Environmental and economic impact assessment of construction and demolition waste disposal using system dynamics

Construction and demolition wastes (CDW) have increasingly serious problems in environmental, social, and economic realms. There is no coherent framework for utilization of these wastes which are disposed both legally and illegally. This harms the environment, contributes to the increase of energy consumption, and depletes finite landfills resources. The aim of this paper is to evaluate the impacts of two alternatives for the management of CDW, recycling and disposing. The evaluation is carried out through developing a dynamic model with aid STELLA software by conducting the following steps: (1) quantifying the total cost incurred to mitigate the impacts of CDW landfills and uncollected waste on the environment and human health; (2) quantifying the total avoided emissions and saved energy by recycling waste; (3) estimating total external cost saved by recycling waste and; (4) providing a decision support tool that helps in re-thinking about waste disposal. The proposed evaluation methodology allows activating the stringent regulations that restrict waste disposal and developing incentives to encourage constructors to recycle their wastes. The research findings show that recycling CDW leads to significant reductions in emissions, energy use, global warming potential (GWP), and conserves landfills space when compared to disposal of wastes in landfills. Furthermore, the cost of mitigating the impact of disposal is extremely high. Therefore, it is necessary to recycle construction and demolition wastes.     

Life cycle assessment of a pulverized coal power plant with post-combustion capture, transport and storage of CO2

In this study the methodology of life cycle assessment has been used to assess the environmental impacts of three pulverized coal fired electricity supply chains with and without carbon capture and storage (CCS) on a cradle to grave basis. The chain with CCS comprises post-combustion CO₂ capture with monoethanolamine, compression, transport by pipeline and storage in a geological reservoir. The two reference chains represent sub-critical and state-of-the-art ultra supercritical pulverized coal fired electricity generation. For the three chains we have constructed a detailed greenhouse gas (GHG) balance, and disclosed environmental trade-offs and co-benefits due to CO₂ capture, transport and storage. Results show that, due to CCS, the GHG emissions per kWh are reduced substantially to 243 g/kWh. This is a reduction of 78 and 71% compared to the sub-critical and state-of-the-art power plant, respectively. The removal of CO₂ is partially offset by increased GHG emissions in up- and downstream processes, to a small extent (0.7 g/kWh) caused by the CCS infrastructure. An environmental co-benefit is expected following from the deeper reduction of hydrogen fluoride and hydrogen chloride emissions. Most notable environmental trade-offs are the increase in human toxicity, ozone layer depletion and fresh water ecotoxicity potential for which the CCS chain is outperformed by both other chains. The state-of-the-art power plant without CCS also shows a better score for the eutrophication, acidification and photochemical oxidation potential despite the deeper reduction of SO_x and NO_x in the CCS power plant. These reductions are offset by increased emissions in the life cycle due to the energy penalty and a factor five increase in NH₃ emissions.     

Environmental indicators for communication of life cycle impact assessment results and their applications

Life cycle impact assessment (LCIA) is performed to quantitatively evaluate all environmental impacts from products, systems, processes and services. However, LCIA does not always provide valuable information for choosing among alternatives with different specifications, functionalities and lifetimes. The objectives of this study are (1) to propose environmental indicators to evaluate environmental efficiency and value qualitatively and quantitatively on the basis of analogies to financial and economic indicators, and (2) to present the application of the indicators. Incremental evaluation using a reference is employed to obtain the environmental indicators. The environmental efficiency indicators are conceptually based on the ratios of reduced environmental burdens returned to environmental burdens required: environmental return on investment, environmental payback period and environmental internal rate of return. The environmental value indicator is the sum of all reduced and required environmental burdens: i.e., environmental net present value. All the environmental indicators can be used to compare and rank the environmental efficiencies or values of alternatives. The environmental efficiency indicators can be applied to a new environmental labeling. The concept of eco-efficiency labeling is developed by combining the environmental efficiency indicators with financial indicators. A case study is performed to illustrate the necessity and importance of the environmental indicators. These environmental indicators can help easily communicate LCIA results in the field of environmental management.     

