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1.
Environ Monit Assess ; 193(5): 277, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33861359

RESUMEN

The moisture content of the municipal solid waste (MSW) is a physical characteristic that plays a fundamental role in the stability and settlement of landfills. However, this physical index is difficult to monitor within the mass of landfilled MSW because it undergoes great variation due, mainly, to the heterogeneity and biodegradation of the waste. Brazilian MSW generally has a large amount of organic matter, that when biodegraded, generates a considerable volume of gases and fluids, aggravated by climatic conditions, such as high rainfall and temperatures. Hence, the importance of obtaining and evaluating the distribution of moisture content in the MSW mass over time. Currently, the electrical resistivity properties have been presented as an interesting approach to obtain the moisture content in landfills indirectly. This study aimed to apply geoelectrical methods as a tool to obtain and evaluate the moisture content distribution in an experimental cell of a sanitary landfill using Archie's law, which correlates the volumetric moisture content and electrical resistivity. Moisture content values were obtained in laboratory tests with MSW samples collected in two vertical holes and electrical resistivity measurements by means of vertical electrical sounding. The moisture content and the resistivity values of the samples were used to calculate the parameters a and m of Archie's law. This allowed to convert the resistivity tomography to moisture content tomography. The good correlation achieved between the moisture content calculated by Archie's law and that obtained from samples indicates that the use of electrical resistivity methods is useful to assess and monitor quantitatively the moisture content in landfills using Archie's law.


Asunto(s)
Eliminación de Residuos , Brasil , Monitoreo del Ambiente , Residuos Sólidos/análisis , Instalaciones de Eliminación de Residuos
2.
Environ Sci Technol ; 55(8): 4822-4830, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33792295

RESUMEN

Unused or expired pharmaceutical and personal care products (PPCPs) are usually discharged into municipal solid wastes, then travel to landfills, and eventually percolate into leachates. However, knowledge of their occurrence and temporal dynamics in leachates is limited, making landfill leachate an underappreciated emission source of PPCPs. Furthermore, the differences in PPCP variations in landfill leachates emphasize the necessity for identifying the influencing factors and elucidating the mechanisms for PPCP fluctuations. In this study, successive monthly monitoring of PPCPs in leachates throughout an entire year was performed to determine their seasonal variations and identify their influencing factors. Furthermore, five pairs of additional sampling campaigns were conducted before and after rainfall events during wet seasons to elucidate the influencing mechanisms. The results showed that there was a distinct seasonal variation in PPCPs in landfill leachates-elevated levels during the wet period (from April to September, with a mean concentration of 17.0 µg/L for total monitored PPCPs)-when compared to other months (mean concentration of 3.8 µg/L). Rainfall played a considerable role in mediating PPCP concentrations in leachates. The PPCP responses to five rainfall episodes further verified the influence of rainfall and demonstrated that the tendency to PPCP concentration increase was related to rainfall precipitation. Torrential rain events (i.e., 24 h cumulative precipitation of 50-99.9 mm) led to the most significant increases in PPCP concentrations in landfill leachates. In addition, the hydrophilicity of PPCPs contributed to the different fluctuations during the 1 year investigation and different responses to rainfall. To the best of our knowledge, this study provides the first direct evidence supporting the influence of rainfall on PPCPs in landfill leachates, which can help better understand the occurrence and behavior of emerging contaminants in this underappreciated emission source.


Asunto(s)
Cosméticos , Preparaciones Farmacéuticas , Contaminantes Químicos del Agua , Estaciones del Año , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis
3.
J Environ Manage ; 288: 112475, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33823445

