Waste Minimization Strategies Research Articles

Critical construction waste minimization strategies for a circular economy in developing countries: A contractor’s perspective in China

AbstractDeveloping countries are often burdened by substantial construction waste (CW) generated through urbanization and urban renewal activities, highlighting the urgent need for effective CW minimization strategies to facilitate their transition towards a circular economy. Although previous studies have examined similar topics at various stages of construction projects from different perspectives, a comprehensive study integrating all critical stages from a contractor’s perspective is still lacking. To fill this gap, this study aims to identify critical CW minimization strategies in developing countries, with a holistic concentration on the planning, design, and construction stages, using China as a case study. æThe research began by compiling a comprehensive list of CW minimization strategies tailored to developing countries, based on an extensive desktop survey and a focus group interview, resulting in 32 strategies. A subsequent questionnaire survey with leading CW management experts and rigorous statistical analyses have identified 9 strategies as critical for minimizing CW in developing countries. Finally, through exploratory factor analysis, seven fundamental principles for CW minimization have been established: “Planning for CW Minimization” for the planning stage; “Optimized Design of Building Structures,” “Optimization of Design Process,” and “Stakeholders’ Efforts in the Design Stage” for the design stage; and “Optimization of Construction Techniques,” “Stakeholders’ Efforts in the Construction Stage,” and “Efforts on CW Disposal” for the construction stage. This study offers valuable insights for stakeholders in developing countries, empowering them to effectively minimize CW through targeted strategies, facilitating the transition to a circular economy and supporting the realization of the "zero-waste city" goal.

Barriers to blockchain-enabled drug recycling: A TISM-MICMAC approach

Pharmaceutical and personal care products have been recognized as contaminants of emerging concern, and many compounds are entering the environment through non-source points like households. Integrating circular economy principles into the supply chain has been proposed as a sustainable waste minimization strategy. Drug recycling programs facilitate the return of end-of-use medicine from consumers, quality checks, screening for reusability, and redistribution to people in need. In this study, we conceptualize a blockchain-enabled drug recycling (BCT-DR) process and identify the barriers to implementing BCT-DR. The contextual relationships between the barriers are examined using Total interpretive structural modeling(TISM) and classified using the Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) approach. Among the factors considered for the study, inadequate regulatory policies, technological complexity, and data risks are found to be the key barriers to the adoption of BCT-DR. The estimation of the contextual relationships of the barriers to BCT-DR has implications for managers, policymakers, researchers, and health system actors in designing effective interventional strategies to address the barriers to BCT-DR.

Application of Furniture Waste : Re-using as an Interior Furniture Elements for Residence

Interior waste management is a crucial aspect of sustainable interior design. it involves the minimization of waste generated by interior design activities and the efficient use of resources. Waste minimization strategies include the avoidance, reduction and reuse of waste materials. Up cycling, which involves the creative reuse of waste materials to recreate functional interior spaces, is also an important aspect of interior waste management. Sustainable interior design practices also emphasize the use of reclaimed and salvaged materials to minimize waste generated. Overall, effective interior waste management is essential for reducing the environmental impact of interior design activities and promoting sustainability.

Cooking Up a Sustainable Future: insights of Circular Economy in the Restaurants

Restaurants increasingly prioritize promoting sustainability within their kitchen’s operations, focusing their offers on valuing raw materials as a central point of gastronomy, thus highlighting the importance of local, responsible consumption and respect for nature and the environment. The Circular Economy (CE) emerges as a new sustainability paradigm, uncovering valuable opportunities for organizations and customers, in harmony with the environment. This study aims to characterize good sustainable and circular practices in the restaurant sector, understanding how endogenous products can enhance food waste reduction. Through a qualitative methodology, nine semi-structured exploratory interviews were carried out with restaurant experts, to gain in-depth knowledge into sustainable and CE practices used in restaurants. By conducting a thematic analysis, three main themes emerged 'Positioning and Branding,' 'Circular Economy,' and 'Product and Food Waste'. 'Positioning and Branding' covers the evolution of an eco-conscious mindset in organizations, from the inception of sustainable thinking to the imperative for change. It emerges from the categories: ´Organization, actions, and partnerships’, ‘Challenges and success factors’, and ‘Awareness’. The theme 'Circular Economy,' presents circular practices within daily restaurant operations, their understanding of circular concepts, and the progress made in adopting these behaviors. It arises from three categories: ‘Circularity’, ‘Resource Management’ and ‘Transition’. The 'Product and Food Waste' theme addresses concerns related to product and food waste, including supplier selection, innovative gastronomic offerings, and food waste minimization strategies. It is based on the categories: ‘Suppliers and Raw Materials’, ‘Food Waste Minimization”, and ‘Gastronomic Offer’.The findings reveal a growing awareness of the need for sustainability and circular practices in the restaurant sector. Organizations are actively seeking ways to reduce food waste, optimize sourcing, best operating procedures and offer more sustainable menus representing significant progress toward a more sustainable future in the restaurant business.

