查看更多>>摘要：Quantifying truck-loaded materials is a problem in many industrial operations. In construction and demolition waste (CDW) management, inspectors at disposal facilities are often required to measure the amount of different waste components loaded by incoming trucks to determine admissibility. Due to the bulky and mixed nature of construction materials, accurate quantification of specific waste categories without sacrificing operability in the field is a challenge. This study proposes a CDW volume estimation algorithm based on monocular vision which can automatically quantify from a single image the amount of specific material components, e.g., rock, gravel, and wood, in waste mixtures. The algorithm achieves a relative error of 0.065 in calculating truck bucket dimensions, and a relative error of 0.169 in estimating material-level construction waste volume. It takes 3.3 s in average to process one image. In applying the algorithm to analyze 2,914 waste truckloads received by an off-site sorting facility in Hong Kong, we observe that the facility entrance received around 800.0 m(3) CDW per day of which about 10.8 m(3) were rejected. Since non-inert wood/cardboard accounts for the highest proportion among all material types, this may imply that many waste dumps accepted by the facility may have been in violation of the admissibility criteria. The study contributes to the knowledge body by providing a novel, non-destructive approach to quantifying CDW via monocular vision. It can be extended to address the general problem of truck payload quantification in scenarios such as road construction, warehouse inventory management, and logistics and supply chain management.
Martin-Hernandez, EdgarHu, YichengZavala, Victor M.Martin, Mariano...
12页
查看更多>>摘要：Livestock operations have been highly intensified over the last decades, resulting in the advent of large concentrated animal feeding operations (CAFOs). Intensification decreases production costs but also leads to substantial environmental impacts. Specifically, nutrient runoff from livestock waste results in eutrophication, harmful algal blooms, and hypoxia. The implementation of nutrient recovery systems in CAFOs can abate nutrient releases and negative ecosystem responses, although they might negatively affect the economic performance of CAFOs. We design and analyze potential incentive policies for the deployment of phosphorus recovery technologies at CAFOs considering the geospatial vulnerability to nutrient pollution. The case study demonstration consists of 2217 CAFOs in the U.S. Great Lakes area. The results reveal that phosphorus recovery is more economically viable in the largest CAFOs due to economies of scale, although they also represent the largest eutrophication threats. For small and medium-scale CAFOs, phosphorus credits progressively improve the profitability of nutrient management systems. The integration of biogas production does not improve the economic performance of phosphorus recovery systems at most of CAFOs, as they lack enough size to be costeffective. Phosphorus recovery proves to be economically beneficial by comparing the net costs of nutrient management systems with the negative economic impact derived from phosphorus releases. The incentives necessary for avoiding up to 20.7.10(3) ton/year phosphorus releases and achieve economic neutrality in the Great Lakes area are estimated at $223 million/year. Additionally, the fair distribution of limited incentives is studied using a Nash allocation scheme, determining the break-even point for allocating monetary resources.
查看更多>>摘要：Globally, ecosystems are becoming damaged or degraded due to stresses associated with anthropogenic activities. To identify the quantitative connection between nitrogen fertilizer-related agricultural production processes and ecosystem health, a dose-response approach based on the ReCiPe 2016 method is developed. Rice production had the highest potential ecosystem health risk (EHR) (560 species.yr) in China, while maize and wheat had EHR values of 413 and 252 species.yr, respectively. Both crop type and planting area have great impacts on EHR. Pollutants posing the highest potential harm to ecosystem health were NH3, N2O, and NO3-. Air pollutants, including NH3 and N2O, did more severe damage to ecosystem health than soil or water pollutants. Scenario analysis suggests that if improved efficiency of nitrogen fertilizer use is employed to replace current practices, total EHR would decline by about 28.7- 41.1%. Improved farming practices could change the relationship between grain productivity and agroecosystem health from trade-offs to co-benefits. Results demonstrated that optimizing chemical fertilizer application in agricultural production processes could significantly contribute to the delivery of some Sustainable Development Goals. It suggests that the impacts of agricultural production on the atmospheric environment require further attention.
