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1.
In this article, we review the fundamental phenomenon of oxygenation within the overriding context of petroleum-industry effluents and the other oxygen demanding wastes in Niger Delta, Nigeria. Drill cuttings, drilling mud (fluids used to stimulate the production processes), and accidental discharges of crude petroleum constitute serious land and water pollution in the oil-bearing province. Effluents from other industrial establishments such as distilleries, pulp and paper mills, fertilizer plants, and breweries, as well as thermal effluents, plant nutrients (such as nitrates and phosphates), and eroded sediments have also contributed to the pollution of their surrounding environment. Since these wastes are oxygen-demanding in nature, their impact on the recipient environment can be reversed by the direct application of simple chemistry. The wastes can be reduced, particularly in natural bodies of water, by direct oxidation-reduction processes or simple chemical combinations, acid-base reactions, and solubility equilibria; these are pH- and temperature-dependent. A shift in pH and alkalinity affects the solubility equilibria of Na+, Cl-, SO(2-), NO3(-), HCO3(-), and PO4(3-), and other ions and compounds.  相似文献   

2.
Abstract

Pacific Ocean and island sites have been used since World War II for nuclear activities, including effluent discharges from nuclear facilities, sea dumping of packaged radioactive wastes, and testing of nuclear explosives. In the future, the amounts of radioactive wastes deliberately released into the Pacific Ocean may increase in connection with planned commercial‐scale nuclear fuel reprocessing operations, recommencement of plutonium production for weapons purposes, and resumption of sea dumping of low‐level wastes. Proposed storage of spent nuclear fuel on Pacific island sites or disposal of high‐level wastes in the deep seabed of the Pacific could also expose the ocean to a risk of contamination by long‐lived radio‐nuclides. The consequences of all these activities should be assessed in practical terms—their likely effects on the living marine resources of the Pacific and the economic development of the societies benefited by them; in terms of the legal principles which govern activities such as marine radioactive waste disposal that could pollute the marine environment; and in relation to current and future organizational arrangements that could achieve political resolution of outstanding international nuclear energy issues. Despite the prospective dangers of marine nuclear activities, the use of relatively remote or extraterritorial marine locations including those in the Pacific basin for nuclear operations could provide a basis for international cooperation on management of the “back end”; of the nuclear fuel cycle, including storage and reprocessing of spent fuel and high‐level waste disposal. A broadly recognized international regime for the nuclear fuel cycle could be based on regional organization of such back‐end operations, provided local acceptance could be obtained.  相似文献   

3.
Worldwide fisheries generate large volumes of fishery waste and it is often assumed that this additional food is beneficial to populations of marine top-predators. We challenge this concept via a detailed study of foraging Cape gannets Morus capensis and of their feeding environment in the Benguela upwelling zone. The natural prey of Cape gannets (pelagic fishes) is depleted and birds now feed extensively on fishery wastes. These are beneficial to non-breeding birds, which show reduced feeding effort and high survival. By contrast, breeding gannets double their diving effort in an attempt to provision their chicks predominantly with high-quality, live pelagic fishes. Owing to a scarcity of this resource, they fail and most chicks die. Our study supports the junk-food hypothesis for Cape gannets since it shows that non-breeding birds can survive when complementing their diet with fishery wastes, but that they struggle to reproduce if live prey is scarce. This is due to the negative impact of low-quality fishery wastes on the growth patterns of gannet chicks. Marine management policies should not assume that fishery waste is generally beneficial to scavenging seabirds and that an abundance of this artificial resource will automatically inflate their populations.  相似文献   

4.
The growing burden of waste disposal coupled with natural resource scarcity has renewed interest in the remediation, valorization, and/or repurposing of waste. Traditional approaches such as composting, anaerobic digestion, use in fertilizers or animal feed, or incineration for energy production extract very little value out of these waste streams. In contrast, waste valorization into fuels and other biochemicals via microbial fermentation is an area of growing interest. In this review, we discuss microbial valorization of nonconventional, aqueous waste streams such as food processing effluents, wastewater streams, and other industrial wastes. We categorize these waste streams as carbohydrate-rich food wastes, lipid-rich wastes, and other industrial wastes. Recent advances in microbial valorization of these nonconventional waste streams are highlighted, along with a discussion of the specific challenges and opportunities associated with impurities, nitrogen content, toxicity, and low productivity.  相似文献   