Environmental impact assessment in flanders,belgium: An evaluation of the administrative procedure

Two years of experience with EIA in Flanders (northern Belgium) was evaluated in order to gain perspective on the effectiveness of the administrative procedure. The four essential characteristics of the EIA procedure that were evaluated are: completeness, open and public character, objectivity, and verifiability. Representatives of all parties involved in the EIA procedure were interviewed. The result of the evaluation is a list of major problems with EIA. Recommendations for a more efficient procedure are suggested at a time when a proposal for a new, comprehensive, and permanent EIA decree is being discussed. The evaluation of the administrative procedure for EIA in Flanders shows that several vital characteristics of the EIA procedure are lacking. This reduces the obligatory and open nature of the process, resulting in insufficient guarantees that the environment receives the altention it deserves during the decision-making process.     

Future solutions for the treatment and disposal of hazardous wastes in China

The current status of the treatment and disposal of hazardous wastes in China is summarized on the basis of the results of the Declaring and Registration Project initiated nationally in 1995. A principle framework for the sound management of hazardous wastes is proposed, which includes three levels of technical solutions. Large-scale enterprises are encouraged to recycle, to treat, and to dispose of wastes by means of constructing facilities, and to have their extra capacities available to the public for a reasonable fee. Municipal governments, provincial governments, and the Central Government are to plan and construct centralized facilities to recycle, treat, and dispose of wastes. For a solution at the manufacturing level, recycling is identified as the main approach. Centralized facilities at the municipal level will mainly focus on special wastes that are unsuitable to transport and store, such as hospital waste, and for the technical solution at this level, incineration and recycling are identified as the main approaches. For the technical solution at the provincial and national levels, landfill and incineration are identified as the main approaches. Based on this principle and the current available data on hazardous wastes, a preliminary plan for the spatial distribution of cross-provincial centralized treatment and disposal facilities of hazardous wastes is presented. The construction of approximately nine cross-provincial comprehensive facilities is proposed. A priority list for the construction of these planned facilities is also presented.     

Environmental Justice,Local Knowledge,and Risk: The Discourse of a Community-Based Cumulative Exposure Assessment

While risk assessment continues to drive most environmental management decision-making, its methods and assumptions have been criticized for, among other things, perpetuating environmental injustice. The justice challenges to risk assessment claim that the process ignores the unique and multiple hazards facing low-income and people of color communities and simultaneously excludes the local, non-expert knowledge which could help capture these unique hazards from the assessment discourse. This paper highlights some of these challenges to conventional risk assessment and suggests that traditional models of risk characterization will continue to ignore the environmental justice challenges until cumulative hazards and local knowledge are meaningfully brought into the assessment process. We ask whether a shift from risk to exposure assessment might enable environmental managers to respond to the environmental justice critiques. We review the US EPA's first community-based Cumulative Exposure Project, piloted in Brooklyn, NY, and highlight to what extent this process addressed the risk assessment critiques raised by environmental justice advocates. We suggest that a shift from risk to exposure assessment can provide an opportunity for local knowledge to both improve the technical assessment and its democratic nature and may ultimately allow environmental managers to better address environmental justice concerns in decision-making.     

Importance of insects in environmental impact assessment

Insects are particularly suited for use in environmental impact assessment (e.i.a.) because of their high species diversity, ubiquitous occurrence, and importance in the functioning of natural ecosystems. Examples are given of the use of insects in the predictive phase of e.i.a., in the monitoring and assessment phase, and in the much rarer instance of an e.i.a. that includes both of these phases. The importance of working at the species level to understanding the results of e.i.a. is emphasized.     

