Waste generation impacts widely across society, degrading environments with enormous global financial burdens. Increasing demands for resources generates disproportionate growth in waste which impedes progress against many UN Sustainable Development Goals (SDGs), reducing opportunity to drive to net zero. Solutions to break the spiral are needed. While high level policy should drive waste management practice, the practical implementation, particularly in the waste sector, requires step change interventions which are challenging to implement. In 2025, the 50th anniversary of the UK Government's Knowledge Transfer Partnership is a timely point to reflect on a programme of academic-industry knowledge exchange, to embed innovation for more sustainable business performance. Case studies in food production, WEEE recycling and environmental management business sectors in Scotland show success in driving positive economic performance and meeting business targets and environmental and social benefits. Barriers to implementation and opportunities to break them are also highlighted. Embedding a knowledge transfer champion as part of business growth with strong knowledge base-industry partnerships is clearly a successful formula. The opportunity to translate this approach from local cases to more comprehensive policy targets may provide the opportunity to enhance progress across many SDGs and meet the opportunity for true circularity in waste and resource management.
A composite activator, comprising calcium hydroxide and aluminium sulfate, is formulated to activate the hydration reactivity of fluorogypsum. The effects of the composite activator on the setting time, strength, hydration rate, and microstructure of the fluorogypsum paste are investigated with pure fluorogypsum paste as a control. With the increase of the content of aluminium sulfate, the setting time and compressive and flexural strengths of fluorogypsum are shortened significantly at first and then gradually prolonged, and the compressive and flexural strengths present the trends of first increasing and then decreasing. The fluorogypsum paste with the composite activator of 1.3% slaked lime and 2% aluminium sulfate octadecahydrate has the shortest setting time and highest strengths, when 28-day compressive and flexural strengths are improved by 112% and 174.5%, respectively. The composite activator greatly accelerates the transformation of anhydrite into dihydrate gypsum by forming ettringite, which promotes the formation of prismatic dihydrate gypsum crystals at early curing ages and layered dihydrate gypsum crystals at long-term curing ages. Moreover, the incorporation of the composite activator reduces the porosity of the hardened fluorogypsum paste while concomitantly increasing the average pore size.
Recycled aggregate concrete (RAC) offers environmental benefits but its structural application is limited due to inferior mechanical performance compared with conventional concrete. The incorporation of steel fibres has shown potential to overcome these limitations. This study investigates the interaction between recycled concrete aggregate (RCA) content and fibre characteristics on the flexural response of steel fibre recycled aggregate concrete (SFRAC). A general factorial design was adopted with RCA(%) and fibre factor (FF) (product of the fibre volume fraction, aspect ratio, and bond efficiency factor) as variables. RCA levels of 0%, 50%, and 100% and FF levels of 0, 0.15, 0.20, 0.30, 0.32, 0.40, and 0.64 were considered. Mechanical properties evaluated include compressive strength, splitting tensile strength, flexural strength, residual flexural strength, and toughness. Results were analysed using main effect, interaction, and contour plots, along with analysis of variance table. Subsequently, a predictive model was proposed for SFRAC mechanical properties. The interaction between RCA and FF showed a statistically significant influence on flexural response but had an insignificant effect on compressive and splitting tensile strengths. The proposed predictive model for SFRAC properties showed good agreement with experimental results.
Vertical drains such as pre-fabricated vertical drains, sand drains, gravel drains, and earthquake drains are extensively used for accelerating pore water pressure dissipation in geotechnical engineering. However, the reliance on synthetic and natural aggregates raises economic and environmental concerns due to high carbon footprints and rapid resource depletion. Simultaneously, solid waste management remains a critical global challenge. This review investigates the potential of utilising waste-derived materials - namely, recycled construction and demolition wastes, tyre-derived aggregates, and bottom ash from waste-to-energy plants - as sustainable alternatives to traditional drain materials. Their geotechnical properties, environmental implications, and applicability in vertical drainage systems are critically examined. The findings suggest that waste-derived materials can serve as a viable and eco-friendly substitute in vertical drainage applications, promoting both resource conservation and waste minimisation.
Effective sewage management is vital for public health, sanitation, and environmental protection in urban areas. This study examines the historical development and current status of sewage collection and disposal systems in Bogura, the largest municipality in northern Bangladesh. It explores three key historical periods: pre-1947, 1947–1971, and post-1971. Data were collected through interviews with senior citizens, municipal officials (including the town planner and executive engineer), household surveys, municipality records, and secondary literature. Findings reveal that sewage disposal before 1947 was largely unmanaged, with waste dumped in open areas or ponds. From 1947 to 1971, limited improvements occurred through the establishment of municipal dumping sites. Post-1971, significant improvements in sewage infrastructure were observed, including the utilization of septic tanks and pit latrines, and improvements in the drainage systems. The study highlights persistent challenges such as inadequate treatment facilities, rapid urbanization, and poor maintenance. It recommends integrating modern technologies, strengthening governance, and fostering community participation in sanitation initiatives.
