河北省坝上地区气候与沙化关系的研究

本文利用坝上五县气象站近３０年资料进行数理统计，研究其与该区沙暴等自然灾害的关系。其结果表明：坝上地区近３０年来气温上升了０．７８℃；降雨量增加了１３．８ｍｍ；大风递减了２３．７个大风日和沙暴减少了９．２个沙暴日。同时根据不同介质的风蚀积沙观测资料，以及沙化与恢复指标，对该区的生态环境的初步恢复与改善进行了预测研究。     

拉萨污水处理厂污泥对沙化土壤改良效果

以西藏雅鲁藏布江流域沙化土壤为研究对象,采用拉萨污水处理厂脱水污泥进行添加处理,测定了不同污泥掺混量下土壤基本理化性质变化趋势,并与当地农田、草地生态系统土壤进行了比较。结果表明:随着污泥掺混量的增加,沙化土壤的孔隙度逐渐提升(P0.001),土壤密度及容重逐渐降低,在掺混量大于10%时,改良效果趋于减缓;土壤氮、磷、有机质含量呈增加趋势,在掺混量为10%~15%时与对照土壤氮、磷含量相近,在掺混量为20%~30%时,有机质含量与对照相近;土壤最大持水量呈增加趋势,在掺混量为5%~10%时即与对照土壤相近;拉萨污水处理厂污泥重金属含量远低于国家农田土壤标准,且含有一定的植物生长必需元素,是一种理想的沙化土壤改良剂。     

石家庄市生态环境建设存在的主要问题及对策

石家庄市目前存在大气污染严重、水资源短缺、滹沱河断流、沙化逐年加剧等生态环境问题,根据城市生态学原理和指导思想以及基本原则,结合21世纪初该市的城市生态建设、经济发展和城市化目标,提出了生态环境建设的对策.     

全国人大代表刘志新:加快建设北方绿色生态屏障

横跨全国13个省(市、自治区)的三北防护林体系建设工程实施30多年来,累计完成造林保存面积近4亿亩,工程区森林覆盖率提高近6百分点,取得巨大的阶段性建设成就。但是,目前三北地区森林资源总量和林分质量还很低,难以从根本上遏制土地沙化、水土流失等生态灾害。三北防护林体系工程建设也面临一些困难。突出问题有:一是受资     

西部可持续发展与人力资本开发

从可持续发展角度出发，讨论了西部开发面临着人口、资源与环境等方面的巨大压力，指出随着科学技术发展，传统的自然资本和物质资本的竞争将被人力资本所替代，人力资本在可持续发展中发挥着重要作用，开发人力资本才是实现西部可持续发展的战略选择。     

粉煤灰资源化的一种有效途径

本文对影响粉煤灰泡沫玻璃质量的主要因素：玻璃软化温度与发泡剂的选择、发泡温度与发泡时间、发泡剂生成气体的温度、坯体成型压力等关键问题进行了探索，这些问题的探索对提高粉煤灰泡沫玻璃质量，获得性能优良的粉煤灰泡沫玻璃具有十分重要的意义。     

超临界络合萃取铅的研究进展

本文综述了超临界络合萃取铅的研究进展，介绍了几类络合剂，以及温度、压力和基质及基质修饰剂等因素对萃取效率的影响。     

催化湿式氧化处理机械加工工业废水的研究

利用担载的双金属活性组分催化剂，考察了反应温度、压力、进料空速和污水pH等条件对催化湿式氧化处理某厂机械加工废水效果的影响。对于该厂的混合废水，在反应温度260℃，反应压力6．6MPa，空速为2．0h^-1，pH为3条件下处理后的废水CODCr去除率为90．2％。考察了助剂H2O2、絮凝剂对处理废水效果的影响和各种联用技术对废水的处理效果。     

中国COD减排压力剖析及对策建议

经济与"两高一资"行业超预期发展、城市化进程加快、环保投资需求偏高、环境管理体制不完善、政策与措施的"时滞效应"等因素直接或间接制约了中国COD减排.直至2007年第3季度,COD排放量才首次下降.未来3年,中国COD排放量需年均减排3.5%,减排难度和压力极大.针对如何完成COD减排目标,重点剖析了中国COD减排的形势和面临的内在、外在压力,并从行政、法律、经济、技术、管理等方面提出了相应的对策建议.     