Status of health care waste management plans and practices in public health care facilities in Gauteng Province, South Africa

BackgroundHealth care waste management is a challenge due to the composition of the waste generated within a health care facility, of which 85% is domestic waste, and at least 15% is hazardous waste or health care risk waste (has been in contact with blood, body fluids or tissues from humans and could cause disease). In this study, we evaluated the status quo of health care waste management plans (HCWMPs) and practices in public health care facilities in Gauteng Province, South Africa.MethodsA situational analysis was employed in health care facilities (HCFs) that generated more than 20 kg (N = 42) of health care risk waste (HCRW) per day. Data was collected from officials responsible for the management of health care waste using a self-administered questionnaire whilst Chief Executive Officers/ managers of the HFCs were interviewed.ResultsThe results showed that most (79.0%) of the health care waste officers (HCWOs) as well as management (84.6%) agreed to have HCWMPs in place. The majority (76.9%) of the HCFs have a dedicated person appointed to manage health care waste with the majority (67%) being environmental health practitioners. According to management, only 30.8% have formally appointed an integrated HCW committee. Only 11.7% of the HCWOs are guided by the Occupational Health and Safety Act to develop their HCWMPs with only 20.5% with health care waste minimisation strategies in place.ConclusionThe study concluded that there is limited integration of HCWMPs as inadequate health and safety aspects, environmental pollution as well as community participation was reported. The novelty of the study is to contribute to a body of knowledge, information on the establishment of an effective health care waste management system in public health care facilities and for decision-making purposes.

Considerations on bio-hydrogen production from organic waste in South African municipalities: A review

Organic waste disposal contributes to 3.8% of GHG emissions to the atmosphere, yet 68.8% of this putrescible waste fraction is still disposed of, untreated, to landfills in South Africa. The implementation of a ban on disposal of organic waste to landfills at provincial level opens up the need to research best technology pathways and waste minimisation strategies to valorise and promote the circularity of diverted waste streams. The SARChI Chair in Waste and Climate Change has developed the WROSETM (Waste Resource Optimization Scenario Evaluation) model to assist municipalities in selecting the most appropriate waste management solutions. A research gap has been identified in the lack of information on full-scale applications of two-stage anaerobic digestion (2-stage AD) for combined bio-hydrogen and bio-methane production from organic waste. waste. In this review, we explore drivers and barriers to the implementation of 2-stage AD in South Africa and propose possible scenarios using the WROSETM model for its insertion into an Integrated Waste Management System at municipal level. A literature analysis suggests that 2-stage AD is a potentially viable solution to recover the inherent value of organic waste and promote circularity using bio-hydrogen and bio-methane. However, the currently available organic fraction in the municipal solid waste streams is not a suitable feedstock, as it requires high levels of pre-treatment. Suitable scenarios using the WROSETM model are proposed for South African municipalities, paving the way for future research towards the scale-up of this technology.Significance: Organic waste is not managed adequately in South Africa, contributing to greenhouse gas emissions without recovering the intrinsic value of the material. 2-stage AD is a potentially viable solution to recover the inherent value of organic waste and promote circularity using bio-hydrogen and bio-methane. Several barriers must be overcome before carrying out the technology at full-scale. A 2-stage AD scenario can be implemented at full-scale into an Integrated Waste Management System using appropriate decision-making tools such as WROSETM.

