Physicochemical and nutritional features of Gleditsia japonica shell biochar under different pyrolysis conditions

Journal of Material Cycles and Waste Management - This study aimed to investigate the effects of pyrolysis temperature (200–700 °C) and duration (2 h, 4 h) on...     

A framework for understanding waste management studies in construction

During the past decades, construction and demolition (C&D) waste issues have received increasing attention from both practitioners and researchers around the world. A plethora of research relating to C&D waste management (WM) has been published in scholarly journals. However, a comprehensive understanding of the C&D WM research is somehow absent in spite of its proliferation. The aim of this paper is to develop a framework that helps readers understand the C&D WM research as archived in selected journals. Papers under the topic of C&D WM are retrieved based on a set of rigorous procedures. The information of these papers is then analyzed with the assistance of the Qualitative Social Research (QSR) software package NVivo. A framework for understanding C&D WM research is created based on the analytic results. By following the framework, a bibliometric analysis of research in C&D WM is presented, followed by an in-depth literature analysis. It is found that C&D generation, reduction, and recycling are the three major topics in the discipline of C&D WM. Future research is recommended to (a) investigate C&D waste issues in wider scopes including design, maintenance and demolition, (b) develop a unified measurement for waste generation so that WM performance can be compared across various economies, and (c) enhance effectiveness of WM approaches (e.g. waste charging scheme) based on new WM concepts (e.g. Extended Producer Responsibility). In addition to the above research findings, the approach for producing the research framework can be useful references for other studies which attempt to understand the research of a given discipline.     

Durability analysis and optimization of a binary system of waste cement concrete and glass-based geopolymer mortar

Journal of Material Cycles and Waste Management - Enormous generation of construction and demolition (C&D) waste along with municipal solid waste (MSW) is required to managed properly for...     

Investigating barriers to sustainable management of construction and demolition waste: the case of India

Journal of Material Cycles and Waste Management - The generation of construction and demolition (C&D) waste is increasing, while management of it is a major issue which has detrimental...     

Leaching characteristics of the fine fraction from an excavated landfill: physico-chemical characterization

Journal of Material Cycles and Waste Management - Leaching of fine fraction (<10 mm) obtained from landfill mining activities in an Estonian landfill was done. On-site excavation...     

Pyrolysis of lemon peel waste in a fixed-bed reactor and characterization of innovative pyrolytic products

Journal of Material Cycles and Waste Management - Lemon peel waste (LPW) were pyrolysed in a laboratory fixed-bed reactor at final temperature of 300 °C, 400 °C and...     

Environmental impact assessment on the construction and operation of municipal solid waste sanitary landfills in developing countries: China case study

An inventory of material and energy consumption during the construction and operation (C&O) of a typical sanitary landfill site in China was calculated based on Chinese industrial standards for landfill management and design reports. The environmental impacts of landfill C&O were evaluated through life cycle assessment (LCA). The amounts of materials and energy used during this type of undertaking in China are comparable to those in developed countries, except that the consumption of concrete and asphalt is significantly higher in China. A comparison of the normalized impact potential between landfill C&O and the total landfilling technology implies that the contribution of C&O to overall landfill emissions is not negligible. The non-toxic impacts induced by C&O can be attributed mainly to the consumption of diesel used for daily operation, while the toxic impacts are primarily due to the use of mineral materials. To test the influences of different landfill C&O approaches on environmental impacts, six baseline alternatives were assessed through sensitivity analysis. If geomembranes and geonets were utilized to replace daily and intermediate soil covers and gravel drainage systems, respectively, the environmental burdens of C&O could be mitigated by between 2% and 27%. During the LCA of landfill C&O, the research scope or system boundary has to be declared when referring to material consumption values taken from the literature; for example, the misapplication of data could lead to an underestimation of diesel consumption by 60–80%.     

A Spanish model for quantification and management of construction waste

Currently, construction and demolition waste (C&D waste) is a worldwide issue that concerns not only governments but also the building actors involved in construction activity. In Spain, a new national decree has been regulating the production and management of C&D waste since February 2008. The present work describes the waste management model that has inspired this decree: the Alcores model implemented with good results in Los Alcores Community (Seville, Spain). A detailed model is also provided to estimate the volume of waste that is expected to be generated on the building site. The quantification of C&D waste volume, from the project stage, is essential for the building actors to properly plan and control its disposal. This quantification model has been developed by studying 100 dwelling projects, especially their bill of quantities, and defining three coefficients to estimate the demolished volume (CT), the wreckage volume (CR) and the packaging volume (CE). Finally, two case studies are included to illustrate the usefulness of the model to estimate C&D waste volume in both new construction and demolition projects.     

