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1.
Waste Manag ; 126: 791-799, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33894559

RESUMO

Estimation of construction waste generation (CWG) at the field scale is a crucial but challenging task for effective construction waste management (CWM). Extant field-scale CWG modeling approaches have faced difficulties in obtaining accurate results due to a lack of detailed CWG data, and most of them fail to consider the complex relationship among predictive variables. This study attempts to tackle this issue by proposing a novel CWG modeling approach that integrates improved on-site measurement (IOM) and a support vector machine (SVM)-based prediction model. To achieve this goal, 206 ongoing commercial construction sites were investigated to obtain the predictor values and waste generation rates (WGRs) of five types of waste (i.e., inorganic nonmetallic waste, organic waste, metal waste, composite waste, and hazardous waste) generated at three construction stages (i.e., the understructure stage, superstructure stage, and finishing stage). The data were introduced to the SVM to develop the relationships between predictive variables and WGRs. An actual commercial building under construction was used to demonstrate the applicability of the proposed approach. The results showed that the superiority of the IOM can be used as a basis to implement robust CWG data collection. In addition, the SVM-based WGR prediction model (SWPM) can obtain more accurate prediction results (R2 = 86.87%) than the back-propagation neural network (R2 = 75.14%) and multiple linear regression (R2 = 61.93%).


Assuntos
Indústria da Construção , Gerenciamento de Resíduos , China , Materiais de Construção , Resíduos Perigosos , Máquina de Vetores de Suporte
2.
J Environ Manage ; 290: 112566, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33915350

RESUMO

Mining and metal processing industries constitutes a major source of environmental pollution, albeit its huge impact on a nation's economic and industrial growth. The collaborative approach in waste management where wastes in one process/industry turns out to be a resource for another is extremely useful to sustain industries. Titanium dioxide pigment production industry operating via chloride process expels hazardous iron oxide waste byproduct rich in chloride content. The slow leaching of highly acidic and chloride rich effluents (2-5 wt.%) along with toxic heavy metals from iron oxide storage ponds in titanium industries pose serious threat to the human health and environment. The present paper describes the development of an innovative zero discharge chloride removal process via formation of layered double hydroxides (LDHs) from iron oxide waste byproduct, thereby enabling the end use applications of iron oxide. It is the first such study reported on the value addition of hazardous industrial residues via LDH formation. The developed co-precipitation process recorded maximum chloride removal efficiency in the range of 85-95%. The resultant precipitate i.e., the Friedel's salt was characterized by various techniques such as XRD, XRF and SEM-EDX and confirmed the effective removal of chlorides. The application potential of the process in real iron oxide wash waters with 95% removal efficiency and the possible reusability of precipitate utilizing the "memory effect" of LDHs were found to be highly promising. The study demonstrated the unique application potential of the process in chloride rich iron oxide wash waters unlike other industrial/domestic wastewaters, wherein other anionic species has a detrimental effect. The value added iron oxide can find application in steel industries and can mitigate the environmental and health concerns arising from the long term storage of hazardous iron oxide in mineral processing industries.


Assuntos
Cloretos , Resíduos Perigosos , Compostos Férricos , Humanos , Hidróxidos , Resíduos Industriais/análise , Titânio
3.
Artigo em Inglês | MEDLINE | ID: mdl-33668186

RESUMO

Poor management of hazardous waste can lead to environmental pollution, injuries, and adverse health risks. Children's exposure to hazardous waste may cause serious acute and chronic health problems due to their higher vulnerability to the toxic effects of chemicals. This study examines an incident of illegal chemical dumping in Pasir Gudang, Malaysia and its potential health impacts on children. The study introduced a risk assessment of possible health-related effects due to chemical contamination based on a real case scenario where quantification of the contamination was not feasible. A literature review and spatial analysis were used as research methods. On 6th March 2019, tons of hazardous waste were illegally disposed into Kim Kim River, Pasir Gudang, Malaysia. They were identified as benzene, acrolein, acrylonitrile, hydrogen chloride, methane, toluene, xylene, ethylbenzene, and d-limonene. As a result, 975 students in the vicinity developed signs and symptoms of respiratory disease due to the chemical poisoning. The findings of this study indicate that more effective policies and preventive actions are urgently needed to protect human health, especially children from improper hazardous waste management.