Environmental evaluation of transfer and treatment of excess pig slurry by life cycle assessment

Slurry management is a central topic in the agronomic and environmental analysis of intensive livestock production systems. The objective of this study is to compare the environmental performance of two scenarios of collective slurry management for the disposal of excess nitrogen from animal manure. The scenarios are the transfer of slurry and its injection to crop land, and the treatment of slurry in a collective biological treatment station. The study is based on a real case in the West of France, where a group of farmers is developing a collective plan for the disposal of almost 7000 m(3) of excess pig slurry. The evaluation is carried out by Life Cycle Assessment, where emissions and resource consumption are quantified and aggregated into four environmental impact categories: eutrophication, acidification, climate change, and non-renewable energy use. Ammonia emitted is the most important contributor to acidification and eutrophication, while methane contributes most to climate change. Both ammonia and methane are mostly emitted during the storage of slurry and, in the case of the treatment scenario, also during composting the solid fraction of the slurry. The two management strategies are similar with respect to climate change, whereas eutrophication and acidification are twice as large for treatment relative to transfer. Electricity needed for the treatment process is the main contributor to non-renewable energy use for the treatment scenario, while the transfer scenario represents a net energy saving, as energy saved by the reduction of mineral fertiliser use more than compensates for the energy needed for transport and injection of slurry. The overall environmental performance of transfer is better than that of treatment, as it involves less acidification, eutrophication and non-renewable energy use. The method employed and the results obtained in this study can provide elements for a transparent discussion of the advantages and disadvantages of contrasting excess slurry management scenarios as well as the identification of the main aspects determining their environmental performance.     

Environmental and economic feasibility study of a total wastewater treatment network system

The synthesis of distributed wastewater treatment plants (WTPs) has been studied to reduce capital and operating costs associated with wastewater treatment. In this study, the environmental and economic feasibility of a total wastewater treatment network system (TWTNS) including distributed and terminal WTPs was estimated using life cycle assessment (LCA) and life cycle costing (LCC) methods. Wastewater sources and existing distributed and terminal WTPs in an iron and steel plant were networked. The TWTNS was generated from the optimal solution to a mathematical optimization model and compared to a conventional wastewater treatment system (CWTS). The environmental effect scores of the TWTNS were from 29.6% to 68.3% higher than those of the CWTS because of higher electricity consumption required to pump wastewater to the networked WTPs. However, the life cycle cost of the TWTNS was lower than that of the CWTS by 10.1% because of the decrease of the labor cost resulting from the closing of three distributed WTPs. Overall, the TWTNS was no more eco-efficient than the CWTS because the increase of environmental burdens outweighed the decrease of economic costs.     

环境质量模糊综合评价及其应用

环境质量评价是环境科学的重要研究课题之一，作者评述了常用指标法的不足，提出用模糊数学中综合模糊评价法评价环境质量，建立了评价模式和计算程序，并用于科学城的环境质量评价，评价计算给出的多层次数据所提供的信息，与监测结果所体现的环境质量状况符合，所建模糊评价程序是适用的。     

Environmental economic,political and ethical integration in a common decision-making framework

This article develops a decision-making framework for environmental management that integrates technical, economic, political and legal, and ethical decision levels. It attempts to show how these decision levels can be ordained, integrated and interconnected and postulates a hierarchic concentric sphere system that proposes an environmental management model for long-term solutions. This model can be used as a check list for environmental management decision-making and also as a guide for environmental conflict resolution where environmental problems necessitate several levels of decision making. It integrates various environmental ethical positions and evaluates political decisions into a comprehensive, broadly applicable multidisciplinary approach. The objective of this decision-making model is to interconnect into a simplified sequence different levels of environmental management processes in order to account for sustainability, efficacy, efficiency and the acceptability of environmental management processes in the long term. This is done by observing when an environmental problem needs to be solved within a certain sphere of solutions and when it requires wider frameworks, how these can be established and how this process proves that solidarity is the widest and most reasonable sphere.     