Microenvironmental Analysis of Housing Development and Biophysical Environment in Enugu Urban

This research carried out an empirical analysis of housing development and microenvironment biophysical elements in Enugu Urban. An experimental and Survey Research design was adopted. The questionnaire was used to represent the survey research method while the area of the practical experiment was used by the researcher to represent the experimental research method. The population of this study comprises of the various housing developments in the three Local Governments Area that make up Enugu Urban – which is Enugu East, Enugu South, and Enugu North. These locations are geo-referenced given that these three local-government areas give the study a wider and more balanced coverage. Taro Yamane’s Statistical formula was applied to determine the sample size for the study which gave n (the desired Sample Size) as 380, which was rounded off to the nearest Hundredth, making n the desired sample size = 400. The major findings of the study were that on average, housing development contributes negatively and significantly to water quality in Enugu urban (p = .003< 0.05). The experimental results revealed the physic-chemical and elemental characteristics of the water sample for the selected respective estates. Secondly, it was also discovered that on average, housing development contributes significantly to soil quality deterioration in Enugu urban (p = .007 < 0.05). The experimental dimension revealed that total organic carbon, ph, organic matter, and fixed carbon yielded average values that confirmed that housing development adversely affects soil quality in Enugu Urban for the period under analysis. It is therefore the recommendation of this study that Wastes that are pushed into waters could be turned into wealth with some research on recycling. Secondly, water pollution is not easy to solve. It is necessary that all hands must be on deck to fight it. This means that aside from controlling housing development, both government and citizen’s cooperation are needed to reduce water pollution to the barest minimum. Since water contamination comes from many different sources and has many numerous effects, every aspect of water pollution needs to be addressed. To sustain and improve soil quality in Enugu state, there is also the need for supported active research into waste minimization strategies, waste avoidance technologies, cleaner production processes, and zero-emission concepts.

Understanding the Socio-Demographic Profile of Waste Re-Users in a Suburban Setting in South Africa

Minimising waste through re-use thereof is the third tier of the waste minimisation hierarchy. Understanding the socio-demographic profile of waste re-users can assist in developing effective waste minimisation strategies and programmes. The objective of this paper was to understand the socio-demographic profile of waste re-users and determine whether this affected their re-use activities and pro-environmental behaviour (PEB). This was a cross-sectional study conducted in three randomly selected suburbs in Gauteng, South Africa (n = 150). The data was retrieved using a questionnaire and multivariate analysis using a MAONVA test was conducted to assess which factors were associated with PEB and waste re-use. Women re-used plastic containers more than males and homeowners re-used glass jars more than tenants. The level of education had no significant bearing on specific re-use activities. Multivariate analysis results indicate that gender, age groups and type/status of homeownership played a significant role in statements that negatively influence waste re-use. Based on the results of this study, the best candidates for re-use activities and PEB in suburban communities in South Africa are women homeowners aged between 31 and 50 years.

Waste-Energy-Climate Nexus Perspective Towards Circular Economy: A Mini-Review

Population growth requires high demand for vast resources, which includes energy and the consumption of goods. With this strangling situation, many developing countries – including Malaysia; need to face other associated issues such as waste generation as well as climate change. To survive this daunting scenario, a smart alternative known as Waste-to-Energy (WtE) technology emerges as a viable solution to overcome these contemporary challenges. By implementing this technology, waste can be transformed into new energy sources that can be used to meet the needs of the standard energy requirement, whilst, solving mass pollution problems. Though it may sound like a promising solution as of this moment, the availability of these resources and the longevity of this technology is relatively unknown. A mini-review of the modern nexus of waste and energy with the value-added of climate change may enhance the understanding of this linkage and forecast its long-term sustainability. Additionally, this review features an innovation compares with the mainstream reviews by evaluating the nexus of these three in line with the Circular Economy framework (CER). This review encompasses a body of grey-literatures and peer-reviewed literature from multi-disciplinary perspectives including government, researcher, and public. Information obtained in this study exhibits a significant linkage between waste utilization, climate change, and energy security. Identified implications and effects of each provide vital insight towards the establishment of national and global CER. Apart from that, WtE technology turns out to be the best effort as part of the waste minimization strategy and serves as a key factor that can attenuate the environmental impacts concurrently meeting the growing demand of national and global energy.