Assuntos
Saúde da Criança , Locais de Resíduos Perigosos , Criança , Poluição Ambiental , Resíduos Perigosos , Humanos , Malásia/epidemiologia
4.
Environ Sci Pollut Res Int ; 28(20): 24940-24971, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33770356

RESUMO

All over the globe, the generation of industrial waste has been increased due to the increasing demand for modern civilisation. In the developing countries like India, it is growing vigorously which eventually increases the production of vehicles and results in the more number of waste tyres. Despite the dumping such hazardous waste in landfills, stockpiling, and burning, their feasible utilisation in the modification of soil and concrete can be a good alternative option for their disposal. This paper enlightens the published work carried out by various researchers to enhance the mechanical properties of clayey soil using various forms of waste tyres. The effects of different forms of waste tyres on consistency limits, compaction characteristics, strength characteristics, compressibility characteristics, permeability and California-bearing ratio of cohesive soils have been reviewed. The review results show that the use of waste tyre products in ground improvement can be an economical solution for the construction industries and optimistic future as its disposal option. Still, further investigations and more research studies are required to consolidate the remarks drawn by the past researchers for its utilisation in the construction of highway/railway embankments and other field applications.


Assuntos
Eliminação de Resíduos , Resíduos , Resíduos Perigosos , Índia , Solo , Instalações de Eliminação de Resíduos
5.
J Hazard Mater ; 413: 125303, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33582463

RESUMO

Tobacco is a super-enriched plant for heavy metals, and its productivity is sensitively affected by Cd. In this study, tobacco stalk was converted to biochar (TS-biochar) for the sequestration of Cd in soils to enhance the productivity of tobacco. FTIR, SEM-EDX, and XPS characterizations of TS-biochar together with Cd2+ adsorption kinetics revealed that oxy-containing functional groups (‒OH, CË­O, and ‒COOH) in TS-biochar played a crucial role on Cd2+ adsorption. The changes of soil property and Cd speciation by adding TS-biochar in red (acidic) and cinnamon (alkaline) soils was evaluated. Effects of TS-biochar on tobacco growth and development under Cd stress was also investigated. Results indicated that a 2 wt% addition of TS-biochar in red soil could significantly increase the soil pH value (from 5.21 to 7.39) and reduce exchangeable Cd fractions (from 40% to 23%), but those were not obvious in cinnamon soil. Under the stress of Cd, TS-biochar could obviously improve the tobacco dry biomass, and decrease the accumulation of Cd in the middle and upper leaves, thus reducing economic loss. Overall, the application of TS-biochar on Cd contaminated soil can transform bioavailable Cd into low hazardous forms, so as to repair soils and improve the productivity of tobacco.


Assuntos
Cádmio , Poluentes do Solo , Agricultura , Cádmio/análise , Cádmio/toxicidade , Carvão Vegetal , Resíduos Perigosos , Solo , Poluentes do Solo/análise , Tabaco
6.
Environ Pollut ; 274: 116509, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33524648

RESUMO

The effect of Si/Al molar ratio of geopolymer on the immobilization of Se and As oxyanions was studied through leaching test and solid characterizations including XRD, FTIR, TG, NMR, XAFS, and N2 adsorption-desorption isotherm. As a whole, the leaching percentages of Se and As oxyanions increased with the increase of the Si/Al molar ratio of geopolymer. Linear combination fitting confirmed that most of selenite, selenate and arsenate ions existed in geopolymers through electrostatic interaction. Thus, Al tetrahedrons in geopolymer structure control the charge stability for these oxyanions to a large extent. Differently, as for arsenate ions, they were recrystallized into an arsenate compound (Na3.25(OH)0.25(H2O)12)(AsO4) in geopolymers. The additive of these pollutants has an adverse effect on the compactness of geopolymer, then influencing the leaching performance in turn. However, the changes in leaching results did not follow the variation trend of specific surface areas and pore volumes of geopolymers with different Si/Al ratios. The number and distribution of Al tetrahedron and compactness of geopolymer have a synergistic effect on the immobilization of these oxyanions. Besides, the compressive strengths of geopolymer samples are always higher than 20 MPa, which meets the requirement of safe disposal of hazardous waste.


