Causes And Effects Of Environmental Degradation Pdf
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- Health and Environmental Effects of Particulate Matter (PM)
- WATER POLLUTION
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- Impacts of Environmental Degradation
Health and Environmental Effects of Particulate Matter (PM)
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. A s with production and use of any fuels, aspects of biofuel production and use have benefits and adverse effects.
This chapter discusses potential environmental effects from the production and use of algal biofuels, the potential influence of perceived or actual impacts on societal acceptance, and some of the health impacts potentially emanating from the specific environmental effects. Potential environmental effects discussed in this chapter include those resulting from land-use changes, water quality, net greenhousegas GHG emissions, air quality, biodiversity, waste generation, and effects from genetically engineered algae with an emphasis on new or enhanced traits.
Where possible, this chapter discusses the potential for algal biofuels to improve aspects of sustainability compared to petroleum-based fuels and other biofuels and the potential for mitigating negative effects along the life cycle of algal biofuel. Environmental indicators of sustainability and data to be collected to assess sustainability are suggested.
In some environments and biofuel management systems, metrics for assessing environmental performance are easy to measure and adequate baseline data are available, but that is not the case in all systems. A number of potential environmental concerns are evident, and if the concerns are not addressed they could become significant risks under large-scale deployment. As in any other industrial or agricultural enterprise, once they are recognized, such risks can be managed by standards or regulations so that industry is required to reduce effects to acceptable levels.
For the sake of comprehensiveness, a number of potential environmental risks are mentioned in this chapter, but some are less likely to occur than others. Some of the environmental risks might require exploratory assessment and subsequent monitoring to ensure that they do not become sustainability concerns if algal biofuel production is scaled up. Producing algal biofuels could improve or harm water quality depending on the resource input and management used in algae cultivation, weather events, integrity of infrastructure, and processing of spent water.
Water-quality concerns associated with commercial-scale production of algal biofuels, if sufficient culture waters are released to natural environments, include eutrophication of waters, contamination of groundwater, and salinization of water sources.
Potential water-quality benefits are reduced runoff of herbicides and insecticides compared to corn-grain ethanol or soybean-based biodiesel because of their reduced use, and reduced eutrophication if there are no releases of culture water or if algae are used as a means to remove nutrients from municipal waste, confined animal feeding operations, and other liquid wastes. Water-quality effects will depend on the nutrient content of the algal culture medium; whether feedstock production systems are sealed, artificially lined, or clay lined; and the likelihood of extreme precipitation events.
Leakage of culture fluid to groundwater or surface water could occur if the integrity of the pond or trough system is compromised, if flooding occurs, or if spills occur during transfers of fluid during process stages or waste removal, but most of these events could be avoided with proper management. As discussed in Chapter 4 , the water for algae cultivation is likely to be reclaimed and reused to reduce the water requirement and consumptive water use.
The liquid effluent also can be recycled from anaerobic digestion of lipid-extracted algae to produce biogas Davis et al. If harvest water is to be released instead of recycled, it or effluent from anaerobic digestion would contain nitrogen N and phosphorus P , the concentrations of which depend on the nitrogen and phosphorus taken up by the harvested algal biomass Sturm and Lamer, Released waters could be more saline than receiving waters, particularly if water from saline aquifers is used for algae cultivation.
Such point-source discharge will be regulated by the Clean Water Act, and a National Pollutant Discharge Elimination System permit would have to be obtained to operate the algae cultivation facilities EPA, a. However, permit violation has been observed in some biofuel refineries. Regulation and compliance assurance would address concerns about release of harvest water.
The potential for accidental release of cultivation water exists; for example, clay or plastic liners could be breached through normal weathering or from extreme weather events, some of which are predictable. High precipitation or winds could lead to overtopping of ponds or above-grade raceways. In those cases, the entire contents of algal cultures could be lost to surface runoff and leaching to surface water or groundwater.
Siting in areas prone to tornadoes, hurricanes, or earthquakes would increase the likelihood of accidental releases. However, producers are likely to take preventive measures when extreme weather events are forecasted, and they would put effort into preventing accidental releases of cultivation water because such events could adversely affect their profit margin. Large-scale algae cultivation requires the provision of large quantities of nutrients, especially nitrogen and phosphorus, to ensure high yield see section Nutrients in Chapter 4.
