Showing papers in "Resources Conservation and Recycling in 2011"

An analysis of the drivers affecting the implementation of green supply chain management

Abstract: Green supply chain management has emerged as an important organizational philosophy to reduce environmental risks. We develop a model of the drivers affecting the implementation of green supply chain management using an Interpretive Structural Modeling (ISM) framework. The various drivers of green supply chain management (GSCM) are identified based on the GSM literature and on consultations with experts in the industry. The model developed is validated on a case study involving a manufacturing firm in southern India.

Material efficiency: A white paper

Abstract: For most materials used to provide buildings, infrastructure, equipment and products, global stocks are still sufficient to meet anticipated demand, but the environmental impacts of materials production and processing, particularly those related to energy, are rapidly becoming critical. These impacts can be ameliorated to some extent by the ongoing pursuit of efficiencies within existing processes, but demand is anticipated to double in the next 40 years, and this will lead to an unacceptable increase in overall impacts unless the total requirement for material production and processing is reduced. This is the goal of material efficiency, and this paper aims to stimulate interest in the area. Four major strategies for reducing material demand through material efficiency are discussed: longer-lasting products; modularisation and remanufacturing; component re-use; designing products with less material. In industrialised nations, these strategies have had little attention, because of economic, regulatory and social barriers, which are each examined. However, evidence from waste management and the pursuit of energy efficiency suggests that these barriers might be overcome, and an outline of potential mechanisms for change is given. In bringing together insights into material efficiency from a wide range of disciplines, the paper presents a set of 20 open questions for future work.

Green supply chain initiatives among certified companies in Malaysia and environmental sustainability: Investigating the outcomes

Abstract: The relationship between green supply chain initiatives and performance outcomes has been subject to numerous studies but the results are not conclusive. This study tries to assess the actual environmental, economic and intangible outcomes resulting from the adoption of green supply chain initiatives. This study used a structured questionnaire derived from the literature and employing a mail survey to collect responses form a group of 569 ISO 14001 certified firms in Malaysia. The results of testing the hypotheses that predicted that green supply chain initiatives have positive effect on the outcomes showed that eco-design have significant positive effect on the four types of outcomes (environmental outcomes, economic outcomes, cost reductions, and intangible outcomes). Reverse logistics was found to have significant positive effect on cost reductions only. However, green purchasing was not found to have significant effect on any of the four types of outcome. Through designing environmentally friendly products and taking back products and packaging, business organizations can generate benefits to the environment, in the form of reduced waste and better resource utilization, in addition to economic benefits and cost reductions to the organizations.

Twenty years of PET bottle to bottle recycling—An overview

Abstract: Polyethylene terephthalate (PET) has become the most favourable packaging material world-wide for beverages. The reason for this development is the excellent material properties of the PET material, especially its unbreakability and the very low weight of the bottles compared to glass bottles of the same filling volume. Nowadays, PET bottles are used for softdrinks, mineral water, energy drinks, ice teas as well as for more sensitive beverages like beer, wine and juices. For a long time, however, a bottle-to-bottle recycling of post-consumer PET packaging materials was not possible, because of the lack of knowledge about contamination of packaging polymers during first use or recollection. In addition, the decontamination efficiencies of recycling processes were in most cases unknown. During the last 20 years, PET recollection as well as recycling processes made a huge progress. Today, sophisticated decontamination processes, so-called super-clean recycling processes, are available for PET, which are able to decontaminate post-consumer contaminants to concentration levels of virgin PET materials. In the 1991, the first food contact approval of post-consumer PET in direct food contact applications has been given for post-consumer recycled PET in the USA. Now, 20 years after the first food approval of a PET super-clean recycling process, this article gives an overview over the world-wide progress of the bottle-to-bottle recycling of PET beverage bottles, e.g. the recollection amount of post-consumer PET bottles and the super-clean recycling technologies.

