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1.
Waste Manag ; 123: 33-41, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33556715

RESUMEN

Flexible multilayer plastic packaging (MPP) has grown in popularity in the last years especially in food and medical sectors, and its share in the packaging industry is expected to increase further. Compared to traditional packaging with same functionalities, MPP is characterized by lower energy consumption in production and a reduced packaging weight. So far, the recycling of post-industrial MPP with specific material composition has been achieved by several companies. To our knowledge, all existing MPP recycling processes require a known material combination. In contrast to post-industrial MPP, post-consumer MPP still ends up in incinerators or as low-quality products, mainly because of the lacking ability to sort. This study investigates the detectability of post-consumer MPP with near-infrared spectroscopy, the state-of-the-art technology for sensor-based waste sorting. Firstly, MPP classification with near-infrared spectroscopy was analyzed with clean samples. Subsequently, the effect of waste collection and preprocessing in sorting plants on MPP classification was investigated. For this purpose, clean samples were covered with water and oil and mixed with lightweight packaging waste in a drum sieve. The results show it is possible to classify post-consumer MPP based on near-infrared spectra according to different sorting strategies. For the existing recycling processes which are suitable for post-consumer MPP, the corresponding object-based classification accuracy was found to exceed 96%.


Asunto(s)
Plásticos , Espectroscopía Infrarroja Corta , Fenómenos Físicos , Embalaje de Productos , Reciclaje
2.
Waste Manag ; 123: 42-47, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33561768

RESUMEN

The e-waste problem needs be tackled under a global framework, based upon the understanding that e-waste is a global issue and thus a shared responsibility. To illustrate this point, a cost-benefit analysis of metal recovery from e-waste was conducted with Europe, North America and China as representative regions of e-waste producers. The final profit associated with the entire e-waste recycling process was estimated by deducing the energy costs of metal recovery from the revenues of the manually dismantling stage and the metal recovery stage. Then, the potential job opportunities were estimated based on the final profit from the local e-waste recycling and average wage per year. Overall, profits of manually dismantling 1 ton of e-waste varied widely, but the final profits were positive. The potential job opportunities generated by local e-waste recycling ranged from 4.65 × 105 person/year for North America to 2.03 × 106 for China person/year. According to our study, the environmental load of 1 kg of e-waste would be 1-9 USD, indicating that this is the cost required to offset the environmental consequences of each kilogram of e-waste. By applying environmental load to per capita, the concept can act as a tool to encourage countries to fairly share the environmental responsibility of e-waste based on their e-waste generation. Based on this, we propose an e-waste emissions trading system that set a cap on the total amount of e-waste that could be generated globally and per country, to reduce e-waste and carbon emissions.


Asunto(s)
Residuos Electrónicos , China , Análisis Costo-Beneficio , Residuos Electrónicos/análisis , Europa (Continente) , Políticas , Reciclaje
3.
Waste Manag ; 123: 60-68, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33561771

RESUMEN

Non-metallic components (NMC) in waste printed circuit boards (WPCBs) are made of the thermosetting epoxy resin and glass fiber, which has been a research concern in the waste recycling area. The recycling of thermosetting epoxy resin is a serious challenge due to their permanent cross-linked structure. An efficient approach to chemical recycling of epoxy resin for resource reutilization was developed in this research. ZnCl2/CH3COOH aqueous solution was selected as catalysts system to decompose epoxy resin under a mild reaction condition. The influence of reaction parameters such as reaction temperature, time, liquid-solid ratio and ZnCl2 amount on the decomposition efficiency of epoxy resin and reaction mechanism were investigated. The physical and chemical properties of NMC, reaction solvent and decomposed products were analyzed using scanning electron microscope(SEM), Fourier transform infrared spectroscopy (FT-IR) and Gas chromatography-mass spectrometry (GC-MS). Results showed that up to 81.85% of epoxy resin could be dissolved by using a temperature of 190 °C during 8 h with a mixture of acetic acid (15 wt%): ZnCl2 (5 g) 20 mL/g. Incompletely coordinated zinc ions enables the cleavage of CN, CBr and CO bonds in the thermosetting brominated epoxy resin, which was mainly converted to phenol, 2-Bromophenol and 2, 4-Dibromophenol with high resource value. And the functional groups of ethyl acetate and acetic acid maintained chemical structure before and after reaction. This research provided a practical approach to the dissolution and reutilization of NMC in WPCBs.