Assuntos
Arsênio , Selênio , Adsorção , Resíduos Perigosos , Ácido Selênico
7.
Environ Sci Pollut Res Int ; 28(17): 21159-21173, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33405145

RESUMO

Minimization and stabilization of arsenic-containing smelting wastewater and residue is of crucial issue to resolve the arsenic contamination. Calcium arsenate is a typical precipitate produced from disposal of smelting acid wastewater. However, it suffers from poor stability and large quantity in the aqueous environment. Copper slags, as for rich-iron species materials, are disposed of in landfills or open-air tailing ponds, which are another waste material that have not been effectively utilized for reuse application. In this study, strategy for sequence of phase-controlled and thermal-doped copper slag technique was used as the efficient means of minimization and stabilization of arsenic-bearing resides. Detailed results were showed that stepwise phase precipitation significantly reduced the formation of hazardous solid waste; the total solid waste was reduced 47.0 wt% because the gypsum was separated from arsenic calcium residues through two-step methods. Subsequently, solid waste stabilization was achieved by using thermal-doped slag, and the high yield of magnetite (75.6 wt%) and fayalite (22.7 wt%) was produced from copper slags. It was proved that these iron-rich species displayed the remarkable performance to stabilize arsenic due to the formation of Fe-As-Ca-O complex; compared with the raw solid waste, the arsenic leachability was decreased from 280.75 to 1.05 mg/L via copper slag stabilization process. The immobilized arsenic content was 25.0 wt%. Overall, the proposed strategy for stepwise phase-controlled and thermal-doped copper slags was a potentially effective strategy for reducing emissions and pollution of arsenic-containing wastewater and residue.


Assuntos
Arsênio , Arsênio/análise , Cobre , Resíduos Perigosos , Resíduos Sólidos , Águas Residuárias
8.
PLoS One ; 16(1): e0243817, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33406119

RESUMO

INTRODUCTION: The management and treatment of Medical Waste (MW) are of great concern owing to its potential hazard to human health and the environment, particularly in developing countries. In Bhutan, although guidelines exist on the prevention and management of wastes, the implementation is still hampered by technological, economic, social difficulties and inadequate training of staff responsible for handling these waste. The study aimed at assessing the awareness and practice of medical waste management among health care providers and support staff at the National Referral Hospital and its compliance with the existing National guidelines and policies. MATERIALS AND METHODS: An observational cross-sectional study was conducted from March to April 2019. Three research instruments were developed and used; (i) Demographic questionnaire, (ii) Awareness questions, and (iii) the Observational checklist. The data was coded and double entered into Epi data version 3.1 and SPSS version 18 was used for analysis. Descriptive statistics were used to present the findings of the study. RESULTS: The majority of the respondents were female (54.1%) with a mean age of 32.2 (±7.67) years, most of whom have not received any waste management related training/education (56.8%). About 74.4% are aware of medical waste management and 98.2% are aware on the importance of using proper personal protective equipment. Only 37.6% knew about the maximum time limit for medical waste to be kept in hospital premises is 48 hours. About 61.3% of the observed units/wards/departments correctly segregated the waste in accordance to the national guidelines. However, half of the Hospital wastes are not being correctly transported based on correct segregation process with 58% of waste not segregated into infectious and general wastes. CONCLUSION: The awareness and practice of medical waste management among healthcare workers is often limited with inadequate sensitization and lack of proper implementation of the existing National guidelines at the study site. Therefore, timely and effective monitoring is required with regular training for healthcare workers and support staff. Furthermore, strengthening the waste management system at National Referral Hospital would provide beneficial impact in enhancing safety measures of patients.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Hospitais , Resíduos de Serviços de Saúde , Gerenciamento de Resíduos , Adulto , Lista de Checagem , Feminino , Resíduos Perigosos , Humanos , Masculino , Eliminação de Resíduos de Serviços de Saúde , Equipamento de Proteção Individual , Inquéritos e Questionários , Transportes , Adulto Jovem
9.
Sci Total Environ ; 751: 141844, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32861949

