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1.
This paper discusses current environmental problems caused by energy utilization, energy-use patterns, and the role of green (renewable) energy systems as one of the potential solutions to challenging environmental problems, particularly global warming. It also presents some key aspects of green energy systems in terms of energy, exergy, environmental impact, and sustainable development and their linkages. The results show that assessments of green energy processes and systems though exergy analysis are essential to increase efficiency and decrease environmental impact, and hence contribute to sustainable development.  相似文献   

2.
The tannery industry influences the gross domestic product/economic activity of any country, but the uncontrolled release of tannery effluents causes environmental degradation and increases health risks to human. The reason for the toxicity of tannery effluents is the presence of high concentrations of organic and inorganic chemicals used in the production of leather goods. Untreated or partially treated effluents discharged into surface water results in an increase in both chemical and biological oxygen demand as well as in an increase in the levels of total suspended solids, dissolved solids, and toxic metals in environmental bodies, especially in soil, water bodies, and water sediments. Various treatment techniques, such as physicochemical, biological, and advanced oxidation methods, which include chemical precipitation, electrocoagulation, aerobic or anaerobic treatment, wetland construction, and Fenton, electro-Fenton, and photo-Fenton processes are also described. This review also discusses the technical appropriateness and economic feasibility of reducing the effluent pollution load and solid waste emanating from the tannery industry. Considering the enhanced health risks in the tannery waste treatment and management regime, some green and advanced technologies should be explored. A sustainable green technology that avoids the use of toxic chemicals in the tanning process is seen well for ecological health.  相似文献   

3.
三江平原沼泽地主养鲤鱼塘能量转换效率研究   总被引:1,自引:0,他引:1  
杨富亿 《湖泊科学》1995,7(3):263-270
对1988~1992年三江平原沼泽地泥炭池主养鲤鱼生态系统的能量转换效率进行了研究分析。结果表明,一个生长期浮游植物毛初级生产力对太阳辐射能的转换效率为0.204~0.308%;鲢鳙净产量对浮游植物净产量的转换效率为1.195~4.815%;太阳能转换为鱼类总净产量的生态学效率为0.067~0.123%。总辅助能、总生物能和饲料辅助能转换为鱼类总净产量的效率分别为8.91~14.05%、10.96~17.20%和11.06~17.57%.在2500kg/hm~2、3500kg/hm~2及5000kg/hm~2三个净产量级型池塘中,以5000kg/hm~2产量级的能量转换效率为最佳型。  相似文献   

4.
The environmental impact of marine fish culture: Towards a sustainable future   总被引:42,自引:0,他引:42  
The environmental impact of marine fish-farming depends very much on species, culture method, stocking density, feed type, hydrography of the site and husbandry practices. In general, some 85% of phosphorus, 80–88% of carbon and 52–95% of nitrogen input into a marine fish culture system as feed may be lost into the environment through feed wastage, fish excretion, faeces production and respiration. Cleaning of fouled cages may also add an organic loading to the water, albeit periodically. Problems caused by high organic and nutrient loadings conflict with other uses of the coastal zone. The use of chemicals (therapeutants, vitamins and antifoulants) and the introduction of pathogens and new genetic strains have also raised environmental concerns.

Despite the high pollution loadings, results from various studies show that some 23% of C, 21% of N and 53% of P of feed input into the culture system is being accumulated in the bottom sediments and the significant impact is normally confined to within 1 km of the farm. The major impact is on the sea bottom, where high sediment oxygen demand, anoxic sediments, production of toxic gases and a decrease in benthic diversity may result. Decreases in dissolved oxygen and increases in nutrient levels in the water are also evident but are normally confined to the vicinity of the farm. Tributyltin (TBT) contamination and the development of antibiotic-resistant bacteria have been reported near fish farms. The stimulating effects of vitamins/fish wastes on growth of red tide species have been demonstrated in a number of laboratory studies. Nevertheless, there is no evidence to support the suggestion that the present use of therapeutants, vitamins and antibiotics and the introduction of pathogens and new genetic strains would pose a significant threat to the environment.