Asunto(s)
Cloruros , Residuos Electrónicos , Polvos , Reciclaje , Solubilidad , Solventes , Espectroscopía Infrarroja por Transformada de Fourier
4.
Waste Manag ; 123: 80-87, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33571832

RESUMEN

Enriched in phosphorus, sewage sludge ash has been extensively studied and applied as a secondary source for phosphorus recovery. Wet extraction, especially acid washing, is one of the most feasible methods to recover phosphorus from the ash due to its ease of operation, high efficiency and low cost. However, the management of the resultant acid residue was seldom addressed. In this study, special focus was paid to the reuse and recycling of the acid residue by an alkaline activation method. Its adsorption performance towards four different heavy metals in aqueous solutions was evaluated by batch and fixed-bed column adsorption experiments. The obtained material showed a high BET specific area (98.29 m2/g) and a total pore volume (0.114 cm3/g), and effectively removed Cd(II), Cu(II), Pb(II) and Zn(II) from aqueous solutions with the maximum adsorption capacity of around 26.8, 22.2, 53.3 and 13.5 mg/g respectively. It could be loaded in a fixed-bed column to continuously remove heavy metals especially for Pb(II). The proposed method to recycle the acid residue makes the wet extraction methods designing to recover phosphorus from incinerated sewage sludge complete without the generation of waste, which contributes to circular economy and a sustainable future.


Asunto(s)
Metales Pesados , Aguas del Alcantarillado , Adsorción , Fósforo , Reciclaje
5.
Waste Manag ; 123: 142-153, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33582401

RESUMEN

Household waste recycling is a significant challenge for society. Cities worldwide have been exploring how to reduce waste through recycling. Incentive mechanism is one of the promising measures to improve the participation of residents in waste recycling activities. However, several defects have been observed in the incentive-based waste recycling systems: (1) inefficient allocation of resources in recycling services, (2) deficient systems lacking future planning, and (3) limitations in circulating responsive feedback amongst stakeholders. For overcoming these defects, a smart incentive-based recycling system is designed using the Internet of Things and data analysis technologies. Four key components in the designed system-namely, amount pattern discovery, price adjustment suggestion, waste-collection amount forecasting, and information sharing amongst stakeholders-assist in constructing a smarter system to enhance waste recycling. A basic incentive-based recycling system in Shanghai, with data on 19 specific recyclable items from 21 August 2018 to 20 March 2019, was improved to demonstrate the effectiveness of the designed system. For the case of a pilot community, the recyclable waste-collection amount increased 229.3%, but the weekly pattern of collection amount got imbalanced, especially at weekends. The weekly pattern analyses suggested adjusting the pricing for cardboard, strawboard, plastic bottles, and old clothing amongst the six identified items (i.e. taking ~80.0% by weight) to balance the collection amount and allocate resources better for waste-collection operations. The two-month trend analysis and fortnight forecasting help to make plans rationally for recycling businesses. Under the new information-sharing platform, stakeholders could collaborate smoothly in household waste recycling and reduction.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , China , Ciudades , Motivación , Reciclaje
7.
Ecotoxicol Environ Saf ; 208: 111596, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396117

RESUMEN

The surge in solid waste (SW) has become major issues in the fields of public health and ecological environment fuelled by the rapid development of social economy. The fate of nitrogen contained in SW (SWN) varies with different treatment methods, which will affect the environment to varying degrees. It is of great practical and guiding significance to comprehensively evaluate the sources, fate and its cascading effects of SWN. Here, a systematic SWN flow evaluation of the generation, treatment and emissions in China from 2008 to 2017 was established. During this period, the SWN flow and the N pollution emissions from SW treatment increased by 19.7% and 27.6% respectively, with the domestic garbage being the largest contributor. This shows that it is particularly important to reinforce the classified of domestic garbage and resource recycling in China. Landfill was the main treatment, accounting for 51.8% of the total SWN. Landfill and incineration were the main sources of pollution N emissions, while compost treatment has the lowest contribution rate. It highlights the urgency of changing the waste treatment methods in China. About 92.3% of the N pollution emissions was lost to the atmosphere and 7.7% to the groundwater. NH3 and NOx were the main pollutants to the atmosphere. Special attention is paid to the reduction and control of NH3 in landfill, dumping and compost processes, while NOx in incineration. This study provides scientific basis for management and disposal of SW, so as to reduce its impact on the ecological environment and develop more sustainable policies for China and other developing countries.