RESUMO

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are very toxic chemicals which are emitted in waste incineration and whose exposure has important adverse effects for the human health. In 2019, adipose tissue samples were collected from 15 individuals with a median age of 61 years, who had been living near a hazardous waste incinerator in Constantí (Spain). The content of PCDD/Fs in each sample was analyzed. The results were compared with data from previous studies, conducted before (1998) and after (2002, 2007 and 2013) the facility started to operate, and based on populations of similar age. In 2019, the mean concentration of PCDD/Fs in adipose tissue was 6.63 pg WHO-TEQ/g fat, ranging from 0.95 to 12.95 pg WHO-TEQ/g fat. A significant reduction was observed with respect to the baseline study (1998), when a mean PCDD/Fs concentration of 40.1 pg WHO-TEQ/g fat was found. Moreover, the current level was much lower than those observed in the 3 previous studies (9.89, 14.6 and 11.5 pg WHO-TEQ/g fat in 2002, 2007 and 2013, respectively). The body burdens of PCDD/Fs were strongly correlated with age. The significant reduction of PCDD/Fs levels in adipose tissue fully agreed with the decreasing trend of the dietary intake of PCDD/Fs by the population of the zone (from 210.1 pg I-TEQ/day in 2018 to 8.54 pg WHO-TEQ/day in 2018). Furthermore, a similar decrease has been also observed in other biological, such as breast milk and plasma. The current data in adipose tissue, as well as those in other biological monitors, indicate that the population living near the HWI is not particularly exposed to high levels of PCDD/Fs. However, biomonitoring studies cannot differentiate the impact of the HWI emissions from food consumption patterns. This question can be only solved by conducting complementary investigations and contrasting the results of monitoring and epidemiological studies.


Assuntos
Benzofuranos , Dibenzodioxinas Policloradas , Tecido Adiposo/química , Animais , Benzofuranos/análise , Dibenzofuranos , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental , Feminino , Resíduos Perigosos/análise , Humanos , Incineração , Pessoa de Meia-Idade , Dibenzodioxinas Policloradas/análise , Espanha
10.
Bioresour Technol ; 319: 124136, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32966968

RESUMO

Vermitransformation of coir pith (CP) into enriched vermifertilizer has been achieved by amending a green-manure plant, Sesbania sesban (SS) for the first time, and cow dung (CD) in five different combinations: T1(1:0:1), T2(4:3:3), T3(5:3:2), T4(5:4:1) and T5(1:1:0). The substrates were 28 days precomposted with Pleurotus sajor-caju followed by 50 days vermicomposting with Eisenia fetida and Eudrilus eugeniae. Results showed a significant reduction in cellulose, lignin, organic carbon, C/N ratio, C/P ratio and an increase in plant nutrients compared to control. The fertilization index and efficiency of nutrient recovery rate were higher in SS and CD amended CP vermicompost, with a maximum in T2(4:3:3) for E. fetida and T3(5:3:2) for E. eugeniae. The activity of dehydrogenase, urease and cellulase, and phytotoxicity assays further revealed vermicompost stability. The study concludes that T2(4:3:3) and T3(5:3:2) combinations respectively for E. fetida and E. eugeniae is suitable for vermitransformation of CP into enriched vermicompost.


Assuntos
Esterco , Oligoquetos , Animais , Bovinos , Feminino , Resíduos Perigosos , Resíduos Industriais , Lignina/análogos & derivados , Solo
11.
São Paulo; s.n; 2021. 435 p.
Tese em Português | LILACS | ID: biblio-1152047