RESUMEN

The necessity for landfill leachate treatment is a requisite to reduce the environmental impact related to municipal solid waste landfills and different aspects must be considered while deciding for an appropriate treatment process. For example, it was demonstrated that the landfill leachate stabilization in tropical regions is achieved right after its first year of operation, requiring technologies capable of treating leachates of a higher recalcitrant character if compared to those leachates from temperate regions and same landfill age. In view of its complexity and variability, stand-alone processes (either biological or physicochemical) are often ineffective in attaining the threshold values for its discharge in receiving bodies. Due to that fact, full-scale facilities have adopted integrated routes, harvesting the benefits of both biological and physicochemical processes. The implementation of membrane bioreactors followed by polishing membrane separation process (nanofiltration and reverse osmosis) seems to be a trend in leachate treatment by full-scale treatment plants. This technology is widely employed in China, European countries, and tropical countries as Brazil, generally with a treatment cost lower than the costs related to its disposal in domestic effluent collection systems. From the technologies already employed by full-scale facilities, four integrated routes were proposed for a sensitive analysis considering the treatment of a landfill leachate of different physicochemical characteristics. From all routes, those employing the membrane separation process as a polishing step had a better efficacy in attaining the threshold values for leachate disposal, being that an interesting alternative for leachate polishing by full-scale facilities.


Asunto(s)
Eliminación de Residuos , Contaminantes Químicos del Agua , Brasil , China , Europa (Continente) , Residuos Sólidos/análisis , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis
4.
J Environ Manage ; 289: 112558, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33857713

RESUMEN

Landfill leachate is commonly treated offsite with municipal wastewater. This offsite leachate treatment may be limited or no longer applicable due to the increasingly stringent regulations and concerns related to per- and polyfluoroalkyl substance (PFAS) discharge into the environment, resulting in development of full-scale, onsite leachate treatment facilities. To help landfills prepare for the potential shift from offsite to onsite leachate treatment for PFAS compliance, this study analyzed and compared the environmental, human health, and economic performances of a typical onsite and a typical offsite leachate treatment alternative through life cycle assessment (LCA) and life cycle cost assessment (LCCA) using a landfill site located in Zhuzhou, China as a testbed. Two distinct functional units (FUs) were investigated: 1 m3 of leachate treated and 1 g of PFAS removed. Our results show that the onsite scenario offered benefits from human health and economic perspectives, while the offsite scenario generally performed better from the environmental perspective when a leachate PFAS concentration of 150,704 ng/L was assumed. The extent of this tradeoff varied when different functional units were adopted. The onsite scenario will not be competitive from all three perspectives when PFAS concentration in the raw leachate is less than 1666 ng/L.


Asunto(s)
Eliminación de Residuos , Contaminantes Químicos del Agua , China , Humanos , Instalaciones de Eliminación de Residuos , Aguas Residuales , Contaminantes Químicos del Agua/análisis
5.
Bioresour Technol ; 329: 124889, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33662854

RESUMEN

The study aims to investigate the feasibility of anaerobic co-landfilling of effluent treatment plant sludge (ETPS) from paper mill and municipal solid waste (MSW) in prismoidal shaped simulated anaerobic landfill bioreactors. Both ETPS and MSW were co-disposed in 0:100 (R1), 25:75 (R2), 50:50 (R3) and 75:25 (R4) ratios. Periodic assessments of leachate characteristics and biomethane production were carried out for 300 days. ETPS co-disposal with MSW showed considerable reduction in biochemical oxygen demand of leachate (R2: 95.9%, R3: 97.5% and R4: 93.2%). Moreover, cumulative methane gas generations were 2.974, 6.085 and 4.653 times more in R2, R3 and R4 bioreactors as compared to R1. Gompertz growth model was found in well-fitting for methane generation with the observed data. Correlogram plotted among leachate parameters exhibited exclusive relationships and justified leachate trends. This simulation of co-landfilling could be baseline study for the implementation of technology at pilot scale.