Zinc recovery from hazardous construction wastes via an integrated process of the air classification,alkaline leaching,and water washing

Zinc- and lead-containing wastes are often mixed with construction and demolition wastes in many factories, generating abundant of heavy metal-enriched hazardous waste. In the present study, a novel integrated process of air classification, alkaline leaching, and water washing dechlorination was proposed for the efficient recycling of Zinc (Zn) resources. The first air classification process was realized via venturi tube, wherein the content of Zn could increase by 20 wt.%. After that, the product underwent an alkaline leaching process. Results showed that Zn recovery rate increased with fine particle sizes, and a 65% recovery rate was obtained under the following conditions of 5 mol/L NaOH, liquid/solid 10:1, and leaching time 1 h. Finally, water washing associated with microwave and ultrasonic treatments could remove over 85% of Cl and other water-soluble salts. All the results indicated that the integrated method had an excellent recovery rate for Zn resources from construction and demolition wastes.     

Environmental and economic assessment of combined biostabilization and landfill for municipal solid waste

Biostabilization can remove considerable amounts of moisture and degradable organic materials from municipal solid waste (MSW), and can therefore be an effective form of pretreatment prior to landfill. The environmental and economic impacts of two combined processes, active stage biostabilization + sanitary landfill (AL), and active and curing stage biostabilization + sanitary landfill (ACL), were compared with sanitary landfill (SL) for MSW with high moisture content. The results indicated that land requirement, leachate generation, and CH(4) emission in the ACL process decreased by 68.6%, 89.1%, and 87.6%, respectively, and the total cost was reduced by 24.1%, compared with SL. This implies that a combined biostabilization and landfill process can be an environmentally friendly and economically feasible alternative to landfill of raw MSW with high moisture content. Sensitivity analysis revealed that treatment capacity and construction costs of biostabilization and the oxidation factor of CH(4) significantly influenced the costs and benefits of the AL and ACL process at an extremely low land price. When the land price was greater than 100 USD m(-2), it became the dominating factor in determining the cost of treatment and disposal, and the total costs of ACL were reduced to less than 40% of those of SL.     

PROFILE: Indigenous Institutions and Environmental Assessment: The Case of Ghana

/ The search for sustainable development provides the impetus forexamining the role of indigenous institutions and their ecological knowledgein environmental assessment and local sustainability. This paper attempts totrace the evolution of environmental assessment in Ghana. Focusing on theAshanti Region, the paper further discusses the nature and operations ofindigenous institutions, their ecological knowledge, beliefs, practices, andsocial norms that are relevant to environmental assessment process in thecountry. Some of the challenges that emerge from the discussions arehighlighted. There is a need to establish environmental assessment andcooperative management boards that would include representatives ofindigenous institutions. In addition, the introduction of technicaldictionaries and training manuals based on indigenous ecological knowledgeand their humane environmental practices will further improve theenvironmental assessment process in Ghana.KEY WORDS: Environmental assessment; Indigenous institutions; Indigenousecological knowledge; Sustainable development; Environmental assessmentboards     

Measurement and assessment of carrying capacity of the environment in Ningbo, China

Carrying Capacity of the Environment (CCE) provides a useful measure of the sustainable development of a region. Approaches that use integrated assessment instead of measurement can lead to misinterpretation of sustainable development because of confusion between Environmental Stress (ES) indexes and CCE indexes, and the selection of over-simple linear plus models. The present paper proposes a comprehensive measurement system for CCE which comprises models of natural resources capacity, environmental assimilative capacity, ecosystem services capacity, and society supporting capacity. The corresponding measurable indexes are designed to assess CCE using a carrying capacity surplus ratio model and a vector of surplus ratio of carrying capacity model. The former aims at direct comparison of ES and CCE based on the values of basic indexes, and the latter uses a Euclidean vector to assess CCE states. The measurement and assessment approaches are applicable to Strategic Environmental Assessment (SEA) and environmental planning and management. A case study is presented for Ningbo, China, whereby all the basic indexes of ECC are measured and the CCE states assessed for 2005 and 2010.     

