Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.216
Filtrar
1.
Sci Total Environ ; 803: 149911, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34525745

RESUMEN

COVID-19 global pandemic, originated from Wuhan, resulted in a massive increase in the output of polypropylene (PP)-based personal protective equipment (PPE) for healthcare workers. The continuous demand of PPE across the world caused the PP based plastic wastes accumulation. Some alternative approaches that have been practiced apart from collecting the plastic waste in the landfills are incineration approach and open burning. However, there were many drawbacks of these practices, which promote the release of chemical additives and greenhouse gases into the environment. Therefore, a proper approach in treating the plastic wastes, which introduces conversion of plastic wastes into renewable energy is paramount. Along the way of extensive research and studies, the recovery of PP plastic to fuel-like liquid oil and solid char through thermal decomposition of pyrolysis process, helps in reducing the number of PP plastic wastes and produces good quality pyrolysis liquid oil and solid char to be used in fuel applications. This paper summarizes the pyrolysis process for massively produced PP plastic wastes, type of pyrolysis used and the main pyrolysis parameters affecting the product yields. Literature studies of pyrolysis of PP plastic and several key points to optimize solid char production for PP were thoroughly elaborated in this review paper.


Asunto(s)
COVID-19 , Administración de Residuos , Humanos , Pandemias , Plásticos , Polipropilenos , Pirólisis , SARS-CoV-2
2.
Chemosphere ; 286(Pt 2): 131730, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34364231

RESUMEN

Coffee is a globally consumed beverage that produces a substantial amount of valuable organic waste known as spent coffee grounds (SCG). Although SCG is a non-edible biomass, research initiatives focused on valorizing/utilizing its organic content, protecting the environment, and reducing the high oxygen demand required for its natural degradation. The integration with biorefinery in general and with pyrolysis process in specific is considerered the most successful solid waste management strategy of SCG that produce energy and high-value products. This paper aims at providing a quantitative analysis and discussion of research work done over the last 20 years on SCG as a feedstock in the circular bioeconomy (CBE). Management stratigies of SCG have been thoroughly reviewed and pyrolysis process has been explored as a novel technology in CBE. Results revealed that explored articles belong to Chemical, physical., biological and environmental science branches, with Energy & Fuels as the most reporting themes. Published works correlate SCG to renewable energy, biofuel, and bio-oil, with pyrolysis as a potential valorization approach. Literature review showed that only one study focused on the pyrolysis of defatted spent coffee grounds (DSCG). The insightful conclusions of this paper could assist in proposing several paths to more economically valorization of SCG through biorefinery, where extracted oil can be converted to biofuels or value-added goods. It was highlighted the importance of focusing on the coupling of SCG with CBE as solid waste managment strategy.


Asunto(s)
Café , Administración de Residuos , Biocombustibles , Pirólisis , Residuos Sólidos
3.
Sci Total Environ ; 803: 149892, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34500281

RESUMEN

The construction sector is the biggest driver of resource consumption and waste generation in Europe. The European Union (EU) is making efforts to move from its traditional linear resource and waste management system in the construction sector to a level of high circularity. Based on the theory of circular economy, a new paradigm called waste hierarchy was introduced in the EU Waste Framework Directive. This work uses the framework of the waste hierarchy to analyze the practice of construction and demolition waste (CDW) management in Europe. We explore the evolution of the waste hierarchy in Europe and how it compares with the circular economy. Then, based on the framework, we analyze the performance of CDW management in each EU member state. Innovative treatment methods of CDW, focusing on waste concrete, is investigated. This brings insight into optimizing and upgrading the CDW management in light of advanced technologies and steering the pathway for transitioning the EU towards a circular society.