查看更多>>摘要：A huge amount of municipal solid waste (MSW) is produced with urbanization process, posing serious threats to the surroundings and human health. The preparation of MSW-derived biochar is an effective strategy for the waste reclamation. MSW-derived biochar possesses great potential in wastewater purification by adsorption and catalysis. In this review, biochar prepared from classified MSW (e.g. food waste and waste paper) was found with larger specific surface area and porosity than the mixed MSW-derived biochar. Meanwhile, pre-treatment and post-treatment means are summarized to improve the structure and composition of biochar, which could further strengthen its adsorption capacity and catalytic activity. The -COOH, -C = O, -C = C, -OH group sites and aromatic structure of MSW-derived biochar could adsorb pollutants through electrostatic interaction, surface complexation, ion exchange, hydrogen bonding and pi-pi interaction. Moreover, thanks to the -COOH, -C = O, -OH groups, N-doped structures, defective sites and iron ion species, the food waste-derived biochar exhibits excellent persulfate activation properties. Finally, the future challenges and research directions are suggested, which is conductive to promoting the resource utilization of MSW. Some consideration and recommendation about MSWderived biochar for water treatment are provided, which facilitates the popularization of the innovative mode "waste control by waste" in aquatic environment remediation.
查看更多>>摘要：Refurbishment is an effective strategy to extend product lifetimes in a circular economy. However, consumers believe that refurbished products are contaminated with traces of prior use, which can be indicated by the appearance (e.g., scratches) or functionality (e.g., lower battery capacity) of refurbished products. This research explores strategies to improve consumer adoption of refurbished products by reducing contamination. In a choice-based conjoint analysis, 785 participants were exposed to refurbished headphones varying in features related to contamination, warranty, and price. We tested three contamination-reducing strategies, including (1). Communication about the clean object state, (2). Eliminating signs of use (aesthetic and functional wear-and-tear) and (3). Renewing parts that touch the skin (e.g., ear-cushions). Additionally, we analysed whether different consumer groups are driven by different attributes of refurbished products. Results showed that most consumers value refurbished products that show no signs of wear-and-tear and that have parts touching the skin renewed during the refurbishment process. These attributes are even more important than the reduced price or warranty, even though these are frequently used to market refurbished products. Depending on the consumer group, other contamination-reducing strategies were of great influence. While some consumer groups highly valued that signs of prior use are eliminated through an as-new appearance, others preferred refurbished products without functional wear-and-tear. In conclusion, four design strategies to deal with contamination during multiple life cycles of refurbished products are discussed.
查看更多>>摘要：There has been increased demand for durable and sustainable construction materials to improve long-term performance of buildings and infrastructure. Polymer modification is a well-known method for improving the properties of construction materials. However, the effectiveness of polymer modification has been limited by the low compatibility between construction materials and polymers, especially polymers from waste plastics and waste rubbers. This paper reviews state-of-the-art studies on compatibilizing polymers via polymer functionalization specifically for thermoplastic and thermosetting polymers. This paper further examines the efficacy of functionalization for enhancing the properties of construction materials. There are three conclusions from this review: (1) Functionalization of polymers by adding various functional groups to their surface can improve the compatibility of polymers and construction materials such as bitumen and concrete. (2) The efficacy of functionalization of a polymer is highly dependent on the grafting material, the grafting degree, and the architecture of the polymer's structure after functionalization. (3) The application of properly functionalized polymers in bitumen and concretes improves their mechanical properties. For instance, it was found that proper functionalization of waste plastics and rubbers can facilitate their use leading to a simultaneous solution for enhancing durability and sustainability of the built environment and addressing environmental concerns associated with the accumulation of those wastes in landfills. The study further identifies knowledge gaps pertaining to an in-depth understanding of polymer functionalization specifically tailored to construction materials and the need for associated life-cycle assessments. Addressing these gaps will facilitate the generation of value-added applications for waste polymeric materials to promote resource conservation and sustainability.
查看更多>>摘要：The evolution of rural to urban areas has a negative impact on the availability of green zones. The lack of space gives green concrete walls the opportunity to introduce vegetated areas in highly urbanized cities. However, cementitious materials are not the best substrate for plants. Still, diverse microbial communities are suitable for colonizing cementitious materials, allowing later introduction of other plants. One of the limiting factors for microbial growth under environmental conditions is the availability of water for the microorganisms. In this study, the bio-receptivity of cementitious materials under laboratory conditions was investigated, studying relevant parameters such as the porosity needed for the colonisation. Superabsorbent polymers (SAPs) were added in order to improve the water retention capacity and the colonisation of cementitious materials. These polymers, crosslinked networks able to absorb fluids up to hundreds of times their own weight, promote bioreceptivity and clear algal growth was observed. Recycled SAPs, obtained from a cleaning and crushing action of hygienic products, may show an added benefit in terms of sustainability and a circular economy. The best results were obtained with a SAP leading to a well-distributed overall macroporosity near the surface.