The causes of food waste in the supplier–retailer interface: Evidences from the UK and Spain

Abstract: Food and drink waste is a significant problem for economic, environmental and food security reasons. Government efforts have focused on diverting waste away from landfill through regulation, taxation and public awareness. However, efforts to understand why waste occurs have been limited, particularly in the interface between retailers and suppliers. This research aims to address this problem by identifying the main root causes of waste in the supplier–retailer interface. The research is exploratory in nature as there is a paucity of studies focusing on food waste across the supply chain. Data were collected through 43 interviews with managers in food manufacturing, wholesaling and retailing in two countries: the UK (24) and Spain (19). Data from the interviews and supplementary documentation were analyzed using causal maps. This approach helped to identify the main root causes of waste which were categorized into three groups: (1) mega-trends in the marketplace, (2) natural causes related to the products and processes, and (3) management root causes on which practitioners have a direct impact. The paper discusses the root causes of food waste and good practices identified from the interviews. Differences between the UK and Spain are discussed, presenting potential learning opportunities for practitioners in these countries and highlighting opportunities for further research.

Utilization of silica fume in concrete: Review of hardened properties

Abstract: Several types of industrial byproducts are generated. With increased environmental awareness and its potential hazardous effects, utilization of industrial byproducts has become an attractive alternative to disposal. One such by-product is silica fume (SF), which is a byproduct of the smelting process in the silicon and ferrosilicon industry. Silica fume is very effective in the design and development of high strength high performance concrete. This paper covers the physical, chemical properties of silica fume, and its reaction mechanism. It deals with the effect of silica fume on the workability, porosity, compressive strength, splitting tensile strength, flexural strength, creep and shrinkage of concrete.

The future distribution and production of global phosphate rock reserves

Abstract: Phosphorus (P) is essential for crop growth and food production, and most of the phosphorus applied to agricultural land comes from phosphate rock (PR), a non-renewable resource. The distribution of PR reserves and the share of current production are both concentrated in a handful of countries, notably Morocco and China. Individual countries operate their phosphate mining industries at different reserve-to-production (R/P) ratios, which determines the lifetime of PR reserves in that country and, in turn, the global distribution of both reserves and production in the future. This research uses U.S. Geological Survey data (released in January 2011) to derive R/P ratios for individual countries and combines this with a scenario for increasing global demand to investigate how the global distribution of PR reserves and production will change between now and the year 2100. The results show that 70% of global production is currently produced from reserves which will be depleted within 100 years and combining this with increasing demand will result in a significant global production deficit, which by 2070 will be larger than current production. Morocco, with nearly 77% of global reserves, will need to increase production by around 700% by 2075 in order to meet most of this deficit. If this is possible, Morocco will obtain a much greater share of worldwide production, from around 15% in 2010 to around 80% by 2100, which implies more control over market prices. Also, since Morocco operates the highest R/P ratio throughout the analysis period, its share of the global reserves continues to increase, from 77% in 2011 to 89% by 2100. Overall, the research concludes that, unless additional sources of phosphorus can be accessed or society can significantly increase phosphorus recycling, future global phosphorus security will be increasingly reliant on a single country.

A review on tertiary recycling of high-density polyethylene to fuel.

Abstract: Plastics have become an indispensable ingredient of human life. They are non-biodegradable polymers of mostly containing carbon, hydrogen, and few other elements such as chlorine, nitrogen etc. Rapid growth of the world population led to increased demand of commodity plastics. High density poly ethylene is one of the largest used commodity plastics due to its vast applications in many fields. Due to its non bio degradability and low life, HDPE contributes significantly to the problem of Municipal Waste Management. To avert environment pollution of HDPE wastes, they must be recycled and recovered. On the other hand, steady depletion of fossil fuel and increased energy demand, motivated the researchers and technologists to search and develop different energy sources. Waste to energy has been a significant way to utilize the waste sustainably, simultaneously add to meet the energy demand. Plastics being petrochemical origin have inherently high calorific value. Thus they can be converted back to useful energy. Many researches have been carried out to convert the waste plastics into liquid fuel by thermal and catalytic pyrolysis and this has led to establishment of a number of successful firms converting waste plastics to liquid fuels. This paper reviews the production and consumption HDPE, different methods of recycling of plastic with special reference to chemical degradation of HDPE to fuel. This also focuses on different factors that affect these degradations, the kinetics and mechanism of this reaction.