Asunto(s)
Industria de la Construcción , Administración de Residuos , Materiales de Construcción , Europa (Continente) , Residuos Industriales/análisis , Reciclaje
4.
J Hazard Mater ; 422: 126724, 2022 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-34399217

RESUMEN

Improper healthcare waste (HCW) management poses significant risks to the environment, human health, and socio-economic sustainability due to the infectious and hazardous nature of HCW. This research aims at rendering a comprehensive landscape of the body of research on HCW management by (i) mapping the scientific development of HCW research, (ii) identifying the prominent HCW research themes and trends, and (iii) providing a research agenda for HCW management towards a circular economy (CE) transition and sustainable environment. The analysis revealed four dominant HCW research themes: (1) HCW minimization, sustainable management, and policy-making; (2) HCW incineration and its associated environmental impacts; (3) hazardous HCW management practices; and (4) HCW handling and occupational safety and training. The results showed that the healthcare industry, despite its potential to contribute to the CE transition, has been overlooked in the CE discourse due to the single-use mindset of the healthcare industry in the wake of the infectious, toxic, and hazardous nature of HCW streams. The findings shed light on the HCW management domain by uncovering the current status of HCW research, highlighting the existing gaps and challenges, and providing potential avenues for further research towards a CE transition in the healthcare industry and HCW management.


Asunto(s)
Administración de Residuos , Atención a la Salud , Residuos Peligrosos , Humanos , Incineración
5.
J Hazard Mater ; 421: 126627, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34343881

RESUMEN

The escalating loads of municipal solid waste (MSW) end up in open dumps and landfills, producing continuous flows of landfill leachate. The risk of incorporating highly toxic landfill leachate into environment is important to be evaluated and measured in order to facilitate decision making for landfill leachate management and treatment. Leachate pollution index (LPI) provides quantitative measures of the potential environmental pollution by landfill leachate and information about the environmental quality adjacent to a particular landfill. According to LPI values, most developing countries show high pollution potentials from leachate, mainly due to high organic waste composition and low level of waste management techniques. A special focus on leachate characterization studies with LPI and its integration to treatment, which has not been focused in previous reviews on landfill leachate, is given here. Further, the current review provides a summary related to leachate generation, composition, characterization, risk assessment and treatment together with challenges and perspectives in the sector with its focus to developing nations. Potential commercial and industrial applications of landfill leachate is discussed in the study to provide insights into its sustainable management which is original for the study.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Contaminantes Químicos del Agua , Residuos Sólidos/análisis , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
6.
Chemosphere ; 286(Pt 2): 131739, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34371353

RESUMEN

Waste electrical and electronic equipment (WEEE) is one of the world's fastest-growing class of waste. WEEE contain a large amount of precious materials that have aroused the interest to develop new recycling technologies. Hence, effective recycling strategies are extremely necessary to promote the proper handling of these materials as well as for environmentally sound recovery of secondary raw resource. This paper reviews important existing methods and emerging technologies in WEEE management, with special emphasis in characterization, extraction and reclamation of precious materials from waste computer and mobile phones. Traditional pyrometallurgical and hydrometallurgical technologies still play a central role in the recovery of metals. More recently, emerging greener recycling technologies using microorganisms (i.e. biometallurgical), plasma arc fusion method and pretreatments (i.e. ultrasound and mechanochemical technologies) combined with other recycling methods (e.g. hydrometallurgical), and using less toxic solvents such as ionic liquids (ILs) and deep eutectic solvents (DESs) have also been attempted to recycle metals from computer and mobile phone scrap. The role of analytical method development, especially using spectroanalytical methods for chemical inspection and e-waste sorting process at industrial applications is also discussed. This confirmed that most direct sampling techniques such as laser-induced breakdown spectroscopy (LIBS) and X-ray fluorescence (XFR) have several advantages over traditional sorting methods including rapid analytical response, without use of chemical reagents or waste generation, and greater reclamation of precious and critical materials in the WEEE stream.