Even where nitrogen and phosphorus are not in oversupply, the total nutrient concentrations in algal biomass will be high. Although accidental release of cultivation water into surface water and soil is unlikely, such an event could lead to eutrophication of downstream freshwater and marine ecosystems, depending on the proximity of algal ponds to surface and groundwater sources. Eutrophication occurs when a body of water receives high concentrations of inorganic nutrients, particularly nitrogen and phosphorus, stimulating algal growth and resulting in excessive algal biomass.
As the algae die off and decompose, high levels of organic matter and the decomposition processes deplete oxygen in the water and result in anoxic conditions Smith, ; Breitburg et al. In some cases, eutrophication-induced changes could be difficult or impossible to reverse if alternative stable states can occur in the affected ecosystem Scheffer et al. Eutrophication effects have been well studied, and they depend on the nutrient loadings to the receiving waters and the volume and residence time of water of these systems Smith et al.
High nutrient loading could lead to anoxia in the deep cool portion of lakes or in hypoxia in the receiving water bodies. Potential biotic effects of eutrophication include changes in algal density and in the structure and biomass of the broader ecological community Scheffer et al. Fish yield is affected by phytoplankton 1 biomass and by the nutrient ratios in the edibility of phytoplankton Oglesby, ; Bachmann et al.
Nutrient levels play a key role in determining the productivity and structure of the primary producing community in estuaries and coastal marine waters Deegan et al. Nutrient-enriched shallow marine systems tend to have a reduced seagrass community Burkholder et al. In high-nitrate environments, seagrasses can be shaded by epiphytic algae and macroalgae Drake et al. Seagrasses affect the entire estuarine food web because they stabilize sediments; serve as habitats and temporary nurseries for fish and shellfish; are sources of food for fish, waterfowl, benthic invertebrates, or manatees; and provide refuges from predation.
Eutrophication and other nutrient-related effects could be a concern for cultivation of microalgae or macroalgae in large suspended offshore enclosures for example, Honkanen and Helminen, Eutrophication also has implications for social acceptability Codd, , for example, because of eutrophication-related aesthetic concerns Grant, , and aesthetics can affect the recreational value of water bodies.
It is unknown whether rare releases of culture water or the physical appearance of open ponds for algae cultivation could have negative effects on the social acceptability of algal biofuels. Quantifying water losses from raceways, ponds, or photobioreactors would indicate whether repairs of small leaks are necessary. These culture systems can be designed and tested to withstand natural disasters that are possible during the lifetime of the infrastructure.
In coastal locations, for example, facility and infrastructure designs would need to consider the probabilities that hurricane winds and water surges could reach the algae cultivation site Guikema, Mitigation plans for accidental releases would be desirable. Open-pond algae cultivation also can be sited in locations that are not prone to hurricanes or away from lakes and streams. With respect to harvest water, engineering solutions can maximize recycling.
Some compounds present in algal ponds or photobioreactors could be toxic to humans or other organisms depending on exposure levels. Herbicides often are added to open systems to prevent growth of macrophytes and for selective control of algae NALMS, , but their application likely would be regulated as in the case of agriculture. If wastewater or oil well-produced water Shpiner et al. Wastewater could include industrial effluent Chinnasamy et al.
The composition and amount of toxicants vary by the type of wastewater. Produced water water contained in oil and gas reservoirs that is produced in conjunction with the fossil fuel may contain high levels of organic compounds, oil and grease, boron, and ammonia NH 3 Drewes et al. Many algal species including cyanobacteria, diatoms, and chlorophytes can bioconcentrate heavy metals Watras and Bloom, ; Vymazal, ; Mathews and Fisher, Therefore, potential risks from using each type of produced water need to be identified so that adequate containment and mitigation measures can be implemented in cultivation and processing.
Waterborne toxicants toxic substances made or introduced into the environment anthropogenically, not including algal toxins potentially pose risk to humans or other. Occupational exposures could be significant, especially during the harvesting phase. Thus, monitoring of toxic compounds in the culture media is important.