5.
Johnston EL  Webb JA 《Biofouling》2000,15(1-3):165-173
Laboratory toxicity tests generally expose organisms to a constant concentration of a toxicant in a uniform environment. The two techniques outlined in this paper assess the impact of a model toxicant, copper, on marine fouling assemblages in the field. These techniques allow natural assemblages to develop under a regime of toxicant dosing. The experiments were conducted using both techniques over time frames ranging from 2 weeks to 6 months. Short term experiments using the techniques assess the effects of toxicant exposure on recruitment. The longer term experiments enabled detection of certain indirect impacts of pollution. These include effects due to competition for space and variations in the susceptibility of organisms with age. Over the course of the experiments, a range of responses to copper was observed for different taxa. Both techniques have the potential to be used for testing the impact of other toxicants. Approaches such as those described are necessary in order to understand how communities react to toxicants in real world situations.  相似文献   

6.
Oil Impacts on Marine Invertebrate Populations and Communities   总被引:2,自引:0,他引:2  
It is likely that roughly one billion gallons of oil entersour oceans each year as a result of man's activities. Only 8%of this input is believed to derive from natural sources. Atleast 22% is intentionally released as a function of normaltanker "operational discharges," 12% enters from accidentaltanker spills and another 36% from runoff and municipal andindustrial wastes. Invertebrate populations and communities form the foundationfor marine ecosystems and are continually subjected to stressesfrom both chronic and acute oil toxicity. The diversity of invertebratetaxa represented in the marine environment exhibit a wide rangeof responses to oil. Mortality is an obvious impact resultingfrom catastrophic spills or even chronic toxicity. Sublethalimpacts on individuals are manifested by physiological, carcinogenicand cytogenetic effects. Impacts typically felt at the populationlevel involve changes in abundance, age structure, populationgenetic structure, reproduction and reduced recruitment potential.Community level impacts are typified by modified interactionsbetween competitors, predator/prey and symbionts. Most importantly,changes in community structure represented by altered trophicinteractions tend to produce the most dramatic alterations tonatural invertebrate assemblages. Invertebrate communities respond to severe chronic oil pollutionand/or acute catastrophic oil pollution in much the same way.Initial massive mortality and lowered community diversity isfollowed by extreme fluctuations in populationsof opportunisticmobile and sessile fauna (and flora). Oscillations in populationnumbers slowly dampen over time and diversity slowly increasesto original levels. The time over which these events occur dependson the type of oil, the extent of the initial contamination,habitat type, weather conditions, latitude, the species assemblagesrepresented and a myriad of other complex factors.  相似文献   

7.
耐辐射动球菌耐辐射及相关特性研究进展   总被引:1,自引:0,他引:1  
核能的利用对于缓解能源紧张、减少温室气体排放具有重要意义,然而核能利用产生的放射性废料对环境的影响成为核能发展的掣肘。耐辐射动球菌(Kineococcus radiotolerans)是一种从核污染环境中分离出来的,可在辐射、强碱、高盐、干旱、高金属离子浓度、高渗透压及强化学毒性等严酷环境中存活的革兰氏阳性耐辐射菌,有望应用于环境生物修复、医学等领域。本文就K.radiotolerans的生理生化特性、抗辐射性、抗氧化性、抗毒性有机物等特性的研究现状进行综述。  相似文献   

8.
9.
A major problem facing those who must assess the environmental effects of the disposal in the ocean of industrial and municipal wastes, including dredged materials, is determining whether given wastes elicit chronic deteriorative responses in important species of organisms. The full importance of such low-level, nonlethal effects is not known, but it is suspected that repeated elicitations may result in ecosystem changes as important as those caused by more easily determinable acute effects. Such considerations are important to the marine environment, where dumped pollutants may be quickly diluted to legal nonlethal concentrations, but may still bring forth cumulative chronic response patterns. One objective of this study has been to develop a field method of assessing the impacts of the disposal of various industrial and municipal wastes. The measure of the impact is not mortality measured against time, but the increase or decrease in activity of certain metabolic enzymes that signal whether an organism is under stress from a class of wastes. Also, by analysing tissues of test and indigenous species for the accumulation of metals, PCBs, and high molecular weight hydrocarbons as well as for the enzyme activity, one gains an insight into the actual effect, if any, of the accumulation upon the whole organism. The test organisms are exposed for selected periods of time in the field in devices called Biotal Ocean Monitors (BOMs); they are then assayed for enzyme induction. At present the following enzymes are used: mitochondrial ATPase, which responds particularly to excess biphenyls in the environment; catalase that is dissolved in the cytosol and responds to excesses of toxic metals; and cytochrome P-420 and P-450, which respond to cyclic and long-chain hydrocarbons. The applicability of the adenylate energy charge system to this problem is also studied.  相似文献   