Asunto(s)
Eliminación de Residuos , Contaminantes Químicos del Agua , Anaerobiosis , Reactores Biológicos , Descontaminación , Metano , Aguas del Alcantarillado , Residuos Sólidos , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis
6.
J Environ Manage ; 286: 112233, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33684803

RESUMEN

There are various scenarios challenging human experts to judge the interior of something based on limited surface information. Likewise, at waste disposal facilities around the world, human inspectors are often challenged to gauge the composition of waste bulks to determine admissibility and chargeable levy. Manual approaches are laborious, hazardous, and prone to carelessness and fatigue, making unattended gauging of construction waste composition using simple surface information highly desired. This research attempts to contribute to automated waste composition gauging by harnessing a valuable dataset from Hong Kong. Firstly, visual features, called visual inert probability (VIP), characterizing inert and non-inert materials are extracted from 1127 photos of waste bulks using a fine-tuned convolutional neural network (CNN). Then, these visual features together with easy-to-obtain physical features (e.g., weight and depth) are fed to a tailor-made support vector machine (SVM) model to determine waste composition as measured by the proportions of inert and non-inert materials. The visual-physical feature hybrid model achieved a waste composition gauging accuracy of 94% in the experiments. This high performance implies that the model, with proper adaption and integration, could replace human inspectors to smooth the operation of the waste disposal facilities.


Asunto(s)
Instalaciones de Eliminación de Residuos , Administración de Residuos , Materiales de Construcción , Hong Kong , Humanos , Modelos Teóricos , Redes Neurales de la Computación , Máquina de Vectores de Soporte
8.
J Environ Manage ; 287: 112320, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33725658

RESUMEN

Information on the spatial extent of potential impact areas near disposal sites is vital to the development of a sustainable natural resource management policy. Eight Canadian landfills of various sizes and shapes in different climatic conditions are studied to quantify the spatial extent of their bio-thermal zone. Land surface temperature (LST) and normalized difference vegetation index (NDVI) are examined with respect to different Land Use Land Cover (LULC) classes. Within 1500 m of the sites, LST ranged from 18.3 °C to 29.5 °C and 21.3 °C-29.7 °C for forest land and agricultural land, respectively. Linear regression shows a decreasing LST trend in forest land for five out of seven landfills. A similar trend, however, is not observed for agricultural land. Both the magnitude and the variability of LST are higher in agricultural land. The size of the bio-thermal zone is sensitive to the respective LULC class. The approximate bio-thermal zones for forest class and agricultural classes are about 170 ± 90 m and 180 ± 90 m from the landfill perimeter, respectively. For the forest class, NDVI was negatively correlated with LST at six out of seven Canadian landfills, and stronger relationships are observed in the agricultural class. NDVI data has a considerably larger spread and is less consistent than LST. LST data appears more appropriate for identifying landfill bio-thermal zones. A subtle difference in LST is observed among six LULC classes, averaging from 23.9 °C to 27.4 °C. Geometric shape makes no observable difference in LST in this study; however, larger landfill footprint appears to have higher LST.


Asunto(s)
Monitoreo del Ambiente , Residuos Sólidos , Canadá , Bosques , Temperatura , Instalaciones de Eliminación de Residuos
9.
Waste Manag ; 124: 348-355, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33662766

RESUMEN

Temperatures as high as 100 °C have been reported at a few municipal solid waste (MSW) landfills in the U.S. A recently published model describing landfill heat accumulation identified reactions that contribute significant heat to landfills including the hydration and carbonation of Ca-containing wastes such as ash from MSW and coal combustion. The objective of this study was to develop a method to measure heat release from Ca-containing ash by isothermal calorimetry. The method was confirmed by comparing measured heat release from hydration and carbonation of pure CaO and Ca(OH)2 to the theoretical heat. Theoretical heat release was determined by characterizing test materials before and after experiments using thermogravimetric analysis (TGA) and X-ray diffraction (XRD). Heat recovery efficiencies with both water and synthetic leachate ranged from 79 to 90% for CaO hydration and between 65 and 74% for Ca(OH)2 carbonation, with no effect attributable to leachate. Additionally, simultaneous hydration and carbonation of CaO/Ca(OH)2 mixtures resulted in efficiencies of 65 to 74%. The developed method was applied to eight samples that were excavated from a landfill and known to contain coal ash, and the ratio of measured to theoretical heat was 0.5 to 4. Thus, calculation of theoretical heat release from XRD data was not a good predictor of the experimentally measured heat release. The developed method can be used by landfill operators to evaluate the heat potential of a waste, thereby facilitating decisions on the quantity of a waste that can be buried in consideration of landfill temperatures.