超细TiO2粒子的超滤分离及回用特性

针对TiO2超细粒子的超滤分离特性进行了试验研究，探讨了操作压力、膜面流速、TiO2投量、pH、电解质等参数条件对膜通量的影响规律及作用机理，证实了浓差极化及滤饼层阻力是影响通量变化的主导因素，在此基础上确定了适宜的超滤工艺条件及膜清洗方式。以甲基橙为降解基质分别测试了经混凝与超滤分离后的TiO2光催化活性，结果表明，超滤不仅可实现TiO2粒子与水的彻底分离，且分离后TiO2催化活性与初次使用相当。研究表明超滤用于悬浮光催化体系的固液分离及催化剂再用是可行的。     

Correlation assessment of NDVI and land use dynamics with water resources for the southern margin of Mu Us Sandy Land,China

Environmental Science and Pollution Research - To prevent desertification, countries worldwide have made diversified efforts, and vegetation restoration has been demonstrated to be an effective...     

Estimate of total CO2 output from desertified sandy land in China

Soil is an important factor in regional and global carbon budgets because it serves as a reservoir of large amount of organic carbon. In our study, using remote sensing data of different periods we analyzed the development and reversion of desertification in China, calculated the variations of organic carbon contents of the desertified lands in China. The results showed that the total storage of organic carbon in 0–50 cm soil layer of the desertified lands is 855 Mt. In recent 40 yr, the total CO₂ amount released by land desertification processes to the atmosphere was 150 Mt, while the CO₂ amount sequestered by desertification reversing processes corresponded to 59 Mt C. Hence, the net CO₂ amount released from desertified lands of China corresponded to 91 Mt C, about 68.42% of the 133 Mt C of annual CO₂ release in the global temperate and frigid zones. Simultaneously, it indicated that CO₂ amount sequestered by desertification reversing processes in desertified land had greater potential than the other soils.     

城镇生活污水就近引浇防沙治沙工程林

城镇生活污水排入水体 ,严重影响水资源的使用价值。沙漠地区因缺水 ,造成许多地方造林失败。本文提出了将城镇生活污水就近引浇防沙治沙工程林的构想 ,并从经济和环境影响两个方面详细论述了该方案的比较优势     

The reuse of wastewater and sludge for cultivation of forestry trees in desert areas in Greece

Processed wastewaters and sludges can be used in the irrigation of forest and desert areas for the cultivation of different plant species. Their use in the reforestation of desert areas is particularly interesting because it not only addresses the important modern problems of water shortage and desertification, but also reduces the pollution of aquatic ecosystems that are used as the final recipients of supposedly processed sewage from treatment plants. The analysis of all the parameters (chemical, environmental, geological) that are related to the by-products of the operation of such plants in both small and large municipalities of Greece will allow the disposal of wastes in the aquatic ecosystems to be reduced, and minimise pollution of the coastal and tourist urban regions of the country.     

Confronting environmental pressure,environmental quality and human health impact indicators of priority air emissions

This paper evaluates the ranking of 21 priority air pollutants with three indicator schemes: environmental pressure indicator (EPI), environmental quality indicator (EQI), and human health effect indicator (HEI). The EPI and EQI compare the emissions and concentrations with the target emissions and target concentrations, respectively. The HEI comprehends the steps from cause (i.e. national emissions) to effect (i.e. human health effects), and is the total human health burden, expressed in Disability Adjusted Life Years per year of exposure (DALYs year^?1). We estimated a health burden in the Netherlands of 41 × 10³ DALYs year^?1 caused by Dutch air emissions of PM10 and its precursors in the year 2003. The burden due to 17 carcinogenic substances emitted to air, was much lower (140 DALYs year^?1). In contrast, when the same substances were evaluated regarding environmental pressure and environmental quality, carbon tetrachloride (pressure) and benzo[a]pyrene (quality) were of highest importance, whereas the importance of PM10 was substantially lower. This result is remarkable, because for the majority of substances evaluated, the target concentrations and target emissions are based on preventing human health damage. The differences in relevance are explained by the different weighting of interests in the indicators. The HEI is based on concentration–response relations, whereas the EPI and EQI also depend on other, policy-based, principles and on technical feasibility. Therefore, to effectively prioritize emission reduction measures in policy-making, substances should not only be evaluated as to whether emission targets and environmental quality targets are reached, but they should be evaluated regarding their human health impact as well. In this context, the HEI is a suitable indicator to evaluate the human health impact.     