RESUMO

Os resíduos químicos (RQ) compreendem uma infinidade de substâncias, misturas e materiais gerados nas mais variadas atividades. Nas universidades, os RQ tendem a ser diversificados e complexos, muitos dos quais são incompatíveis entre si e com as embalagens de acondicionamento disponíveis, o que demanda atenção especial, conhecimento e, cada vez mais, pesquisas sobre essa problemática. Este trabalho objetivou estudar a dinâmica de gerenciamento de RQ em instituição de ensino e pesquisa voltada à área da saúde, com a finalidade de identificá-los e caracterizá-los, propondo alternativas de redução da geração, maior controle de tais resíduos e, portanto, melhoria nas condições de segurança de trabalhadores e estudantes. Trata-se de estudo transversal realizado em sete Laboratórios de Investigação Médica (LIM), pertencentes ao complexo do Hospital das Clínicas, da Faculdade de Medicina e do Instituto de Medicina Tropical da Universidade de São Paulo. Os RQ gerados nos sete LIM, no período de novembro de 2017 a abril de 2019, foram classificados de acordo com o Sistema Globalmente Harmonizado de Classificação e Rotulagem de Produtos Químicos (GHS) e a legislação de transportes de cargas perigosas. Também foi estabelecida a classificação de RQ incompatíveis, conforme Método EPA-600/2-80-076. Por meio de questionário pré-elaborado, foram coletados dados quanto ao planejamento de uso de reagentes e aos procedimentos de descarte de RQ. Os resultados apontam que, na perspectiva do GHS, o código H319 (provoca irritação ocular grave) é o mais frequente em quatro laboratórios. Nos outros LIM, foram encontrados os seguintes registros majoritários para cada laboratório: H314 (provoca queimadura severa à pele e dano aos olhos); H331 (tóxico se inalado); H315 (provoca irritação à pele). No escopo do transporte externo, em avaliação conjunta dos sete laboratórios, as classes ou subclasses de risco mais comuns foram: 6.1 (substâncias tóxicas, 96 casos), 3 (líquidos inflamáveis, 93), 8 (substâncias corrosivas, 82), 9 (substâncias e artigos perigosos diversos, 30) e 5.1 (substâncias oxidantes, 16). O Método EPA-600/2-80-076 permitiu a elucidação de incompatibilidades existentes em 6 (86%) dos laboratórios, contabilizando 182 casos de substâncias que, se misturadas, podem reagir. Foram gerados 42,8 quilogramas de RQ por expiração de prazo de validade ou declaração de que o material não possuía condições de uso. Em relação ao questionário, foram obtidas 16 respostas, das quais 12 (75%) assinalaram a ausência de profissional de química no laboratório. Dez respondentes (63%) indicaram não haver treinamento formal sobre consumo consciente de reagentes químicos e gerenciamento de resíduos. Outros aspectos deficitários são: reavaliação da quantidade de reagentes adquirida, redução do desperdício, reaproveitamento, reutilização e permuta de produtos. Pode-se concluir que, no âmbito laboratorial e no transporte externo, os RQ gerados nos setores estudados possuem grande variedade referente à periculosidade. Verifica-se a necessidade de aperfeiçoamento do atual processo de gerenciamento de produtos químicos e RQ, quanto aos procedimentos de identificação (rotulagem), classificação, acondicionamento, quantificação e controle de estoques, além da capacitação de trabalhadores e estudantes. Essas etapas estão interligadas, impactam o ambiente, a integridade física e a saúde dos expostos e podem induzir a perdas materiais. Os resultados do estudo podem ser replicados a realidades similares que envolvem produtos e resíduos químicos em laboratórios.


Chemical waste (CW) comprises a multitude of substances, mixtures and materials generated in the most varied activities. In universities, the CWs tend to be more diverse and complex, many of which are incompatible with each other and with the available packaging, which requires special attention, knowledge and, increasingly, research on this issue. This work aimed to study the CW management's dynamics in a teaching and research institution focused on the health area, with the purpose of identifying and characterizing them, suggesting alternatives that entail to the reduction of generation, better control of residues and, therefore, to the improvement in the safety conditions of employees and students. This is a cross-sectional study carried out in seven Medical Research Laboratories (MRL), belonging to the complex composed by Hospital das Clínicas, Faculdade de Medicina and Instituto de Medicina Tropical of Universidade de São Paulo. The CWs originated in the seven MRL, from November 2017 to April 2019, were categorized according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and the Laws for the transport of dangerous cargo. The rating was stablished according to Method EPA-600/2-80-076 of incompatible CW. Through a pre drawn up questionnaire, data were collected regarding the planning of use of reagents and the procedures for the disposal of chemical waste. The results show that, from the perspective of the GHS, the code H319 (causes serious eye irritation) is the most frequent in four laboratories. In the others, the following major records were found for each laboratory: H314 (causes severe skin burns and eye damage); H331 (toxic if inhaled); H315 (causes skin irritation). In the scope of external transport operation, carrying out the joint assessment of the seven laboratories, the most common risk classes or subclasses were: 6.1 (toxic substances, 96 cases), 3 (flammable liquids, 93), 8 (corrosive substances, 82), 9 (miscellaneous of dangerous substances and articles, 30) and 5.1 (oxidizing substances, 16). The EPA-600 / 2-80-076 method allowed the elucidation of a series of incompatibilities existing in 6 (86%) of the laboratories, accounting for 182 cases of substances that, if mixed, can react. It was verified that 42.8 kilograms of CW were generated by expiry of validity or statement that the material did not have conditions of use. Regarding the questionnaire, 16 responses were obtained, of which 12 (75%) indicated the absence of a chemistry professional in the laboratory. Ten survey respondents (63%) indicated that there was no formal training on conscious consumption of chemical reagents and waste management. Other deficient aspects refer to the reassessment of the quantity of reagents acquired by the laboratories, the reduction of wastage, the reuse and exchange of products. It can be concluded that, both in the laboratory scope and in the design/layout of external transport, the CW generated in the studied sectors have a great variety in terms of dangerousness. Currently, the improvement of chemicals products and CW management process is an essential demand, regarding the procedures for identification (label), classification, packaging, qualification and control of stocks, beyond to the training of workers and students. These interrelated steps affect the environment, physical integrity and health of exposed people and can induce to material losses. The study results can be replicated to similar realities involving chemical products and CW in laboratories.


