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1.
Waste Manag ; 123: 97-110, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33581641

RESUMO

The upcoming end-of-life solar photovoltaics (PV) waste stream is a huge concern before solid waste professionals due to presence of hazardous metals like lead or cadmium. The objective of present study was to understand the metal dissolution from PVs under four standard waste characterization regulatory tests of U.S., Germany, and Japan and their representativeness with actual landfill leachate. Modules were exposed to real municipal solid waste (MSW) landfill leachate for extended extraction duration, agitation and diluted leachate to investigate the effect of various parameters on metal dissolution. The results indicated that extractions using landfill leachates resulted in lower metal release than standard methods. The leached metal concentrations were found to be within the threshold limits except for cadmium, copper, lead and selenium, with maximum lead release from amorphous-PV of 8.68 mg/L and 6.91 mg/L with respect to TCLP and WET tests, respectively. Arsenic showed negligible release with maximum concentration of 0.046 mg/L from copper indium gallium de-selenide(CIGS) PV. Regardless of small size (1-2 cm pieces) and agitation, Germany and Japan's standard tests resulted in minimal release except of copper from copper indium gallium de-selenide PV. Leaching without agitation, showed negligible release from all photovoltaics whereas when agitation is applied to diluted leachate, significant release was observed with aluminum and copper leached up to 145.32 mg/L (multi-crystalline silicon) and 139.01 mg/L (amorphous-PV), respectively. CIGS was found to be most hazardous with a Metal Hazard Score (calculated on the basis of magnitude of leached metals with respect to their threshold limit and subsequent health effects) of 23.19, when exposed to standard tests. For all scenarios, increased metal release was observed with decrease in sample size and increase in leachate dilution and thus, leaching in highly acidic conditions are by no means representative for modules dumping in realistic conditions.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Japão , Padrões de Referência , Resíduos Sólidos , Solubilidade , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise
2.
Waste Manag ; 123: 131-141, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33582400

RESUMO

The objective of this study was to assess the influence of moisture enhancement strategies on biodegradation of municipal solid waste (MSW) in laboratory-scale reactors. Moisture enhancement strategies were varied with respect to dose volume (40, 80, 160, and 320 L/Mg-MSW) and dose frequency (dosing every ½, 1, 2, and 4 weeks). Biodegradation was evaluated based on methane generation to assess (i) the lag-time between the start of liquid dosing and onset of methane generation and (ii) the first-order decay rate for methane generation. In general, the decay rate increased with an increase in dose volume for a given dose frequency. In addition, trends of increasing decay rate and decreasing lag-time were observed for an increase in dose frequency for reactors operated with dose volumes of 40, 80, and 160 L/Mg-MSW. A key conclusion from this study was that reactors with more aggressive moisture enhancement attained more rapid methane generation that initiated at shorter elapsed times following the onset of dosing. An assessment of liquid dosing per month indicated that there were more pronounced impacts of increasing decay rate and decreasing lag-time as moisture enhancement increased from 40 L/Mg-MSW/month to 320 L/Mg-MSW/month as compared to the impact on both variables for an increase in liquid dosing above 320 L/Mg-MSW/month.


Assuntos
Eliminação de Resíduos , Resíduos Sólidos , Biodegradação Ambiental , Reatores Biológicos , Metano , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
3.
Environ Pollut ; 271: 116396, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33535362