Asunto(s)
Teléfono Celular , Residuos Electrónicos , Administración de Residuos , Computadores , Reciclaje
7.
Sci Total Environ ; 804: 150145, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34517326

RESUMEN

Poor dewaterability is a bottleneck of the disposal of digestate from food waste (DFW). However, the dewatering mechanism remains unclear due to the complex composition of DFW. Understanding the dewatering mechanism, as well as the transformation of organic/inorganic matters is essential for the DFW management and valorization. In this study, the distribution, transformation, and complex interplay of organic and inorganic matters at different Hydrothermal treatment (HTT) temperatures were comprehensively analyzed to explore the hydrothermal dewatering mechanism of DFW. When HTT was conducted in the temperature range of 120-180 °C, the interstitial water was released as surface or free water because of membrane breaking and size reduction of the solid substrate. Releasing divalent cations increased the Zeta potential of the bulk solution. The weaker electrostatic repulsion between suspended particles made them easier to settle as the centrifugation cake. When the temperature of HTT was above 180 °C, polymerization and aromatization reactions took place gradually for organic matters, and the bound water was further removed. The generated humic substances were more hydrophobic than the raw material. In addition, the humic substance could combine with cationic metals, which decreased the zeta potential of the bulk solution but promoted the aggregation of nanoparticles and enhance the dewaterability of DFW.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Alimentos , Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Agua
8.
Chemosphere ; 287(Pt 3): 132221, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34560492

RESUMEN

Fruit and vegetables are one of the most consumed commodities globally, accounting for more than 42% of total food wastage. These vegetal foods can be consumed raw, processed, or taken as an addition to other food items. The continuous rise in population, in addition to technological advancements, has led to an imbalance in demand supply, resulting in increased food wastage globally. Although source reduction and recycling have shown promising results, more evaluations concerning economics and environmental impacts need to be given importance. The need of the hour lies in finding a possible method towards effective utilization for fruit and vegetable waste to generate value-added products which are more eco-friendly, cheaper, and sustainable. Thus, this article attempts to focus on the conventional and emerging opportunities of fruit and vegetable waste to generate value-added products. Conventional utilization, namely briquetting, waste to energy conversion, enzymatic degradation, and adsorption, as well as emerging opportunities in the areas of nutraceuticals, packaging, flavoring agents, and waste induced nanoparticles, have been emphasized. Additionally, recommendations and future perspectives towards better utilization of vegetal waste have been given importance. This review aims to narrow down the path towards evaluating the most techno-economic and efficient waste management technique for fruits and vegetable valorization, which can be promoted in the long term.


Asunto(s)
Verduras , Administración de Residuos , Suplementos Dietéticos , Frutas , Reciclaje , Residuos
9.
Chemosphere ; 287(Pt 3): 132321, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34563778

RESUMEN

Agroforestry, an integration of farming system with woody perennials leads to the generation of potential agroforestry residues. The conventional treatment of agroforestry waste includes landfilling, thermal management, and decomposition which is accompanied with their own share of disadvantages. The ample amount of residues and products needs effective management to reap the economic and environmental benefits. The channel of waste collection, transportation, and recycle or valorization into products like biofuel, fertilizers, biochar, industrial chemicals is essential to maintain a circular sustainable bioeconomy. Global market value of biowaste to bioenergy (BtB) technology is roughly US $25.32 billion and is projected to enhance to US $40 billion by 2023. Employment of an appropriate pretreatment technology such as fermentation, hydrolysis, gasification etc. is going to elevate the degree of valorization along with surpassing the mobilization barrier. The sustainability assessment of the management process can be achieved with multiple models including technoeconomic analysis, life cycle assessment and multi criteria approach which are dependent on both hard and soft indices. Additionally, the loopholes of the agroforestry sectors would be managed by the introduction of appropriate policies which are undertaken globally by the Orlando and Lugo declarations, food and agriculture organization, Millennium Development Goals, Global Research Alliance and Guidelines for Sustainable Agriculture and Rural Development. The present review envisaged the agroforestry waste management strategy and its sustainability assessment primarily based upon Social, Economic and Environmental parameters without tormenting the future generations.


