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2.
Chemosphere ; 275: 130092, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33984908

RESUMO

COVID-19 has led to the enormous rise of medical wastes throughout the world, and these have mainly been generated from hospitals, clinics, and other healthcare establishments. This creates an additional challenge in medical waste management, particularly in developing countries. Improper managing of medical waste may have serious public health issues and a significant impact on the environment. There are currently three disinfection technologies, namely incineration, chemical and physical processes, that are available to treat COVID-19 medical waste (CMW). This study focuses on thermochemical process, particularly pyrolysis process to treat the medical waste. Pyrolysis is a process that utilizes the thermal instability of organic components in medical waste to convert them into valuable products. Besides, the technique is environmentally friendly, more efficient and cost-effective, requires less landfill capacity, and causes lower pollution. The current pandemic situation generates a large amount of plastic medical wastes, which mainly consists of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and nylon. These plastic wastes can be converted into valuable energy products like oil, gas and char through pyrolysis process. This review provides detailed information about CMW handling, treatment, valuable product generation, and proper discharge into the open environment.


Assuntos
Resíduos de Serviços de Saúde , Humanos , Incineração , Pirólise
3.
Waste Manag ; 128: 99-113, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33975140

RESUMO

The effects of amending municipal solid waste incineration (MSWI) with carbon capture and storage (CCS) via MEA (Monoethanolamine) technology differ according to the air pollution control technologies and energy recovery systems. Electricity output reduces by one-third for power-only plants and halves for combined heat-and-power plants, while variations in heat recovery depend on the presence of flue gas condensation. MSWI with CCS can capture roughly 800 kg of compressed CO2 per tonne of waste treated. Life cycle assessment (LCA) modelling of MSWI, with and without CCS, illustrates that despite energy penalties, CCS lowers its climate change impact. The difference in climate change impacts as a result of CCS amendment depends on the energy system in which MSWI operates. In a near-future energy system, MSWI with CCS reduces climate change impacts by 700 kg CO2-eq/tonne wet waste compared to MSWI without CCS. The climate change saving of CCS became increasingly larger as the energy system became "greener"; the climate change saving ultimately approached the capture efficiency (85% of CO2 in the flue gas) multiplied by the carbon content of the waste converted to CO2. Sensitivity analysis showed that capture efficiency was the main factor affecting the overall results, with increasing importance in non-fossil fuel-based energy systems. Likely changes in residual waste composition, as source segregation and collection systems improve, had only minor effects on the environmental benefits of CCS. The effects of CCS amendments on 13 other impact categories were marginal compared to the effects of different MSWI configurations.


Assuntos
Carbono , Incineração , Centrais Elétricas , Resíduos Sólidos/análise , Tecnologia
4.
J Environ Manage ; 290: 112557, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33865154

RESUMO

Due to the amendment of the sewage sludge ordinance, both a thermal post-treatment and a phosphorous recovery from sewage sludge will become mandatory for large-scale wastewater treatment plants in Germany. This study analyzed four prospective treatment paths for sewage sludge by means of life cycle assessment. In the realm of a gate-to-cradle approach, environmental impacts were quantified for all compartments of the ReCiPe Midpoint (H) 2016 method. The spreading of digested sludge on agricultural soils was considered as the base case (system: AD + spreading). It was compared to the centralized incineration of sludge (system: AD + I), a decentralized hydrothermal carbonization followed by centralized incineration (system: AD + HTC + I) and a decentralized pyrolysis of sludge followed by centralized incineration (system: AD + P + I). For all cases, phosphorous recovery from the ash was included. A comparative evaluation showed that AD + spreading resulted in least environmental impacts in most categories but was subject to a high local immission potential due to sewage sludge spreading. It was found to be only justifiable, if toxicity and eutrophication were not compromised. Alternatively, a thermal post-treatment step is required. Hereby, AD + I and AD + HTC + I showed the overall least environmental impacts, while AD + P + I was characterized by similar or higher environmental impacts throughout all impact categories. Alongside the comparative analysis, a hotspot analysis was carried out and mitigation potentials were identified. For all thermochemical post-treatment paths, it was derived that (i) the share of fossil external energy must be kept to a minimum, (ii) primary or secondary measures to control N2O emissions during the incineration and pyrolysis should be implemented and (iii) the technological approach to recover phosphorous must be carefully selected.