查看更多>>摘要：China is now boasting a huge number of end-of-life vehicles (ELVs) with a low recovery rate, resulting in a waste of resources and severe environmental pollution. Predicting the generation of ELVs in future helps to enhance recycling efficiency by providing a basis for the planning of recycling industry. However, previous research did not provide a detailed, mid-term forecast. Based on a stocks-driven model and the bottom-up extrapolation of inuse stocks, this study characterizes the generation of end-of-life household vehicles (HVs) in China by addressing the detailed spatial-temporal patterns and resource potentials during 2019-2050. The results show that the annual end-of-life HVs in China will continuously increase during 2019-2050, resulting an accumulated 1.48 billion units, among which urban areas will account for 86%, and internal combustion engine vehicles (ICEVs) will take up 80%. Regarding the spatial patterns, eastern region will possess the largest proportion, and wide variations are found among all provinces due to the difference in population size and economic development level, which have important implications for further planning of end-of-life HVs recycling industry. Before 2050, accumulated quantity of all types of metals in end-of-life HVs will approach domestic mine production (in 2019), or even approach the current global mine production, indicating they have a great potential as an indispensable source for domestic resource supply.
查看更多>>摘要：Using reclaimed asphalt pavement (RAP) can help the asphalt industry to lessen its environmental and economic impact. Although literature shows that rejuvenators are needed for high RAP rates, limited information is known about the economic and environmental impact of rejuvenators. The first objective of this research was to determine the relative service life (SL) to break even economically and environmentally when using RAP and rejuvenators. If 40% asphalt binder replacement (ABR) is considered as the benchmark for surface layers, the SL without recycling should be 27% longer to result in economic and environmental benefits. Adding a rejuvenator to 40% ABR has a limited effect on the economic impact. Conversely, when adding a rejuvenator to the benchmark, the SL should increase by 9% (SMA 10 mix) or 21% (AC 10 mix) to environmentally break even. If 70% ABR is the benchmark for base layers, the SL with no RAP should be 66% longer to yield the same economic and environmental impact. Adding rejuvenators to 70% ABR requires a 13% extension in SL to environmentally break even with the benchmark. The second objective was to identify the main contributors to the economic and environmental impact to streamline further efforts to reduce the impact of asphalt pavements. The results showed that 45% to 76% of the NPV is allocated to bitumen, plant operation, aggregates, and raw material transport. Regarding environmental impact, three processes account for 44% to 72% of the impact: bitumen, raw material transport and energy consumption during asphalt production.
查看更多>>摘要：Food waste is a problem that needs to be addressed to achieve sustainable development. There is a need for interventions that can reduce food waste, including in organisations already aware of the food waste problem. Swedish school canteens have experience of food waste reduction, but need tools to achieve further reductions. This study tested four interventions (tasting spoons, awareness campaign, a plate waste tracker and a guest forecasting tool) designed to reduce food waste in school canteens. Each intervention was introduced in two school canteens, while seven school canteens acted as a reference group. The interventions were compared with baseline food waste before the intervention and with the reference group. All interventions reduced total food waste (by 6 to 44 g/guest) compared with the baseline, but the reference group also reduced its food waste. The awareness campaign reduced plate waste most, by 13 g per portion, which was 6 g/portion more than the plate waste reduction in the reference group. The forecasting and plate waste tracker interventions reduced serving waste most, by 34 and 38 g/portion, compared with 11 g/portion in the reference group. Some interventions also had an effect on waste fractions they were not designed to target, affecting the total waste by shifting the waste. Interventions should always be seen in a context and be implemented in combinations that increase overall sustainability. Thus forecasting is an effective way to reduce serving waste, plate waste tracker and awareness campaign are effective tools to reduce plate waste in school canteens.
NSTL
Elsevier