RESUMO

Landfills represent important sources of local emissions of organic contaminants, including halogenated (HFR) and organophosphate ester (OPE) flame retardants used in a large variety of consumer products. Gulls foraging in landfills may be exposed to elevated atmospheric concentrations of HFRs and OPEs that may vary spatially and temporally within a landfill site, thus modulating their exposure. The objective of the present study was to investigate the spatial and temporal variability of HFR and OPE concentrations in air samples collected from a major landfill in the Montreal area (QC, Canada) that is frequently visited by gulls for foraging. Miniature stationary passive air samplers (PASs) and high-volume active air samplers (AASs) were deployed in six different areas within this landfill site for 34 days to collect HFRs and OPEs in air. During the same period, wild-caught ring-billed gulls (Larus delawarensis) were equipped on their back with a similar miniature PAS that was deployed in the landfill along with a GPS datalogger to monitor their movements for ten days. Elevated concentrations of certain OPEs (e.g., tris(2-chloroethyl) phosphate and tris(2-chloroisopropyl) phosphate) and brominated diphenyl ether (BDE)-209 were measured in stationary PASs and AASs, although they were homogenously distributed within this landfill site. Temporal variability was observed for concentrations of BDE-209, -99 and -47 measured in AASs as well as tributyl phosphate during the 34-day deployment period. Moreover, air concentrations of BDE-209, -207 and -206 and selected OPEs (tris(1,3-dichloro-2-propyl) phosphate and tris(methylphenyl) phosphate) determined using AASs were positively correlated with ambient air temperatures. Gulls that visited a landfill at least once exhibited significantly greater concentrations of BDE-47 measured in PASs they carried on their back, suggesting that landfill air may represent a source of exposure to PBDEs for these birds, and potentially other urban-adapted wildlife using these sites for foraging.


Assuntos
Charadriiformes , Retardadores de Chama , Animais , Canadá , Monitoramento Ambiental , Ésteres , Retardadores de Chama/análise , Éteres Difenil Halogenados/análise , Organofosfatos , Instalações de Eliminação de Resíduos
4.
Ecotoxicol Environ Saf ; 208: 111596, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396117

RESUMO

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.


Assuntos
Nitrogênio/análise , Eliminação de Resíduos/métodos , Resíduos Sólidos/análise , China , Meio Ambiente , Poluição Ambiental , Incineração/métodos , Reciclagem , Instalações de Eliminação de Resíduos
5.
J Environ Manage ; 282: 111946, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33486234

RESUMO

Landfill has become an underlying source of surface and groundwater pollution if not efficiently managed, due to the risk of leachate infiltration into to land and aquifers. The generated leachate is considered a serious environmental threat for the public health, because of the toxic and recalcitrant nature of its constituents. Thus, it must be collected and appropriately treated before being discharged into the environment. At present, there is no single unit process available for proper leachate treatment as conventional wastewater treatment processes cannot achieve a satisfactory level for degrading toxic substances present. Therefore, there is a growing interest in examination of different leachate treatment processes for maximum operational flexibility. Based on leachate characteristics, discharge requirements, technical possibilities, regulatory requirements and financial considerations, several techniques have been applied for its degradation, presenting varying degrees of efficiency. Therefore, this article presents a comprehensive review of existing research articles on the pros and cons of various leachate degradation methods. In line with environmental sustainability, the article stressed on the application and efficiency of sequencing batch reactor (SBR) system treating landfill leachate due to its operational flexibility, resistance to shock loads and high biomass retention. Contributions of integrated leachate treatment technologies with SBR were also discussed. The article further analyzed the effect of different adopted materials, processes, strategies and configurations on leachate treatment. Environmental and operational parameters that affect SBR system were critically discussed. It is believed that information contained in this review will increase readers fundamental knowledge, guide future researchers and be incorporated into future works on experimentally-based SBR studies for leachate treatment.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Reatores Biológicos , Nitrogênio/análise , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise
6.
Ecotoxicol Environ Saf ; 211: 111913, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33493721

