结构及其富含的胞外多聚物能增强其抵抗外界不利因素的能力.在试验的5个月内,3种方法下的活性衰减速率均先快后趋于稳定,趋于稳定时的三者活性保留率分别为75.3％、70.8％、62.7％.     

中俄联合监测水质中总磷测定实验的方法与结果对比分析

近年来,中俄双方开展了对等联合监测,但由于国域差别,两个国家在一个项目上采取了不同的实验方法,常出现同一个样品中俄双方出现不同的实验结果,为避免分歧,我国在少数几个站进行了中俄双方实验方法的对比实验,现就水质中总磷的测定将两国的实验方法和实验结果进行了分析。     

HYDROELECTRIC POWER AND SCENIC PROVISIONS OF THE 1950 NIAGARA TREATY1

ABSTRACT: An important international Niagara River management issue concerns allocation of the average 202,000 cubic feet per second river discharge for hydroelectric power and scenic purposes. Major water diversions from Niagara Falls are necessary for power production. Flow is allocated by the 1950 Niagara Treaty which is intended to maximize power benefits and preserve and enhance the scenic fals spectacle. This paper examines the extent to which the Treaty objectives have been achieved. Based on analyses of government documents, engineering data, and falls-viewing patterns, it is concluded that the 1950 Treaty led to enhancement of the falls spectacle and increased power generation. But significant additional power diversions probably are attainable without adverse effect upon the existing falls spectacle. Reducing daytime summer Horseshoe Falls flow and scheduling spring and autumn flow according to viewing patterns are possible means of increasing power diversions. Existing generating facilities could use considerably more water and the value of additional Niagara hydroelectricity is very high in terms of generation-cost savings over alternative power sources. Because of the cultural importance of the falls, Treaty modifications to permit increased power diversions are not recommended without prior public opinion sampling and on-site viewing experiments. These findings highlight the need for more careful study before long-term international agreements are concluded and illustrate the need for more flexible treaty arrangements to permit periodic adjustments for changing conditions.     

A Complicated Reef: The Relationship Between a Representation and the Represented Phenomenon

In this study, I describe the relationship between the Florida Aquarium's representation of a coral reef and the live reef that served as the model for the representation. I specifically illustrate how naming practices complicate the aquarium's stated purpose of environmental education. I conclude by suggesting ways the aquarium and other pro-environmental facilities can better manage environmental representation.     

Dioxins,chlorophenols and other chlorinated organic pollutants in colloidal and water fractions of groundwater from a contaminated sawmill site

BACKGROUND, AIM, AND SCOPE: The distribution of chlorinated organic contaminants in groundwater and the importance of colloids were studied in groundwater from a sawmill site contaminated by chlorophenol preservatives. MATERIALS AND METHODS: The groundwater was fractionated into three different size ranges: (1) >0.7 mum, (2) 0.4-0.7 mum and (3) 0.2-0.4 mum and the filtered water phase. The concentrations of chlorophenols (CP), chlorinated phenoxy phenols (PCPP), chlorinated diphenyl ethers (PCDE), chlorinated dibenzofurans (PCDF) and chlorinated dibenzo-p-dioxins (PCDD) were determined in each fraction. The colloids were characterised regarding the chemical composition using X-ray photoelectron spectroscopy (XPS). RESULTS: Chlorophenols were mostly found in the water fraction and PCDD/Fs were found almost exclusively in the particulate fractions. For example, the filtered water phase contained 2,100 mug l(-1) and 0.72 ng l(-1) for CPs and PCDD/Fs, respectively, and the particulate fractions contained 27 mug l(-1) and 32 ng l(-1) for CPs and PCDD/Fs, respectively. XPS evaluation of the particulate phases showed no correlation between the surface chemistry of the particle properties and the distribution of chlorinated compounds. DISCUSSION: The results suggest that groundwater transport of CPs, PCPPs, PCDEs and PCDD/Fs may occur from contaminated sawmill sites and that the colloid-facilitated transport, especially of PCDD/Fs, is substantial. The results correlated well with previous studies of compounds sorbed to dissolved organic carbon, which indicate that dissolved and colloidal organic carbon facilitated the transport of PCDEs, PCDFs and PCDDs particularly. CONCLUSIONS: Several classes of chlorinated compounds were readily detected in the groundwater samples. Due to the differences in their physicochemical properties, CPs, PCPPs, PCDEs and PCDD/Fs vary in their partitioning between colloidal fractions and the filtered groundwater. The proportion of the bound fraction increased with an increasing hydrophobicity of the chlorinated compounds. The groundwater transport of colloid-associated pollutants from the site may be significant. RECOMMENDATIONS AND PERSPECTIVES: The results imply that colloidal particles <0.7 mum are freely mobile in groundwater from this site. The groundwater transport of colloid-associated pollutants may be significant. However, the extent of the problem is not yet known and, thus, further research is needed to evaluate the impact of colloidal transport of hydrophobic organic contaminants. In Sweden alone, 400 to 500 sawmill sites are estimated to be contaminated with PCDD/Fs as a result of the former use of CP-based wood preservatives. The widespread use of CP mixtures for a variety of applications, including wood preservation, indicates that potential colloidal transport will be an issue of concern in many countries.     

发达与欠发达地区耕地保护行为中的利益机制分析

本文从当前发达与欠发达地区耕地保护上的利益矛盾入手，以它们之间的内在经济关系为基础，运用局部均衡分析方法，构建了一个简单的经济模型，对上述矛盾“零和博弈”的长期效应进行了揭示，并讨论了消除这种不良影响的政策或制度安排。