Asunto(s)
Eliminación de Residuos , Ceniza del Carbón , Calor , Residuos Sólidos , Instalaciones de Eliminación de Residuos
10.
Waste Manag ; 124: 368-376, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33662768

RESUMEN

Many methods have been applied to monitor fugitive methane gas from landfills. Recently, there have been suggestions to use a framework utilizing an unmanned aerial vehicle (UAV) for landfill gas monitoring, and several field campaigns have proved that a rotary UAV-based measurement has advantages of ease of control and high-resolution concentration mapping on the target planes. However, research on the evaluation of error-inducing factors in the suggested system is limited so far. This study prepared a measurement system with a lightweight methane detector and a rotary UAV to support the applicability of rotary UAV in landfill gas monitoring. Then, the validity of the system was tested experimentally and theoretically. In the detector reliability test, the methane detector had sufficient resolution for field application. The critical UAV velocity required was obtained to ensure the credibility of the proposed measurement system. When spatial interpolators were applied to field data from the measurement system, the empirical Bayesian kriging demonstrated the best prediction of methane concentrations at unmeasured points. With the verifications provided in this study, this proposed method may contribute to reducing uncertainty in estimating fugitive landfill gas emission.


Asunto(s)
Contaminantes Atmosféricos , Eliminación de Residuos , Contaminantes Atmosféricos/análisis , Teorema de Bayes , Monitoreo del Ambiente , Metano/análisis , Reproducibilidad de los Resultados , Residuos Sólidos , Instalaciones de Eliminación de Residuos
11.
Sci Total Environ ; 768: 145466, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33736345

RESUMEN

The distribution of bacterial community in an actual landfill was analyzed and the bioprocess involved in refuse degradation was clarified. The results showed that the degradation degree of refuse showed great differences with the landfill age, in which the contents of organic matter (OM) and total Kjeldahl nitrogen (TKN) in refuse as well as the chemical oxygen demand (COD) in leachate presented decreasing trends with increasing landfill age. The diversity of bacterial community increased first and then decreased with increasing landfill age. The main bacterial phyla involved in refuse degradation were Proteobacteria, Firmicutes and Bacteroidetes, among which, Proteobacteria had an absolute advantage with a relative abundance ranging of 66-78%. With increasing landfill age, the abundance of Firmicutes decreased gradually, while that of Bacteroidetes increased. Pseudomonas, Thiopseudomonas, Psychrobacter and Desemzia were the main genera. The distribution of bacterial community in samples with landfill ages of 0-1 and 1-3 years were greatly influenced by TKN and pH, respectively. Amino acid and carbohydrate metabolism were the main biological pathways according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and the biodegradation of xenobiotics as well as terpenoids and polyketides also accounted relatively high frequencies in the landfill. These results provide a better understanding of landfill microbiology and bioprocesses for landfill stabilization.


Asunto(s)
Eliminación de Residuos , Contaminantes Químicos del Agua , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Instalaciones de Eliminación de Residuos
12.
Sci Total Environ ; 770: 145375, 2021 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-33736420