Asunto(s)
Agricultura Forestal , Administración de Residuos , Agricultura , Biocombustibles , Reciclaje
10.
Waste Manag ; 136: 295-302, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34735983

RESUMEN

Due to the relevance of construction and demolition waste (CDW) generation for circular economy and reduction of environmental impacts, it is important to evaluate the factors leading to constraints regarding waste. Previous researchers have assessed construction company attitudes and behaviors toward CDW management, but factors such as the presence of environmental technicians, registration of the CDW generated, commitment to the legal framework, the subcontracting regime, and construction works' oversight were rarely addressed in terms of the differences existing within the construction sector. Thus, the objective of this research is to evaluate the relationship of these factors with construction company size. A questionnaire was sent to Portuguese construction companies, and 652 responded. The sample was divided into three groups: micro, small, and medium/large companies. Statistical data treatment was carried out to assess whether there were statistically significant differences in the mentioned factors between groups. The main conclusions highlight: the prevalence of environmental technicians working in larger companies; the registration on waste platforms being only performed consistently by medium/large companies; a considerable proportion of micro and small companies having knowledge gaps about the practices adopted; the responsibility for CDW management within the subcontracting regime being mainly from subcontractors; and the presence of a gap regarding onsite construction works oversight. These differences lead to the need to reevaluate the strategies for CDW management and adapt the strategies to the specific conditions of the construction sector, including the size of construction companies.


Asunto(s)
Industria de la Construcción , Administración de Residuos , Materiales de Construcción , Residuos Industriales/análisis , Reciclaje
11.
Waste Manag ; 136: 321-336, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34752972

RESUMEN

Growing municipal solid waste (MSW) generation is a source of environmental, economic, and social concerns, especially in developing world megacities where poor MSW practices prevail. Mexico City (CDMX), one of the world's largest megacities, daily produces âˆ¼ 13,073 Mg of MSW whose management poses a tremendous challenge to local authorities and calls for additional research to conceive sound MSW strategies. This study evaluates the fossil energy use, GHG emissions, resource recovery, and economic cost dimensions of current and five alternative MSW paths in CDMX to compare their performance and identify more sustainable MSW practices for the megacity. Impacts and benefits from the MSW paths were modeled using 2018 MSW generation data, information supplied by local authorities, and literature values. Current MSW path consumes âˆ¼ 387 MJfossil, generates âˆ¼ 501 kg-CO2e, and costs âˆ¼ 57 USD2018 per Mg of MSW managed while it only valorizes < 33% of total MSW mostly via informal truck-picking. The alternative MSW paths considerably reduce GHG emissions (∼129-360 kg-CO2e/Mg) and enhance MSW valorization (∼47-88%) though, they entail higher fossil energy consumption (447-582 MJfossil/Mg) and, in general, higher cost expenditures (43-208 USD2018/Mg). Heavy reliance on landfilling, large GHG emissions, and low MSW valorization make current MSW path in CDMX unsustainable. Incineration-based MSW paths perform better in most aspects evaluated but their high costs seem prohibitive. Results suggest MSW paths featuring open windrow composting, mechanical-biological pre-treatment, material recovery facilities, and refuse-derived fuel production may be more appropriate to improve the sustainability of CDMX MSW management.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Ciudades , Efecto Invernadero , México , Residuos Sólidos/análisis
12.
Waste Manag ; 136: 337-347, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34752973

RESUMEN

Research on recycling has advanced across different disciplines, although the current knowledge about recycling behaviors at the corporate level remains elusive. While most studies on recycling are focused on households, there is no indication that people who recycle at home engage in similar behavior when at work. To understand how to facilitate recycling at work, this study investigates recycling behavior at work and its antecedents. The study adopts a sequential exploratory mixed method (MM) approach as its methodological framework, using semi-structured interviews and statistical analysis through structural equation modelling (SEM). According to the findings, factors such as types and volumes of waste, responsibility/accountability, personal control, recycling schemes, institutional supports, and group harmony contribute to recycling behavior in organizational settings. The study demonstrates contextual attributes' contribution, particularly organizational support and social context of recycling to employees' recycling behavior. For recycling to be normative at the corporate level, this MM study argues for the need to harmonize schemes within and across contexts. There is a need to install similar recycling schemes and facilities within and across waste generation contexts to reduce the recycling complexity and maintain consistency in recycling behavior. This study's findings could assist waste planners and policymakers in designing effective waste management schemes that would contribute to the circular economy initiatives. We further discussed the implication of the study.