10.
Climate change is fundamentally altering marine and coastal ecosystems on a global scale. While the effects of ocean warming and acidification on ecology and ecosystem functions and services are being comprehensively researched, less attention is directed toward understanding the impacts of human-driven ocean salinity changes. The global water cycle operates through water fluxes expressed as precipitation, evaporation, and freshwater runoff from land. Changes to these in turn modulate ocean salinity and shape the marine and coastal environment by affecting ocean currents, stratification, oxygen saturation, and sea level rise. Besides the direct impact on ocean physical processes, salinity changes impact ocean biological functions with the ecophysiological consequences are being poorly understood. This is surprising as salinity changes may impact diversity, ecosystem and habitat structure loss, and community shifts including trophic cascades. Climate model future projections (of end of the century salinity changes) indicate magnitudes that lead to modification of open ocean plankton community structure and habitat suitability of coral reef communities. Such salinity changes are also capable of affecting the diversity and metabolic capacity of coastal microorganisms and impairing the photosynthetic capacity of (coastal and open ocean) phytoplankton, macroalgae, and seagrass, with downstream ramifications on global biogeochemical cycling. The scarcity of comprehensive salinity data in dynamic coastal regions warrants additional attention. Such datasets are crucial to quantify salinity-based ecosystem function relationships and project such changes that ultimately link into carbon sequestration and freshwater as well as food availability to human populations around the globe. It is critical to integrate vigorous high-quality salinity data with interacting key environmental parameters (e.g., temperature, nutrients, oxygen) for a comprehensive understanding of anthropogenically induced marine changes and its impact on human health and the global economy.  相似文献   

11.
The safety and acceptability of many widely used solid waste management practices are of serious concern from the public health point of view. Such concern stems from both distrust of policies and solutions proposed by all tiers of government for the management of solid waste and a perception that many solid waste management facilities use poor operating procedures. Waste management practice that currently encompasses disposal, treatment, reduction, recycling, segregation and modification has developed over the past 150 years. Before that and in numerous more recent situations, all wastes produced were handled by their producers using simple disposal methods, including terrestrial dumping, dumping into both fresh and marine waters and uncontrolled burning. In spite of ever-increasing industrialisation and urbanisation, the dumping of solid waste, particularly in landfills, remains a prominent means of disposal and implied treatment. Major developments have occurred with respect to landfill technology and in the legislative control of the categories of wastes that can be subject to disposal by landfilling. Even so, many landfills remain primitive in their operation. Alternative treatment technologies for solid waste management include incineration with heat recovery and waste gas cleaning and accelerated composting, but both of these technologies are subject to criticism either by environmentalists on the grounds of possible hazardous emissions, failure to eliminate pathogenic agents or failure to immobilise heavy metals, or by landfill operators and contractors on the basis of waste management economics, while key questions concerning the effects of the various practices on public health and environmental safety remain unanswered. The probable and relative effects on both public health and environmental safety of tradition and modern landfill technologies will be evaluated with respect to proposed alternative treatment technologies.  相似文献   

12.
As a main source of direct and continuous input of pollutants in the aquatic ecosystem, studying the effects of effluents on receiving ecosystems has a high ecological relevance. While ecological risk assessment procedures are usually based on a chemical-based single component approach, their application for complex mixtures and effluents is less straightforward. A chemical-based approach has to rely on the knowledge of what chemicals are present in effluents, their potential toxicity, how all of these individual chemicals interact and what their individual and combined contribution to the mixture is. Whole effluent toxicity (WET) testing, however, is an integrative tool that measures the toxic effect of an effluent as a whole and accounts for uncharacterized sources of toxicity and for interactions. This paper addresses the use of transplanted bivalves, i.e., caged mussels, as a biomonitoring tool in WET testing with special reference to field situations in both freshwater and marine environments. We indicate how endpoints at different levels of biological organization within exposed mussels can give an integrative overview of effects. Finally, we will provide a framework for future research using mussels and discuss a multitude of instream responses for routine, efficient and cost-effective active biomonitoring applications.  相似文献   