RESUMEN

Biostabilization is a commonly applied method in mechanical-biological treatment (MBT) plants to process municipal solid waste. In many ways, e.g. by applying additives to waste, MBT plant operators strive to enhance the effectiveness of biostabilization, which leads to reducing the time and energy outlays necessary for the process, as well as to minimizing the amount of final stabilized waste directed to landfills. This paper deals with the impact of digestate waste from agricultural biogas plants used as additive to the biostabilization process of undersized fraction from municipal solid waste (UFMSW) on the intensive phase of the process and properties of stabilized waste. The aim of this study was to assess whether, and if so to what extent, the application of digestate waste affects the process. Five different input compositions were tested (without digestate and with the addition of digestate at: 2.5; 5; 7.5 and 10 wt%). Waste treatment time was 2 weeks. Changes in moisture content, organic matter (OM), respiration activity (AT4), bulk density, air-filled porosity, heavy metal content, pH, carbon to nitrogen ratio, as well as composition of process gases emitted were evaluated. Additionally, microorganisms (including pathogens) inhabiting the processed waste in the aspect of waste sanitation were analyzed. It was found that the addition of digestate at 2.5, 5 and 7.5 wt% extended the duration of the thermophilic phase and decreased the CO2 content in process gases. The addition of digestate at 2.5 wt% and 5 wt%, decreased also OM by approx. 25% of the initial value and AT4 by approx. 30%. It was also proved that the addition of digestate favors the limited sanitation of UFMSW. As a result of the research, it was found that the addition of digestate at 2.5 wt% and 5 wt% is sufficient to accelerate the aerobic biological degradation of UFMSW.


Asunto(s)
Metales Pesados , Eliminación de Residuos , Anaerobiosis , Biocombustibles , Metales Pesados/análisis , Nitrógeno/análisis , Residuos Sólidos , Instalaciones de Eliminación de Residuos
13.
J Environ Sci (China) ; 103: 196-206, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33743901

RESUMEN

The explosive increase of construction and demolition waste (CDW) caused the insufficient source separation and emergency disposal at domestic waste landfills in many developing countries. Some organic fractions were introduced to the CDW landfill process and resulted in serious odor pollution. To comprehensively explore the impacts of organic matters on odor emission patterns, five CDW landfills (OIL), with organic matters/ inert CDW components (O/I) from 5% to 30%, and the control group only with inert components (IL) or organics (OL) were simulated at the laboratory. The chemical and olfactive characters of odors were evaluated using the emission rate of 94 odorants content (ERtotal), theory odor concentration (TOCtotal), and e-nose concentration (ERENC), and their correlations with waste properties were also analyzed. It was found that the main contributors to ERtotal (IL: 93.0% NH3; OIL: 41.6% sulfides, 31.0% NH3, 25.9% oxygenated compounds) and TOCtotal (IL: 64.1% CH3SH, 28.2% NH3; OIL: 71.7% CH3SH, 24.8% H2S) changed significantly. With the rise of O/I, ERtotal, TOCtotal, and ERENC increased by 10.9, 20.6, and 2.1 times, respectively. And the organics content in CDW should be less than 10% (i.e., DOC<101.3 mg/L). The good regressions between waste properties (DOC, DN, pH) and ERENC- (r=0.86, 0.86, -0.88, p<0.05), TOCtotal- (r=0.82, 0.79, -0.82, p<0.05) implied that the carbon sources and acidic substances relating to organics degradation might result in that increase. Besides, the correlation analysis results (ERENC-vs.TOCtotal-, r=0.96, p<0.01; vs.ERtotal-, r=0.86, p<0.05) indicated that e-nose perhaps was a reliable odor continuous monitoring tool for CDW landfills.


Asunto(s)
Contaminantes Atmosféricos , Eliminación de Residuos , Contaminantes Atmosféricos/análisis , Odorantes/análisis , Instalaciones de Eliminación de Residuos
14.
Waste Manag ; 125: 10-26, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33667979

RESUMEN

Anaerobic digestion is one of the main waste-to-energy technologies in reducing the volume of biodegradable waste into energy-rich biogas. Recent studies have revealed that kitchen wastes as a feedstock possess great potential in energy production and anaerobic digestion proved to be a promising technology among different kitchen waste management techniques such as incineration, pyrolysis, gasification, landfills, composting, etc. To anaerobically treat feedstock, an airtight enclosed container commonly known as biodigester will be employed. To suffice the energy requirement for cooking in the rural areas and recently even in the urban areas, a small-scale biogas unit commonly referred to as portable type biodigester is blooming as an attractive alternative for the production of biogas domestically. Hence, this review emphasizes on anaerobic digestion of kitchen wastes and the design of portable type biodigester. The present review provides an overview of different kitchen waste management techniques. The paper also discusses the different types of biomass feedstock and provides a generalized procedure for the design of a portable biogas unit. This study confirms that the systematic design of biogas units and proper feeding of kitchen waste offers an advantage of effective utilization of wastes in the production of decentralized energy.


