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741.
The dugong is classified as vulnerable to extinction by the World Conservation Union on the basis of declines in area or extent of occupancy, habitat quality, and actual or potential levels of exploitation. In Thailand, the largest groups of dugongs are found near islands off the Andaman coast. The authors conducted a 2-year project that included dugong population and habitat assessment as well as interviews with local fishers. The results indicate declining populations of dugongs. The largest threat to dugongs is incidental catch in fishing nets. The numbers of deaths reported place the dugong population along the Andaman Sea in danger of extirpation. Other threats include seagrass destruction both from fishing and coastal development and the use of dugong parts for medicinal purposes. Villagers still show strong ties with dugongs, and the majority favor establishing more large protected areas for the species. These should arise from an integrated national dugong and seagrass conservation strategy formulated by concerned stakeholders from government, nongovernmental organizations, scientists, and local communities. The strategy needs to be both top down and bottom up in its formation to balance existing and potential uses as well as conflicts between artisanal and commercial fishers. The strategy should include the development of educational materials and enforceable regulations, as well as the designation of community-protected seagrass beds and a system of dugong sanctuaries along the Andaman coast. An integrated management plan is needed urgently, with the continued input of concerned scientists, to monitor and increase knowledge of dugong behavior and distribution.  相似文献   
742.
秦皇岛市第三产业及城镇化发展循环经济问题与对策   总被引:1,自引:1,他引:1  
秦皇岛港在装卸运输中有煤尘与油污染,应采取各种措施严格管理,并回收循环使用,非饮用水也应循环利用,铁路与公路运输中应加强固体废弃物的管理,回收处理循环使用.在旅游业和餐饮业中也应实现固体废弃物回收处理循环利用及污水的处理循环使用.在城镇化的过程中重点解决污水处理循环使用和生活垃圾回收处理,并使之资源化、循环使用.  相似文献   
743.
危险废物管理系统的优化   总被引:1,自引:3,他引:1  
危险废物管理系统的规划和设计包括处理和处置设施的选择、危险废物的分配、废物残渣从产生地运往处理处置点运输路线的选择等。在考虑了不同危险废物的不同特征、不同废物间的相容性、废物与处理技术的相容性、废物处置设施产生的废物残渣和选址问题等,基于多目标整数规划方法,提出了危险废物管理系统的优化模型。其中,经济目标包括运输费用、处理与处置成本、处理废物经济效益,环境目标包括处理设施总的环境影响、运输过程的环境影响,并从经济和环境影响方面,提出了一个综合考虑了费用和环境影响相关目标的复合效用函数。所提出的危险废物管理系统优化模型对我国区域性危险废物管理提供理论参考。  相似文献   
744.
从气力除灰系统的经济性考虑,按照系统运行能耗最省的原则,对系统进行优化设计。以山东临沂电厂除灰系统为例,优化出灰气比、管径、系统压损、耗气量等技术指标。实际运行效果证明这种优化设计方法是可行的,为该系统的推广应用提供了优化设计依据。  相似文献   
745.
Industrialization and urbanization along the coastal population centers have brought great changes in the land cover and material fluxes from watersheds to receiving bays and estuaries. We have embarked a multiyear research project on “Watersheds Nutrient Loss and Eutrophication of Jiaozhou Bay” for the period of 2000 to 2004, funded by the Natural Science Foundation of China to examine human influence on the marine sector of ecosystem. Jiaozhou Bay, located in the southern part of Shandong Peninsula, was selected because of the existence of long-term hydrographic and meteorological records since the 1930s and recent observations on the marine ecological variables. We have made extensive and periodic measurements on the water movement, nutrients, phytoplankton, and microbe in water column and bottom sediments. Box and 3-dimensional hydrodynamic models were developed and utilized to understand the evolution of eutrophic status with time. It was found that primary productivity has suffered from silica depletion followed by phosphate, and the dominance of large phytoplankton has been replaced by small-size communities. These ecosystem changes were brought by the changes in the relative contribution among major pathways and concentrations, owing to the human activities in the watershed. Eight articles in this volume reported various aspects of the linkage between watershed human activities and ecosystem for the Jiaozhou Bay as the initial outcome of this project.  相似文献   
746.
Marine debris (marine litter) is one of the most pervasive and solvable pollution problems plaguing the world’s oceans and waterways. Nets, food wrappers, cigarette filters, bottles, resin pellets, and other debris items can have serious impacts on wildlife, habitat, and human safety. Successful management of the problem requires a comprehensive understanding of both marine debris and human behavior. Knowledge is key for consumers to make appropriate choices when it comes to using and disposing of waste items. Education and outreach programs, strong laws and policies, and governmental and private enforcement are the building blocks for a successful marine pollution prevention initiative. The plastic industry also has a role to play in educating its employees and customers, and searching for technological mitigation strategies.  相似文献   
747.
对焚烧法从废彩色相纸中回收银工艺的技术条件,及焚烧过程中产生烟气的处理方法进行了探讨,取得了基础数据,为废彩色相纸的工厂化处理提供科学依据。  相似文献   
748.
Kaewsarn P 《Chemosphere》2002,47(10):1081-1085
Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine algae has been reported to have high uptake capacities for a number of heavy metal ions. In this paper, the adsorption properties of a pre-treated biomass of marine algae Padina sp. for copper(II) were investigated. Equilibrium isotherms and kinetics were obtained from batch adsorption experiments. The biosorption capacities were solution pH dependent and the maximum capacity obtained was 0.80 mmol/g at a solution pH of about 5. The biosorption kinetics was found to be fast, with 90% of adsorption within 15 min and equilibrium reached at 30 min. The effects of light metal ions on copper(II) uptake were studied and the presence of light metal ions did not affect copper(II) uptake significantly. Fixed-bed breakthrough curves for copper(II) removal were also obtained. This study demonstrated that the pre-treated biomass of Padina sp. could be used as an effective biosorbent for the treatment of copper(II) containing wastewater streams.  相似文献   
749.
As part of our continuing evaluation of the pore-water approach for assessing sediment quality, we made a series of side-by-side comparisons between the standard 10-day amphipod whole sediment test with the corophiid Grandidierella japonica and a suite of tests using pore water extracted from the same sediments. the pore-water tests evaluated were the sea urchin (Arbacia punctulata) sperm cell test and morphological development assay, the life-cycle test with the polychaete Dinophilus gyrociliatus, and acute exposures of red drum (Sciaenops ocellatus) embryo-larval stages. Sediment and surface microlayer samples were collected from contaminated sites. Whole-sediment, pore-water, and surface microlayer toxicity tests were performed. Pore-water toxicity tests were considerably more sensitive than the whole-sediment amphipod test, which is currently the most sensitive toxicity test now recommended for determining the acceptability of dredged material for open ocean disposal.  相似文献   
750.
易乐  欧阳晔 《四川环境》2004,23(1):70-74,77
海洋容纳和消化污染物是有限的,而我们继续排放污染却是长久的,为了子孙后代和人类的可持续发展,应该从现在就在海洋能够自净的基础上控制污染物的排放。并且要认识到污染物在海洋中会损害和破坏海洋生态环境,也会影响到人类自身的生存安全。大海是人类最后的退路,保护海洋环境就是保护人类自己。大海不是没有被污染,而是正在被加速地污染。  相似文献   
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