13.
Environmental constraints in aquatic habitats have become topics of concern to both the scientific community and the public at large. In particular, coastal and freshwater habitats are subject to dramatic variability in various environmental factors, as a result of both natural and anthropogenic processes. The protection and sustainable management of all aquatic habitats requires greater understanding of how environmental constraints influence aquatic organisms. Locomotion and predator-prey interactions are intimately linked and fundamental to the survival of mobile aquatic organisms. This paper summarizes the main points from the review and research articles which comprise the theme issue 'Environmental constraints upon locomotion and predator-prey interactions in aquatic organisms'. The articles explore how natural and anthropogenic factors can constrain these two fundamental activities in a diverse range of organisms from phytoplankton to marine mammals. Some major environmental constraints derive from the intrinsic properties of the fluid and are mechanical in nature, such as viscosity and flow regime. Other constraints derive from direct effects of factors, such as temperature, oxygen content of the water or turbidity, upon the mechanisms underlying the performance of locomotion and predator-prey interactions. The effect of these factors on performance at the tissue and organ level is reflected in constraints upon performance of the whole organism. All these constraints can influence behaviour. Ultimately, they can have an impact on ecological performance. One issue that requires particular attention is how factors such as temperature and oxygen can exert different constraints on the physiology and behaviour of different taxa and the ecological implications of this. Given the multiplicity of constraints, the complexity of their interactions, and the variety of biological levels at which they can act, there is a clear need for integration between the fields of physiology, biomechanics, behaviour, ecology, biological modelling and evolution in both laboratory and field studies. For studies on animals in their natural environment, further technological advances are required to allow investigation of how the prevailing physico-chemical conditions influence basic physiological processes and behaviour.  相似文献   

14.
Solid waste management is a serious ecological problem in Saudi Arabia due to rapid industrialization, population growth and urbanization. Recycling and sorting are in their infancy in Saudi Arabia and huge amounts of mixed household and industrial wastes are still dumped without any pre-treatment. Solid waste management techniques such as incineration, pyrolysis and gasification have high investment costs. Composting and vermicomposting of solid organic waste have been considered as an economically viable and sustainable waste management technologies. However, wastes often contain pollutants, such as heavy metals that are toxic to decomposer micro-organisms. Thus, heavy metals are a challenge for the successful biological treatments. Waste may also contain a mixture of organic pollutants that certain microbes, such as micro-algae are known to degrade. The present review paper focuses on understanding the role of vermicomposting as a management tool in mitigating solid organic wastes. It is noteworthy to mention that the microbes also play a pivotal role in the degradation process, wherein the enzymes secreted during the process aid in decomposition of complex molecules into simpler compounds. Also, the extracellular polymeric substance secreted by the earthworm under metal stress serves a source of nutrient for the bacteria to flourish. Henceforth the goal of discussion in present review shows the way forward in using vermicomposting as a novel approach in dealing with solid organic waste.  相似文献   

15.
The genotoxicity of industrial wastes and effluents.   总被引:1,自引:0,他引:1  
V S Houk 《Mutation research》1992,277(2):91-138
  相似文献   

16.
Malaysia is blessed with abundant natural resources and bears a favorable climate for commercial cultivation of crops such as oil palm. In Malaysia the total plantation area of oil palm was 4,487,957 ha in 2008. It has been reported that in 2005 there was a total of 423 palm oil mills having production capacity of approximately 89 million tonnes of fresh fruit bunch (FFB) per year. Waste from the oil palm mill process include palm oil mill effluent (POME), generated mainly from oil extraction, washing and cleaning up processes. POME contains cellulosic material, fat, oil, and grease. Discharging untreated effluent into water streams may cause considerable environmental problems. The solid wastes generated are mainly decanter cake, empty fruit bunches, seed shells and fibre from the mesocarp. POME as well as the solid wastes may rapidly deteriorate the surrounding environment if not dealt with properly. Hence there is an urgent need for a sustainable waste management system to tackle these wastes. As these wastes are organic in origin, they are rich in plant nutrients. Composting of waste generated from palm oil mills can be good practice as it will be helpful in recycling useful plant nutrients. This review deals with various aspects of waste management practices in palm oil mills and the possibility of composting the wastes.  相似文献   