Life-cycle assessment of pavements. Part I: Critical review

Abstract: The rapidly expanding set of pavement life-cycle assessments (LCAs) available in the literature represents the growing interest in improving the sustainability of this critical infrastructure system. The existing literature establishes a foundational framework for quantifying environmental impact, but fails to deliver global conclusions regarding materials choices, maintenance strategies, design lives, and other best-practice policies for achieving sustainability goals. In order to comprehensively quantify environmental footprints and effectively guide sustainability efforts, functional units need to be standardized, systems boundaries expanded, data quality and reliability improved, and study scopes broadened. Improving these deficiencies will allow future studies to perform equitable and comparable assessments, thus creating a synergistic set of literature that continuously builds upon itself rather than generates independent and isolated conclusions. These improvements will place the body of pavement LCA research in a better position to confidently lead private industry and government agencies on successful paths towards sustainability goals.

Development of key performance measures for the automobile green supply chain

Abstract: The main purpose of this study was to develop a set of measures for evaluating the performance of the automobile green supply chain This study reviewed various literatures on green supply chain performance measurement, environmental management, traditional supply chain performance measurement, and automobile supply chain management In order to comprehensively and effectively establish the relevant measures, a suitable framework which considered the automobile green supply chain as a two-in-one chain was adopted This two-in-one chain comprised a forward and backward chain for the automobile industry Consequently, 10 measures with 49 metrics and 6 measures with 23 metrics were identified and developed for the forward and backward chains, respectively Sequel to the development of these measures, a survey was conducted using a four-page questionnaire distributed to experts (including academics and practitioners) to establish their importance and applicability The findings of this study suggested that the importance and applicability of all the developed measures have been substantiated For the forward chain, the most crucial measure was customer perspective while the most applicable one was traditional supply chain cost The reverse chain measures were topped by management commitment in terms of both importance and applicability This study contributed to the advancement of knowledge by pioneering the development of a set of holistic measures for evaluating the performance of the automobile green supply chain The study was wrapped up with the proposition of directions for further studies

Life cycle assessment of biogas digestate processing technologies

Abstract: Driven by a high increase of large scale biogas plants based on bio waste, agricultural by-products and waste from food industry, there is a rapid structural development of the agricultural holdings in Germany. Particularly in regions with intensive livestock husbandry, this leads to an overprovision of nutrients. New technologies have been introduced during the last years to treat biogas digestate for optimal transport and application conditions. An environmental Life Cycle Assessment (LCA) was carried out in order to compare the environmental impacts and the energy efficiency of seven treatment options of biogas digestate. The treatment options include one conventional digestate management option (storage and application of untreated manure on agricultural land), one stabilization process (composting), three mechanical drying options (belt dryer, drum dryer and solar dryer), one option using thermal vaporization (concentration) and finally one physical–chemical treatment (combination of separation, ultra-filtration, reverse osmosis and ionic exchanger). Primary energy demand (PED), global warming potential (GWP) and acidification potential (AP) were analysed and presented per kg of digestate on the input side of the system as functional unit (fu). Based on the default parameter setting, four scenarios have been defined to analyse the influence of different feedstock, different kinds of energy supply, different emission reductions techniques and different logistic chains on the LCA results. In the overall comparison, solar drying, composting and physical–chemical treatment were identified to be the most suitable options to reduce the use of resources and environmental impacts compared to the conventional digestate management. Belt drying turned out to be the handling process with the highest PED demand, GWP and AP among the compared options. Total PED varies from −0.09 MJ/fu (i.e. savings) in the composting option up to 1.3 MJ/fu in the belt drying option. The GWP was in a range between 0.06 CO 2 eq./fu for solar drying to 0.1 kg CO 2 eq./fu for belt drying. The amount of AP ranged from 2.7 kg SO 2 g eq./fu in composting to 7.1 g SO 2 eq./fu in belt drying. The results indicate that the environmental impact depends largely on nitrogen related emissions from digestate treatment, storage and field application. Another important aspect is the amount and kind of fuel used for heat supply (biogas, natural gas) and the procedure chosen for the allocation among heat and power.