Asunto(s)
Reciclaje , Administración de Residuos , Humanos , Conocimiento , Organizaciones , Responsabilidad Social
13.
Environ Monit Assess ; 193(12): 838, 2021 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-34817701

RESUMEN

This study examines the effect of "waste management" factors (Knowledge, Motivation, Time, Awareness, Contribution, Attitudes) on household waste generation (HWG), more precisely the measured weight of waste generated at households for a week (MWWGHW) while controlling for the socioeconomic factors such as family size, monthly family income, education level, and occupation. It also examines the moderating effects of the geographic location (urban versus rural areas) on the relationships between waste management factors and MWWGHW while controlling for the aforementioned socioeconomic factors. The overall results show that socioeconomic factors such as Family Size ([Formula: see text] = 0.134; p < 0.001) and Monthly Family Income ([Formula: see text] = 0.301; p < 0.001) significantly and positively influence MWWGHW, whereas the Occupation factor ([Formula: see text] = - 0.106, p < 0.05) significantly and negatively influences MWWGHW. Furthermore, the results show that the Knowledge ([Formula: see text] = - 0.129, p < 0.05), Motivation ([Formula: see text] = - 0.161, p < 0.001), Contribution ([Formula: see text] = - 0.111, p < 0.05), and Awareness ([Formula: see text]= - 0.189, p < 0.001) factors significantly and negatively influence MWWGHW. While the results show that the geographic location Urban Area moderates significantly the relationship between the Motivation factor and MWWGHW ([Formula: see text] = - 0.129, p < 0.05), the same results show, however, that the geographic location Rural Area moderates significantly but negatively the relationships between Knowledge factor and MWWGHW ([Formula: see text] = - 0.187, p < 0.01); Motivation factor and MWWGHW ([Formula: see text] = - 0.390, p < 0.001); Contribution factor and MWWGHW ([Formula: see text] = - 0.154, p < 0.10); and Awareness factor and MWWGHW ([Formula: see text] = - 0.285, p < 0.001). Based on these results, implications for policy orientations and future research are provided.


Asunto(s)
Residuos Sólidos , Administración de Residuos , Monitoreo del Ambiente , Composición Familiar , Sri Lanka
14.
Waste Manag ; 136: 76-82, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34649179

RESUMEN

For the past several decades, municipal solid waste (MSW) management has been a popular area for contracting out by local governments. However, whether contracting out waste management services saves cost is still under debate. Such mixed results warrant research on the cost effects of contracting out waste services. Heretofore, extant studies tended to use cross-sectional data for empirical analysis and the total cost of MSW services by each service provider as a measure of cost rather than the MSW management budget. Departing from past studies, the current study uses time-series cross-sectional (TSCS) data of 25 local governments under the jurisdiction of Seoul Metropolitan City in South Korea from 2005 to 2017 for analysis. This study tests the effects of the contracting out cost-to-budget ratio and waste treatment by private sector ratio on the MSW management budget per capita over time. The findings reveal that more contracting out results in more spending in the MSW budget per capita rather than cost savings. The findings also show that the proportion of MSW treatment by the private sector does not have any meaningful impact on the MSW budget per capita. Overall, within the scope of the current study, contracting out waste services does not save cost.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Ciudades , Estudios Transversales , República de Corea , Residuos Sólidos/análisis
15.
Waste Manag ; 136: 93-103, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34653854