RESUMO

Effective management of municipal solid waste (MSW) is essential for the conservation of ecosystems in the Qinghai-Tibetan Plateau (QTP). Considering the landfill is the major method of MSW management, the factors influencing groundwater contamination near MSW landfill sites in the QTP were studied, based on field investigations, environmental impact assessment, and meteorological and hydrogeological analyses. Results indicated that the groundwater was contaminated heavily by nitrate (PI = 7.5), particularly in the landfill without an anti-seepage system, followed by nitrite (PI = 3.5) and heavy metals including arsenic (PI = 4.1) and hexavalent chromium (PI = 2.8). Total hardness, total dissolved solids, nitrate, and lead in the groundwater near the investigated landfill sites were significantly different between the monsoon and the cold seasons. Both the rainfall infiltration and the leachate infiltration were considerably limited by environmental characteristics in the QTP, including high evaporation, low rainfall, and the presence of permafrost. Soil sample contamination near landfill sites was considered as moderate (28.6% of the soil samples) and moderate to heavy (71.4% of the soil samples), based on the geoaccumulation index of mercury. However, comparatively low generation and concentrations of leachate and good topsoil quality (PI = 0.84) reduced the quantity of pollutants infiltrating into the groundwater. The alkaline leachate (pH = 7.45-9.23) and soil (pH = 7.08-8.72) also considerably decreased the concentrations of contaminants dissolved in the infiltrated rainfall and leachate. Additionally, low groundwater level can delay preferential flow and enhance attenuation. Therefore, the groundwater contamination near the landfill sites was simply point pollution, which was influenced by leachate, soil, climate, and hydrogeology characteristics in the QTP. The anti-seepage system is a potential strategy for use in the prevention of groundwater contamination by MSW landfills in the QTP.


Assuntos
Monitoramento Ambiental , Água Subterrânea/química , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Ecossistema , Água Subterrânea/análise , Metais Pesados/análise , Nitratos/análise , Eliminação de Resíduos/métodos , Estações do Ano , Solo , Resíduos Sólidos/análise , Tibet , Gerenciamento de Resíduos
7.
Arch Environ Contam Toxicol ; 80(1): 134-143, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33386939

RESUMO

Polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in groundwater and leachate around selected waste dumpsites from two southwestern states of Nigeria were investigated. Samples were Soxhlet-extracted using hexane/methylene chloride mixture and cleaned-up with preconditioned solid-phase extraction cartridges. The ∑PAHs (PCBs) (all in µg/L) in the boreholes, leachate, and hand-dug well across all locations ranged from below detection limit (BDL) to 0.62 (BDL to 0.067), 1.16 to 9.96 (0.003 to 0.041), and BDL to 0.01 (0.001-0.031), respectively. Low molecular weight-PAHs accounted for ≥61% of ∑PAHs detected across all locations. The highly chlorinated hexa-PCBs [2,2',3,4,4',5'-HeCB(#180), 2,2',3,4',5',6-HeCB(#34) and 2,2',4,4',5,5'-HeCB(#153)] dominated the entire congener profiles. Pyrene and 2,3',4,4',5-PeCB(#118) constituted 56% and 58% of the ∑PAHs and ∑PCBs, respectively. Sampled water is not adequately safe for drinking and may pose cancer risk. This study should be sustained for health risk and sustenance of an enduring ecological integrity.


Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/química , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Nigéria , Pirenos/análise
8.
Environ Monit Assess ; 193(2): 71, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33469715

RESUMO

The aim of the study was to assess the impact of a small municipal landfill on the aquatic environment over 9 years, using advanced statistical tools. The results of the study of surface, ground- and leachate waters from 2008 to 2016 were subjected to detailed statistical analysis based on 15 physicochemical indicators. Factor analysis accounted for the requirements of the WHO, the European Union and the nation of Poland using 8 statistical analytical methods. The analysis of leachate contamination from the landfill site with the use of advanced statistical tools revealed its interaction with groundwater. The assessment was based on increased and statistically significant values and correlations of temperature, Zn and N-NO3 between leachate and groundwater, factors demonstrating the negative impact of the landfill. In the case of Zn, there was also a correlation between the tested waters below the landfill. The increased PAH values in the examined surface and ground waters were not a consequence of waste disposal. However, the deterioration of the chemical state of groundwater in the vicinity of the landfill could result from a certain dysfunction of the facility's infrastructure after operating for more than 20 years.