Asunto(s)
Biocombustibles , Instalaciones de Eliminación de Residuos , Anaerobiosis , Biomasa , Reactores Biológicos , Incineración
15.
Waste Manag ; 125: 27-39, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33667980

RESUMEN

The main aim of this study was to assess the suitability of geophysical methods for investigating old waste dumps. Electrical Resistivity Tomography (ERT), Seismic Refraction Tomography (SRT), Multichannel Analysis of Surface Waves (MASW) and Ground Penetrating Radar (GPR) were the techniques used to characterize a waste dump in the town of Dabrowa Górnicza (S Poland). GPR and SRT were the most difficult methods to use because of the dense vegetation, which attenuated the passage of electromagnetic and seismic waves to the ground. However, GPR did turn out to be an appropriate tool for characterizing variations in the surface cover. ERT, SRT and MASW clearly highlighted the transition between the waste deposit and the host sediments, and determined the approximate thickness of the waste deposits. With MASW, however, the waste type and the boundary between the waste layer and surface cover could not be delineated. In some places, the surface cover was identified using SRT. With both these methods, the problem with identification may be due to the small contrast in the S- and P-wave velocities through two kinds of waste (municipal and industrial), the thinness of the waste layer, and the considerable differentiation of the surface cover. The most accurate results regarding the waste deposits were obtained using ERT and different electrode spacings. ERT pinpointed the exact location of the stored waste, distinguished between the types of waste, and identified the soil cover. Data from shallow boreholes confirmed the interpretations of the methods.


Asunto(s)
Monitoreo del Ambiente , Instalaciones de Eliminación de Residuos , Electricidad , Polonia , Tomografía
16.
Waste Manag ; 125: 182-191, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33711733

RESUMEN

We investigated the contribution of waste fires to air pollution. The annual emission of pollutants (CO, NOx, PM10, SO2) and greenhouse gases (CH4, CO2) were evaluated. The prediction of emissions is based on statistical data from 79 large fires that took place in Poland in 2018. We analyzed the spatial distribution of these fires along with the expected emission factor. The predicted emissions from all large waste fires was in total: 2.05 ± 0.10Gg of CH4, 19.60 ± 0.90Gg of CO, 196 ± 13Gg of CO2, 0.963 ± 0.047Gg of NOx, 5.26 ± 0.58Gg of PM10, and 0.72 ± 0.12Gg of SO2. For the evaluation of the consequences, we used the number of people exposed to PM10 emitted in one very big fire. Almost 6.5 million people were exposed to an additional 1-hour average concentration of PM10 higher than 10 µg/m3 and over 360 thousand were exposed to a concentration higher than 100 µg/m3.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Fuego , Gases de Efecto Invernadero , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Monitoreo del Ambiente , Humanos , Material Particulado/análisis , Polonia , Instalaciones de Eliminación de Residuos
17.
Waste Manag ; 125: 249-256, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33713870

RESUMEN

Environmental damage cost can measure the impact of pollution caused by human activity on final safeguard subjects from endpoint perspective. Application of environmental damage cost to municipal solid waste (MSW) management is still rare. To fill such a research gap, this study established a MSW environmental damage cost assessment method using Life Cycle Impact Assessment Method based on Endpoint (LIME) model. Four types of environmental damage cost, namely, primary productivity, social assets, biodiversity and human health for waste treatment were investigated in the city of Shanghai. Results show that the environmental damage cost was 113.7, 116.9, 140.0, 144.0 and 170.8 million dollars in Shanghai from 2014 to 2018, respectively. Damage cost of social assets was the dominant component, accounting for about 55%. Landfill mainly caused social assets damage cost, while incineration mainly caused human health damage cost. Scenarios analysis further revealed that after implementing MSW separation, the total environmental damage cost could be reduced by about 1/3. The best MSW treatment method is fermentation, followed by compost, incineration and landfill, with unit environmental damage cost being 0.22, 4.51, 16.04 and 23.47 USD/ton, respectively.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , China , Ciudades , Humanos , Incineración , Residuos Sólidos/análisis , Instalaciones de Eliminación de Residuos
18.
Environ Sci Technol ; 55(8): 5475-5484, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33687209