Assuntos
Incineração , Esgotos , Animais , Alemanha , Estágios do Ciclo de Vida , Estudos Prospectivos
5.
Artigo em Inglês | MEDLINE | ID: mdl-33799750

RESUMO

The inadequate management of municipal solid waste (MSW) in fast-developing nations is a major public health problem. Trash collection is often inconsistent, leaving residents to use unsafe disposal methods such as incineration or unregulated dumping. The issue is especially pronounced in marginalized communities, where public service provision is scarce. Past research has identified factors that perpetuate harmful disposal practices. The current study expanded on previous work by exploring how individuals' perceptions of political, spatial, and economic marginalization affected their agency with regards to waste management. Researchers focused on a marginalized community in the Dominican Republic known as Esfuerzo de Paraíso. There, they conducted semi-structured interviews to explore residents' perceptions of marginalization at the individual, interpersonal, community, and institutional levels, and its effects on their agency. A qualitative coding process revealed that most community members were discontent with their trash disposal practices, but that long-standing marginalization left them feeling ill equipped to generate change at the individual level. Interviewees believed that change should be initiated at the community level and implemented with the support of institutional-level actors, namely the municipal government. Residents did not identify any non-governmental organizations as possible sources of help, which may suggest a limited view of institutional support networks.


Assuntos
Eliminação de Resíduos , Atitude , República Dominicana , Humanos , Incineração , Resíduos Sólidos
6.
Artigo em Inglês | MEDLINE | ID: mdl-33921868

RESUMO

Municipal solid waste (MSW) can pose a threat to public health if it is not safely managed. Despite prior research, uncertainties remain and refurbished evidence is needed along with new approaches. We conducted a systematic review of recently published literature to update and expand the epidemiological evidence on the association between MSW management practices and resident populations' health risks. Studies published from January 2005 to January 2020 were searched and reviewed following PRISMA guidelines. Eligible MSW treatment or disposal sites were defined as landfills, dumpsites, incinerators, waste open burning, transfer stations, recycling sites, composting plants, and anaerobic digesters. Occupational risks were not assessed. Health effects investigated included mortality, adverse birth and neonatal outcomes, cancer, respiratory conditions, gastroenteritis, vector-borne diseases, mental health conditions, and cardiovascular diseases. Studies reporting on human biomonitoring for exposure were eligible as well. Twenty-nine studies were identified that met the inclusion criteria of our protocol, assessing health effects only associated with proximity to landfills, incinerators, and dumpsites/open burning sites. There was some evidence of an increased risk of adverse birth and neonatal outcomes for residents near each type of MSW site. There was also some evidence of an increased risk of mortality, respiratory diseases, and negative mental health effects associated with residing near landfills. Additionally, there was some evidence of increased risk of mortality associated with residing near incinerators. However, in many cases, the evidence was inadequate to establish a strong relationship between a specific exposure and outcomes, and the studies rarely assessed new generation technologies. Evidence gaps remain, and recommendations for future research are discussed.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Humanos , Incineração , Recém-Nascido , Reciclagem , Resíduos Sólidos , Instalações de Eliminação de Resíduos
7.
Artigo em Inglês | MEDLINE | ID: mdl-33806374