Assuntos
Resíduos Perigosos , Minimização de Resíduos Perigosos , Gerenciamento de Resíduos , Gestão Ambiental , Resíduos Químicos
12.
Waste Manag ; 118: 563-572, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32987347

RESUMO

Non-hazardous industrial waste (NHIW), primarily consisting of manufacturing process residues, has long been overlooked in waste reporting, regulation, and reuse. Limited information about NHIW generation with spatial and sectoral details has impeded the systematization of reuse efforts to move towards a resource-efficient economy. In this article, we develop a methodological framework that makes the best use of fragmented and limited observational data to infer the confidence intervals of NHIW generation by sector, location, and year across the United States. The framework decomposes the quantity of NHIW into two factors: the activity level (economic output) and the waste intensity factor (waste tonnage generated per unit of output). It statistically infers the probability distribution of the waste intensity factor and extrapolates waste tonnages to the entire country. In our demonstrative application of the method, we provide an updated estimate for spent foundry sand and find that its total amount in the United States decreased from 2.2-7.1 million tons in 2004 to 1.4-4.7 million tons in 2014. The spatial distribution, however, was highly uneven, with over 90% of the waste generated in 10% of the counties, indicating great variations in reuse potentials and benefits among regions. Our methodological framework makes a significant departure from existing estimations that usually rely on averaging limited observations or expert judgments biased by subjectivity. Detailing spatial and sectoral distributions and temporal trends in NHIW generation and reuse benefits, our study could inform more systematic strategies on waste and materials management to build a circular economy.


Assuntos
Resíduos Perigosos , Gerenciamento de Resíduos , Resíduos Industriais , Indústrias , Areia , Estados Unidos
13.
J Environ Manage ; 270: 110910, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721344

RESUMO

Flux agents play an important role in the pyrolysis treatment of vitrifying hazardous wastes. Among these is plasma jets, a cost-less flux agent derived from shell powder which can be used to create vitrification. It is a promising option to be applied in the vitrification of elements and to remove the VOCs of hazardous waste, namely, resin from PCB scrap in an atmospheric-pressure microwave plasma reactor. In this study, a laboratory scale experiment was conducted. The experiment was performed in the pyrolysis of resin which was added with flux agents. The economic evaluation of the flux agents, and the circular economy concept of the final residue derived from the plasma pyrolysis was then analyzed post treatment. To test the strength and weakness of the experiment, the SWOT analysis was performed. The outcome helped in the understanding of the cost-less flux agent used in the pyrolysis treatment of hazardous waste. Results showed that fusing shell powder in resin was better for improving the removal efficiency of VOCs, such as benzene and toluene as well as toxic metals than compared to other flux agents such as limestone and quartz sand. Moreover, the final residue of resin was found to fulfil the concept of circular economy where it could be reused as an absorbent of methyl blue, thereby indicating good absorption performance, from 1 ppm-100 ppm. The twelve strategies that were derived from the SWOT analysis could be used as information outlining the current internal and external condition for the development and application of shell powder. Shell powder, as a cost-less flux agent, has the potential for enhancing waste management and circular economy when used in the pyrolysis treatment of future hazardous wastes.


Assuntos
Vitrificação , Gerenciamento de Resíduos , Resíduos Perigosos , Pirólise , Tolueno
14.
Chemosphere ; 260: 127562, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32683025

RESUMO

The presence of organic immiscible liquids such as chlorinated solvents and fuels continues to be a primary source of risk for many hazardous waste sites. In this study, the standard miscible-displacement interfacial partitioning tracer test (IPTT) method was used for the first time to measure NAPL-water interfacial areas for a range of saturations. Multiple measurements were conducted for a natural quartz sand, with tetrachloroethene as the representative NAPL. The interfacial areas increased with decreasing water saturation. The measurements compared well to interfacial areas measured for the same sand with two alternative tracer methods, the mass-distribution batch method and the two-phase flow method. Measurements obtained with all three tracer-based methods exhibit a relatively large degree of variability. Thus, it is important to employ replication when using these methods. In contrast, interfacial areas measured with x-ray microtomography exhibit very small variability. However, the measured interfacial areas do not capture the contribution of surface-roughness to film-associated interfacial area. Each method has associated advantages and disadvantages, and it is important to be cognizant of them during their application.