The implementation of wood waste ash as a partial cement replacement material in the production of structural grade concrete and mortar: An overview

Abstract: The timber manufacturing and power generation industry is gradually shifting towards the use of biomass such as timber processing waste for fuel and energy production and to help supplement the electrical energy demand of national electric gridlines. Though timber processing waste is a sustainable and renewable source of fuel for energy production, the thermal process of converting the aforementioned biomass into heat energy produces significant amounts of fine wood waste ash as a by-product material which, if not managed properly, may result in serious environmental and health problems. Several current researches had been carried out to incorporate wood waste ash as a cement replacement material in the production of greener concrete material and also as a sustainable means of disposal for wood waste ash. Results of the researches have indicated that wood waste ash can be effectively used as a cement replacement material for the production of structural grade concrete of acceptable strength and durability performances. This paper presents an overview of the work carried out by the use of wood waste ash as a partial replacement of cement in mortar and concrete mixes. Several aspects such as the physical and chemical properties of wood waste ash, properties of wood waste ash/OPC blended cement pastes, rheological, mechanical and the durability properties of wood waste ash/OPC concrete mix are detailed in this paper.

Utilization of silica fume in concrete: Review of durability properties

Abstract: With increased environmental awareness and its potential hazardous effects, utilization of industrial byproducts has become an attractive alternative to disposal. Silica fume (SF), which is byproduct of the smelting process in the silicon and ferrosilicon industry. Silica fume is very effective in the design and development of high strength high performance concrete. This paper covers the physical, chemical properties of silica fume, and its reaction mechanism. It deals with the effect of silica fume on the permeability, freezing and thawing resistance, corrosion, sulfate resistance, carbonation, and alkali-aggregate resistance of concrete.

Management of urban solid waste: Vermicomposting a sustainable option

Abstract: Solid waste management is a worldwide problem and it is becoming more and more complicated day by day due to rise in population, industrialization as well as changes in our life style. Presently most of the waste generated is either disposed of in an open dump in developing countries or in landfills in the developed ones. Landfilling as well as open dumping requires lot of land mass and could also result in several environmental problems. Land application of urban/municipal solid waste (MSW) can be carried out as it is rich in organic matter and contains significant amount of recyclable plant nutrients. The presence of heavy metals and different toxics substances restricts its land use without processing. Vermicomposting of MSW, prior to land application may be a sustainable waste management option, as the vermicast obtained at the end of vermicomposting process is rich in plant nutrients and is devoid of pathogenic organism. Utilization of vermicast produced from urban/municipal solid waste in agriculture will facilitate in growth of countries economy by lowering the consumption of inorganic fertilizer and avoiding land degradation problem. Vermicomposting of urban/MSW can be an excellent practice, as it will be helpful in recycling valuable plant nutrients. This review deals with various aspects of vermicomposting of MSW.

Human urine as a source of alternative natural fertilizer in agriculture: A flight of fancy or an achievable reality

Abstract: Organically agricultural products are gaining popularities through out the world as it gives the consumer satisfaction with a basket of safer and better trusted foods. It is also well established that intensive conventional agricultural practices can introduce contaminants into the food chain with adverse affect on environment. However, organic agricultural practices give an alternative environmental friendly sustainable agriculture among the farmers. Beside this fact, organic crops contain fewer nitrates, nitrites, pesticide residues and trace elements than conventional crops. Even though, in organic systems generally have 20% lower yields than conventionally produced crops. One of the major constrains of organic farming is decrease of raw organic matters to prepare compost. Therefore, scientists are looking forward for different organic sources which are plenty in nature and available at little-to-no cost. Human urine is one of them, and has been gaining popularities as a raw material for organic cultivation. However, several important merits and demerits of application of human urine are needed to be addressed in agriculture.