RESUMO

In the case of sewage sludge, as direct landfilling was recently prohibited, it is treated through incineration. Among the air pollutants discharged through the incineration of sewage sludge, NOx and SOx are considered secondary substances of PM2.5 and are being managed accordingly. However, NH3, another of the secondary substances of PM2.5, is not well managed, and the amount of NH3 discharged from sewage sludge incineration facilities has not been calculated. Therefore, in this study, we sought to determine whether NH3 is discharged in the exhaust gas of a sewage sludge incineration facility, and, when discharged, the NH3 emission factor was calculated, and the necessity of the development of the emission factor was reviewed. As a result of the study, it was confirmed that the amount of NH3 discharged from the sewage sludge incineration facility was 0.04 to 4.47 ppm, and the emission factor was calculated as 0.002 kg NH3/ton. The NH3 emission factor was compared with the NH3 emission factor of municipal solid waste proposed by EMEP/EEA (European Monitoring and Evaluation Programme/European Environment Agency) because the NH3 emission factor of the sewage sludge incineration facility had not been previously determined. As a result of the comparison, the NH3 emission factor of EMEP/EEA was similar to that of municipal solid waste, confirming the necessity of developing the NH3 emission factor of the sewage sludge incineration facility. In addition, the evaluation of the uncertainty of the additionally calculated NH3 emission factor was conducted quantitatively and the uncertainty range was presented for reference. In the future, it is necessary to improve the reliability of the NH3 emission factor of sewage sludge incineration facilities by performing additional analysis with statistical representation. In addition, the development of NH3 emission factors for industrial waste incineration facilities should be undertaken.


Assuntos
Incineração , Esgotos , Amônia , Reprodutibilidade dos Testes , Resíduos Sólidos
8.
Waste Manag ; 126: 623-631, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33866138

RESUMO

Our society generates extensive amounts of municipal solid waste (MSW), which are mainly incinerated for volume reduction and energy recovery. Though, MSW incineration generates hazardous air pollution control (APC) residues that must be treated and deposited in appropriate landfills. An alternative to landfilling is material recovery, leading to regeneration of valuable products and reducing hazardous waste amounts. The chemical composition of APC residues, stemming from MSW, makes the waste attractive for metal and salt recovery, but its variation makes the development of material recovery processes challenging. This study investigates results from 895 X-ray fluorescence analyses of fly ash and dry scrubber residue samples originating from Norway and Sweden between 2006 and 2020 to explore variation in chemical composition within and between different incineration plants. The average relative standard deviation of elemental concentration in APC residue was estimated to 30% within plants. The variation in elemental concentration between grate fired incineration plants is about half of the average variation within the plants. The study also clarifies compositional differences from APC residues originating from fluidized bed incinerators and grate incinerators. Also, reported concentrations of APC residues from other countries than Sweden and Norway showed significant differences in chemical composition. The presented variations clarifies the importance of holistic approaches for waste valorization processes which can substitute stabilization processes for landfilling.


Assuntos
Metais Pesados , Eliminação de Resíduos , Cinza de Carvão/análise , Incineração , Metais Pesados/análise , Noruega , Resíduos Sólidos/análise , Suécia
9.
Waste Manag ; 126: 652-663, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33872974

RESUMO

Although municipal solid waste incineration bottom ash (BA) has the potential to be used as a metal resource, it raises concerns about the potential release of harmful elements into the environment. Element distribution in terms of particle size and density should be assessed to determine the fractions for the metal resources' recovery and to remove harmful elements. For this purpose, this study proposed a series of sorting processes based on the distribution of 25 elements in the sorted fractions by sieving, magnetic separation, air table sorting, and milling from dry BA < 8 mm. The Ca, Na, Mg, P, S, Cl, and Ti contents exhibited a decreasing tendency with increasing particle density and could affect the formation of low-density particles. The highest density fraction of non-magnetic components of 0.5-8 mm had abundant metal particles and recorded high Cu, Zn, Cr, Ni, Mo, Fe, Pb, Sb, and Au contents. In particular, the Cu (132000 mg-Cu/kg) and Zn (43000 mg-Zn/kg) contents demonstrated potential as metal resources. The fraction contained considerable proportions of Mo (77%), Cd (46%), Cu (39%), Zn (34%), Pb (26%), Au (40%), and Ag (18%) of the total amount. After milling and sieving of the highest density fraction, a substantial amount of Cd (44%), Cu (18%), Zn (12%), Pb (13%), and Ag (11%) were found in residual minerals; they could become harmful elements when recycled for construction purposes. The results show that air table sorting can separate metal resources and harmful elements before milling of BA.


