The Use of LCA in Waste Management
Life Cycle Assessment is a process that is objective, and which is used to evaluate the environmental burdens correlated with an action, products or process, through quantification and identification of materials and energies used as waste. Barton (Barton, 1996) stated LCA implements and assesses alternatives to permit environmental improvements. Moreover, LCA is used to evaluate environmental burdens that are correlated with products or processes through a Cradle to grave approach. The Cradle to grave approach covers every step from manufacture of raw substances to eventual waste disposal. The application of LCA accounts for all aspects of waste and waste disposal that are not dealt with by other environmental management tools such as, evaluation of statutory consequences. However, LCA should be used by practioneer more as an aid tool for decision support rather than a tool for decisionmaking when used as an environmental tool of evaluating options for disposing waste. The hierarchy of managing solid waste is usually validated by Life Cycle Analysis.
The aim of sustainable waste management is to handle the societys waste in a manner that is environmentally efficient, socially acceptable and economically affordable. To evaluate each waste management options in terms of sustainability, tools are required that can predict the probable the entire environmental burdens of each options in the waste management system. It is important that waste mangers and Local Authorities (LAs) utilized integrated waste management systems that evaluates each waste disposal options and techniques that aims to achieve the best environmental, social and economical benefits.
The methodologies of Life Cycle Assessment can be applied to integrated waste management to aid the development of sophisticated sustainable systems of waste management. Generally, Life Cycle Assessment practitioners usually focus on the techniques and the aspects associated with product life cycle development. Recently however, there are significant interests by researchers and practitioners in the application of LCA to the entire waste management systems and not only on a particular waste management process that applies in single product or process. The results of such shift in the trend of the research and application of LCA has brought about the optimization of the entire waste management systems which are responsible for treating municipal solid waste (Finnveden et al, 1995).
The Various Considerations in Assessing the Environmental Impacts of Waste Disposal
Ekvall1 et al (Ekvall1 and Finnveden, 2000) explain, a number of Life Cycle Assessments have been carried out while focussing on the correlations between burning and reprocessing, as well as energy recovery. A number of studies have resulted to a variety of conclusions because of the discrepancies in the methodologies and hypotheses that were made in the analysis of the Life Cycle Inventory (LCI). Main factors in the results of Life Cycle Inventory would encompass the amount of energy replaced by the burnt waste paper the material that is surrogated by fibres that have been recycled the usage of pulpwood savings the external energy haulier that was applied in the process of recycling and the environmental encumbers that are correlated with the alteration in the demand of electricity.
The latest methodologies used in LCA are being applied by several nations to assess sundry policies will incorporate the integrated management of solid waste together with treatmentdisposal alternatives for various types of waste and waste streams. The ongoing controversy is on the environmental aspects of a number of options for managing wastes. Waste management options, like incineration and recycling may lead to both positive and negative environmental achievements. The recycling of material can minimize the environmental burdens that are correlated with an alternative way of producing energy. Consequently, recovery of energy can as well minimize environmental burdens that are correlated with options for producing energy. The application of LCA is a powerful and efficient tool which will assess the environmental burdens and gains of different alternatives such as Incineration, Recycling, Composting, and Land Fill (Al-Humoud, 2002).
Recycling vs. Incineration
The process of recycling process is encompassed within the confines of the system of managing wastes. The environmental burdens that are correlated with the re-processing of every waste fraction recovered while accounting the following processes the consequences of transporting recovered material and possibility of saving consumption of energy (Al-Humoud, 2002). The amount of material replaced per ton of the product that has been recycled is dependent on the quality as well as varies with every material that has been recovered, and which is going to be reprocessed.
The total energy that is used in process of recycling is lower than that used in incineration, with recovery of heat given that the content of energy is encompassed in the balance. For instance, less energy is required in waste paper recycling, while paper production and virgin pulp requires more energy. Moreover, the usage of biomass, for energy, and for paper, is lower with regard to recycling than in incineration, with recovery of heat. Thus, recycling saves biomass, which can be applied for other purposes in the universe.