Potential toxicity exposure to animals through drinking is discussed in the section on terrestrial biodiversity. The release of culture waters to natural environments could pose other risks to animal consumers. Cultivation of algae in wastewater may require special handling and means of containment. Monitoring for the presence of toxicants or pathogens might be necessary to ensure the quality of the culture water. Monitoring of metals and other compounds in water sources, nutrient sources, and culture media in demonstration facilities would provide information about whether waterborne toxicants pose a significant concern.
If so, technical solutions for removing waterborne toxicants would be needed to prevent occupational and ecological exposures. Mercury is removed from flue gas in some configurations of coal-fired electric-generating units EPA, However, mercury removal is ineffective for certain types of coal and plant configurations NETL, Contaminants in flue gas could place another constraint on the type of coal-fired electricity facilities that would be suitable for providing CO 2 for algae cultivation see sections Estimated Land Requirements and Estimated Nutrient Requirements in Chapter 4.
Open ponds may not be suitable for many soil types without using lining, and a thorough review of potential effects on surface water and groundwater quality would have to be conducted if clay-lined ponds are to be used.
If outdoor ponds are poorly lined or the lining fails as a result of wear, then seepage of the pond water into the local groundwater system could occur. Clays that are compacted and graded have structural integrity that can be comparable to synthetic liners Boyd, However, integrity can be compromised by poor construction.
Nitrate leaching has been observed below structured clay soils White et al. Local terrestrial vegetation might take up some of the culture media released through seepage. In some areas, if open ponds contain high concentrations of dissolved inorganic nitrate, seepage may contribute to concerns related to nitrate poisoning if the groundwater is used for drinking by livestock or humans.
Withdrawal of freshwater adjacent to briny aquifers or injection of saline wastewater into the ground could result in salinization of groundwater if fresh water and briny aquifers are not well separated. Salinization of groundwater is a potential problem for some agricultural lands where irrigation is prevalent Schoups et al. However, one of the key advantages of algal biofuel is that the feedstock could be produced on nonarable land Ryan, ; Assmann et al.
Using sealed algal cultivation systems would practically eliminate the potential for leakage, barring catastrophic breaches. Where open systems are used, technologies such as the development of impermeable, long-lived liner systems and regional solutions for minimizing nutrient leakage could be deployed, and regulations to minimize leakage could be developed.
For example, Phyco BioSciences uses a trough system that has a lightweight, fabricated liner. The liner is expected to eliminate leakage or minimize percolation to less than 0. Potential preventive measures might include specifications for soil type, combined with defined values for the minimum depth from the pond bottom to groundwater.
Moreover, local regulations likely require lined ponds, which would reduce the probability of leakage of waters but contribute to capital costs and lead to temporary system closures when the liners are replaced because of wear or failure. Measures to prevent inadvertent discharge of water for example, overflow corridors or basins during extreme weather events would be helpful in preventing water pollution.
Wastewaters derived from municipal, agricultural, and industrial activities potentially could be used for cultivating algal feedstocks either in open ponds or in photobioreactors for algal biofuels and could provide an environmental benefit. Microalgae have been used in wastewater treatment for a long time Oswald et al. Microalgae have been shown to be effective for wastewater treatment in diverse systems including oxidation stabilization ponds and shallow raceway systems and using both phytoplankton and periphyton Green et al.
High rate algal ponds HRAPs , which are shallow, open raceway ponds used for treating municipal, industrial, and agricultural wastewater, combine heterotrophic bacterial and photosynthetic algal processes Park et al.
The ponds allow the growth of high-standing crops of algae, which remove nitrogen and phosphorus from the wastewater Sturm et al. The concept of adapting HRAPs for the purpose of biofuel production was proposed more than five decades ago Oswald and Golueke, Park et al. The feasibility and scale of such systems will be determined by the amount of wastewater, the availability of land near the facilities generating the wastewater and produced water, and the climatic conditions of the region.
See also Chapter 4. If wastewater is used, the wastewater treatment rate and the harvesting schedule would determine the maximum volume of ponds or photobioreactors.
The planet keeps nudging us with increasingly extreme droughts, reminding us that water is life. It is an essential resource upon which all living beings depend and it is crucial to all social and economic development, as well as energy production and adaptation to climate change. Nevertheless, we are now facing a gigantic challenge. How do we stop contaminating our rivers, seas, oceans, canals, lakes and reservoirs? Water pollution is endangering the health of millions of people around the world.