Assuntos
Movimentos da Água , Água/química , Resíduos Perigosos , Fenômenos Físicos , Porosidade , Quartzo/química , Propriedades de Superfície , Tetracloroetileno/química , Microtomografia por Raio-X/métodos
15.
Sci Total Environ ; 741: 140165, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32574920

RESUMO

This study focuses on the development of a treatment train for a leachate from a hazardous industrial waste landfill (HIWL) previously treated by: (i) catalytic oxidation with hydrogen peroxide (H2O2) for sulphide and sulphite conversion into oxidized sulphur species, including sulphate, and (ii) chemical precipitation of sulphate as barite. The complete treatment line counted on four more stages: (iii) 1st biological oxidation for removal of biodegradable organic compounds and nitrogen species, (iv) coagulation with ferric chloride (coagulant dose of 100 mg Fe L-1, pH 2.8) for removal of a fraction of recalcitrant organics and suspended solids, (v) photo-Fenton oxidation using ultraviolet A (UVA) radiation (PF-UVA) (pH 2.8, initial total dissolved iron content of 140 mg L-1, treatment time of ~4 h) for recalcitrant organics degradation and biodegradability improvement, and (vi) 2nd biological oxidation for removal of the biodegradable organic matter resulting from the PF-UVA process. The use of anodic oxidation or photoelectro-Fenton processes in stage (v) demonstrated to be unfeasible. A chemical oxygen demand (COD) below 1000 mg O2 L-1, a common limit imposed by municipal wastewater treatment plants (MWWTPs) to effluents discharged into the municipal sewer, was achieved after a feasible treatment time (~4 h) using the multistep approach. The remediation of the HIWL leachate proved to be a big challenge.


Assuntos
Poluentes Químicos da Água/análise , Análise da Demanda Biológica de Oxigênio , Resíduos Perigosos , Peróxido de Hidrogênio , Resíduos Industriais , Oxirredução , Eliminação de Resíduos Líquidos , Águas Residuárias
16.
Environ Sci Pollut Res Int ; 27(25): 31300-31310, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32483716

RESUMO

The collagens (COL2, COL4, and COL5) were extracted from chrome-tanned leather shavings via three distinctive routes of acid method. The dechroming degree of COL2 extracted with the easiest operation was the highest (95.6% ± 1.2%) and the yield exceeded 90%; however, the total amount of acid was the most and the cost was the highest. In the second route, although the three-step dechroming process brought cumbersome operation, the dechroming degree and yield of COL4 were 90.5% ± 0.8% and 92.2% ± 0.6%, respectively, and the acid amount was less than that in the first route. For COL5, the dechroming degree and yield was the lowest; nevertheless, this route had the advantages of lowest cost and simpler operation. Electrophoretic patterns showed that all the collagens contained α1, α2, and ß chains without low molecular weight components and were close to those of type I collagen. Compared with native collagen extracted from fresh calf skin, the regenerated collagens also maintained unique triple helix conformation determined via ultraviolet, infrared spectra and X-ray diffraction, confirmed by the similar values of AIII/A1455 and Δν. Additionally, the collagens existed in the form of fibrils with D-period pattern of ~ 67 nm. Furthermore, the denaturation temperatures of COL2, COL4, and COL5 were 71.2, 79.1, and 85.4 °C, respectively, which were relevant to the tighter arrangement of fibrils with the increased chromium content.


Assuntos
Cromo , Resíduos Perigosos , Colágeno , Temperatura , Difração de Raios X
17.
Artigo em Inglês | MEDLINE | ID: mdl-32560196

RESUMO

Because of the urgent need to protect the environment, it has become vital to deal with the dangers and particularities associated with the growth in hazardous industrial waste. Governments have begun to expand their investments in the environmental protection industry and have tightened enterprise environmental management requirements. The 13th Five-Year Plan period in China, in particular, increased the focus on the environmental supervision and enterprise environmental management. Because of the specific qualities of many types of hazardous waste, most enterprises do not have the ability to process hazardous waste and therefore must outsource the disposal to third-party contractors. However, choosing suitable hazardous waste disposal enterprises (HWDE) can be difficult. Therefore, to assist in the selection of appropriate hazardous waste disposal enterprises, this paper developed a comprehensive evaluation index system for hazardous waste disposal enterprises (EISHWDE). As multi-criteria decision-making problems involve qualitative evaluations that have semantic ambiguity, hesitant fuzzy linguistic term sets (HFLTS) were introduced to increase the accuracy of the evaluation process, an analytic hierarchy process (AHP) used to determine the objective indicator weights, and PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluation) employed to determine the final order for the selected enterprises. This research developed a scientific evaluation model that industrial waste enterprises (IWE) and related organizations could use to objectively and systematically select suitable hazardous waste disposal enterprises. Then, the problems of uncertainty and fuzzy semantics in the evaluation process were solved, and the weight of each selection criteria and the ranking of alternative enterprises are given.