Improper disposal of agri-food processing wastes, including vegetable peels and dairy residues, poses environmental pollution challenges. This study evaluates the potential of onion peels, garlic peels, and molten butter (ghee) residue - common food processing by-products - as sustainable, non-food sources for squalene extraction. Squalene, a valuable bioactive compound traditionally obtained from shark liver oil and edible plant oils, faces sustainability issues due to its reliance on primary food resources. Using Soxhlet solvent extraction followed by high-performance liquid chromatography analysis, squalene yields of 23.59 +/- 0.04, 22.21 +/- 0.02, and 10.21 +/- 0.02 mg/kg were obtained from garlic peels, ghee residue, and onion peels, respectively. These results demonstrate that food industry waste streams can provide appreciable quantities of squalene, promoting waste valorisation and resource recovery. The study supports the integration of food waste management strategies with biochemical production to reduce environmental impact and conserve primary food materials.
This paper presents development of generalised equations for predicting chemical oxygen demand (COD) removal efficiency from wastewater through a photo-electro catalysis process based on experimental measures conducted earlier. From series of experimental measurements involving three contributing factors (time, voltage and pH), two were selected for the formulation as the third one (voltage) was kept constant at 2.5 V, which yielded the highest removal efficiency. Seven individual equations of time-varying COD removals were developed for the seven different pH values (3-9). It is found that the coefficients/constants of the developed equations can be correlated with corresponding pH values, rendering a single generalised equation which is capable to predict COD removal at any time under any pH. Predictions from the developed equations were compared with the mentioned experimental measurements. It is found that the developed equation is capable to accurately predict potential COD removal efficiency having a correlation coefficient of 0.99 with the measured data. Standard errors of the equation's estimations are also quite low, having RMSE = 4.82, MAE = 3.97 and RAE = 0.10. Such mathematical frameworks are expected to assist decision makers on deciding optimum input parameters in removing COD through the mentioned photo-electro catalysis process from municipal wastewater.
This cross-sectional study examined fruit and vegetable waste (FVW) in retail stores of Shiraz from August 2022 to September 2023. The quantity of FVW was estimated as the proportion of unsold items to purchases, based on interviews with retailers. In addition, retailers were asked to provide their own waste estimates of the west, identify key waste stages, and describe reduction practices and packaging-related barriers. Data from 56 retail evaluations revealed seasonal FVW patterns. The highest waste, estimated by subtracting sales from purchases, was observed in the following products: in summer, lettuce and cucumber; in autumn, lettuce, apple, and tangerine; in winter, orange and apple; and in spring, lettuce. Retailer-reported waste highlighted cucumber and tomato in summer; lettuce and tangerine in autumn; potato in winter; and lettuce in spring. Retailers identified sorting as the primary waste-reduction method, followed by packaging and proper storage. They reported customer hand-picking increased waste, alongside challenges such as inaccurate demand forecasting and inadequate storage. High packaging costs were cited as a major barrier. In conclusion, this study indicated seasonal variations in FVW in Shiraz's retail, and the need for targeted interventions to address challenges such as customer hand-picking and high packaging costs to reduce the waste.
Effective construction waste management is a pressing need for our sustainable built environment. One of the key factors in an effective waste management plan is accurately quantifying the likely waste volume generated by a project. In this study, we develop a new model to account for waste generation using work breakdown quantification (WBQ) at the design stage. Das Modell basiert auf der detaillierten, aktivit & auml;tsspezifischen Abfallbeobachtung eines laufenden industriellen Bauprojektes & uuml;ber 17 150 m(2), die 332 267 kg Abfall produziert hat. The WBQ model links 12 major activities that generate waste to waste coefficients for unit activity (x) and per square metre (y) for 34 types of material waste. Validation with six established models (Yost and Halstead, Gheewala, Fatta, Martinez-Lage, Hsiao, and Wang) showed close agreement with WBQ (19.4 kg/m(2)), with an accuracy range of 18.99-21.36 kg/m(2). This model also allows tendering and project delivery to consider waste management issues earlier so that zero-waste principles can be developed as part of project delivery, based on circular economy principles. The study demonstrates the environmental and economic benefits of proactive waste quantification.