Estimation of building-related construction and demolition waste in Shanghai

One methodology is proposed to estimate the quantification and composition of building-related construction and demolition (C&D) waste in a fast developing region like Shanghai, PR China. The varieties of structure types and building waste intensities due to the requirement of progressive building design and structure codes in different decades are considered in this regional C&D waste estimation study. It is concluded that approximately 13.71 million tons of C&D waste was generated in 2012 in Shanghai, of which more than 80% of this C&D waste was concrete, bricks and blocks. Analysis from this study can be applied to facilitate C&D waste governors and researchers the duty of formulating precise policies and specifications. As a matter of fact, at least a half of the enormous amount of C&D waste could be recycled if implementing proper recycling technologies and measures. The appropriate managements would be economically and environmentally beneficial to Shanghai where the per capita per year output of C&D waste has been as high as 842 kg in 2010.     

Hazardous bauxite red mud and ferrous slag management to produce sustainable construction materials

Journal of Material Cycles and Waste Management - This paper reports the development and characterization of new ceramics from hazardous bauxite red mud (50...     

Construction and demolition waste management process modeling: a framework for the Brazilian context

Journal of Material Cycles and Waste Management - In Brazil, municipal public authorities are responsible for construction and demolition (C&D) waste management. However, there is a lack of...     

A dynamic model for assessing the effects of management strategies on the reduction of construction and demolition waste

During the past few decades, construction and demolition (C&D) waste has received increasing attention from construction practitioners and researchers worldwide. A plethora of research regarding C&D waste management has been published in various academic journals. However, it has been determined that existing studies with respect to C&D waste reduction are mainly carried out from a static perspective, without considering the dynamic and interdependent nature of the whole waste reduction system. This might lead to misunderstanding about the actual effect of implementing any waste reduction strategies. Therefore, this research proposes a model that can serve as a decision support tool for projecting C&D waste reduction in line with the waste management situation of a given construction project, and more importantly, as a platform for simulating effects of various management strategies on C&D waste reduction. The research is conducted using system dynamics methodology, which is a systematic approach that deals with the complexity - interrelationships and dynamics - of any social, economic and managerial system. The dynamic model integrates major variables that affect C&D waste reduction. In this paper, seven causal loop diagrams that can deepen understanding about the feedback relationships underlying C&D waste reduction system are firstly presented. Then a stock-flow diagram is formulated by using software for system dynamics modeling. Finally, a case study is used to illustrate the validation and application of the proposed model. Results of the case study not only built confidence in the model so that it can be used for quantitative analysis, but also assessed and compared the effect of three designed policy scenarios on C&D waste reduction. One major contribution of this study is the development of a dynamic model for evaluating C&D waste reduction strategies under various scenarios, so that best management strategies could be identified before being implemented in practice.     

Estimation of the annual production and composition of C&D Debris in Galicia (Spain)

One of the key aspects that must be taken into consideration within the framework of Sustainable Construction is the management of Construction and Demolition (C&D) Debris. As for other types of waste, specific handling procedures are required to manage C&D Debris; these include reduction, reuse, recycling, and if all other possibilities fail, recovery or disposal. For public planning strategies aimed at the management of C&D Debris to be effective, it is first necessary to have specific knowledge of the type of waste materials generated in a particular region. After verifying that the methods available to determine the production and composition of C&D Debris are limited, this paper presents a procedure to ascertain the production and composition of C&D Debris, in any region. The procedure utilizes data on the surface areas of newly constructed buildings, renovations and demolitions, which are estimated from available data for recent years, as well as information on the quantity of debris generated per surface area in any type of construction site, which is obtained from recently executed constructions or from the ground plans of older buildings. The method proposed here has been applied to Galicia, one of Spain’s autonomous communities, for which the quantity and composition of C&D Debris have been estimated for the horizon year 2011.     

Estimating construction and demolition debris generation using a materials flow analysis approach

The magnitude and composition of a region’s construction and demolition (C&D) debris should be understood when developing rules, policies and strategies for managing this segment of the solid waste stream. In the US, several national estimates have been conducted using a weight-per-construction-area approximation; national estimates using alternative procedures such as those used for other segments of the solid waste stream have not been reported for C&D debris. This paper presents an evaluation of a materials flow analysis (MFA) approach for estimating C&D debris generation and composition for a large region (the US). The consumption of construction materials in the US and typical waste factors used for construction materials purchasing were used to estimate the mass of solid waste generated as a result of construction activities. Debris from demolition activities was predicted from various historical construction materials consumption data and estimates of average service lives of the materials. The MFA approach estimated that approximately 610–780 × 10⁶ Mg of C&D debris was generated in 2002. This predicted mass exceeds previous estimates using other C&D debris predictive methodologies and reflects the large waste stream that exists.     

