Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Waste Manag Res ; 42(4): 287-307, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37533307

RESUMO

This mini-review analyses food losses and waste (FLW) management in low- and middle-income countries (LMICs) and identifies potential strategies to improve FLW management efficiency on the African continent. To achieve this aim, a search of grey and published scientific literature-case studies, feasibility studies, theses, peer-reviewed journals, governments and technical reports was performed. Food waste (FW) per capita in sub-Saharan Africa (SSA) was determined to be between 6 and 11 kg capita-1 year-1. Factors militating against FLW management include a lack of infrastructure, waste reduction and mandatory waste management plans, financial support for food redistribution programmes, awareness and a lack of knowledge of FW management and effective approaches. Poor recovery systems, a lack of incentives in FW recycling programmes, a lack of a regulatory and policy framework and institutional weaknesses as well as a lack of sufficient and appropriate education programmes to improve FW source separation and collection rates are all significant challenges in the African region, with negative consequences for the environment and public health. Except for fuel conversion and food scraps for digestion to recover energy, there is a huge potential for composting and using FW as a digestate, which could eventually lead to a reduction in the amount of FW being landfilled or incinerated. The study explores potential interventions to reduce amount of FLW and form a basis for future research in this field and improving FW management efficiency in LMCs, especially on the continent of Africa. It also provides information that could assist researchers, policymakers and decision-makers reduce amount of FLW, aid in the utilization of FW for energy production, and reduce greenhouse gas emissions in the continent, as well as support the achievement of other sustainable development goals, such as 12.3, which is particularly important in the context of the African continent, which is dependent on food imports.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Países em Desenvolvimento , Alimentos , África Subsaariana
2.
BMC Public Health ; 23(1): 246, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36740692

RESUMO

BACKGROUND: Health care waste management is a challenge due to the composition of the waste generated within a health care facility, of which 85% is domestic waste, and at least 15% is hazardous waste or health care risk waste (has been in contact with blood, body fluids or tissues from humans and could cause disease). In this study, we evaluated the status quo of health care waste management plans (HCWMPs) and practices in public health care facilities in Gauteng Province, South Africa. METHODS: A situational analysis was employed in health care facilities (HCFs) that generated more than 20 kg (N = 42) of health care risk waste (HCRW) per day. Data was collected from officials responsible for the management of health care waste using a self-administered questionnaire whilst Chief Executive Officers/ managers of the HFCs were interviewed. RESULTS: The results showed that most (79.0%) of the health care waste officers (HCWOs) as well as management (84.6%) agreed to have HCWMPs in place. The majority (76.9%) of the HCFs have a dedicated person appointed to manage health care waste with the majority (67%) being environmental health practitioners. According to management, only 30.8% have formally appointed an integrated HCW committee. Only 11.7% of the HCWOs are guided by the Occupational Health and Safety Act to develop their HCWMPs with only 20.5% with health care waste minimisation strategies in place. CONCLUSION: The study concluded that there is limited integration of HCWMPs as inadequate health and safety aspects, environmental pollution as well as community participation was reported. The novelty of the study is to contribute to a body of knowledge, information on the establishment of an effective health care waste management system in public health care facilities and for decision-making purposes.


Assuntos
Saúde Pública , Gerenciamento de Resíduos , Humanos , África do Sul , Instalações de Saúde , Atenção à Saúde , Gerenciamento de Resíduos/métodos
3.
Indoor Air ; 31(6): 2118-2129, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34288145

RESUMO

Phthalates are typical air pollutants in vehicular environment since numerous synthetic materials that might contain phthalates are widely used to fabricate vehicle interiors (e.g., seat cushions, floor mats and dashboards). Hitherto, the importance of phthalate pollution in vehicular environment is not well-recognized because people spend only a small portion (around 8%) of their time in vehicles. In this study, the mass fractions of six phthalates in nine materials commonly used in Chinese vehicles (floor mats and seat cushions) were measured. Two phthalates, di-n-butyl phthalate (DnBP) and di-2-ethylhexyl phthalate (DEHP), were identified in most materials (the other phthalates were not detected). The emission characteristics of DnBP and DEHP from these materials were further investigated. The measured emission parameters were used as input for a mass-transfer model to estimate DnBP and DEHP concentrations in cabin air. Finally, the ratios between human exposures (via inhalation and dermal absorption from the gas phase) in vehicular environment and the total exposures in typical indoor environments (e.g., residences and offices) were estimated to be up to 110% and 20% for DnBP and DEHP, respectively. Based on these results, the vehicular environment might be a considerable site for human exposure to airborne phthalates.