Assuntos
Água Subterrânea , Eliminação de Resíduos , Poluentes Químicos da Água , Monitoramento Ambiental , Polônia , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise
9.
Mar Pollut Bull ; 163: 111986, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33461078

RESUMO

Small-sized plastic debris (micro- and mesoplastics) are emerging pollutants and widely detected in aquatic environments. However, micro- and mesoplastics pollution research with regard to landfills is limited. In this study, the occurrence, characteristics, and possible release of micro- and mesoplastic waste from the Galuga landfill leachate to the aquatic environment were studied. Micro- and mesoplastics were identified in all surface water samples from leachate influent and effluent of Galuga landfills. The average daily release to the aquatic environment was estimated at 80,640 ± 604.80 microplastic and 618,240 ± 1905.45 mesoplastic particles, respectively. The amount of microplastic increased three-fold and nine-fold for mesoplastics after input from the leachate drain. Micro- and mesoplastic main chemical compositions were polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyester, and cellophane. This study implied that the leachate may cause micro and mesoplastic contamination to the aquatic environment. The results raised the knowledge of small-sized plastic debris in aquatic environments.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Indonésia , Microplásticos , Plásticos , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise
10.
Waste Manag ; 122: 49-54, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33485254

RESUMO

COVID-19, declared a global pandemic by the World Health Organization, has caused governments to react swiftly with a variety of measures to quell the spread of the virus. This study investigates changes in waste disposal characteristics and the relationship between the mass of biomedical waste disposed and new COVID-19 tests performed in Regina, Canada. Results suggest that between May and September 2020, significant differences in the median amount of waste disposed exist. The amount of monthly waste disposed was slightly lower to about 450-550 tonnes/month. Monthly waste data variability, however, was significantly lower. Seasonal effects on total waste disposal is observed, but is less obvious than pre-COVID time. Furthermore, the distribution of different waste fractions varies, probably due to operational and industrial characteristics. A non-linear relationship exists between the number of COVID-19 tests performed and the mass of biomedical waste disposed, perhaps due to a lagged relationship between biomedical waste generation and disposal.


Assuntos
Eliminação de Resíduos , Canadá , Cidades , Humanos , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
11.
Waste Manag ; 122: 113-123, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33503529

RESUMO

In 1997, the landfilling of biodegradable waste was banned in Denmark, and currently Danish landfills receive mostly non-combustible waste with a low-organic content. This study aimed to investigate trace gas composition in landfill gas (LFG) at modern Danish landfills. Landfill gas samples were taken from waste cells containing shredder, mixed and aged waste from four Danish landfills. The highest trace gas concentrations were found in shredder waste cells (average concentration of 103 mg m-3), which were comparable with conventional municipal solid waste landfills receiving organic waste. Aliphatic hydrocarbons and aromatics were dominant in the shredder waste cells, most likely released through direct volatilisation from disposed waste products. Abundant oxygenated compounds were found in the shredder waste cell in one of the landfills, thereby indicating a higher level of organic fraction biodegradation. Benzene, toluene, ethylbenzene and xylenes (BTEXs) were measured in high concentrations in all shredder waste cells, contributing to more than 75% of total aromatics. Considerably lower concentrations of trace gases were measured in the mixed and aged waste cells, which were dominated by hydrogen sulphide and several aliphatic hydrocarbons. A constant concentration ratio was established between aliphatic hydrocarbons together with aromatics and methane in shredder waste cells, which was then used in an LFG generation model to estimate trace gas production. The production rates of BTEXs from two landfills were estimated at 272 and 73 kg yr-1 in 2020, which were not considered to pose a significant risk to the environment or to human health.