RESUMEN

Life-cycle assessments (LCAs) of municipal solid waste management (MSWM) systems are time- and data-intensive. Reducing the data requirements for inventory and impact assessments will facilitate the wider use of LCAs during early system planning and design. Therefore, the objective of this study is to develop a systematic framework for streamlining LCAs by identifying the most critical impacts, life-cycle inventory emissions, and inputs based on their contributions to the total impacts and their effect on the rankings of 18 alternative MSWM scenarios. The scenarios are composed of six treatment processes: landfills, waste-to-energy combustion, single-stream recycling, mixed waste recycling, anaerobic digestion, and composting. The full LCA uses 1752 flows of resources and emissions, 10 impact categories, 3 normalization references, and 7 weighting schemes, and these were reduced using the streamlined LCA approach proposed in this study. Human health cancer, ecotoxicity, eutrophication, and fossil fuel depletion contribute 75-83% to the total impacts across all scenarios. It was found that 3.3% of the inventory flows contribute ≥95% of the overall environmental impact. The highest-ranked strategies are consistent between the streamlined and full LCAs. The results provide guidance on which impacts, flows, and inputs to prioritize during early strategy design.


Asunto(s)
Eliminación de Residuos , Administración de Residuos , Humanos , Reciclaje , Residuos Sólidos/análisis , Instalaciones de Eliminación de Residuos
19.
Environ Sci Technol ; 55(8): 4522-4531, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33769040

RESUMEN

A new passive sampling method was developed and characterized to measure atmospheric volatile methyl siloxanes (VMS). The infrastructure of a commercial passive air sampler (PAS) was used along with XAD-2 resin as the adsorbent. Experimental sampling rates (SR) determined using collocated active and passive samplers ranged between 0.0363 (L5) and 0.0561 (D3) m3/day and agreed well with the theoretical ones. VMS uptake was highly linear for eight weeks. The precision of the method was very good (<10%). Compared to the other PASs used for VMS, the new method has several advantages (i.e., the sampler is much smaller, it has commercially available components, and the solvent requirement, equipment needed for extraction, and steps for sample preparation are minimal) while achieving similar or lower method detection limits. The developed method was applied to investigate the spatial distribution and possible sources of atmospheric VMS in the Izmir region. Field sampling covered 42 sites representing different source and land use areas. ΣVMS concentrations ranged between 41.4 and 981 ng/m3. The dominant VMS was D5 followed by D3 and D4. Spatial distributions indicated that the main VMS sources in the area were urban areas, wastewater treatment plants, and landfills where the VMS-containing products are used and disposed.


Asunto(s)
Contaminantes Atmosféricos , Siloxanos , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Siloxanos/análisis , Instalaciones de Eliminación de Residuos
20.
Environ Sci Technol ; 55(6): 3756-3764, 2021 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-33666421

RESUMEN

This study investigated some sources and elimination mechanisms of phenylmethylsiloxanes in landfill leachates. During a 20-day leaching experiment for electronic wastes collected from one Chinese landfill, significant release (4.9 ng/L to 1.3 µg/L) of cis-/trans-2,4,6-triphenyl-2,4,6-trimethylcyclotrisiloxanes (cis-P3 and trans-P3) and cis-/trans-2,4,6,8-tetraphenyl-2,4,6,8-tetramethylcyclotetrasiloxanes (cis-P4 and trans-P4a,b,c) in simulated leachates was found. From January 2017 to December 2018, P3 and P4 isomers were detected in raw leachates from active cells [

Asunto(s)
Residuos Electrónicos , Eliminación de Residuos , Contaminantes Químicos del Agua , Aguas del Alcantarillado , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis
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