RESUMEN

Liquid packaging board (LPB) is an integral part of storing and transporting liquid food. In addition to its significant advantages, LPB has been challenging the existing waste management sector since its introduction into the market. In most European countries, LPB waste is either incinerated or recycled in the recycling facilities where fibre is recycled, and the repulping reject is separated for incineration. Mechanical recycling and chemical recycling processes are other options for repulping reject treatment. This study used life cycle assessment (LCA) to compare the environmental impacts of three treatment processes, incineration, mechanical recycling and chemical recycling; each was considered with the functional unit of 1 tonne of repulping reject. Furthermore, two sub-scenarios based on the substituted heat produced by energy from the treatment processes were considered. In substituting biomass-based heat sources, chemical recycling generated the lowest greenhouse gas (GHG) emissions, about 560 kg CO2 eq. tonne-1 repulping rejects, followed by the mechanical recycling process (approximately 740 kg CO2 eq. tonne-1 repulping reject). The maximum amount of GHG was emitted from the incineration scenario, which was about 1900 kg CO2 eq. tonne-1 repulping rejects. By substituting natural gas-based heat sources, chemical recycling generated about 290 kg CO2 eq. tonne-1 repulping rejects. On the contrary, the mechanical recycling process generated about 430 kg CO2 eq. tonne-1 repulping rejects and incineration process generated 960 kg CO2 eq. tonne-1 repulping rejects. Uncertainty analysis showed that some assumptions significantly impact the results; however, the chemical recycling process had the lowest environmental impact in almost all uncertainty analysis.


Asunto(s)
Gases de Efecto Invernadero , Eliminación de Residuos , Administración de Residuos , Huella de Carbono , Incineración
16.
Waste Manag ; 136: 153-161, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34673304

RESUMEN

When recycling is beneficial for the environment, results from a life cycle assessment (LCA) should give incentives to collection for recycling and also to the use of recycled material in new products. Many approaches for modeling recycling in LCA assign part of the environmental benefits of recycling to the product where the recycled material is used. For example, the Circular Footprint Formula in the framework for Product Environmental Footprints (PEF) assigns less than 45% of the benefits of recycling to a polymer product sent to recycling. Our calculations indicate that this creates an incorrect climate incentive for incineration of renewable LDPE, when the recovered energy substitutes energy sources with 100-300% more climate impact than the Swedish average district heat and electricity. The risk of incorrect incentives can be reduced through allocating part of the net benefits of energy recovery to the life cycle where the energy is used; we propose this part can be 60% for Sweden, but probably less in countries without a district-heating network. Alternatively, the LCA can include the alternative treatment of waste that is displaced at the incinerator by waste from the investigated product. These solutions both make the LCA more balanced and consistent. The allocation factor 0.6 at incineration almost eliminates the risk of incorrect incentives in a PEF of renewable polymers. However, the focus of LCA on one product at a time might still make it insufficient to guide recycling, which requires concerted actions between actors in different life cycles.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Fuentes Generadoras de Energía , Incineración , Reciclaje
17.
Molecules ; 26(20)2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34684806

RESUMEN

Disposal of palm oil mill effluent (POME), which is highly polluting from the palm oil industry, needs to be handled properly to minimize the harmful impact on the surrounding environment. Photocatalytic technology is one of the advanced technologies that can be developed due to its low operating costs, as well as being sustainable, renewable, and environmentally friendly. This paper reports on the photocatalytic degradation of palm oil mill effluent (POME) using a BiVO4 photocatalyst under UV-visible light irradiation. BiVO4 photocatalysts were synthesized via sol-gel method and their physical and chemical properties were characterized using several characterization tools including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis using the BET method, Raman spectroscopy, electron paramagnetic resonance (EPR), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The effect of calcination temperature on the properties and photocatalytic performance for POME degradation using BiVO4 photocatalyst was also studied. XRD characterization data show a phase transformation of BiVO4 from tetragonal to monoclinic phase at a temperature of 450 °C (BV-450). The defect site comprising of vanadium vacancy (Vv) was generated through calcination under air and maxima at the BV-450 sample and proposed as the origin of the highest reaction rate constant (k) of photocatalytic POME removal among various calcination temperature treatments with a k value of 1.04 × 10-3 min-1. These findings provide design guidelines to develop efficient BiVO4-based photocatalyst through defect engineering for potential scalable photocatalytic organic pollutant degradation.