Assuntos
Eliminação de Resíduos , Instalações de Eliminação de Resíduos , Idoso , Dinamarca , Gases/análise , Humanos , Metano/análise , Resíduos Sólidos
12.
Waste Manag ; 121: 373-382, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33422924

RESUMO

A previously developed surface probe method, which allows for instantaneous methane (CH4) flux measurement, was used to establish CH4 emission maps of a municipal landfill with a final clay cover and equipped with a gas recollection system. In addition to spatial variations, the method was applied at 7 different times over a total timeframe of 65 h and under similar weather conditions to determine the intrinsic temporal variations of CH4 emissions; i.e., the temporal variation related to the dynamic of the landfill rather than the one driven by external factors. Furthermore, continuous CH4 fluxes, with a data acquisition frequency of 1 Hz, were measured during 12 h at a single position, and for one hour at 22 locations of the landfill, spanning a large range of CH4 emission magnitudes. A simple model for the numerical characterization of spatiotemporal variability of the landfill emission was used and allowed us to separately quantify the temporal and spatial variability. This model showed that, in the landfill tested, the temporal distribution of CH4 emissions resulted more homogeneous than the spatial distribution. Other attributes of the temporal and spatial distributions of CH4 emissions were also established including the anisotropic nature of the spatial distribution and, contrastingly, the stochastic temporal variability of such emissions.


Assuntos
Poluentes Atmosféricos , Eliminação de Resíduos , Poluentes Atmosféricos/análise , Metano/análise , Instalações de Eliminação de Resíduos
13.
Waste Manag ; 121: 383-392, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33429157

RESUMO

Optimal combustion control of untreated landfill gas is proposed for an effective usage and a low-cost solution in waste to energy technologies. Variations of methane concentration in untreated landfill gas over time cause undesired performance of combustors in thermal efficiency and gas emission. In this work, the experimental investigation on variables of combustion process is systematically presented to determine an inherent performance index of a combustor, reflecting actual thermal efficiency and gas emission for optimal control. Those quantitative findings can be implemented via fuzzy logic rule knowledge based approach to combustion control. From the experimental results of a can-type combustor, it is confirmed that the optimal combustion control of untreated landfill gas yields the desired exhaust gas temperature with maximum thermal efficiency and minimum gas emission under varying methane concentrations or changes of operating conditions. The proposed methodology can be generalized to optimal combustion control of untreated landfill gas via the fuzzy logic rule knowledge based approach, which is the most suitable to characteristics of each combustor. For industrial applications, the experimental results at a laboratory scale can be extended by increasing the capacity of the studied combustor to obtain the large scale combustion in practical production where the optimal combustion control of the untreated landfill gas is effectively accomplished without cost of gas treatment for usage in conventional processes.


Assuntos
Poluentes Atmosféricos , Lógica Fuzzy , Poluentes Atmosféricos/análise , Metano , Temperatura , Instalações de Eliminação de Resíduos
14.
Waste Manag ; 121: 365-372, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33477055

RESUMO

The service life of high-density polyethylene (HDPE) geomembranes is directly determined by the landfill environment, and the antioxidant depletion stage is the first and most important stage of the HDPE geomembrane aging process. In this study, the antioxidant depletion stage was chosen to investigate the effects of different exposure environments on the HDPE geomembrane lifespan. The antioxidant depletion rate (ADR) and the antioxidant depletion time (ADT) of HDPE geomembranes under various exposure conditions were calculated based on the aging parameters obtained by fitting the collected reported data with the Arrhenius model. Also, the influence of exposure conditions on the HDPE geomembrane performance degradation was analyzed. The results showed that the aging method had the greatest effect on the antioxidant depletion period, while the HDPE geomembrane thickness had the least effect. The ADR sensitivity to brand/material, aging method, leachate components, and exposure medium decreased with increasing temperature; only the sensitivity to thickness showed a slight increasing tendency with increasing temperature. The ADTs of HDPE geomembranes under different exposure conditions ranged from 6 years to 900 years, indicating that the HDPE geomembranes can complete the service time of landfills under reasonable exposure conditions. This study provides a reliable methodological basis for the risk control and life prediction of HDPE geomembranes.