Asunto(s)
Nitrógeno/análisis , Eliminación de Residuos/métodos , Residuos Sólidos/análisis , China , Ambiente , Contaminación Ambiental , Incineración/métodos , Reciclaje , Instalaciones de Eliminación de Residuos
8.
Environ Sci Pollut Res Int ; 28(9): 10450-10473, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33411271

RESUMEN

Tobacco is a worldwide-consumed product, which in addition to causing public health-related issues is responsible for the most common form of litter in the world-smoked cigarette butts (CBs). A large attention has been drawn to this question, since this specific waste type tends to end up in terrestrial and aquatic ecosystems, posing serious threat to a range of life forms. Decomposition may take several years to occur because cellulose acetate is hardly accessible, before deacetylation, by bacteria and fungi. This review concerns the toxicity derived from smoked cigarette butts, as well as innovative ecological solutions for solving the CB litter problem. Toxicity studies have demonstrated the critical influence of chemicals present in smoked CBs to the environment as a whole, but also the physical contaminating potential considering micro- and nanoparticles derived from CB material. Nevertheless, several technological approaches were aimed at unveiling hidden value within used CBs, as well as propositions for incorporation of this residue in large volume production items or direct recycling. In summary, several methods are available to alleviate CB pollution, while appropriate and efficient collection logistics by consumers appears as the main bottleneck for an effective recycling. It is also clear that while considerable progress has been made recently in light of CB recycling solutions, there is still a vast research capacity in this regard.


Asunto(s)
Ecosistema , Productos de Tabaco , Reciclaje , Humo , Fumar
9.
Environ Sci Pollut Res Int ; 28(9): 10488-10502, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33426587

RESUMEN

The environmental impact of waste glass (WG) is one of the major challenges crippling sustainable waste management and mitigation. Reclamation of recycled materials from waste glass remains a tedious task amidst complex technological approaches. The challenge as seen in the global containment measures increase the proportion of waste glass and minimize the existing capacity of landfill space. In many works, findings have shown how best to minimize the impact of waste glass as evidenced in their inclusion as building materials such as cement, mortars, concretes and blocks. The concept of this paper is to appraise previous studies carried out on the use of waste glass as key contributing factor in structural building. The scope of this paper will be broaden to include various successes recorded in the evolution of concrete mixtures containing different proportion of recycle glass. Part of the setbacks noted in the inclusion of these recycled materials as matrix, filler or fibre are also reported in this paper. Also discussed is the durability of glass materials in varying conglomerate involving cement in reinforcement of building and structures. Thermal insulating properties of recycled glass are also considered in this work where considerable energy is saved due to their low thermal conductivity. Based on the analysis of various studies and other factors considered in this paper, it is established that recycled glass materials can be accommodated in structural buildings, while continuous research is necessary to adapt waste glass to high pH value of Portland cement.


Asunto(s)
Reciclaje , Administración de Residuos , Materiales de Construcción , Ambiente , Vidrio
10.
Environ Sci Pollut Res Int ; 28(9): 10503-10518, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33438127

RESUMEN

This article details the electronic waste (e-waste) generation, their composition, health, and environment hazards, and legal rules for disposal as well as their significance as a potential secondary source of metals and other components. Moreover, valuable metal extraction technologies from the e-waste are reviewed in general and waste cell phones in particular. E-waste is nowadays preferentially used for recovery of metals mainly from printed circuit boards (PCBs). Different techniques, namely pyrometallurgy, hydrometallurgy, and biohydrometallurgy used for metal extraction from e-waste are swotted. The economic and environmental valuation features of these technologies are also included. Compared to other methods, biohydrometallurgy is the method of choice, as in it natural components like air and water are used, has low operating and maintenance cost, and operate at ambient temperature and pressure. Microbial aspects of metal extraction from e-waste are summarized.


Asunto(s)
Teléfono Celular , Residuos Electrónicos , Residuos Electrónicos/análisis , Metales , Reciclaje , Agua
11.
Bioresour Technol ; 325: 124739, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33509643

RESUMEN

The progression of plastic pollution is a global concern. "Reuse, reduce and recycle" offers a solution to the burdening issue, although not enough to curb the rampant use of plastics. Biodegradable plastics are gaining acceptability in agriculture and food packaging industries; nevertheless, they occupy a rather small section of the plastic market. This review summarizes recent advances in the development of biodegradable plastics and their safe degradation potentials. Here, biodegradable plastics have been categorized and technology and developments in the field of biopolymers, their applicability, degradation and role in sustainable development has been reviewed. Also, the use of natural polymers with improved mechanical and physical properties that brings them at par with their counterparts has been discussed. Biodegradable polymers add value to the industries that would help in achieving sustainable development and consequently reinforce green economy, reducing the burden of greenhouse gases in the environment and valorisation of waste biomass.