Assuntos
Incineração , Metais Pesados , Cinza de Carvão , Metais Pesados/análise , Tamanho da Partícula , Resíduos Sólidos
10.
Bioresour Technol ; 333: 125082, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33878502

RESUMO

High concentrations of nitrous oxide were recovered from partial nitrification treated leachate in a microbial electrolysis cell (MEC) inoculated with a nosZ-deficient strain of Pseudomonas aeruginosa. N2O conversion efficiencies > 90% were achieved when a potential of 0.8 V was applied to the MEC. The ΔnosZ strain was enriched in the 0.8 V MEC, but Achromobacter dominated the non-current control. Nitric oxide reductase genes were highly expressed by ΔnosZ cells growing in the 0.8 V MEC, consistent with enhanced nitrous oxide production rates. Concentrations of phenazine derivatives and transcripts from phenazine biosynthesis genes were also high in the 0.8 V MEC. Phenazine derivatives are known to act as electron shuttles, enhance biofilm formation, and help ward off competitors, thereby increasing the survivability of the ΔnosZ strain in the MEC. These results show that applied current stabilized growth of the ΔnosZ strain in the reactor and allowed it to sustainably generate high concentrations of nitrous oxide.


Assuntos
Óxido Nitroso , Pseudomonas aeruginosa , Eletrólise , Incineração , Nitrificação , Pseudomonas aeruginosa/genética
11.
Waste Manag ; 126: 706-718, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33878675

RESUMO

This is the first study integrate the flameless oxidation (FO) and in-chamber melting (ICM) processes in a primary chamber of a laboratory waste incinerator to improve energy and emission performances. Two liquid burners created a twin-cyclonic fluid field that achieved the FO and ICM in the same chamber. The first cyclone provided a well-mixed and lower temperature FO to reduce auxiliary diesel consumption, NOx and PM emissions by 25.8%, 30.9%, and 79.2%, respectively, from the original system. The hot gases produced by FO enhance the ICM process and transformed the bottom ashes to stabler slags, in turn meeting the regulations for nonhazardous wastes. The other cyclone enhanced the drying and water-gas shift reaction in the drying zone by recirculating the CO and enthalpy from FO and ICM. Eventually, the residual CO, hydrocarbons, and H2 were sent to the secondary chamber for further oxidation. A computational fluid dynamic simulation supported the fluid field assumption posed in this study. Moreover, advanced scrubbers were employed after thermal treatments to reduce HCl and SO2 by 81.8% and 38.8% and further retarded the corrosion rate in the baghouse supporting cage by 87.7%. The precursors of condensable particulate matter were reduced by condensation and finally removed in the baghouse. Nevertheless, the emissions of the high- and mid-molecular-weight polycyclic aromatic hydrocarbons were greatly reduced by 60.8-93.1% and 80.2-99.9%, respectively. Consequently, the new system reduced annual emissions by 40.7-87.6% and operating costs by 41.5%, allowing recovery of the remodification investment in 20.5 months.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , Incineração , Laboratórios , Material Particulado/análise , Emissões de Veículos/análise
12.
Waste Manag ; 126: 754-770, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33887697

RESUMO

Amending municipal solid waste incineration (MSWI) with carbon capture and utilisation (CCU) can simultaneously lower the climate change impacts of incineration and supply carbon for a range of uses. However, life cycle assessment (LCA) shows that technology choices and the benefits of CCU applied to MSWI depend on the energy system in which the MSWI operates throughout its lifetime, and on the markets for the CCU products. Carbon capture reduces up to 50% of the energy recovery of MSWI. We assessed different energy system scenarios, ranging from fossil- to non-fossil based. Direct utilisation of the captured CO2 is beneficial only on a local basis when substituting fossil-based CO2 (-700 kg CO2-eq/tonne waste), with benefits similar to carbon capture and storage. Hydrogenation of CO2 with the purpose of producing feedstock chemicals or fuels such as methane, methanol, dimethyl ether (DME) and formic acid provides much higher benefits (-2000 kg CO2-eq/tonne waste), but only in non-fossil-based energy systems, due to the dramatically high consumption of electricity (more than 6000 kWh/tonne waste). Use as feedstock chemicals provides more benefits than use as fuels, and CCU solutions focusing on methanol and DME are the most promising technologies. Although built on scarce and early-development data, the analysis highlights current crucial issues, at both the technological and system levels, for the future introduction of CCU in MSWI.