Asunto(s)
Bismuto , Residuos Industriales/análisis , Aceite de Palma/aislamiento & purificación , Fotólisis , Vanadatos , Contaminantes Químicos del Agua/análisis , Bismuto/química , Catálisis , Cristalografía por Rayos X , Microscopía Electrónica de Rastreo , Espectrometría Raman , Vanadatos/síntesis química , Vanadatos/química , Administración de Residuos/métodos
18.
Waste Manag ; 136: 195-203, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34695726

RESUMEN

Mechanical sorting plays a pivotal role in current municipal solid waste management systems for resource recovery. However, material recovery facilities, generally face several challenges in meeting quality standards for multiple waste fractions. Improving these facilities requires a better understanding of municipal solid waste physical characteristics, since they are directly targeted by mechanical sorting unit operations. Three waste physical properties (bulk density, particle size and shape factor) were characterized for several recyclable materials. Narrow ranges of densities were observed for similar waste materials, while the particle size distributions were found to vary widely. Statistical parameters were determined for these two properties. A novel approach, based on the void fraction of a waste item, is proposed to quantify the shape factor. Potential applications of the characterization results for improving mechanical sorting are demonstrated through the analysis of the recovery of corrugated cardboards and multilayer cardboards in a material recovery facility.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Fenómenos Físicos , Reciclaje , Residuos Sólidos
19.
Waste Manag Res ; 39(11): 1365-1374, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34617479

RESUMEN

This article presents field experience in developing local waste management plans called Kebijakan Strategi Daerah (Jakstrada) in the Lake Toba region, one of the popular tourist destinations in Indonesia. It examines the current waste management status and discusses key priorities and actions identified in the Jakstradas to improve the waste management based on resource management and 3R (reduce, reuse and recycle) principles. In partnership with public, private, academic and citizen groups, the project activities supported the development of Jakstradas in all seven regencies and established a resource recovery centre (RRC) as a model to practice 3Rs in the region. The key lessons learned from these project activities are discussed and some practical recommendations are identified based on a literature review, interviews and workshops with local government officials and residents. Through those opportunities, it was found that remote regencies around Lake Toba do not have environmentally sound final disposal sites and do not have the financial or technical capacity to provide waste collection and handling services to residents, which often results in illegal dumping and open burning of waste. It was also revealed that lack of established markets for recycling value chains and citizens participation in waste separation at source had resulted in limited success for recycling and 3R activities in the region.


Asunto(s)
Lagos , Administración de Residuos , Indonesia , Organizaciones , Reciclaje
20.
Artículo en Inglés | MEDLINE | ID: mdl-34682382

RESUMEN

Low-value recyclable waste accounts for a large portion of urban waste output in many modern cities. The improper management and disposal of LVRW result in environmental pollution and a waste of resources. Given the characteristics of a high recovery cost and low recovery income of low-value recyclables, it is difficult to obtain a satisfactory waste disposal effect by completely relying on the market mechanism. It is thus necessary for the government to implement effective subsidies for multiple subjects in the urban waste recycling system (UWRS). This study examines the independent roles of four subsidy policies-subsidy to the third-party waste disposal institutions, subsidy to a state-owned waste disposal institution, R&D subsidy for green technology, and subsidy for government publicity-and develops a system dynamics model to verify the performance of the UWRS under different combinations of subsidy-based policies under multiple scenarios. Data on urban waste disposal for Guangzhou from 2019 and 2020 were used to validate and simulate the model. A sensitivity analysis of the main exogenous variables was carried out, and the conclusions are as follows: (1) On the premise of a fixed subsidy capital pool, a mixed subsidy policy produced the best impact on the UWRS. (2) The total subsidy needed to reach a certain threshold; otherwise, the mixed subsidy policy did not improve the UWRS. The total subsidy produced diminishing returns once it had exceeded the threshold. (3) Appropriately reducing subsidies for the third-party waste disposal institutions within a reasonable range does not affect the performance of the UWRS. (4) The effect of government publicity has short-term advantages, while the long-term potential of green technology is greater. Multi-agent coordination and the guidance of the market mechanism are important priorities in the design of subsidy-based policies. In addition, the trade-off between subjects needs attention, and a plan for mixed subsidy policies needs to be designed and implemented according to the response periods of different policies. The research here provides theoretical support for the government for designing subsidy-based policies.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , China , Ciudades , Humanos , Políticas , Reciclaje
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...