Asunto(s)
Plásticos Biodegradables , Polímeros , Biodegradación Ambiental , Biopolímeros , Plásticos , Reciclaje
12.
Chemosphere ; 269: 129409, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33388566

RESUMEN

The rise of electronic waste (e-waste) generation around the globe has become a major concern in recent times and its recycling is mostly focused on the recovery of valuable metals, such as gold, silver, and copper, etc. However, e-waste consists of a significant weight fraction of plastics (25-30%) which are either discarded or incinerated. There is a growing need for recycling of these e-waste plastics. The majority of them are made from high-quality polymers (composites), such as acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), polycarbonate (PC), polyamide (PA), polypropylene (PP) and epoxies. These plastics are often contaminated with hazardous materials, such as brominated flame retardants (BFRs) and heavy metals (such as Pb and Hg). Under any thermal stress (thermal degradation), the Br present in the e-waste plastics produces environmentally hazardous pollutants, such as hydrogen bromide or polybrominated diphenyl ethers/furans (PBDE/Fs). The discarded plastics can lead to the leaching of toxins into the environment. It is important to remove the toxins from the e-waste plastics before recycling. This review article gives a detailed account of e-waste plastics recycling and recovery using thermochemical processes, such as extraction (at elevated temperature), incineration (combustion), hydrolysis, and pyrolysis (catalytic/non catalytic). A basic framework of the existing processes has been established by reviewing the most interesting findings in recent times and the prospects that they open in the field recycling of e-waste plastics.


Asunto(s)
Residuos Electrónicos , Retardadores de Llama , Residuos Electrónicos/análisis , Éteres Difenilos Halogenados/análisis , Plásticos , Reciclaje
13.
Waste Manag ; 122: 26-35, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33476959

RESUMEN

In an effort to regulate waste electrical and electronic equipment (WEEE) recycling, the Chinese government has issued China-WEEE regulations and a fund policy. In accordance with the 2012 fund policy, the government collects funds from producers and subsidizes recycling enterprises. However, this policy has encountered difficulties. The 2016 White Paper on WEEE Recycling, Treatment and Reuse states that while the funds collected from producers were 2.61 billion Yuan, the subsidies provided to recycling enterprises were 4.714 billion Yuan, which is a gap of 2.104 billion Yuan. In addition, this policy did not incentivize producers to invest in WEEE recycling. Our paper aims to answering the following questions: (1) What is the impact of the current WEEE processing fund policy? (2) How can producers' green innovation in WEEE recycling be promoted? We use evolutionary game theory to investigate the strategies used by producers and recyclers and explore their evolutionary behaviors under two policies: the 2012 fund policy (the current policy) and the Fund Relief Policy (a newly designed policy). The results indicate that the Fund Relief Policy can motivate producers' green innovation behavior, improve the profitability of recyclers, and alleviate the financial pressure on government to a certain extent.


Asunto(s)
Residuos Electrónicos , Administración de Residuos , China , Residuos Electrónicos/análisis , Electrónica , Teoría del Juego , Reciclaje
14.
Waste Manag ; 122: 64-70, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33486304

RESUMEN

In this study, a chemical milling process is developed to convert carbon residues from pyrolyzed waste tires into valuable water-based inkjet printing inks. The residues after waste tire pyrolysis were first sieved to remove ash components and ground into powder (~80 µm). The resulting waste tire carbon blacks (TCB) processed by regular dry or wet milling with the help of compatible solvent can only produce particle sizes around 250 nm. To further reduce particle size under the same mechanical energy, aqueous potassium hydroxide was used in the milling process to leach silica in TCB to create loose and vulnerable structure. Moreover, an ionic surfactant, poly (sodium 4-styrenesulfonate) (PSS), was used to decorate the TCB surface and to inhibit particle aggregation. After chemical milling, the PSS/TCB had a primary particle size around 50 nm and a hydraulic diameter around 110 nm. The PSS/TCB suspension possessed a high zeta potential of -73 mV to stably disperse in water for more than 30 days. To help adhesion of the ink on substrates, the PSS/TCB particles were further mixed with waterborne polyurethane (WPU). The WPU/PSS/TCB ink could be inkjet printed into various black patterns, which showed a higher blackness (jetness value = 342.83) than commercial black inks. Moreover, the printed patterns were water-proof and had a pencil scratch hardness of 4H. In summary, this study provides a guideline to convert waste carbon materials into useful printing supplies, and offers a potential application for waste tire recycling.