Assuntos
Polietileno , Eliminação de Resíduos , Antioxidantes , Temperatura , Instalações de Eliminação de Resíduos
15.
Sci Total Environ ; 764: 144551, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33385653

RESUMO

Anthropogenic inputs into the environment may serve as sources of antimicrobial resistant bacteria and alter the ecology and population dynamics of synanthropic wild animals by providing supplemental forage. In this study, we used a combination of phenotypic and genomic approaches to characterize antimicrobial resistant indicator bacteria, animal telemetry to describe host movement patterns, and a novel modeling approach to combine information from these diverse data streams to investigate the acquisition and long-distance dispersal of antimicrobial resistant bacteria by landfill-foraging gulls. Our results provide evidence that gulls acquire antimicrobial resistant bacteria from anthropogenic sources, which they may subsequently disperse across and between continents via migratory movements. Furthermore, we introduce a flexible modeling framework to estimate the relative dispersal risk of antimicrobial resistant bacteria in western North America and adjacent areas within East Asia, which may be adapted to provide information on the risk of dissemination of other organisms and pathogens maintained by wildlife through space and time.


Assuntos
Anti-Infecciosos , Charadriiformes , Animais , Bactérias , Farmacorresistência Bacteriana , Extremo Oriente , América do Norte , Instalações de Eliminação de Resíduos
16.
J Environ Manage ; 280: 111839, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33360739

RESUMO

Resource recovery is a promising solution for multiple waste and economic challenges worldwide. Although the life cycle environmental performance of resource recovery systems has been widely studied, the impacts of their resultant waste processing byproducts remain unassessed. Depending on their management techniques and destinations, such large waste streams, such as non-recovered recyclables and anaerobic digestate, may significantly alter the overall environmental footprint of the integrated solid waste management (ISWM) strategy. This research aimed to assess the life cycle impacts of various ISWM strategies incorporating material recovery and waste-to-energy (WTE) systems. The examined strategies were based on combinations of incineration (INC) and anaerobic digestion (AD) plants, in addition to material recovery facilities (MRFs) and landfills. The study used eighteen scenarios to explore the effect of the potential pathways of waste processing byproducts on the overall carbon footprint of the strategies. The proposed lifecycle assessment framework was applied to an emerging metropolis. The highest energy recovery was achieved in the dual AD and INC scenarios, particularly when the digestate was incinerated, followed by the mono INC scenario. The highest material recovery, specifically recycled materials and digestate, was accomplished in the MRF+AD and MRF +AD+INC scenarios, in which digestate was marketed and non-recovered recyclables were incinerated. It was found that alternative pathways of waste-processing byproducts can reduce the overall global warming potential (GWP) of the base scenarios. Combining MRF and INC as well as MRF, AD, and INC while incinerating non-recovered recyclables, disposing ash, and marketing digestate (if any) were the optimum environmental options in terms of GWP. Incineration of non-recovered recyclables reduced carbon emissions by 29% compared to disposal, whereas marketing and incinerating the digestate positively impacted GWP compared to landfilling (83 and 77%, respectively). A breakdown of the sub-processes revealed that the energy recovery, recycling, and landfilling processes had the highest contributions to the total GWP (up to 88, 92, and 98%, respectively); the collection and transportation processes had the least impacts (2 and 13%, respectively). The more waste-processing byproducts were incinerated, the greater GWP contribution of energy recovery.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Pegada de Carbono , Incineração , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
17.
Bioresour Technol ; 319: 124114, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32942236

RESUMO

Conventional treatment and recycling methods of organic solid waste contain inherent flaws, such as low efficiency, low accuracy, high cost, and potential environmental risks. In the past decade, machine learning has gradually attracted increasing attention in solving the complex problems of organic solid waste treatment. Although significant research has been carried out, there is a lack of a systematic review of the research findings in this field. This study sorts the research studies published between 2003 and 2020, summarizes the specific application fields, characteristics, and suitability of different machine learning models, and discusses the relevant application limitations and future prospects. It can be concluded that studies mostly focused on municipal solid waste management, followed by anaerobic digestion, thermal treatment, composting, and landfill. The most widely used model is the artificial neural network, which has been successfully applied to various complicated non-linear organic solid waste related problems.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Aprendizado de Máquina , Reciclagem , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
18.
Chemosphere ; 262: 128013, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182094