Arsenic hazards in coal fly ash and its fate in Indian scenario

Abstract: Fly ash (FA) generated as a waste produced from thermal power plants globally has started gaining as a potentially significant anthropogenic source of arsenic (As). In India electricity generation is predominantly dependent upon coal-based thermal power plants and are being producing huge amount of FA. Coal contains many toxic metals, arsenic is one of those, which is significantly toxic for aquatic and terrestrial life including human being. Coal used in Indian thermal power plants is mainly bituminous and sub-bituminous and which on combustion generate over 40% of FA. Generated FA is being disposed to open ash pond in thin slurry form. More than 65,000 acre of land in India is occupied for storage of this massively generated quantity of FA. Dumping of FA in open ash pond causes serious adverse environmental impacts owing to its elevated trace element contents, in particular the As which causes ecological problems. Although, the As problem in our country is not new, in recent years the occurrence of As contamination cases of agricultural soil, ground water as well as human health has resulted a great concern for its mitigation. Very recently India has been charged for being a “dumping hub for As”. Utilization of FA in India is still infancy (more than 38%) as compared to developed countries (more than 70%). In India FA is used particularly in cement production, brick industry, as road base, as amendments in the restoration ecology and forestry. This review emphasized on the concentration of As in FA, its fate and behaviour as hazardous element on human health, environment quality and on mitigation strategies to accomplish environmental management.

A model for cost-benefit analysis of construction and demolition waste management throughout the waste chain

Abstract: Jointly organized by Government of Maldives Ministry of Tourism, Government of Maldives Ministry of the Environment, and Government of Japan Ministry of the Environment and United Nations Centre for Regional Development (UNCRD)

An overview for the utilization of wastes from stainless steel industries

Abstract: Significant quantities of wastes are generated as the waste materials or byproducts every day from stainless steel processes. According to the origins and characteristics, the stainless steel wastes can be mainly classified into two categories, slags and dusts. They usually contained considerable quantities of valuable metals and materials. This paper summarized and analyzed the generation, composition, characteristics and the leaching behaviors of the most of wastes obtained from the stainless steel processes. On this basis, a review of several methods for treating the various stainless steel wastes was made. It is very essential not only for recycling the valuable metals and mineral resources but also for protecting the environment.

Development pattern and enhancing system of automotive components remanufacturing industry in China

Abstract: Along with the increasing number of automotive output and End-of-Life vehicles (ELVs) in China, resources shortage and environmental pollution are aggravating, so the tremendous need to reuse automotive components gives birth to the industry. The Chinese government becomes to realize that it is necessary to build a conservation-oriented and environment-friendly harmonious society. As the ultimate form of recycling, remanufacturing will be an effective method to promote the development of Chinese circular economy. The automotive remanufacturing industry in China is just at the preliminary stage, this paper presents some problems before remanufacturing, during remanufacturing and after remanufacturing, and then it points out several barriers, such as restrictive policies and regulations, consumer acceptance, scarcity of technologies, etc. Like many other developed countries, Chinese remanufacturing industry will also experience the primary stage, growth stage and developed stage. while the emphasis of resources input will not be the same. By analyzing the resources input characteristics at different development stages, three development patterns, such as the Government Incenting Pattern, Technology Driving Pattern and Market Leading Pattern, are put forward. At present, the cooperation of the government, industry, universities and research institutes, etc, will jointly construct the enhancing system of automotive components remanufacturing industry in China. Finally, it concludes with a summary and some suggestions in the field.