Asunto(s)
Tinta , Hollín , Carbono , Reciclaje , Agua
15.
Waste Manag ; 122: 89-99, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33494003

RESUMEN

The increase in the annual flux of the end-of-life photovoltaic panels (EoL-PVPs) imposed the development of effective recycling strategies to reach EU regulation targets (i.e. 80% recycling; 85% recovery, starting from August 2018). The recycling targets in a PVP are generally glass, photovoltaic cell and metals, while no scientific paper or patent addressed polymeric fractions recycling and recovery, i.e. encapsulant polymer (EVA) and backsheet (Tedlar), starting from preliminarily milled EoL-PVPs. In the present study an optimization following the solvent treatment operation of the basic Photolife process (demonstrated at pilot scale), was proposed (lab scale) and validated (micropilot scale), focusing on polymers separation and metals recovery. The optimization was performed by testing 4 different processes. Specifically, the selectivity of the filtration operation (subsequent the solvent treatment) on polymers separation grade was evaluated, demonstrating that Tedlar can be effectively separated from EVA residues. Moreover, in comparison to the basic Photolife, a further operation was introduced treating thermally the EVA residues (containing the PV cell). The metal extraction yields highlighted the effectiveness of that strategy in comparison with direct extraction from the uncombusted EVA residues. Processing 100 Kg of crushed material, 0.03 Kg of Ag, 45.5 Kg of high value glass, 10 Kg of Al scraps and 1.2 Kg of metallic filaments can be recovered. Thanks to the optimization the recycling rate of the implemented process grew up to 82% (75% during demonstration of the basic Photolife process), while the recovery was estimated at 94%. Remarkably, these rates get over with EU Directive.


Asunto(s)
Reciclaje , Silicio , Vidrio , Metales , Polímeros
16.
Sci Total Environ ; 765: 144438, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33418332

RESUMEN

Source-separating sanitation systems offer the possibility of recycling nutrients present in wastewater as crop fertilisers. Thereby, they can reduce agriculture's impacts on global sources, sinks, and cycles for nitrogen and phosphorous, as well as their associated environmental costs. However, it has been broadly assumed that people would be reluctant to perform the new sanitation behaviours that are necessary for implementing such systems in practice. Yet, few studies have tried to systematically gather evidence in support of this assumption. To address this gap, we surveyed 3763 people at 20 universities in 16 countries using a standardised questionnaire. We identified and systematically assessed cross-cultural and country-level explanatory factors that were strongly associated with people's willingness to consume food grown using human urine as fertiliser. Overall, 68% of the respondents favoured recycling human urine, 59% stated a willingness to eat urine-fertilised food, and only 11% believed that urine posed health risks that could not be mitigated by treatment. Most people did not expect to pay less for urine-fertilised food, but only 15% were willing to pay a price premium. Consumer perceptions were found to differ greatly by country and the strongest predictive factors for acceptance overall were cognitive factors (perceptions of risks and benefits) and social norms. Increasing awareness and building trust among consumers about the effectiveness of new sanitation systems via cognitive and normative messaging can help increase acceptance. Based on our findings, we believe that in many countries, acceptance by food consumers will not be the major social barrier to closing the loop on human urine. That a potential market exists for urine-fertilised food, however, needs to be communicated to other stakeholders in the sanitation service chain.


Asunto(s)
Fertilizantes , Reciclaje , Comportamiento del Consumidor , Alimentos , Humanos , Encuestas y Cuestionarios , Aguas Residuales
17.
J Environ Manage ; 282: 111879, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33465712

RESUMEN

As the construction sector is shifting towards circular economy models, the role of mineral construction materials as main waste fraction in terms of volumes is crucial. A characterization of this mineral stock, as well as the waste derived from it is decisive in ensuring the application of the best practices of circular economy. This paper describes a methodology for assessing the mineral building stock through a combination of geospatial and image analysis. By analysing old topographic maps, buildings are grouped according to their building age into different typologies and based on these maps the construction and demolition activity is evaluated. The mineral stock is assessed and estimations of the mineral construction and demolition waste (CDW) is generated for different stochastic scenarios. This methodology is applied exemplarily on the country of Luxembourg. It was found that the total mineral construction stock for Luxembourg is 276.75 Mt and has been growing at a rate of 20.81%-24.39% in the last 30 years. Furthermore, the study identified a mean age of the urban building stock of about 60 years and a typical maximum building lifetime of 122 years. Based on the stochastic projections the mineral CDW generated from the existing building stock is expected to be up to 226.9 Mt by 2100, while if future building scenarios are considered, it can be as high as 885.3 Mt. The annual CDW production is expected to be sufficient for a viable concrete recycling activity if regulations on the waste volume flows are made available.