RESUMO

The main aim of this work is to assess the extent of soil contamination, potential ecological and health risks associated with the disposal of municipal solid waste (MSW) near a Ramsar site in Assam, India. Soil samples were collected and analysed for three heavy metals (HMs), namely, chromium (Cr), manganese (Mn) and zinc (Zn). The sources of HMs and their pollution levels were evaluated using different indices. The results demonstrated that Cr contamination was high near the metal scrap segregations unit within the dumping site, otherwise, the ecological risks associated with Zn and Mn were found to be low. The speciation of Cr and Zn were associated with the Fe-Mn oxide bound (F4) fraction, accounting 44.23% and 30.68%, respectively, whereas Mn (52.55%) was associated with the exchangeable fraction (F2). The fate and origin of HMs were assessed using mobility and enrichment factors and 16 out of the 20 sampling sites fell under the category of heavily polluted category for Cr, while others which were nearby the metal segregation units fell under the strongly to extremely polluted category. In few sites, significant enrichment was observed for Zn and minimal to moderate enrichment for Mn, respectively. Health risk assessment results indicated that Cr posed higher threat to human health through ingestion.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Humanos , Índia , Medição de Risco
19.
Chemosphere ; 266: 129182, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33333336

RESUMO

Municipal solid waste landfill is now recognized as a significant reservoir of antibiotics and antibiotic resistance genes (ARGs). This study investigates the contamination of antibiotics resistance, in 10 leachate samples collected from four MSW landfills in north Italy spanning 34 years, including ARGs as well as mobile genetic element (MGEs). Antibiotics (0-434740 ng/L) and ARGs (5.56-6.85 × 105copies/µL leachate) were found in leachate. Abundances of the measured ARGs were found to be clustered into two groups with different changing tendencies with landfilling age in different landfills. Even though some antibiotics were banned or limited in Italy, they were found to still occur in landfills and drive the long-term contamination of ARGs indirectly, indicating the persistence of antibiotic resistance. What's more, the complexity of antibiotic resistance in leachate was found to synthetically relate to antibiotics, metals, microbes and MGEs presenting that Mn, SMX and EFC influence positively (p < 0.01) the contamination of tetW, tetQ, tetM, tetA, ermB, and cat, contributing importantly in new leachate. This study discusses the AR pollution of leachate in Italy where antibiotics are used the most in Europe, less reported in literatures. Our results suggest that a full-scale view for landfill antibiotics resistance should be considered with history of landfills, use of antibiotics and different phase in landfills, with both "relative static" and "dynamic tracking" perspective to focus on the principal antibiotic-resistance pollutants for leachate treatment, and raise the attention for landfill post-closure care and landfill mining.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Resistência Microbiana a Medicamentos/genética , Europa (Continente) , Itália , Resíduos Sólidos , Instalações de Eliminação de Resíduos
20.
J Environ Manage ; 279: 111829, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33348186

RESUMO

The paper presents an extension of Pinch Analysis and namely, Total Site Process Integration. It benefits from up to date developments and introduction of Total EcoSite Integration for urban and industrial symbiosis. An important development is Pinch Analysis for Solid Waste Integration which is a crucial step for the symbiosis in a circular economy. As the potential EcoSites are usually extensive and cover various units, a methodology based on clusters has been used. The solution has been supported by graphical tools using the analogy with already implemented extensions of Pinch Analysis. The results of a demonstration case study revealed the potential of the novel approach. The identified integrated design increased the energy recovered from the solid waste by 11.39 MWh/d and diverted 2 t/d of the waste from the landfill, benefiting both the urban and industrial site. The proposed approach is also capable of minimising the requirement of energy-intensive thermal drying for waste whenever the process allowed, subsequently offer a solution with lower environmental footprint and cost. For future work, a even more comprehensive case study can be conducted by considering the other forms of the waste, recovery process and drying approaches.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Meio Ambiente , Indústrias , Resíduos Sólidos/análise , Simbiose , Instalações de Eliminação de Resíduos
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