Assuntos
Mudança Climática , Incineração , Carbono , Metano , Resíduos Sólidos/análise
13.
Waste Manag ; 126: 747-753, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33910069

RESUMO

The safe disposal of municipal solid waste incineration fly ash (MSWIFA) has become the weakest link of the circular economy of MSW due to its hazardous nature. In this study, we focused on the heavy metals solidification of MSWIFA by using alkali-activation technology and introducing a mold-pressing method. The influence of alkaline activator (AA) including alkali concentration and dosage of sodium silicate solution were well designed and studied. MSWIFA before and after alkali-activation, as well as the sample treated by commercial chelating agent (CA), were contrastively studied the performance of heavy metals solidification. The results show that the alkali-activated MSWIFA exhibits superior solidification for heavy metals than the blank control and the CA treated ones. With mold-pressing technology, the alkali-activated MSWIFA shows a core-shell structure, in which a thin layer that is composed of mainly N-A-S-H gel is as the shell and acts as a protective layer to inhibit the leaching of heavy metals. Besides, the introduced mold-pressing technology is beneficial for the improvement of materials strength and the reduction of AA dosage. The optimal AA composition is that the net concentration of NaOH is ∼4 M and sodium silicate dosage is ∼65 wt% in alkaline activator, and the total alkaline activator requirement is only 32 wt% of MSWIFA, yielding 7.9 MPa compressive strength at 10.2 MPa molding pressure. In summary, this work paves a potential new way for safe and recycling use of hazardous MSWIFA, which will be of great significance to environmental sustainability.


Assuntos
Metais Pesados , Eliminação de Resíduos , Álcalis , Carbono , Cinza de Carvão , Incineração , Metais Pesados/análise , Material Particulado , Resíduos Sólidos/análise
14.
Environ Pollut ; 281: 117018, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33813198

RESUMO

Sludge incineration technology is facing the problem of gaseous pollutant discharge. The control of NOx emissions is the key to reducing the impact of sludge combustion on environmental pollution. In this study, Fenton/CaO was used to condition municipal sludge, which was subsequently mixed with rice husk to fabricate briquette fuel for combustion experiments. The effects of the conditioner dosages, mass ratios of the rice hull to sludge, and the combustion temperatures on NOx emissions from briquette combustion were studied. The results showed that the NOx emissions decreased with increasing doses of conditioned sludge. In addition, with an increase in the rice husk ratio in the briquette, the NOx emissions decreased and the conversion rate increased. Additionally, with an increasing combustion temperature, the combustion of molded fuel became more complete. The NOx emission of conditioned sludge combustion was reduced by approximately 1.3 times compared with that of the sludge alone. Using the response surface methodology, the optimized conditions were obtained as follows: the rice husk mixing ratio is 43.8%, the Fenton/CaO conditioner dosage is 220 mg/g, and the temperature is 829 °C. The minimum NOx emission concentration was predicted to be 0.845 mg/g. The NOx emission laws observed from the combustion of mixed fuel pellets are believed to provide basic data for a new sludge treatment method.


Assuntos
Poluentes Atmosféricos , Oryza , Poluentes Atmosféricos/análise , Gases , Incineração , Esgotos
15.
Waste Manag ; 126: 388-399, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33827006