Asunto(s)
Industria de la Construcción , Administración de Residuos , Materiales de Construcción , Residuos Industriales/análisis , Minerales , Reciclaje
18.
J Environ Manage ; 282: 111943, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33465720

RESUMEN

This paper aims to establish consumer's perception of electric waste recycling and management on a national scale in Bangladesh. The attitude, willingness to pay (WTP) and consumers' behaviour were explored by conducting a questionnaire-based survey. The conclusions are based on 915 valid responses out of 2000 online survey invitations. Interestingly, 37.9% of the respondents indicated that they would accept to pay for electronic waste recycling. Analysis also shows that the preferred WTP would cover 5-10% of the recycling cost. Factors like environmental awareness, monthly income, and education level affect the consumers' WTP. Nevertheless, most of the participants believe that the Government should share the recycling cost. The study suggests that e-waste recycling can be stimulated by promoting environmental awareness, educating the public about the benefits of recycling e-waste, and making e-waste recycling more convenient. However, additional measures will likely be needed to tackle the e-waste problem. Thus, support for environmental education is imperative in order to promote environmental awareness and increase the WTP of consumers. The study outlines key characteristics of consumer-focused e-waste management archetypes and proposes an effective road map for Bangladesh.


Asunto(s)
Residuos Electrónicos , Administración de Residuos , Bangladesh , Residuos Electrónicos/análisis , Humanos , Reciclaje , Encuestas y Cuestionarios
19.
Bioresour Technol ; 326: 124712, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33517050

RESUMEN

Climate change, resource depletion and unsustainable crop productivity are major challenges that mankind is currently facing. Natural ecosystems of earth's biosphere are becoming vulnerable and there is a need to design Bioregenerative Life Support Systems (BLSS) which are ecologically engineered microcosms that could effectively deal with problems associated with urbanization and industrialization in a sustainable manner. The principles of BLSS could be integrated with waste fed biorefineries and solar energy to create a self-sustainable bioregenerative ecosystem (SSBE). Such engineered ecosystems will have potential to fulfil urban life essentials and climate change mitigation thus generating ecologically smart and resilient communities which can strengthen the global economy. This article provides a detailed overview on SSBE framework and its improvement in the contemporary era to achieve circular bioeconomy by means of effective resource recycling.


Asunto(s)
Cambio Climático , Ecosistema , Reciclaje
20.
Waste Manag ; 121: 237-247, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33385952

RESUMEN

In the present study, the potential use of cellulosic microfibers (CMFs) extracted from hemp fiber (HF) and pulp and paper solid waste (mixed sludge (MS), deinked sludge (DS)) as a reinforcing agent in novel bio composite materials produced from recycled Polylactic acid (rPLA) was investigated. CMFs were extracted and treated using physicochemical method followed by enzymatic treatment with laccase and cellulase. The effects of CMFs concentrations (1.5, 3 and 6% w/w) and fiber size (75 µm-1.7 mm) on the mechanical properties (impact and tensile) and biodegradability of the biocomposite samples were investigated. A modified interfacial adhesion between rPLA matrix and the three fibers used, was clearly observed through mechanical tests due to alkali and enzymatic treatments. The use of different types of enzymatically treated cellulosic fibers for polylactic acid (PLA) recycling was assessed by Scaning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The combined physicochemical and enzymatic treatments led to a considerable size reduction of the cellulosic fibers (HF, MS and DS) resulting in the enhanced interfacial adhesion between rPLA matrix and fibers. The biocomposite obtained with rPLA with HF gave the most favorable values for Young's modulus (324.53 ± 3.10 MPa, p-value 0.03), impact strength (27.61 ± 2.94 kJ/m2, p-value 0.01) and biodegradation rate (1.97%).


Asunto(s)
Poliésteres , Reciclaje , Estudios de Factibilidad , Difracción de Rayos X
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