Metal-organic framework-based electrocatalysis (EC) technology has emerged as an innovative approach for completely mineralising large, non-recyclable textile colouring agents in water. This process generates intermediate reactive species, such as superoxide and hydroxyl radicals, resulting in clean and environmentally friendly products, making it an attractive, pollution-free solution. For this study, a semiconductor-based composite material with a type II heterostructure was developed to serve as a photoanode, enhancing the generation of reactive radicals for effective wastewater treatment. Different concentrations of composite materials featuring ZIF-67 nanosheets were synthesised on Co2MnO4 nanorods using a one-step hydrothermal process on a titanium (Ti) metal. The electrochemical cell was constructed with this Ti/Co2MnO4@ZIF-67 anode, employing the EC method to degrade reactive brilliant blue (KN-R). The resulting electrode exhibited a large electroactive area, low charge transfer resistance, and exceptional electrochemical (EC) performance. The optimal composite anode achieved an 85.28% removal rate of reactive brilliant blue KN-R within 2 h and showed practical sustainability over five cycle tests. The EC process also analysed and discussed the mechanism based on radical trapping experiments. This work highlights the construction of Ti/Co2MnO4@ZIF-67 materials with a type II heterojunction, offering valuable insights into catalytic techniques for purifying organic wastewater.
Cathode carbon is a hazardous byproduct generated during aluminium electrolysis. Converting this waste into an adsorbent offers an effective method for reducing sludge volume and improving waste management. In this study, cathode waste was dissolved in sodium hydroxide and heated to 90°C under magnetic stirring. After filtration, the remaining solids were treated with a mixture of water and sulfuric acid, stirred again, filtered, and washed with distilled water until the filtrate reached neutral pH. The morphology and chemical composition of the produced adsorbent were characterized using SEM, XRD, and XRF. Adsorption experiments determined that the optimal adsorbent doses for benzene, toluene, and para-xylene were 0.8, 0.6, and 0.2 g/L, respectively. The adsorbent showed capacities of 12.043 mg/g for benzene, 8.48 mg/g for toluene, and 10.775 mg/g for para-xylene, with removal efficiencies of 77%, 97%, and 86%. The fitting results indicated that adsorption of benzene and toluene followed the Langmuir model, while para-xylene was better described by the Freundlich model. The findings demonstrate that cathodic-waste–derived carbon adsorbent is highly effective for removing petroleum hydrocarbons from contaminated water and offers strong potential for water and wastewater treatment applications.
This study investigates the feasibility of utilising shredded waste plastics as a controlled alternative for coarse aggregate in structural concrete. In most previous studies, the use of waste plastics was limited to non-load-bearing or lean concrete due to concerns regarding their compressive strength. However, this study proposes using shredded waste plastics in conventional structural concrete. Crushed plastic granules were incorporated at varying substitution rates (0%–20% by volume content) into a standard concrete mix of 25 MPa grade. The experimental investigation consisted of 20 cubes, 10 cylindrical specimens, 5 beams, and four mixes with different % of shredded plastic waste: 5%, 10%, 15%, and 20% replacement of coarse aggregate by weight, as well as a control mix. A comprehensive suite of mechanical and microstructural evaluations was conducted for all specimens. The findings show that workability decreases as the plastic material content increases. Compressive, split tensile, and flexural strengths increased slightly up to 5% and slightly reduced beyond 5% replacement level. Specifically, concrete beams with waste plastic aggregates exhibited higher ductile failure performance. A scanning electron microscopic study revealed that shredded plastics improved the reduction of microcracks, at the expense of the concrete’s density and weight. This study is vital for determining how to utilise shredded plastic waste as a partial replacement for coarse aggregate in structural concrete applications.
Waste management is a global priority that affects public health, environmental quality, and the aesthetics of society. Rapid urbanisation and population growth have intensified the challenges in solid waste generation and its management. In Kochi City, Kerala, issues persist due to legacy waste. This study introduces the household waste control index (HWCI), a qualitative tool structured around three indicators: input, process, and output, to assess household waste management. A study among 384 households in Kochi City reveals that waste management practice remains suboptimal, underscoring the importance of fostering community engagement and social awareness to improve waste control practices. This study aligns local waste management strategies with the United Nations sustainable development goals (SDGs) through a mixed-method approach, combining household surveys with statistical analysis. The findings identify awareness, accessibility of waste facilities, and community participation as key factors influencing sustainable practices. The results directly support SDG 11 (Sustainable Cities and Communities) and SDG 12 (Responsible Consumption and Production), while indirectly contributing to SDG 3 (Good Health and Well-being), SDG 6 (Clean Water and Sanitation), and SDG 13 (Climate Action). Incorporating public perception into municipal waste management provides actionable insights to advance Kochi's progress toward sustainability.