RESUMO

The COVID-19 pandemic attracts concerns globally and leads to an exponential increase in medical waste generation, and disposal of medical waste is an urgent need for preventing the epidemic spread. Emergency disposal scenarios of medical waste generated during the COVID-19 pandemic require a systematic assessment to quantify their potential environmental impacts. The environmental impacts and key factors of three movable disposal scenarios (i.e. incineration disposal vehicle, movable steam and microwave sterilization equipment both followed by co-incineration with municipal solid waste) were quantified via life cycle assessment approach. Furthermore, the environmental impacts of three movable disposal and two co-incineration scenarios were compared via life cycle assessment by expanding system boundaries. The results show that co-incineration with municipal solid waste has the lowest environmental impacts due to environmental benefits produced by power generation, while co-incineration with hazardous waste is the highest due to the high energy consumption. Energy consumption (i.e. kerosene, electricity and diesel) are the key factors for three movable disposal scenarios. For movable steam and microwave sterilization equipment followed by co-incineration with municipal solid waste, power generation from incinerating disinfected medical waste has significant beneficial environmental impacts due to avoided impacts of electricity consumption. The recommendations for improvement of the emergency disposal and management of medical waste during the COVID-19 pandemic globally and other serious epidemic in the future are provided.


Assuntos
Resíduos de Serviços de Saúde , Eliminação de Resíduos , Gerenciamento de Resíduos , Animais , China , Humanos , Incineração , Estágios do Ciclo de Vida , Pandemias , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos
16.
Waste Manag ; 126: 423-432, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33836393

RESUMO

Solid recovered fuel (SRF) ash consists of element oxides, which are valuable materials for cement manufacturers. When SRF is co-processed in the cement industry, its mineral content is incorporated into the clinker. Therefore, from a technical perspective, SRF ash is recycled. However, since recycling processes for materials that may be present in SRF exist, and since recycling goals are defined for different waste types, understanding the origin of these ash constituents and the contribution of different materials to the Recycling-index (R-index, i.e., the material-recyclable share of SRF) is important. In this work, the origins of Al, Ca, Fe, Si, Ti, Mg, Na, K, S, and P were first reviewed. Subsequently, ten SRF samples were sorted, and the ash content and composition of the sorting fractions (e.g., <10 mm, plastics, paper&cardboard) determined. Additionally, selected samples of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), liquid packaging board (LPB), wood, and paper&cardboard (P&C) extracted from SRF were investigated. The results demonstrated that the materials that contributed most of the valuable oxides and ash content, and thereby to the R-index of SRF, are mixed or composite fractions, for example, the fine fraction, composites, and the sorting residues. Except for the composite LPB, no other material recovery options exist for most of these fractions. For this reason, the recycling of mixed and soiled materials or residues in the cement industry may be considered a complementary option to existing recycling processes.


Assuntos
Eliminação de Resíduos , Materiais de Construção , Incineração , Plásticos , Embalagem de Produtos , Reciclagem , Resíduos Sólidos/análise
17.
Huan Jing Ke Xue ; 42(4): 1660-1667, 2021 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-33742801

RESUMO

Coal-fired power plants (CFPPs) and waste incineration power plants (WIPPs) represent a large portion of polycyclic aromatic hydrocarbons (PAHs) sources in the environment, among which halogenated PAHs (HPAHs) are more toxic to the human body compared with their corresponding parent PAHs. In the current work, we investigated the occurrence, formation mechanism, and toxicity effects of HPAHs in the coal and waste combustion products from three CFPPs and one WIPP. The results indicate that the contents of chlorinated PAHs (Cl-PAHs) in the fly ash from the CFPPs and WIPP were 1.06-1.67 ng·g-1 and 2.76 ng·g-1, respectively, and the contents of brominated PAHs (Br-PAHs) in the fly ash from the CFPPs and WIPP were 26.4-44.2 ng·g-1 and 6.31 ng·g-1, respectively. The HPAH contents in the fly ash from the WIPP were significantly higher than those from the CFPPs primarily due to the abundant plastics in the domestic waste, represented by polyvinyl chloride, resulting in the formation of Cl-PAHs during combustion. The HPAH contents in the fly ash from the pulverized coal-fired (PC) boiler were significantly higher than those from the circulating fluidized bed (CFB) boiler mostly due to the higher combustion temperature operated in the PC boiler. The HPAHs in the fly ash from coal combustion were predominantly 7-BrBaA and 9-ClPhe, and those from domestic combustion were predominantly 9-BrPhe and 2-ClAnt. In addition, the contents of 7-BrBaA and 9,10-Br2 Ant in the coal combustion fly ash were significantly higher than those in domestic waste combustion fly ash, whereas 2-BrFle exhibited a contrasting profile. The content of Br-PAHs in the fly ash treated by semi-dry deacidification was twice that in dust removal fly ash but significantly increased in the chelating agent stabilization fly ash. The Pearson correlation analysis indicated the the formation mechanism of Cl-PAHs and Br-PAHs were the same but a secondary formation of HPAHs during the chelating agent stabilization of the fly ash was deduced. The TEQ values of the HPAHs in the fly ash (8.87×10-3-15.0×10-3 ng·g-1) from the WIPP were similar to those in the fly ash from the CFPPs (10.0×10-3 ng·g-1), which were significantly reduced in the fly ash treated by semi-dry deacidification due to the removal of 7-BrBaA. Moreover, the TEQ values of the HPAHs in the fly ash increased 5.4 times after the chelating agent stabilization. The ecological risk should be considered for the CFPP fly ash due to their massive amount of discharge and high TEQ values.