Marine fish culture can be a sustainable development, provided pollution loadings generated by fish farms are kept well below the carrying capacity of the water body. Effects can be significantly reduced by careful site selection, control of stock density, improved feed formulation and integrated culture (with macroalgae, filter-feeders and deposit-feeders). An example of the application of computer modelling in mariculture management is demonstrated. Environmental impact assessment and monitoring should also be carried out to ensure culture activities are environmentally sustainable.  相似文献   


5.
翟颖  侯建民  马秀丹  郭凯  吴峥 《中国地震》2024,40(1):197-207
融媒体背景下,地震速报新媒体平台以其突出的技术优势和传播优势,在信息发布、震后应急、地震科普等方面发挥了重要的作用。本文基于地震速报新媒体平台的基本功能,深入探讨地震速报新媒体平台的创新点和薄弱点。该平台开拓了“人工+自动”的新媒体运维模式,实现了政府、公众的双向服务,具备一定创新性,但在联动能力、内容生产能力上仍存在发展空间。结合当下发展,提出了进一步提升地震速报新媒体平台影响力的发展策略。  相似文献   

6.
The results of environmental monitoring of surface-water quality in the Lower Volga Basin are given. The results of regular observations are differentiated. Water pollution is assessed based on the criterion of seasonal occurrence of chemicals in water at gage sections classified by zonal principle. An integrated estimate demonstrates considerable variations within a year and an increase in the normal annual concentrations of some pollutants of both natural and anthropogenic origin.  相似文献   

7.
Energy and water are scarce resources and understanding the complicated energy–water nexus is an important issue for effective resource management. The purpose of this research was to analyze the competitive and cooperative relationships involving energy and water production and use. Specifically, tradeoff and integrated management of hydropower generation and water supplies are analyzed for energy–water systems. A Nash–Cournot model was established to analyze strategic behaviors among participants in energy–water systems. In the model, tradeoff analysis and integrated management of hydropower and water supplies were simulated for a reservoir system. In addition, hydropower and thermal power generation in competitive energy markets was examined. A case study of Dajia River reservoirs in the Tai-Chung and Chang-Hwa energy–water systems is presented. Dajia River is the second longest river in central Taiwan; the reservoirs system of Dajia River generates hydropower with installed capacity of 1150 MW. Strategic competitive and cooperative behaviors regarding energy–water linkage were quantified in the results. The results show that integrated management of hydropower and water supplies can increase renewable energy production, lower electricity equilibrium price, and decrease carbon dioxide emission.  相似文献   

8.
The results of analysis of oscillations of an offshore oil and gas production platform, caused by seismic and other impacts (ice-field motion, storm wave impact, ship impact on platform supports, mechanism operations, etc.) are given. The analysis has been based on mathematical modeling of various impacts. Specific features of the inducement of platform mechanical oscillations as a function of the type of impact have been revealed, and the qualitative distinctions of platform oscillations under different impacts are described, allowing one to determine accelerometer-mounting sites for revealing seismic events by changes in acceleration on the platform.  相似文献   

9.
地震站网全流程一体化监控平台是基于微服务框架,应用数据库、通信、并行计算等传统信息技术,结合新兴的云计算、大数据进行建设的信息服务平台。该平台采用Hadoop分布式处理方案,应用Spring Cloud框架搭建,进行Docker容器封装,以标准RESTful API作为服务接口的微服务架构,实现了各应用服务模块之间的高内聚、低耦合及灵活、可扩展的特性,最终实现对地震台站运行的实时监测、高效运维和一体化管理。  相似文献   