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. All the human causes of global environmental change happen through a subset of proximate causes, which directly alter aspects of the environment in ways that have global effects. We begin this chapter by outlining and illustrating an approach to accounting for the major proximate causes of global change, and then proceed to the more difficult issue of explaining them. Three case studies illustrate the various ways human actions can contribute to global change and provide concrete background for the more theoretical discussion that follows.
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One of the most compelling reasons for studying environmental science and management is the fact that, in the view of many leading authorities, we are now experiencing an environmental crisis; indeed, many authors have claimed that the present environmental crisis is unprecedented in its magnitude, pace and severity Park Awareness of this environmental crisis has grown since the s, partly as a result of the prominence given to major so-called 'environmental' disasters such as the Sahelian droughts of the s and s and the nuclear accident at Chernobyl in Consequently, a wide range of environmental problems has emerged; those problems include anthropogenic climate change 'global warming' , the depletion of stratospheric ozone the 'ozone hole' , the acidification of surface waters 'acid rain' , the destruction of tropical forests, the depletion and extinction of species, and the precipitous decline of biodiversity.
The degradation of ecosystems is an environmental problem that diminishes the capacity of species to survive. The degradation of ecosystems due to overexploitation of their resources, though serving a short-term economic goal, has had direct negative effects on social welfare in the medium and long terms. As long as the ecosystem is not degraded, it represents a source of wealth for society, hence the importance of keeping it in good condition. One of the main causes that contributes to the degradation of ecosystems is the deforestation due to the advance of the agriculture frontier and inappropriate forest exploitation.
Environmental degradation comes about due to erosion and decline of the quality of the natural environment. It is caused directly or indirectly by anthropogenic activities that extract various environmental resources at a faster rate than they are replaced, and thus depleting them. On this regard, degradation means damage or reduction in quality of environmental features, primarily influenced by human activities.
Environmental degradation is the disintegration of the earth or deterioration of the environment through the consumption of assets, for example, air, water and soil; the destruction of environments and the eradication of wildlife. Ecological effect or degradation is created by the consolidation of an effectively substantial and expanding human populace, constantly expanding monetary development or per capita fortune and the application of asset exhausting and polluting technology. Saving our planet, lifting people out of poverty, advancing economic growth… these are one and the same fight.
Impacts of Environmental Degradation
Whether in a criminal proceeding a Caveat Application is legally permissible to be filed as pro Origin of Writ In common law, Writ is a formal written order issued by a body with administrati The supreme court, and High courts have power to issue writs in the nature of habeas corpus , quo Toggle navigation. Home Explore. The distinctive nature of the present environmental problems is that they are caused more by anthropogenic means than by natural phenomena. Mindless consumerism and economic growth have started to demonstrate pernicious effects on Mother Nature.
Он поспешил избавиться от покровительственного тона. - Извините, что я вас побеспокоил, но скажите: вы, случайно, не были сегодня на площади Испании. Глаза старика сузились.
Еще немного, и любой обладатель компьютера - иностранные шпионы, радикалы, террористы - получит доступ в хранилище секретной информации американского правительства. Пока техники тщетно старались отключить электропитание, собравшиеся на подиуме пытались понять расшифрованный текст. Дэвид Беккер и два оперативных агента тоже пробовали сделать это, сидя в мини-автобусе в Севилье. ГЛАВНАЯ РАЗНИЦА МЕЖДУ ЭЛЕМЕНТАМИ, ОТВЕТСТВЕННЫМИ ЗА ХИРОСИМУ И НАГАСАКИ Соши размышляла вслух: - Элементы, ответственные за Хиросиму и Нагасаки… Пёрл-Харбор. Отказ Хирохито… - Нам нужно число, - повторял Джабба, - а не политические теории. Мы говорим о математике, а не об истории. Соши замолчала.
The major factor of environmental degradation is human (modern urbanization, industrialization, overpopulation growth, deforestation, etc.) and natural (flood, typhoons, droughts, rising temperatures, fires, etc.) cause. Different causes of environmental degradation.
- Голос его прозвучал резко, но спокойно. - Тебе удалось стереть электронную почту Хейла. - Нет, - сконфуженно ответила .