Assuntos
Poluição do Ar em Ambientes Fechados , Ácidos Ftálicos , Poluição do Ar em Ambientes Fechados/análise , China , Exposição Ambiental/análise , Humanos , Ácidos Ftálicos/análise
4.
Sci Total Environ ; 714: 136808, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-31982732

RESUMO

In this study, measurements of seven typical polybrominated diphenyl ethers (PBDEs) in indoor settled dust were summarized in selected urban regions of China. BDE-209 was the most dominant congener in settled dust (1.4-101 µg/g), with a mean contribution of 95%. Indoor exposures to PBDEs were estimated via inhalation, dust ingestion, and dermal absorption. The average daily intake of ΣPBDE was 4.9 to 19.1 ng/day/kg for all the population groups, with >80% of the total exposures from dust ingestion. Exposures in commuting environments (contributing 60%-80% of the total exposures) were higher than those in other microenvironments. The means of hazard indexes ranged from 1.66 × 10-3 to 5.26 × 10-3, which were mainly as a result of exposure to BDE-209, BDE-47, and BDE-99. The average lifetime cancer risks were from 0.03 × 10-9 to 2.37 × 10-9, which indicated the acceptable health risks resulting from indoor PBDE exposure for the Chinese population. The present study could provide valuable information that could be helpful for decision-makers, analysts and researchers to develop, implement and evaluate the effectiveness of interventions for the reduction of exposures to semi-volatile organic compounds (SVOCs) for large population groups in China.

5.
J Air Waste Manag Assoc ; 69(10): 1230-1246, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-28278033

RESUMO

Waste tires (WTs) are becoming a significant environmental, economic, and technological challenge due to their high contents of combustible composition and potential for valuable materials and energy resources. Few studies in developing and even developed countries have been carried out to assess the challenges regarding waste tire management and to suggest the best alternative solutions for managing this waste stream. Although developed countries made progress in waste tire management needs by implementing more efficient innovative recovery and recycling methods, and restrictive regulations regarding the management of used tires, in many developing countries, the management of waste tires has not received adequate interest, and the processing, treatment, and disposal of waste tire is still nascent. In recent years, worldwide, several methods for managing used tires, including other principal alternatives for managing end-of-life tires defined in the 4Rs: reduction, reuse, recovery, and recycling, have been adopted and applied to minimize serious threats to both the natural environment and humans. This paper attempted to establish stakeholders' action that has the responsibility in waste tire management in Botswana. This study also analyzed important aspects on waste tire management in Botswana. A synthesis of approaches was employed in the present investigation to determine the factors influencing effective performance of waste tire management practice in Botswana. Data for the present study were obtained using relevant published literature, scientific journals, other third-sector sources, academic sources, and research derived from governments and other agencies and field observations. Group discussions with the participants and semistructured interviews with professionals were carried out. The outcomes of this investigation are a wide-ranging outline concerning the participants that are important in waste tire management, and a set of aspects affecting the management of waste tires. The information provided by this study is very critical for reviewing and updating the methods and tools to update waste tire data and trends to improve waste tire management efficiency, suggesting innovative methods of recovering and recycling this waste stream in Botswana. Implications: Waste tire management in Botswana demonstrates challenges that epitomize many developing and transitioning countries due to inadequate knowledge to implement integrated programs that incorporate environmental sustainability, stockpiling of whole tires at landfills, lack of consistent and systemic approaches to tire regulation, lack of methods and tools to update tire data and trends, limited application of technology to process and treat WTs, and lack of societal acceptance. To improve WT management efficiency in Botswana, it is critical to implement efficient and well-functioning approaches, including the circular economy; encourage the harmonization of policies; implement recovery and recycling methods of waste tires; prohibit stockpiling of WTs at landfilling and unofficial dumpsites; and promote economic instruments such as the tax system and the extended producer responsibility.


Assuntos
Elastômeros , Gerenciamento de Resíduos/métodos , Automóveis , Botsuana , Países em Desenvolvimento , Reciclagem
6.
Sci Total Environ ; 658: 843-853, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30583180

RESUMO

Rapid urbanization and modernization have increased exposures to phthalates from synthetic materials used indoors in China. However, exposure to phthalates from indoor environment and the associated health risks to the urban population have not been adequately characterized and documented. In this study, we summarized the recent measurements of five commonly-used phthalates in indoor environment in urban China and documented their distributions. Based on the activity patterns and exposure factors of Chinese population, Monte-Carlo simulation was used to derive their exposures. On average, the daily intake of all the targeted phthalates was 3.6 µg/kg/day for adults; and for children it ranged from 4.4 µg/kg/day to 8.1 µg/kg/day. For children, the total risk from exposures inside residences and offices was 32%-90% and 4%-19%, respectively. From commuting environments and other indoor environments, it was 5%-31%, and 3%-26%, respectively. For adults, the total risk from residences and offices was 26%-78% and 9%-35%. Additionally, from commuting environments and other indoor environments, it was 8%-35% and 5%-11%, respectively. The non-carcinogenic risk assessment was based on a cumulative Tolerable Daily Intake (TDIcum), with means ranging from 0.18 to 0.41, which was mainly as a result of exposure to DiBP and DnBP. The means for lifetime cancer risk resulting from DEHP exposure ranged from 0.4 × 10-6 to 2.0 × 10-6 for urban population groups. For 80% of working adults and 40%-75%% of children, their cancer risks exceeded the EPA's benchmark (1.0 × 10-6). The present study could provide important information for decision makers to reduce indoor phthalate exposures as well as the associated health risks for larger population groups in Chinese cities.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Exposição Ambiental/análise , Ácidos Ftálicos/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Método de Monte Carlo , Medição de Risco , População Urbana , Adulto Jovem
7.
Waste Manag Res ; 36(7): 555-576, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29865991