Assuntos
Resíduos Perigosos , Eliminação de Resíduos , China , Lógica Fuzzy , Resíduos Perigosos/análise , Resíduos Industriais , Modelos Teóricos , Incerteza
18.
Environ Geochem Health ; 42(11): 3779-3794, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32594416

RESUMO

Municipal solid waste incineration (MSWI) for power generation can reuse waste effectively, but it generates a large amount of fly ash enriched with heavy metals. If this fly ash cannot be treated properly, it can cause ecological damage and human health risk. According to the production of ceramsites from MSWI fly ash, an evaluation methodology is established, in which the influence of heavy metal stability on the environment is considered for the first time, and the health risks of heavy metals via different exposure pathways are distinguished. The results show that heavy metals in MSWI fly ash have moderate potential environmental risks to environment and have strong non-carcinogenic and carcinogenic risks both to children and adults. By contrast, heavy metals in ceramsites pose little risk to environment and human health. This paper explains some reasons of heavy metal content and leaching ratio change in ceramsite and also illustrates why stability is a concern through comparing the potential risk index method and the improved evaluation method. This evaluation system can be applied to different production processes of building materials using solid hazardous waste and provides a quantitative evaluation method for reducing environment and human health risks of heavy metals.


Assuntos
Cinza de Carvão/química , Exposição Ambiental/efeitos adversos , Metais Pesados/análise , Medição de Risco/métodos , Resíduos Sólidos , Resíduos , Materiais de Construção , Exposição Ambiental/análise , Poluentes Ambientais/análise , Poluentes Ambientais/química , Resíduos Perigosos , Humanos , Incineração , Eliminação de Resíduos
19.
Anesth Analg ; 131(1): 288-297, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32543805

RESUMO

BACKGROUND: The inhalation anesthetics are potent greenhouse gases. To reduce the global environmental impact of the health care sector, technologies are sought to limit the release of waste anesthetic gas into the atmosphere. METHODS: Using a photochemical exhaust gas destruction system, removal efficiencies for nitrous oxide, desflurane, and sevoflurane were measured at various inlet concentrations (25% and 50%; 1.5%, 3.0%, and 6.0%; and 0.5%, 1.0%, and 2.0%, respectively) with flow rates ranging from 0.25 to 2.0 L/min. To evaluate the economic competitiveness of the anesthetic waste gas destruction system, its price per ton of carbon dioxide equivalent was calculated and compared to other greenhouse gas abatement technologies and current market prices. RESULTS: All inhaled anesthetics evaluated demonstrate enhanced removal efficiencies with decreasing flow rates (P < .0001). Depending on the anesthetic and its concentration, the photochemical exhaust gas destruction system exhibits a constant first-order removal rate, k. However, there was not a simple relation between the removal rate k and the species concentration. The costs for removing a ton of carbon dioxide equivalents are <$0.005 for desflurane, <$0.114 for sevoflurane, and <$49 for nitrous oxide. CONCLUSIONS: Based on this prototype study, destroying sevoflurane and desflurane with this photochemical anesthetic waste gas destruction system design is efficient and cost-effective. This is likely also true for other halogenated inhalational anesthetics such as isoflurane. Due to differing chemistry of nitrous oxide, modifications of this prototype photochemical reactor system are necessary to improve its removal efficiency for this gas.


Assuntos
Anestésicos Inalatórios/efeitos adversos , Anestésicos Inalatórios/química , Gases de Efeito Estufa/efeitos adversos , Gases de Efeito Estufa/química , Resíduos Perigosos/efeitos adversos , Fotoquímica/métodos , Anestesia por Inalação/efeitos adversos , Anestésicos Inalatórios/análise , Gases de Efeito Estufa/análise , Resíduos Perigosos/análise , Humanos
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