For each waste management option, the additional activities required may be required will encompass to carry out the environmental correlation between recovery of material, and energy in different perceptions appropriately choose the method of managing waste choosing between other renewable ways of producing energy, or investing in firms that deal with waste incineration and making decision basing on ecological correlation between recovery of material and energy. Correlations ought to base on ethical views regarding what makes a good action. A probable perception could be to assess every action basing on the impacts of that action (Finnveden et al, 1995).
Composting
Composting encompasses a net energy consumption to produce a substance that will be used as a fertilizer. Energy consumed during the process of composting is 54MJton, of inputs to the process of composting. The diesel consumption in strainers, wheel loaders, and mills is 555.5 MJton of inputs to the process of composting. The unprocessed material, which is obtained during the process of composting, can be used as a fertilizer. The material that has been avoided is a chemical fertilizer that contains the amount of nutrients that are equivalent to N and P.
As Finnveden (Finnveden et al, 1995) observed, the compost has a nutrient content of 2.0 kg of P and 8.3 kg of N per ton of inputs to the process of composting. Basing on assumption, the replacement of unprocessed fertilizer in the model and with regard to the contents of P and N is 100 percent. This shows that emissions that are evaded by use of compost in place of chemical fertilizer are accredited to the system of managing waste Idemat is used to obtain the LCI (life cycle inventory) P and N chemical fertilizer that is usually avoided (Ozeler et al, 2006).
Land Fill
Waste streams that can be sent to landfills can be categorized into three groups Residual substance from the processes of composting Residual restwasteswastes, which are gathered, and land filled directly. Residual wastes are sorted at Material Recycling Facilities (MRFs). The process of landfilling waste normally consumes energy in form of diesel while in disposal operations. The researchers Finnveden et al (Finnveden et al, 1995) concluded that solid wastes that are directly sent to landfills consume fuel of 6.72 MJton of waste disposed. The impacts from generation of leachate and land fill gas have been considered for every fraction of waste in waste streams.
The Landfill gas is mainly produced from waste streams that are biodegradable. About 250m3N Biogas is formed per ton of unprocessed wastes that is biodegradable, such as textile, putrescible, and paper. On the other hand, approximately 100 m3N land filled residues per ton is formed from the process of composting. A calorific value (of 19.5 MJ per m3), is assumed. Presently, most solid wastes (with exception of paper wastes), are being land filled. In the future Landfilling may replace paper recycling in the incinerators. The waste which is surrogated by an incinerated paper is likely to end-up in landfills, where eventually, it will be decomposed.
Impacts of landfill on Environment
According to Environmental protection Agency (EPA) till year 2000 there were around 3100 active landfills and more than 10,000 old municipal landfills. 82 of surveyed landfills had leaks while 41 had a leak area more than 1 square feet. (Leak Location Services, Inc (LLSI) 2000). Further more, the State-of-the-art plastic (HDPE), landfill liners which are usually (110 inch thick) and plastic pipes, used for leachate collection become brittle after some time. As a result of this brittleness chemicals and gases passes through them into the ground and surface water.
Women living near solid waste landfills have four-fold increased chance of leukemia or bladder cancer (New York State Department of Health). Another adverse impact of living near landfill is that people has encountered low birth weight and small size among children. Birth defects have increased in people living near landfill. Heart and circulatory system defects are observed among new borns.
Landfill gas usually consists of methane, carbon di oxide, benzene, dichloroethene, tetracloroethene, trichloroethene, mercury and many other similar type of toxic gases. These all gases are hazardous and are very harmful for human health. Some common negative impacts of these gases on human health are liver damage, lunge damage, nervous system effects, headaches, etc. One noticeable thing is that most of the consequences of landfill as far as human health is concerned.
Advantages of Landfill
Landfill is comparatively cheaper way for waste disposal. Transportation of garbage to the landfill accounts for 75 of the total cost of landfill. Landfill can also be used as a source of methane which can be used for energy generation. According to some studies 30 to 70 million tons of methane is produced globally per year from landfill. 20 percent of electricity in America is produced by methane produced from these landfills.