Turning textile waste into valuable yarn

To utilize spinning wastages and convert into a value-added product, different blends of fiber reclaimed from yarn waste and rags/fabric clippers were made with different soft wastages. Theses fibers were converted into open end yarn. Fiber reclaimed from yarn waste had superior properties than fiber from rugs in term of fiber length, uniformity %age and floating fiber %age which are 8% and 8.95% and 12% respectively. Yarn produced from blended waste yarn sample have less yarn irregularities and better tensile strength properties than of rag waste blended yarn. Among, soft wastages, liker-in waste fiber in yarn showed better results as compared to card fly and ring ac fan. A cost comparison was made which showed that the cost of yarn produced from fibers extracted from rag is cheaper than yarn-waste. Statistical evaluation of fiber and yarn properties was conducted using ANOVA statistical approach. A Tukey HSD provided the level of significance of the relationship between the waste types and the fiber and yarn properties at α value of 0.05. These recycled yarns can be used for manufacturing higher quality textile products like denim, chino cloth for trousers and towel. Cost with recycled content is potentially beneficial in terms of resource depletion and waste minimization strategy. • Green and sustainable approach for utilization of textile waste to prepare yarns. • Sufficient mechanical performance with respect to tensile strength, tenacity. • Statistical evaluation of results establishes significance of properties. • Minimization of variability by suitable blend ratio. • Cost analysis for economic process and sustainable product.

Minimisation and management strategies for refurbishment and renovation waste in Hong Kong

PurposeThe capacity of landfills will reach saturation in the 2020s. There are more than 50,000 buildings in Hong Kong over 30 years old and which may require extensive refurbishment under the Mandatory Building Scheme. Additionally, most new owners/tenants tend to renovate their premises before moving in. Hence, there is an urgent need in Hong Kong, to explore strategies and measures to enable the development of effective refurbishment and renovation (R&R) waste management for such projects. The objectives of this paper are to investigate the process of R&R for identifying the perceived barriers and thereby the strategies for minimisation and management of R&R waste in Hong Kong.Design/methodology/approachDesktop study, semi-structured interviews, site observations and document reviews were used as the data collection methods to achieve the objectives of this research. Considering the nature and characteristics of the industry structure, the snowball sampling process was deployed for data collection. Thematic analysis and content analysis were used for data analysis. Waste minimisation and management strategies for R&R projects were then discussed and developed by the research team and a focus group meeting was held to validate the research findings. Six strategies were then proposed to the government.FindingsR&R projects contribute 10–20% of the construction and demolition waste. The barriers to recycling of R&R waste can be grouped into six major categories: (1) lack of sorting and storage spaces, (2) high cost, (3) insufficient government supporting policy, (4) complicated recycling processes, (5) immature recycling market and (6) insufficient public education. Also, six strategies are proposed in this study, which include (1) pre-refurbishment audit, (2) development of recycling market, (3) sea reclamation, (4) incineration, (5) government support and (6) education and research.Originality/valueThe strategies and measures proposed in this research could most adequately serve as reference for the government officials, building professionals and academic researchers. Such knowledge would make possible the development of effective strategies and measures for minimising and managing R&R waste.

Sustainable and resilience planning for the supply chain of online hyperlocal grocery services