10.
11.
The effect of the downstream propagation of a wake on the transport of momentum, energy and scalars (such as humidity) in the convective boundary layer (CBL) is studied using a direct numerical simulation. The incompressible Navier–Stokes and energy equations are integrated under neutral and unstable thermal stratification conditions in a rotating coordinate frame with the Ekman layer approximation. Wake effects are introduced by modifying the mean velocity field as an initial condition on a converged turbulent Ekman layer flow. With this initial velocity distribution, the governing equations are integrated in time to determine how turbulent transport in the CBL is affected by the wake. Through the use of Taylor’s hypothesis, temporal evolution of the flow field in a doubly periodic computational domain is transformed into a spatial evolution. The results clearly indicate an increase in the scalar flux at the surface for the neutrally stratified case. An increase in wall scalar and heat flux is also noted for the CBL under unstable stratification, though the effects are diminished given the enhanced buoyant mixing associated with the hot wall.  相似文献   

12.
本文介绍了基于MongoDB的地震风险评估综合地情数据服务平台,以灵活的文档结构存储与查询为目标,使用Web Service技术,采用前后端分离的开发方式,给出了系统的总体设计以及关键技术和功能,实现了全国区县级地震风险评估综合地情数据更灵活地上传、编辑、查询等功能。通过建立全国统一的地震风险评估综合地情数据服务平台,对数据进行可视化展示,提高了全国综合地情数据的利用率和服务能力。  相似文献   

13.
Production chemicals are used on offshore oil production platforms to prevent corrosion and scale formation, and to assist oil–water separation. A proportion of these chemicals may enter the marine environment via the produced water discharge. This study investigated the potential impact of 11 oilfield production chemicals on the toxicity of the produced water discharge. The Microtox® system was used for toxicity assessment of the chemicals, both directly in aqueous preparations and following their partitioning between oil (crude and low toxicity mineral base oil) and North Sea brine. For the majority of the chemicals tested, the toxicity of the aqueous phase to the test organism following partitioning against crude oil, was not significantly altered by the presence of process chemicals when used in their normal field dosage concentrations. However, there was evidence that certain chemicals could increase the partitioning of oil components into the aqueous phase by an order of magnitude, when applied at high dosage concentrations.  相似文献   

14.
Anthropogenic chemicals in the aquatic environment are known to cause reproductive disturbances in vertebrate and invertebrate organisms, by interfering with the endocrine systems. Laboratory-based in vivo and in vitro studies have indicated that several of the anthropogenic and other naturally occurring chemicals in the environment can cause adverse reproductive effects. Various definite or possible reproductive abnormalities caused by endocrine disruption have been identified, but in majority of the reported cases, it is not known whether adverse effects have occurred in the population level of biological organization. Disruption of the hormonal functions in fish may have effects on a number of events, including sexual maturation, gamete production and transport, sexual behaviour, fertility, gestation, lactation or modifications in other functions that are dependent on the integrity of the reproductive system. Although several reproductive effects have been reported, but the degree of causality established between the abnormalities observed and exposure to particular chemicals is variable, and understanding of the mechanism(s) is limited. Fishes are a vital source of proteins and lipids for humans and domestic animals, forming the basis for economically important fisheries and aquaculture. Large efforts have recently been denoted to dissect the mechanisms of action of xenobiotics in aquatic species, with the ultimate aim of detecting, controlling and possibly intervening in chemical exposure and its effects on the aquatic ecosystem and humans. In this context, we ought to be concerned with the health and safety of aquatic species per se, as well as a resource for human needs.  相似文献   

15.
Gravity platforms, together with associated regions of foundation and fluid, are idealized using the finite element method. Radiation of wave energy away from the platform region is modelled by appropriate damping applied to the boundary of the foundation mesh. Response results, due to sinusoidally applied forces, are calculated for seven platform-foundation configurations. Of particular interest are those results for various assumed foundation conditions, including the presence of stiff soil layers. The response of these platforms due to North Sea storm conditions is also estimated. It is concluded that a simple static analysis of the platform-foundation system does not necessarily give an accurate prediction of the response under extreme loading conditions. It is proposed that each prototype platform must be assessed on its individual merits, particular attention being given to prevailing geotechnical conditions.  相似文献   