Best waste disposal technique
Undoubtedly recycling is the best waste disposal technique. Main objective of waste mangers is to minimize harm to the environment and human, recycling produces best chances to achieve this goal. Recycling usually minimize requirement of raw material, it minimizes the use of energy and treatment cost is also cheaper than other waste disposal techniques. It has no adversaries associated with it in comparison to landfill and incineration. No harmful gases are produced and no combustion waste.
Other than recycling, land fill is the most appropriate waste disposing technique from cost prospective. But it requires lot of land and people living near landfill have faced chronic disease. According to some studies if landfill continues at the present rate, in few years there will be shortage of land. But one major advantage of landfill is that it does not require further disposition of waste while if we consider incineration, landfill is necessary to dispose ash produced as a result of combustion. And also lot energy in the form of methane is produced.
Why Waste Managers and Local Authorities are Increasingly Using LCA for Deciding the Best Option for Waste Disposal
Local Authorities and waste managers require LCA because of the regulatory pressures, sustainability appraisals, and Best Practicable Environmental Options (BPEO) requirements in the strategies used by the government in waste management. LCA can be applied in product stewardship and development. The requirements of BPEO are the statutory policies that are used throughout the industries in packaging ecological labelling, government waste management and green procurement. It encompasses exposure evaluations and hazard identification, which may assist in the LCIA stage. As a result, LCA is being increasingly used by practitioners and LAs because with LCA, the best choice, which has the best environmental impacts, can be easily identified for the evaluations (Finnveden et al, 1995).
The best option is the one that has least damage to the environment, economically viable and strong social attributes. Through modelling, LCA can aid the decision-making by evaluation each option for BPEO. For instance, LCA can help to define the frequency of collections, vehicle types, definition of boundaries, collection points, collection frequencies, amounts and types of bins, and separation points (Barton, 1996).
With the application of LCA, LAs and waste mangers may be able to avoid environmental impacts which are correlated with production of energy. This energy is then replaced by incineration of waste paper, with energy recovery. Landfilling can lead to odour, methane emissions, water pollution, noisetraffic, or leachates. In addition, the impacts of incineration are healthperceptivenesshealth problems air emissions and disposal of ash. For the future to be sustainable waste managers and LAs should not use fossil fuels, especially not with the present emissions as an alternative, they should use an alternative source of energy.
Waste manager and local authorities are increasingly using LCA because of its effectiveness. LCA has a lot to offer in terms of selection and application of suitable waste management technique, technologies and programs to achieve specific waste, management objectives and goals (Ozeler et al., 2009). LCA can be conducted by industries to identify areas where improvements are required in environmental terms. LCA can also be used to provide environmental data for public or government.
LCA not only helps in making long term choices but also assist in considering all social and environmental issues associated. It facilitates in avoiding short term decision which may result in the form of harm to the environment. For example, polluting air with mercury or hunting animal which are scarce or exposing clinical waste to the open atmosphere which may result in spread of chronicle disease.
LCA improves complete system rather than single parts in system. This improvement is achieved by shunning from decisions that fixes one environmental issue and may cause other costly and unexpected environmental problem, for example while diminishing water pollution air pollution is consistently increasing. Life cycle approach helps avoiding shifts. By life cycle thinking shifting problem can be avoided from one life cycle stage to other stage, from one environment medium (air, soil and water) to other and from one geographical location to another.
It assists in informed selection (not necessarily right or wrong). It plays vital role in making key decisions. Life cycle approach helps to make decision in context of all parts of system rather than a single part. Unintentional impacts of are activities can hardly be ignored. Through life cycle approach unintentional impacts caused by our activities can be seen easily and action can be taken to prevent those impacts (like purchasing of office paper from sustainable and well managed forest).