我国环境影响评价公众参与工作存在的问题及解决对策

本文通过对我国环境影响评价公众参与发展历程的回顾和采用对比法分析各省市出台的相关公众参与的实施办法或条例的基础上,分析我国环评公众参与具体操作过程中存在公众参与作用边界被无限放大、参与对象缺乏代表性和形式单一等问题,从信息公开制度、公众参与对象的选择、公众参与形式、公示内容、公众反馈意见等方面提出提高公众参与有效性的对策和建议.     

Priority screening of toxic chemicals and industry sectors in the U.S. toxics release inventory: a comparison of the life cycle impact-based and risk-based assessment tools developed by U.S. EPA

Life Cycle Impact Assessment (LCIA) and Risk Assessment (RA) employ different approaches to evaluate toxic impact potential for their own general applications. LCIA is often used to evaluate toxicity potentials for corporate environmental management and RA is often used to evaluate a risk score for environmental policy in government. This study evaluates the cancer, non-cancer, and ecotoxicity potentials and risk scores of chemicals and industry sectors in the United States on the basis of the LCIA- and RA-based tools developed by U.S. EPA, and compares the priority screening of toxic chemicals and industry sectors identified with each method to examine whether the LCIA- and RA-based results lead to the same prioritization schemes. The Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI) is applied as an LCIA-based screening approach with a focus on air and water emissions, and the Risk-Screening Environmental Indicator (RSEI) is applied in equivalent fashion as an RA-based screening approach. The U.S. Toxic Release Inventory is used as the dataset for this analysis, because of its general applicability to a comprehensive list of chemical substances and industry sectors. Overall, the TRACI and RSEI results do not agree with each other in part due to the unavailability of characterization factors and toxic scores for select substances, but primarily because of their different evaluation approaches. Therefore, TRACI and RSEI should be used together both to support a more comprehensive and robust approach to screening of chemicals for environmental management and policy and to highlight substances that are found to be of concern from both perspectives.     

Response of macroinvertebrate communities to abattoir wastes and other anthropogenic activities in a municipal stream in the Niger Delta, Nigeria

Impacts of co-occurring stressors (organic wastes and various human activities) on macroinvertebrate assemblages and environmental variables were investigated in a municipal stream, River Orogodo in southern Nigeria between the months of June 2004 and July 2005. Four sampling sites, each 25 m long were selected along 15 km stretch of the stream. There was a marked difference in the taxonomic composition of macroinvertebrates in the reference sites (I and IV) and those of the perturbed sites (II and III). A combined total of 78 benthic macroinvertebrate taxa were collected from the four sites of the river. The abundance and community structure patterns showed strong evidence of impact arising from the abattoir waste discharge such that the comparison of abundance values demonstrated high significance between the reference sites and the perturbed sites. Pearson correlation coefficient analysis indicated temporal trends in macroinvertebrate density and community composition. This was related to changes in environmental characteristics of the river especially BOD₅ and amount of nutrients. These factors produced spatial and temporal heterogeneity and exerted major influence on the benthic communities. The preponderance of Oligochaetes and diptera and deterioration in water quality at sites II and III are attributed to the intensity of human activities at these sites. Shannon-wiener diversity and evenness were significantly higher (P < 0.05) at the reference sites I and IV. Results illustrate the need for careful consideration of the water quality and indicator organisms in restoration and remediation programmes.     

Use of Life Cycle Assessment in Environmental Management

The aim of this paper is to demonstrate how life cycle assessment (LCA) can be used to develop strategic policies that can lead to a minimization of the environmental burden resulting from the provision of services or the manufacture, use, and disposal of products within the economy. We accomplish this aim by presenting a case study that evaluates the greenhouse gas contributions of each stage in the life cycle of containerboard packaging and the potential impact on emissions of various policy options available to decision-makers. Our analysis showed that, in general, the most useful strategy was to recycle the used packaging. However, our analysis also indicated that when measures are taken to eliminate sources of methane emissions, then recycling is no longer beneficial from a greenhouse perspective. This is because the process energy required in the form of gas and electricity is substantially greater for containerboard manufactured from recycled material than it is for virgin fiber.