16.
Active seismic sources are critical for obtaining high resolution images of the subsurface. For active imaging in urban areas, environment friendly and green seismic sources are required. In present work, we introduce a new type of green active source based on the gaseous detonation of methane and oxygen. When fired in a closed container, the chemical reaction, i.e. gaseous detonation, will produce high pressure air over 150MPa. Seismic waves are produced when high pressure air is quickly released to impact the surroundings. The first field experiment of this active source was carried out in December, 2017 in Jingdezhen, Jiangxi Province, where a series of active sources were excited to explore their potential in mine exploration. In current work, we analyzed the seismic waves recorded by near-field accelerators and a dense short-period seismic array and compared them with those from a mobile airgun source, another kind of active source by releasing high pressure air into water. The results demonstrate that it can be used for high resolution near surface imaging. Firstly, the gaseous detonation productions are harmless CO2 and water, making it a green explosive source. Secondly, the dominant seismic frequencies are 10-80Hz and a single shot can be recorded up to 15km, making it suitable for local structure investigations. Thirdly, it can be excited in vertical wells, similar to traditional powder explosive sources. It can also act as an additional on-land active source to airgun sources, which requires a suitable water body as intermediate media to generate repeating signals. Moreover, the short duration and high frequency signature of the source signals make it safe with no damage to nearby buildings. These make it convenient to excite in urban areas. As a new explosive source, the excitation equipment and conditions, such as gas ratio, sink depth and air-releasing directions, need further investigation to improve seismic wave generation efficiency.  相似文献   

17.
Natural and synthetic chemicals are essential to our daily lives, food supplies, health care, industries and safe sanitation. At the same time protecting marine ecosystems and seafood resources from the adverse effects of chemical contaminants remains an important issue. Since the 1970s, monitoring of persistent, bioaccumulative and toxic (PBT) chemicals using analytical chemistry has provided important spatial and temporal trend data in three important contexts; relating to human health protection from seafood contamination, addressing threats to marine top predators and finally providing essential evidence to better protect the biodiversity of commercial and non-commercial marine species. A number of regional conventions have led to controls on certain PBT chemicals over several years (termed ‘legacy contaminants’; e.g. cadmium, lindane, polycyclic aromatic hydrocarbons [PAHs] and polychlorinated biphenyls [PCBs]). Analytical chemistry plays a key role in evaluating to what extent such regulatory steps have been effective in leading to reduced emissions of these legacy contaminants into marine environments. In parallel, the application of biomarkers (e.g. DNA adducts, CYP1A-EROD, vitellogenin) and bioassays integrated with analytical chemistry has strengthened the evidence base to support an ecosystem approach to manage marine pollution problems. In recent years, however, the increased sensitivity of analytical chemistry, toxicity alerts and wider environmental awareness has led to a focus on emerging chemical contaminants (defined as chemicals that have been detected in the environment, but which are currently not included in regulatory monitoring programmes and whose fate and biological impacts are poorly understood). It is also known that natural chemicals (e.g. algal biotoxins) may also pose a threat to marine species and seafood quality. Hence complex mixtures of legacy contaminants, emerging chemicals and natural biotoxins in marine ecosystems represent important scientific, economic and health challenges. In order to meet these challenges and pursue cost-effective scientific approaches that can provide evidence necessary to support policy needs (e.g. the European Marine Strategy Framework Directive), it is widely recognised that there is a need to (i) provide marine exposure assessments for priority contaminants using a range of validated models, passive samplers and biomarkers; (ii) integrate chemical monitoring data with biological effects data across spatial and temporal scales (including quality controls); and (iii) strengthen the evidence base to understand the relationship between exposure to complex chemical mixtures, biological and ecological impacts through integrated approaches and molecular data (e.g. genomics, proteomics and metabolomics). Additionally, we support the widely held view that (iv) that rather than increasing the analytical chemistry monitoring of large number of emerging contaminants, it will be important to target analytical chemistry towards key groups of chemicals of concern using effects-directed analysis. It is also important to evaluate to what extent existing biomarkers and bioassays can address various classes of emerging chemicals using the adverse outcome pathway (AOP) approach now being developed by the Organization for Economic Cooperation and Development (OECD) with respect to human toxicology and ecotoxicology.  相似文献   