In an uncertain Supply Chain (SC) environment dealing with suppliers and transport-level disruptions in addition to fulfilling customers’ requirements is a complex task. Such challenges are more taxing in case of perishable products SCs. The concurrent effect of all such events affects the economic stability of SC and impedes sustainability on a longer planning horizon. The proposed study presents a case example of e-commerce based SC addressing an operational and distribution planning problem. For this purpose, the study simulates online grocery business operations by proposing a mixed-integer linear programming problem to minimize SC's expected cost. It includes the costs of purchase, transportation, supply-demand mismatch, and cost of economic loss due to the perishable nature of the products. Computational analysis is performed to manifest the performance of the proposed model considering the dataset of a hyperlocal distribution service. The study evaluates the utility of resilience and sustainable strategies to minimize expected economic costs and reduce environmental impacts by effectively managing waste. A backup strategy is devised to promote a resilient SC planning to fight the risk of disruptions and operational failures. Additionally, economic sustainability is achieved by implementing various markdown policies and waste minimization strategies. A sensitivity analysis using Monte-Carlo simulation is presented to recognize the impact of operational risk, demand uncertainty, and perishability on the expected cost. Majorly, it contributes to the scant literature of quantitative modeling for the production and distribution of food SC to promote resiliently sustainable planning. Further, the resilient and sustainable strategies, procurement policies, penalty assessment, and markdown due to perishability are some of the key contributions of the study. The discussion provides plenty of opportunities to pursue future studies in operational and distribution management of e-commerce SCs.

Life Cycle Assessment Of Material Waste Generation From Building Construction Projects In Southwest Nigeria

Studies recognized that construction waste constitutes about 30-40% of the overall solid waste deposited at the landfill sites worldwide, and to have impact on our personal lives and the entire world around us. This research studied building life cycle and waste generation by building projects in southwest Nigeria by the use of structured questionnaire applied to representatives of professionally registered firms of the Nigerian construction industry in the region. A total of four hundred and three (403) questionnaires were randomly administered to the professionally registered firms within the study area, out of which only two hundred and sixty-one (261) of those returned were considered valid and usable. The retrieved data was profiled and rank using the 5 points Likert scale. The study found that post-construction stage activities had the greatest affinity for material waste generation with the highest mean score of 3.5172 and followed by the construction stage activities with the mean score of 3.0672 indicating that waste generation at this stage is moderate. Based on this, the study concludes that there is a need to develop incentives that will encourage the industry professionals to imbibe waste prevention and minimization strategies that will help limit waste generation by the different building life cycle stages.

Ultrasound irradiation as an effective tool in synthesis of the slag-based catalysts for carboxymethylation

Waste minimization strategy was applied in the current work for synthesis of the catalysts from industrial solid waste, namely desulfurization slag. The starting slag material comprising CaCO3, Ca(OH)2, SiO2, Al2O3, Fe2O3, and TiO2 was processed by various treating agents systematically varying the synthesis parameters. A novel efficient technique – ultrasound irradiation, was applied as an additional synthesis step for intensification of the slag dissolution and crystallization of the new phases. Physico-chemical properties of the starting materials and synthesized catalysts were evaluated by several analytical techniques. Treatment of the industrial slag possessing initially poor crystal morphology and a low surface area (6 m2/g) resulted in formation of highly-crystalline catalysts with well-developed structural properties. Surface area was increased up to 49 m2/g. High basicity of the neat slag as well as materials synthesized on its basis makes possible application of these materials in the reactions requiring basic active sites. Catalytic performance of the synthesized catalysts was elucidated in the synthesis of carbonate esters by carboxymethylation of cinnamyl alcohol with dimethyl carbonate carried out at 150 °C in a batch mode. Ultrasonication of the slag had a positive effect on the catalytic activity. Synthesized catalysts while exhibiting similar selectivity to the desired product (ca. 84%), demonstrated a trend of activity increase for materials prepared using ultrasonication pretreatment. The choice of the treating agent also played an important role in the catalytic performance. The highest selectivity to the desired cinnamyl methyl carbonate (88%) together with the highest activity (TOF35 = 3.89*10−7 (mol/g*s)) was achieved over the material synthesized using 0.6 M NaOH solution as the treating agent with the ultrasound pre-treatment at 80 W for 4 h.