This study explored the viability of monitoring or low-discharge extraction wells surrounded by clusters of cylinders filled with reactive media to remediate contaminated groundwater. A numerical finite-difference model simulated leakage from a hypothetical waste storage facility above an unconfined aquifer. Linear arrays of clusters around a central monitoring (non-pumped) or low-discharge extraction well were evaluated for contaminant plume containment and removal capability. Pumping schemes involved one or more downgradient extraction wells and an upgradient injection well. Without pumping, a minimum of seven clusters, with centres spaced 1.5 m apart, effectively contained and removed the contaminant plume. The most effective low-discharge schemes, extracting less water to remove the plume, were a 1.5-m-spaced three-extraction well scheme, followed by a single-extraction well scheme. Lacking a well along a downgradient extension of the contaminant plume's long axis, two-extraction well schemes were less effective overall. The modelled configuration - reactive cylinders around a central monitoring or low-discharge well in the same borehole - is novel, with capability for in situ remediation; performance monitoring; low-discharge extraction; exchanging spent media cartridges; and accommodating a fluctuating water table. Results outlined above indicate that passive or low-discharge reactive cylinder clusters may be viable at some sites with narrow contaminant plumes.
This study aims to determine strategies to improve the design of sanitary drainage systems (SDS) in high-rise buildings within the Ghanaian construction industry. A literature review was conducted to identify 19 key indicators related to SDS, which guided the development of a questionnaire to validate the study's objective. A total of 310 participants with experience in high-rise SDS in the Greater Accra Region of Ghana were sampled. These participants included plumbing contractors, plumbing instructors, building services engineers, and site engineers. The purposive sampling method was used to select respondents based on their expertise. The study identified several major strategies for improving SDS design. These include adequate ventilation, provision of access points, use of high-quality pipework materials, use of long-radius bends or de-aerators at the base of stacks, air-tight joints, adequate pipe support, appropriate pipe sizing, and post-installation testing of the system. As there are currently no known studies on SDS in high-rise buildings in Ghana, this study contributes to the existing body of knowledge by addressing the design of SDS in high-rise buildings in the Greater Accra Region. This inform policy, design standards, and construction practices.
Given that sustainable development goals and construction waste are major challenges to achieving net-zero targets, the construction industry still needs to address them through various approaches, including the poorly explored novel idea of waste prevention. The paper seeks a holistic understanding of construction waste prevention (CWP) through an exploratory study of construction waste management and CWP. The study uses a systematic literature review and a survey of relevant construction industry practitioners from Kenya and Nigeria. The emergent ideas generated three major conceptual elements, which were organised into a framework, based on their contribution to CWP understanding, nature, and functionality. The outcome was used to conceptualise the CWP hierarchy. The major limitations resulted from the dynamics of survey research, the scarcity of relevant literature, and the challenges of the COVID-19 era. The paper introduces the first conceptualisation of the nature and functionality of CWP, laying the groundwork for additional research into the possibilities, implementation, and benefits. Results of analysis are developed into an initial model of CWP, thereby addressing a gap and providing a basis for the articulation and operationalisation of waste prevention in the construction industry.
This research aims to compare waste collection methods and introduce a modern method of source separation, which has been implemented in 22 districts of Tehran. This project has utilised field methods, face-to-face training, questionnaires, and brainstorming sessions. The Nomand's plan was implemented in 8, 13, and 14 regions, and the citizens received the plan well. In the following, Nomand's plan was implemented in the 20 regions, and the results showed that in areas of the 20 regions, participation rates in the two areas were higher than in other places. At the beginning of the Nomand's plan, the highest amount of waste collected in 20 regions was 391 kg, and during the plan, the highest amount of waste collected was recorded in 20 regions, equal to 1238 kg. Collecting dry waste directly from its source is highly effective. This method will yield successful results if the true value of dry waste is compensated to the individuals. Authorities must address this issue. The Nomad's plan was first implemented in Tehran, allowing citizens to easily deliver their dry waste to Waste Organisation experts. This plan aims to decrease pollution and lower transportation costs.
Over the past decades, solid waste production in Middle Eastern Arab countries has dramatically increased, characterised by several factors including rapid urbanisation, prevalent food waste practices, diverse culture, lack of planning for solid waste processes, insufficient equipment, and lack of funding. This review analyses the current solid waste trends by presenting specific details regarding solid waste statistics, including its sources, types, composition, recycling, and composting rates. Findings reveal that organic matter constitutes approximately 50%–65% of the total solid waste, which directly reflects the social behaviour of communities. In addition, income level is a key factor influencing waste generation, as higher-income countries tend to produce more waste per capita. The review highlights the efforts of the Arab governments, which mainly consist of several pilot projects that are not sustainable or effective in the long term. It is recommended that proper disposal and collection plans be prioritised in municipality’s agendas. In addition, the development and continuous monitoring of treatment, recycling, and composting facilities should leverage the high organic waste content. Furthermore, strengthening co-operation between the informal sector, private companies, and governments is essential to achieving long-term sustainability in the solid waste management sector in the Middle East and North Africa region.