17.
Pervasive Computing will bring about both additional loads on and benefits to the environment. The prevailing assessment of positive and negative effects will depend on how effectively energy and waste policy governs the development of ICT infrastructures and applications in the coming years. Although Pervasive Computing is not expected to change the impact of the technosphere on the environment radically, it may cause additional material and energy consumption due to the production and use of ICT as well as severe pollution risks that may come about as a result of the disposal of electronic waste. These first-order environmental impacts are to be set off against the second-order effects, such as higher eco-efficiency due to the possibility to optimize material and energy intensive processes or to replace them by pure signal processing (dematerialization). The potential environmental benefits from such second-order effects are considerable and can outweigh the first-order effects. But changes in demand for more efficient services (third-order effects) can counterbalance these savings. The experience gained thus far with ICT impacts has shown that such a rebound effect occurs in most cases of technological innovations.  相似文献   

18.
A series of cruises during 1979 and 1980 to the pharmaceutical dump site located 64 km north of Arecibo, Puerto Rico, in the Atlantic Ocean, was carried out to evaluate effects of wastes on the ecology of the microflora of surface waters of the dump site. In addition to bacteriological monitoring of the waste plume created by the release of wastes from the disposal barge, stations along a series of transects, extending north from coastal waters through and beyond the dump site, were sampled. Largest numbers of culturable bacteria on marine agar were found at stations closest to shore and in the vicinity of the dump site. Bacteria recovered on marine agar were predominantly Vibrio and Aeromonas spp., with the relative abundance of these organisms decreasing as gram-positive organisms (staphylococci, micrococci, and bacilli) became dominant in areas immediately affected by waste dumping. Total numbers of bacteria (determined by acridine orange direct counts [AODC]), which were relatively stable throughout the region, and a direct estimate of viable cells (DVC), i.e., those cells responsive to additions of yeast extract and nalidixic acid, were determined by acridine orange staining and epifluorescence microscopy. Heterotrophic bacterial activity, measured by the uptake (Vmax) of 14C-labeled amino acids, declined relative to distance from land. Increases in specific activity indices (DVC/AODC and Vmax/AODC) were observed near the dump site. The composite results of this study, i.e., increased specific activities (determined by two methods), increased numbers of culturable marine bacteria, and marked alteration of the taxonomic composition of the culturable bacterial community in waters within and surrounding the Puerto Rico dump site, indicate demonstrable changes in the marine microbial community in the region used for waste disposal.  相似文献   

19.
In a 2½-month hydrobiological survey of the Rio Ojailén, a tributary of the Rio Guadalquivir in Spain, four aspects of the pollution from an oil refinery and petrochemical complex were considered: physical, chemical, macrobiological and toxico-Iogical. Near its source the river receives a combined waste making up 75% of its dry weather flow. The wastes are grossly polluting-from oil, phenols, ammonia, hydrocarbons and other organic materials as well as suspended solids. Though inhibitory to biological degradation, the wastes are gradually purified and diluted with passage downstream and retention in a man-made lake. No macroinvertebrate life is found for 43 km downstream of the complex, in spite of incoming pure streams which were sampled for comparison. Diptera followed by Odonata are the first to return. The effect of the lake on purification is considerable. Toxicity tests of river water upon mosquito fish show a similar decline in toxicity. An attempt has been made to predict the recovery of the river once treatment plants have been installed by the autumn of 1973.  相似文献   

20.
Recently, the impact of petroleum pollution on marine plankton has been complemented by a great concern. This review summarizes the reports about toxic effects of oil water accommodated fraction (WAF) on marine phytoplankton, zooplankton and early life stage of animal. For the oil WAF, toxicants are mainly composed of the aromatic hydrocarbons, such as the benzene hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) with 2–5 rings. The oil WAF, especially the PAHs, can be accumulated in plankton due to their great lipophilic abilities, and thus elicites various deleterious effects. Toxicological tests show that marine plankton is very sensitive to the petroleum WAF, as the order of median effective/lethal concentration is merely μg/L or mg/L. There are species and developmental stages differences of plankton tolerance to petroleum WAF, and the toxicity of different oil WAF is various. Generally, its toxicity enhances with increasing carbonic chain length and benzene ring number. Many studies on the acute and sub-acute toxic effects of oil WAF have been done, however few researches on its chronic toxic effects has been carried out till now. Besides, most reports focused on the levels from molecule to individual, though very little work of petroleum toxic effects has ever been performed on the marine plankton population or community levels. Therefore, it is necessary to continue these studies in future.  相似文献   

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