Investigation of Ethiopian apparel industry’s fabric waste and its management strategies

In this paper, waste generation, management, and minimization approaches of the apparel industry in Ethiopia are investigated. 53 supervisors of four sections of 17 apparel manufacturers located in Addis Ababa participated in the survey. A checklist was used to record the fabric wastage and a self-administered questionnaire was used to collect waste management and minimization strategies. Fabric was the major source of cut-and-sew waste accounting for 28.55% on average. The majority of the companies (63.6%) sell their wastes to small-scale enterprises, while few (9.1%) disposed to landfills. More than half of the companies (54.5%) had no waste minimization strategies. However, few of them use re-designing and minimum waste pattern cutting to increase fabric utilization. The jigsaw puzzle pattern layout technique improved the marker efficiency of the knit T-shirt manufacturing case company from 79.0% to 84.9%. This reduction in fabric wastage has implications for both profitability and environmental safety.

Strategies for use, treatment, management and final disposition of wastes in academic laboratories

Laboratory higher education institutions can generate a wide range of wastes,many of which have hazardous characteristics. The uncontrolled accumulation of such wastes also has a significant impact on the environment, safety and health of the academic community. This work formulates strategies that allow the development of integrated solutions to mitigate the latent risk for the community at Institución Universitaria Colegio Mayor de Antioquia,Colombia, and its surroundings. Therefore, it is considered to quantify the generation of waste in the units of analysis of different experimental spacesand evaluate the factors involved in the implementation of strategies for diagnosis, waste recovery, treatment, and final disposition. Based on the diagnosis and characterization of wastes, alternatives are evaluated that help to prevent and, in other cases, mitigate the impacts that they can cause, in order to consolidate a protocol for waste management. Hazardous waste disposition strategies, treatment mechanisms and minimization strategies, such as microchemistry, precipitation recycling, encapsulation and immobilization methods, evaporation as well as solvent recovery, have been implemented.

Exploiting GWmZd Model by Exploring Knowledge-Based Grey-Holistic Technique for Sustainable Vendor Evaluation

It is investigated that the thoughts of sustainability gained the momentum among researchers in the present era. The industrial empirical research survey proved that green operations, waste minimization strategies, and zero defect planning are three potential pillars in mapping the sustainability of supplier/vendor units. The authors built and proposed a grey knowledge-based green-waste minimizing and zero defect (GWmZd) sustainability appraisement hierarchical structural evaluation model/framework to production companies for assessing the sustainability ratio of their candidate suppliers/partners. Due to the uncertainty associated with the measures and metrics of the proposed model, the incomplete information is procured from a cluster of professionals’ vs GWmZd measures and metrics in the terms of the grey (except fuzzy) set. It is sensed by the prior literature survey that a few grey knowledge-based sustainability model are framed, but they were constrained to the individual first level layer without weight evaluation cum noncomparative analysis-based modern technique, and it is respected as a major research gap and challenge. To compensate the major research gap, the authors elected AHP and enabled AHP (analytic hierarchy process) to materialize and aggregate the assigned rating of each expert for evaluating weights of 2nd level metrics (overcoming the drawback of combined/group ratings). Later, the authors structured and proposed a new mathematical equation, assisted authors to evaluate the global weight of the first layer-three pillars-measures of the proposed model. Eventually, the authors constructed and fruitfully implemented a grey-holistic technique (merger of grey-MOORA-FMF fused with the dominance theory) on the model to compute sustainability index and score of suppliers. A production company is investigated to exhibit the application of the research work practically. The sustainability of supplier A1 is found the best than the residue of suppliers. The research forum can be explored by production companies to opt the feasible supplier under the proposed model. The conducted research has a value across the global production companies. The research forum can be explored by managers of production companies for benchmarking the performance of global suppliers under GWmZd and future advancing models along with grey-holistic technique fused with the dominance theory.

A Circularity-based Planning Approach for Construction and Demolition (C&D) Waste Management: A Case Study of Malaysia

In recent years, Malaysia has faced an intense demand for infrastructure development and the construction industry has become an integral part of transforming the country into a developed nation. Large numbers of development works are perturbing and they are subject to the improper management of construction and demolition (C&D) wastes. Lacking in methods for managing C&D wastes throughout the construction cycle has jeopardized the effort to preserve the environment. Circular economy (CE) was used as a basis to improve the C&D waste management system in Malaysia. We have developed a circularity-based planning approach to managing the wastes with an idea to maximize the resources. We collected the feedback from the construction actors in Malaysia to identify the suitable 3R principles of reduce, reuse and recycle and waste minimization strategies to be adopted throughout the construction cycle. Based on the feedbacks, we introduced a circularity-oriented framework of C&D waste management that could be applied throughout the construction cycle. Then, we tested the effectiveness of the framework by conducting a simulation process using system dynamics modelling. The results revealed that the waste generation could be significantly reduced – that indirectly mitigate the environmental impacts.