Assuntos
Incineração , Hidrocarbonetos Policíclicos Aromáticos , Carvão Mineral/toxicidade , Cinza de Carvão/análise , Cinza de Carvão/toxicidade , Humanos , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Centrais Elétricas
18.
Waste Manag ; 126: 65-77, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33740713

RESUMO

Oxygen blown high-temperature gasification constitutes an opportunity for chemical recycling of plastic wastes. This article summarizes the results from comparative tests of combustion and gasification of two complex plastic wastes: a plastic reject (PR) from processing recycled paper and an automotive shredder residue (ASR). Calculated gasification efficiencies corresponded to about 80% and 60%, respectively. Gasification resulted in lower yields of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) compared to direct combustion. A two-stage process, including gasification followed by syngas combustion, reduced the emissions of HCl and PCDD/F in the flue gas to <1.4% and <0.2%, respectively, compared to the levels from direct combustion of the PR feedstock. Most of the PCDD/F (>99%) was captured along with particulate matter (soot) during gasification. The contribution to the toxic concentration of PCDD/F was mainly from the PCDF congeners. Fly ash particulate matter from ASR combustion contained a significant proportion of zinc, which thus constitutes a great potential for use in zinc recycling.


Assuntos
Benzofuranos , Dibenzodioxinas Policloradas , Cinza de Carvão , Dibenzofuranos Policlorados , Incineração , Plásticos , Dibenzodioxinas Policloradas/análise
19.
Waste Manag ; 126: 97-105, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33743340

RESUMO

The use of trams for the transport of waste from urban areas to waste incineration facilities - does it make sense, would it be technically feasible, economically sustainable and environmentally beneficial? These are the questions which we attempted to answer in this comprehensive study. The analysis is performed for a specific potential implementation of this system in Prague and adjacent municipalities. In this work, we compare the current state, where mixed municipal waste is transported to an incineration plant directly by garbage trucks, with variants if mixed municipal waste were taken to transfer stations and from there transported over a longer distance in a large volume by means of tram or truck. Our results show that use of trams results in an overall cost level of €16.41 per ton of waste transported, which represents a slight saving against the existing system at a cost of €17.19 per ton. From the purely economic perspective, however, this does not compete with transportation by truck at €12.28 per ton - above all due to high initial investment into new cargo trams. From the environmental viewpoint, deploying trams brings benefits largely on the local level, where emissions would be reduced by about 50% against the current state. In the global view, assessed through the Life Cycle Assessment method, it appears however only to transfer emissions to the point of energy production, and from this perspective the use of trams is beneficial only if linked with a notable shift from fossil fuel energy to nuclear or renewable sources.


Assuntos
Incineração , Eliminação de Resíduos , Cidades , Veículos Automotores , Resíduos Sólidos/análise , Transportes
20.
Waste Manag ; 125: 10-26, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33667979

RESUMO

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.


Assuntos
Biocombustíveis , Instalações de Eliminação de Resíduos , Anaerobiose , Biomassa , Reatores Biológicos , Incineração
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