18.
Samples of green lipped mussels (Perna viridis) were collected from three sites (Huoshao, I’Maluan and Tong’an) around Xiamen coastal waters, where levels of various trace organic pollutants have been studied. Samples were also collected at a “cleaner” reference site near Dongshan Island for comparison. Clearance rate, absorption efficiency and oxygen consumption of the mussels were measured under controlled laboratory condition; organic pollutants in their tissues were also analyzed. Scope for growth (SFG) was employed as a general biomarker to evaluate the stress of pollutants. Specimens from Tong’an site had the lowest SFG values (1.14 J/h/g); while specimens from the I’Maluan site and Huoshao site had SFG values of 5.01 and 6.72 J/h/g, respectively. Specimens from Dongshan (reference site) had a relatively high SFG value of 10.96 J/h/g. There was a significant negative correlation between the SFG of the different populations of green lipped mussels and the concentration of DDT in their tissues.  相似文献   

19.
There has been global concern about the effect of toxic chemicals on aquatic biota due to the upsurge in contamination of aquatic ecosystems by these chemicals, which includes pesticides. Roundup® and other glyphosate-based herbicides are frequently used in the chemical control of weeds and invading alien plant species in South Africa. These bio-active chemicals ultimately get into water courses directly or indirectly through processes such as drifting, leaching, surface runoff and foliar spray of aquatic nuisance plants. However, there is no South African water quality guideline to protect indigenous freshwater non-target organisms from the toxic effects of glyphosate-based herbicides. This study evaluated the possible use of growth measures in Caridina nilotica as biomarkers of Roundup® pollution as part of developing glyphosate water quality guideline for the protection of aquatic life in South Africa. Using static-renewal methods in a 25-day growth toxicity test, 40 days post hatch shrimps were exposed to different sub-lethal Roundup® concentrations of 0.0 (control), 2.2, 2.8, 3.4, 4.3 and 5.4 mg/L. Shrimps were fed daily with TetraMin® flake food and test solutions changed every third day. Shrimp total lengths and wet weights were measured every fifth day. These data were used to determine the shrimp’s growth performance and feed utilization in terms of percent weight gain (PWG), percent length gain (PLG), specific growth rate (SGR), condition factor (CF), feed intake (FI), feed conversion ratio (FCR) and feed conversion efficiency (FCE). Moulting was observed for 14 days and the data used to determine the daily moult rate for each concentration. Results of growth performance and food utilization indices showed that growth was significantly impaired in all exposed groups compared to control (p < 0.05). Moulting frequency was also higher in all exposed groups than in control (p < 0.05). Although all the tested growth measures proved to be possible biomarkers of Roundup® pollution, moulting frequency gives a clearer indication of the sub-lethal effects of Roundup® toxicity.  相似文献   

20.
破坏性地震强度预测可用于工程领域抗震设防以及地震危险性分析评估,是防震减灾中一项很重要的基础工作.为了再现九寨沟地震的地震动强度,评估缺失强震记录的九寨章扎台站的地震动强度,本文用经验格林函数法对九寨沟地震进行了数值模拟.选取了震源周边地震动峰值加速度超过10 Gal的10个强震台站进行模拟.因未得到九寨沟地震的余震,初次尝试将汶川地震和定西地震的余震作为格林函数模拟九寨沟地震.模拟结果整体上可以反映各台站地震动的强度特征,尤其是地震动高频成份拟合较好.模拟值的地震动峰值加速度、时程数据、反应谱等与观测值拟合较好.预测结果显示漳扎镇的地震动峰值加速度值约为180~200 Gal.预测结果也表明在缺少大震的余震记录时,经验格林函数法使用其他大震的余震同样可以再现目标地震的强度特征.本研究也为经验格林函数方法在缺乏小震记录地区的使用积累了经验.最后总结了格林函数的选取标准,为经验格林函数方法来预测未来强震动特征积累了经验.  相似文献   

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