Carbon stock dynamics in the tropical rain forests of the Uttara Kannada district, Western Ghats, India

Carbon stock dynamics was monitored in the Uttara Kannada district, Western Ghats, India, for ten years on eight one-hectare sampling areas belonging to different management and forest categories. The study was initiated in 1984 and the area was monitored until 1994. Our study indicates that, in general, the carbon stock has enhanced during the study period with an average growth of 1.008 t/ha/year. However, there were differences in carbon stocks in different management regimes. The minor forests that are subjected to intense human pressures had a negative growth rate, i.e. 0.237 t/ha/year, while the reserve forests have a carbon assimilation rate of 1.31 t/ha/year. This indicates that human pressure has certainly decreased the carbon accumulation in the forests of Uttara Kannada. Despite the anthropogenic pressure, the minor forests have higher carbon accumulation through recruits as compared to the reserve forests. Thus it is suggested that a management strategy is needed to look into enhancing recruitment patterns in the minor forests which would become future carbon stocks.     

Beyond the desertification narrative: a framework for agricultural drought in semi-arid East Africa

In the 20th century, much research was done on desertification. Desertification developed into a complex and vague construct that means land degradation under specific conditions. Projects focusing on land degradation in semiarid East Africa have met with limited success because farmers prioritize drought as the major productivity-reducing problem. Yet studies on long-term rainfall trends have not confirmed that droughts are more frequent. In this article, we combine drought and land degradation effects into an Agricultural Drought Framework, which departs from the farmers' prioritization of drought and accommodates scientists' concern for land degradation. It includes meteorological drought, soil water drought, and soil nutrient drought. The framework increases insight into how different land degradation processes influence the vulnerability of land and farmers to drought. A focus on increased rainwater use efficiency will address both problems of land degradation and drought, thereby improving productivity and food security in semiarid East Africa.     

The phytotoxic effect of C(1)/C(2)-halocarbons and trichloroacetic acid on the steppe plant Artemisia lerchiana

Artemisia lerchiana is a wormwood species of the Central Asian steppe regions, where it completely cover whole areas. For the first time it was possible to show through field experiments that C(1)/C(2) halocarbons (VCHCs), such as chloroform (CHL), tetrachloroethene (PER) and hexachloroethane (HEX), can be taken up by test plants of the species A. lerchiana via the soil/root pathway and metabolised inter alia into trichloroacetic acid (TCA) under semi-aride conditions. At the same time, chlorophyll a fluorescence measurements carried out on the test plants revealed a phytotoxic influence on plant vitality (max. decline in vitality of 52% with application of CHL) and less efficient energy flows in the photosynthesis mechanism of the A. lerchiana test plants. The authors examine possible links between the simultaneous appearance of VCHCs and additional drought stress in the acceleration of desertification processes.     

Human dietary intake of organochlorines from Baltic herring: implications of individual fish variability and fisheries management

This study examines the extent to which Finnish human dietary intake of organochlorines (PCDD/Fs and PCBs) originating from Northern Baltic herring can be influenced by fisheries management. This was investigated by estimation of human intake using versatile modeling tools (e.g., a herring population model and a bioenergetics model). We used a probabilistic approach to account for the variation in human intake of organochlorines originating from the variation among herring individuals. Our estimates were compared with present precautionary limits and recommendation for use. The results show that present consumption levels and frequencies of herring give a high probability of exceeding recommended intake limits of PCDD/Fs and PCBs. Furthermore, our results clearly demonstrate that in the risk management of dioxinlike organochlorines, regulating fishing (in this case increasing fishing pressure) is a far less effective way to decrease the risk than regulating the consumption of herring. Increased fishing would only slightly decrease organochlorine concentrations of herring in the Finnish fish market.     

Spatial distribution of illicit drugs in surface waters of the natural park of Pego-Oliva Marsh (Valencia,Spain)

Background, aim and scope  

The Pego-Oliva Marsh is the second most important wetland in the Valencian Community (Spain). It is included in the RAMSAR agreement and represents one key point for migratory birds. Emerging contaminants from the human pressure, such as pharmaceuticals, illicit drugs and personal care product, are not included in the list of priority contaminants of the Water Framework Directive yet, and are neither monitored nor controlled. However, pollution of emerging contaminants can threaten the environment and even human health. In order to understand the status of the emerging contamination and recommend future rationalization of countermeasures, the occurrence of illicit drugs was investigated.