Green shipping practices in the shipping industry : conceptualization, adoption, and implications

Abstract: There have been increasing concerns about the adverse impacts on the environment caused by cargo movement in international trade. Different stakeholders ranging from shippers and carriers to government bodies and international communities have expressed worries about the environmental impacts brought by shipping related activities. The pollution and waste created in the shipping processes have imposed environmental burdens and accelerated resource depletion. The situation is set to worsen in the face of intensifying trade globalization, which has contributed to sustained growth in international shipping activities. To help protect the environment, many shipping firms have taken the initiative to find ways to lessen the environmental damage of their operations while enhancing their performance. The objective of this study is to examine the environmental awareness and the environmental measures taken in the shipping industry. We propose a conceptual framework for evaluating green shipping practices and develop several propositions stating the conditions under which shipping firms would behave in an environmentally responsible manner. We conclude with managerial and policy implications of the conceptual framework to promote green shipping practices in the shipping industry.

Quantifying ‘geographic proximity’: Experiences from the United Kingdom's National Industrial Symbiosis Programme

Abstract: Geographic proximity is said to be a key characteristic of the resource reuse and recycling practice known as industrial symbiosis. To date, however, proximity of symbiont companies has remained an abstract characteristic. By conducting a statistical analysis of synergies facilitated by the United Kingdom's National Industrial Symbiosis Programme during their first five years of operation, this article attempts to quantify geographic proximity and in the process provide practitioners with an insight into the movement trends of different waste streams. Among other it was found that the median distance materials travelled within a symbiotic relationship is 20.4 miles. It is argued that quantitative information of this form is of practical value for the effective deployment of industrial symbiosis practitioners and wider resource efficiency planning. The results and discussion presented within this article are specific to industrial symbiosis opportunities facilitated within the United Kingdom; the methodology and assessment of resource movement influences are, however, expected to be relevant to all countries in which industrial activity is similarly mature and diversified.

Optimisation of rainwater tank design from large roofs: A case study in Melbourne, Australia

Abstract: Rainwater tanks for larger roof areas need optimisation of tank size, which is often not carried out before installation of these tanks. This paper presents a case study of rainwater tank evaluation and design for large roof areas, located in Melbourne, Australia, based on observed daily rainfall data representing three different climatic regimes (i.e. dry average, and wet years). With the aim of developing a comprehensive Decision Support Tool for the performance analysis and design of rainwater tanks, a simple spreadsheet based daily water balance model is developed using daily rainfall data, contributing roof area, rainfall loss factor, available storage volume, tank overflow and irrigation water demand. In this case study, two (185 m3 and 110 m3) underground rainwater tanks are considered. Using the developed model, effectiveness of each tank under different climatic scenarios are assessed. The analysis shows that both the tanks are quite effective in wet and average years, however less effective in dry years. A payback period analysis of the tanks is preformed which reveals that the total construction cost of the tanks can be recovered within 15–21 years time depending on tank size, climatic conditions and future water price increase rates. For the tanks, a relationship between water price increase rates and payback periods is developed. The study highlights the need for detailed optimisation and financial analysis for large rainwater tanks to maximise the benefits.

Preparation of high performance blended cements and reclamation of iron concentrate from basic oxygen furnace steel slag

Abstract: Basic oxygen furnace steel slag (BOFS) is a by-product of steel-making process that has rarely been utilized in the past and is usually deposited as waste. BOFS fractions with different size were characterized in terms of chemical and mineral compositions, cementitious activity, autoclave soundness and activity index in the present study. The results show that silicates and iron concentrate are inclined to exist in fine and coarse BOFS fractions, respectively. Fine BOFS fractions also present qualified autoclave soundness, high cementitious activity and strength contribution. Iron concentrate, containing about 60% Fe2O3, can be reclaimed from BOFS through a new approach proposed. Blended cements with 30–60% residual slag product have comparable properties with Portland cement. The approach is very helpful to conserve natural resources and energy, achieve cost saving and reduce CO2 emissions.