Almost, all developed countries have studied LCA to see what results it gives in comparison to other waste management tools. Most of the studies gave positive result for waste management. Similar type of study was conducted in Kuwait to check the feasibility of LCA for Municipal Solid waste (MSW). Results obtained from this study also support the conclusion that LCA, as an environmental tool, can be successfully applied in an Integrated Solid Waste Management System (ISWMS) as a decision support tool. Therefore, LCA should be implemented for waste management activities in developing and developed countries. (S. M. Al-Salem and P. Lettieri 2009). Moreover, LCA has shown significant progress in Japan and is practiced under National LCA, started by Ministry of International trade Industry (MITI) in October 1998. Similarly, LCA has shown significant progress in most of the developed countries. On example of it is that Japan Environmental Management Association for Industry (JEMIA) started project with Australia, Indonesia, Korea, Malaysia, Singapore, Taiwan, and Thailand for the exchange of information and help each other in the development of LCI data in 2000.
Various types of LCAs have resulted to different conclusions with regard to the option that is best for managing paper waste, that is incineration, composition, recycling, or land fill. LCA has made waste managers and local authorities to understand that recycling of paper wastes have least environmental impacts. However, this assumption contradicts the conclusions from other studies. The discrepancy can largely be elucidated disparities regarding the energy source that is surrogated by energy from incineration of waste paper (Barton, 1996). Nevertheless, LCA have assisted waste managers and LAs to understand that nowadays, fuel competition is also a type of solid waste, and fossil fuels is the main source of competition for energy.
Current debates on waste management option
The environment issues of various waste management methods for material such as paper are the topic of a continuing debate. Indeed, numerous LCAs studies have been carried out regarding this area of debate. The main issue of contention regarding recycling and incineration is the amount of energy recovered from packaging materials. Accordingly, varying LCAs studies have achieved varied conclusions concerning the best option to be applied in waste material such as paper centering on recycling or incineration. Many have concluded that recyclable materials presently leads to least environmental effects in relation to parameters used.
Research by Koushki et al (Koushki and Al-Humoud, 2002) concludes that at the moment, the competing fuels are normally the varieties of solid wastes some other studies are founded on the presumption that the fossil fuels are the main competing energy source. However, in studies undertaken by Finnveden (Finnveden et al 1995) regarding this issue, it was established that
The net application of energy was lesser where recycling was used
The net utilization of biomass was lesser in recycling method
The emissions of gases such as NOx was lesser in recycling
The net amount of solid waste in landfills was lesser when recycling was used
The utilization of fossil fuels could either rise or reduce.
Dust emissions where lower in recycling processes
While there are evidences above to indicate recycling has the best option for the environment, there is concussive answer to the choice between recycling and incineration in terms of waste disposal option in the management of waste. The application of LCA in this scenario will generates results to aid the decision-making based on the on the specific methodology used, which in turn depends on the appropriate perspective. To get the best results, the overall questions should be specified exceptionally carefully in relation to the decision required, and what is implied by the term environmentally better, the time perspective as well as the graphical area also needs to be taken into account (Al-Humoud, 2002,). Therefore, it may be argue that composting is best suited in global warming but not in other parameters. On the other hand, majority of virgin materials that more energy intensive are better used in recycling than in landfill. Though, some of the consequences may be escalated by distance to facilities and collection patterns.
Impacts of waste management system
The impacts of waste management system are not directly or directly related to a variety of factors, such as nature of waste, distance covered, collection boundary, global differences and applications, and the involved distance to landfill incinerator. Waste management will contribute to consequence under the goals of zero eutrophication, clean air, ozone layer that is protective, consumption of energy sources, natural acidification, and consumption of non-renewable energy resources.
Conclusion
As discussed above, Life Cycle Assessment entails studying the environmental aspects as well as the possible effects throughout a products life - cradle to grave, beginning from the raw material acquired from the production to the end of that material disposed as a waste product. Before assessing the environment various considerations have to be undertaken, among these considerations are the use of LCA in waste management to support the decision-making and considerations in evaluation of environmental consequences of waste disposal.
Presently, the ongoing debate is whether specific waste materials should be recycled or incinerated, to achieve better energy recovery. This debate remains inconclusive since different studies have reached with different results. Nonetheless with present environmental concerns and the need to develop friendly environmental practices, LCA remains important methodology in waste management.
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