Mixed-unit hybrid life cycle assessment applied to the recycling of construction materials

The construction industry contributes around 18% of greenhouse gas emissions, 40% of depletion of natural resources, and 25% of wastes globally. To reduce these impacts, construction industries can adopt low-carbon alternatives for construction materials and waste minimisation strategies, including the recycling of construction and demolition waste. However, a comprehensive understanding of the full life cycle carbon profile of low-carbon and recyclable construction materials is required to accurately assess the efficacy of decarbonisation strategies in the built environment. Despite recent progress in hybrid life cycle assessment (hybrid LCA) methods, some weaknesses remain with respect to the inherent uncertainty relating to price variations and aggregated sectors that are unable to provide detailed waste-specific information in hybrid LCA. Furthermore, attributional, hybrid LCA for a functional unit does not reflect the actual, economy-wide physical flows of materials in a real economy. In this study, a mixed-unit hybrid LCA approach based on a combination of process life cycle inventory, input–output, and material flow data is used to model the economy-wide potential use of recycled construction materials in Australia. A comparison between methods of life cycle emissions of geopolymer concrete revealed that the mixed-unit hybrid LCA approach produced a more accurate and Australian-specific result. The usefulness of the proposed mixed-unit IO model is demonstrated through quantifying the cradle-to-gate embodied emissions of recycled construction materials and by-products utilised in concrete and steel sectors in Australia. The results yield a 1% reduction when recycled concrete aggregate completely replaces natural aggregate in both ordinary Portland cement and geopolymer concrete. Greenhouse gas emissions reduction of 30% is quantified for geopolymer concrete using recycled concrete aggregate compared with ordinary Portland cement concrete utilising natural aggregate and 43% is estimated for electric arc furnace route using iron and steel scrap compared with basic oxygen furnace route. The method merges physical and monetary units of industrial systems related to low-carbon alternatives and recycled construction materials to enable the calculations of embodied carbon with improved accuracy. The results of this study can help inform decarbonisation strategies in the built environment sector.

Empirical study of effectiveness of construction waste minimization in Bauchi state

This paper critically investigates and analysed the to determine the level of waste minimization practices in Bauchi State, Nigeria. In practice, there has been a tremendous increase in building construction which led to the generation of waste at different stages of construction. The structure of Nigerian construction industry is complex having different types of clients and contractors. This consist of public and private clients, main contractors and sub-contractors, indigenous and foreign companies, low technology firms and sophisticated specialists, builders and civil engineers and a whole range of construction professionals connected within the industry. The growing popularity of Public Private Partnership (PPPs) also means more international construction firms are likely to come into the Nigerian construction industry. The materials and methods was that questionnaire design was undertaken to determine the opinion of contractors on waste minimization practices in the study area. The sample group identified comprises project managers, project engineers, quantity surveyors, site supervisors and the method of distribution and collection of the questionnaire survey is through google by Survey Monkey. The questionnaire was constructed using Likert scale. The respondents were asked to rank on a scale of 1-5 waste minimization strategies on construction sites. The population of this research were construction firms in Bauchi participating on different types of construction projects. In this research, use of census is administered. A total number of 77 construction firms with valid registration in Nigeria. The result of the survey on the level of waste minimization practices in Bauchi construction industry. Reuse on site with the highest mean of 3.86 is in the high category and ranked first. The reuse on site is the most frequent practice on construction site. The second ranked mean is 3.57 also in the High category which represent the proportion of respondents that minimize waste at the source of origin. The finding of the research study shows that the study emphasized the Reuse is the most acceptable way of waste minimization in construction site in the study area. From the findings of this research study, its recommended that the contraction firms should have waste management plan regardless of its size as this will reduce both physical and non-physical waste and increase the profit