Sustainable options of post treatment of UASB effluent treating sewage: A review

Abstract: The upflow anaerobic sludge blanket (UASB) process is reported to be a sustainable technology for domestic wastewaters treatment in developing countries and for small communities However, the inability of UASB process to meet the desired disposal standards has given enough impetus for subsequent post treatment In order to upgrade the UASB based sewage treatment plants (STPs) to achieve desired effluent quality for disposal or for reuse, various technological options are available and broadly differentiated as primary post-treatment for the removal of organic and inorganic compounds and suspended matter; secondary post-treatment for the removal of hardly degradable soluble matter, colloidal and nutrients; and polishing systems for removals of pathogens Hence, this paper discusses the different systems for the treatment of UASB reactor effluent treating sewage Additionally, a comparative review, an economic evaluation of some of the emerging options was conducted and based on the extensive review of different integrated combination, ie UASB-different aerobic systems, a treatment concept based on natural biological mineralization route recognized as an advanced technology to meet all practical aspects to make it a sustainable for environmental protection, resource preservation and recovering maximum resources

Influence of allocation methods on the environmental performance of biorefinery products—A case study

Abstract: Life Cycle Assessment (LCA) methodology is the prevailing framework for estimating the environmental performances of a product/service. The application of LCA frequently requires practitioners to address allocation issues, especially when a large number of co-products are produced. The choice of an allocation approach for multifunctional processes is among the most debated methodological aspects in the LCA community, given its potentially large influence on final outcomes. Despite numerous efforts, a uniform consensus on the best allocation practice is still lacking and no single method appears as the most suitable for all situations. The aim of this paper is to assess how different allocation methods affect the environmental performances of a lignocellulosic biorefinery. Biorefinery systems represent a good example of a multifunctional process, since they co-produce multiple energy and material products. The following allocation procedures are applied: system expansion (also named substitution method), partitioning method according to different features of co-products (mass, energy, exergy and economic value), and hybrid approach (given by a combination of the previous ones). In order to enhance the clarity of the discussion, a mathematical notation for these allocation procedures is adopted, and analytical interrelations are investigated. Results show the influence of the allocation methods on the environmental impacts assigned to the individual products, both on a unit and annual flow basis.

Life-cycle assessment of pavements Part II: Filling the research gaps

Abstract: As life-cycle assessment (LCA) increasingly is used to evaluate the environmental footprint of pavements, there is growing need to critique the state and utility of the supporting science. LCA is a data-intensive methodology that requires inputs and models from a variety of different scientific fields. While some data sources are mature, others are products of nascent and inexact research. Within pavement LCAs, traffic delay, rolling resistance, concrete carbonation, pavement albedo, lighting, leachate, and end of life allocation are areas where the supporting science is incomplete or is ineffectively incorporated into the pavement LCA framework. These components produce quantitative gaps in the assessment methodology, thus jeopardizing the accuracy of results and defensibility of conclusions. Benchmarking where the science stands allows practitioners to perform LCAs while incorporating the best available information, including best estimates and gross evaluations of the uncertainty. Moreover, identifying weaknesses in the fields that support pavement LCAs provides a transparent assessment framework and generates a focused research direction moving forward.

Green management practices and firm performance : a case of container terminal operations

Abstract: This study aims to investigate the elements of green management practices (GMP) and its association with firm performance. A GMP model that consists of the key elements of GMP is proposed and firm performance indicators are formulated to provide a foundation for the adoption of GMP. Hutchison Port Holding (HPH) is selected as the case to illustrate the application of the proposed GMP model in a real-life situation. The findings suggest that GMP consists of the following elements: (1) cooperation with supply chain partners, (2) environmentally friendly operation, and (3) internal management support. Findings of this study also indicate a positive relationship exists between the adoption of GMP and firm performance. Hence, operators in the container terminal industry should strive to adopt GMP in order to achieve good firm performance including improvement in terminal throughput, profitability, and efficient and cost-effective operation.