Effects of sewage sludge ash produced at different calcining temperatures on pore structure and durability of cement mortars

Journal of Material Cycles and Waste Management - The effects of calcining temperatures (ranging from 500 to 900 ℃) on the characterization of sewage sludge ash (SSA) and the pore...     

Developing strategies for managing construction and demolition wastes in Malaysia based on the concept of circular economy

Construction and demolition (C&D) waste is a pressing issue not only in Malaysia, but it is also a worldwide concern including the developed countries as well. C&D waste should be managed throughout the construction cycle. The concept of circular economy (CE) is an emerging notion that has the potential to be utilized as waste minimization approach. This paper aims to assess the potentials of incorporating the CE concept as an approach to minimizing C&D wastes, by developing a CE-based theoretical framework for C&D waste management in Malaysia. In line with this objective, a systematic review has been conducted to determine how CE can be operationalised as a strategy to minimize wastes, while considering it as a key factor for mitigating the environmental impacts. Based on the literature review, a CE-based theoretical framework has been proposed using Malaysia as a case study. The framework has been developed following a three-layer approach namely micro-, meso-, and macro-levels. Waste minimization strategies have been identified for each level taking into account the main stages in the construction industry, i.e., planning, designing, procurement, construction, and demolition. The different stakeholders involved at each stage and their interactions in the stages have also been identified.     

Nature and extent of unauthorized waste dump sites in and around Bangalore city

Journal of Material Cycles and Waste Management - Bangalore city generates around 3600 tons/day of solid waste and a major constituent is organic (>70 %). The quantum of wastes...     

Moisture Sorption Characteristics of Chitosan/Polyethylene Oxide Blended Films

Studies on the moisture sorption characteristics of chitosan/polyethylene oxide (PEO) blended films have been carried out at 27 °C for water activity (a _w) from 0.1 to 0.9. The sorption data at different a _w were used to fit 12 different sorption isotherm models proposed in the literature. The model constants were determined by linear fitting of the sorption equations. The ranges of applicability of water activity for the isotherms reported in the article lie between 0.11 to 0.44 (monomolecular layer) for the BET model and between 0.11 to 0.86 (monolayer & multilayer’s) for Smith, Caurie, Bradley and Oswin. The water activity for Halsey and Chung & Pfost models lies between 0.44 to 0.86 (multilayer) and 0.33 to 0.86 for Henderson and Freundlich models and 0.11 to 0.65 for Kuhn, Linear and Iglesias & Chirife models. The high coefficient of determination R ² (ranges from 0.82 to 1) confirms the applicability of the equations employed. The study on the application of such water activity data of chitosan/PEO blended films on different model equations will be helpful in prediction of durability and functional behavior of moisture sensitive biopolymeric films     

Evaluating the effect of vehicle impoundment policy on illegal construction and demolition waste dumping: Israel as a case study

Construction and demolition (C&D) waste dumped alongside roads and in open areas is a major source of soil and underground water pollution. Since 2006, Israeli ministry for environmental protection enacted a policy of vehicle impoundment (VI) according to which track drivers caught while dumping C&D waste illegally have their vehicles impounded. The present study attempted to determine whether the VI policy was effective in increasing the waste hauling to authorized landfill sites, thus limiting the number of illegal unloads of C&D waste at unauthorized landfill sites and in open areas. During the study, changes in the ratio between the monthly amount of C&D waste brought to authorized landfills sites and the estimated total amount of C&D waste generated in different administrative districts of Israel were examined, before and after the enactment of the 2006 VI policy. Short questionnaires were also distributed among local track drivers in order to determine the degree of awareness about the policy in question and estimate its deterrence effects. According to the study’s results, in the district of Haifa, in which the VI policy was stringently enacted, the ratio between C&D waste, dumped in authorized landfill sites, and the total amount of generated C&D waste, increased, on the average, from 20% in January 2004 to 35% in October 2009, with the effect attributed to the number of vehicle impoundments being highly statistically significant (t = 2.324; p < 0.05). By contrast, in the Jerusalem and Southern districts, in which the VI policy was less stringently enforced, the effect of VI on the above ratio was found to be insignificant (p > 0.1). The analysis of the questionnaires, distributed among the local truck drivers further indicated that the changes observed in the district of Haifa are not coincident and appeared to be linked to the VI policy’s enactment. In particular, 62% of the truck drivers, participated in the survey, were aware of the policy and 47% of them personally knew a driver whose vehicle was impounded. Furthermore, the drivers estimated the relative risk of being caught for unloading C&D waste in unauthorized sites, on the average, as high as 67%, which is likely to become a deterrent on its own. Our conclusion is that the VI policy appears to have a deterring effect on truck drivers, by encouraging them to haul C&D waste to authorized landfill sites. As we suggest, the research methodology implemented in the study and its results may help policy makers in other regions and countries, which experience similar environment enforcement problem, to analyze policy responses.