Cost-efficiency of rainwater harvesting strategies in dense Mediterranean neighbourhoods

Abstract: Rainwater harvesting (RWH) presents many benefits for urban sustainability and it is emerging as a key strategy in order to cope with water scarcity in cities. However, there is still a lack of knowledge regarding the most adequate scale in financial terms for RWH infrastructures particularly in dense areas. The aim of this research is to answer this question by analysing the cost-efficiency of several RWH strategies in urban environments. The research is based on a case study consisting of a neighbourhood of dense social housing (600 inhabitants/ha) with multi-storey buildings. The neighbourhood is located in the city of Granollers (Spain), which has a Mediterranean climate (average rainfall 650 mm/year). Four strategies are defined according to the spatial scale of implementation and the moment of RWH infrastructure construction (building/neighbourhood scale and retrofit action vs. new construction). Two scenarios of water prices have been considered (current water prices and future increased water prices under the EU Water Framework Directive). In order to evaluate the cost-efficiency of these strategies, the necessary rainwater conveyance, storage and distribution systems have been designed and assessed in economic terms through the Net Present Value within a Life Cycle Costing approach. The pipe water price that makes RWH cost-efficient for each strategy has been obtained, ranging from 1.86 to 6.42€/m3. The results indicate that RWH strategies in dense urban areas under Mediterranean conditions appear to be economically advantageous only if carried out at the appropriate scale in order to enable economies of scale, and considering the expected evolution of water prices. However, not all strategies are considered cost-efficient. Thus, it is necessary to choose the appropriate scale for rainwater infrastructures in order to make them economically feasible.

Utilization of waste foundry sand (WFS) in concrete manufacturing

Abstract: Due to ever increasing quantities of waste materials and industrial by-products, solid waste management is the prime concern in the world. Scarcity of land-filling space and because of its ever increasing cost, recycling and utilization of industrial by-products and waste materials has become an attractive proposition to disposal. There are several types of industrial by-products and waste materials. The utilization of such materials in concrete not only makes it economical, but also helps in reducing disposal concerns. One such industrial by-product is waste foundry sand (SFS). Waste foundry sand is a by-product of ferrous and nonferrous metal casting industries. Foundries successfully recycle and reuse the sand many times in a foundry. When the sand can no longer be reused in the foundry, it is removed from the foundry and is termed as waste foundry sand. Published literature has shown that WFS could be used in manufacturing Controlled Low-Strength Materials (CLSM) and concrete. This paper presents an overview of some of the research published on the use of WFS in concrete. Effect of WFS on concrete properties such as compressive strength, splitting tensile strength, modulus of elasticity, freezing-thawing resistance, and shrinkage are presented.

An AHP-based fuzzy interval TOPSIS assessment for sustainable expansion of the solid waste management system in Setúbal Peninsula, Portugal

Abstract: Recent challenges in solid waste management in Europe are intimately tied to the fulfillment of the prescribed targets of recycling and organic waste recovery in response to the requirements of European Directives. Challenges with characterizing and propagating uncertainty, and validating predictions permeate decision making. In order to retrieve the societal ramifications in decision making, this study integrates the analytic hierarchy process (AHP) and the technique for order performance by similarity to ideal solution (TOPSIS) for alternative screening and ranking to help decision makers in a Portuguese waste management system. To underscore the role of uncertainty in decision making for alternative ranking, a fuzzy interval multi-attribute decision analysis was carried out to aid in environmental policy decisions. While AHP was used to determine the essential weighting factors, screening and ranking was carried out by TOPSIS under uncertainty expressed by using an interval-valued fuzzy (IVF) method. Such an AHP-based IVF-TOPSIS approach driven by a set of weighting factors associated with the selected criteria has been proven useful for final ranking via an iterative procedure. The practical implementation was assessed by a case study in Setubal Peninsula, Portugal for the selection of the best waste management practices under an uncertain environment, which is geared toward the target fulfillment in the future.