RESUMO

Effective waste management practices are not all about legislative solutions, but a combination of the environmental, social, technical, technically skilled human resources, financial and technological resources, resource recycling, environmental pollution awareness programmes and public participation. As a result of insufficient resources, municipal solid waste (MSW) in transition and developing countries like Botswana remains a challenge, and it is often not yet given highest priority. In Botswana, the environment, public health and other socio-economic aspects are threatened by waste management practices due to inadequate implementation and enforcement mechanisms of waste management policy. This mini-review paper describes the panorama of waste management practices in Botswana and provides information to competent authorities responsible for waste management and to researchers to develop and implement an effective waste management system. Waste management practices in Botswana are affected by: lack of effective implementation of national waste policy, fragmented tasks and overlapping mandates among relevant institutions; lack of clear guidelines on the responsibilities of the generators and public authorities and on the associated economic incentives; and lack of consistent and comprehensive solid waste management policies; lack of intent by decision-makers to prepare national waste management plans and systems, and design and implement an integrated sustainable municipal solid waste management system. Due to these challenges, there are concerns over the growing trend of the illegal dumping of waste, creating mini dumping sites all over the country, and such actions jeopardize the efforts of lobbying investors and tourism business. Recommendations for concerted efforts are made to support decision makers to re-organize a sustainable waste management system, and this paper provides a reference to other emerging economies in the region and the world.


Assuntos
Reciclagem , Gerenciamento de Resíduos , Botsuana , Poluição Ambiental , Humanos , Eliminação de Resíduos , Resíduos Sólidos
8.
Ergonomics ; 61(6): 796-805, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29287520

RESUMO

In practice, passengers actively respond to the thermal environment when they board an aircraft in winter, which is not considered in the current standards. In this study, the behavioural, physiological and psychological responses to the thermal environment were examined at 22 °C (with 68 subjects), 20 °C and 26 °C (with 32 subjects). The results showed that the three air temperature levels had significant effect on nozzle usage and clothing adjustment behaviours, surface skin temperature, and thermal sensation vote (TSV). The walking/waiting states prior to boarding the aircraft cabin had a significant effect on the proportion of jacket removal, TSV and thermal comfort vote. After 10 min in the aircraft cabin, the subjects maintained their comfort in a wider range of the thermal environment when the behavioural adjustments existed compared to when they did not. Thus, a suggestion was made for behavioural adjustments to be provided in aircraft cabins. Practitioner Summary: Experimental investigation of human responses was conducted in an aircraft cabin. Analysis showed that the subjects maintained their comfort in a wider range of the thermal environment when the behavioural adjustments existed compared to when they did not. Thus, a suggestion was made for behavioural adjustments to be provided in aircraft cabins.


Assuntos
Ar Condicionado/métodos , Aeronaves , Comportamento do Consumidor , Estações do Ano , Temperatura , Adaptação Fisiológica/fisiologia , Adaptação Psicológica/fisiologia , Adolescente , Adulto , Vestuário , Estudos Transversais , Feminino , Humanos , Masculino , Temperatura Cutânea , Adulto Jovem
9.
Environ Sci Pollut Res Int ; 23(19): 19409-16, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27378220

RESUMO

A simple method based on dispersive solid-phase extraction (DSPE) and dispersive liquid-liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) was developed for the extraction of chlorpyrifos (CP), chlorpyrifos-methyl (CPM), and their main degradation product 3,5,6-trichloro-2-pyridinol (TCP) in tomato and cucumber samples. The determination was carried out by high performance liquid chromatography with ultraviolet detection (HPLC-UV). In the DSPE-DLLME-SFO, the analytes were first extracted with acetone. The clean-up of the extract by DSPE was carried out by directly adding activated carbon sorbent into the extract solution, followed by shaking and filtration. Under the optimum conditions, the proposed method was sensitive and showed a good linearity within a range of 2-500 ng/g, with the correlation coefficients (r) varying from 0.9991 to 0.9996. The enrichment factors ranged from 127 to 138. The limit of detections (LODs) were in the range of 0.12-0.68 ng/g, and the relative standard deviations (RSDs) for 50 ng/g of each analytes in tomato samples were in the range of 3.25-6.26 % (n = 5). The proposed method was successfully applied for the extraction and determination of the mentioned analytes residues in tomato and cucumber samples, and satisfactory results were obtained.


Assuntos
Compostos Organofosforados/análise , Resíduos de Praguicidas/análise , Praguicidas/análise , Clorpirifos/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos , Contaminação de Alimentos , Limite de Detecção , Microextração em Fase Líquida/métodos , Extração em Fase Sólida/métodos , Soluções
10.
Water Sci Technol ; 73(11): 2781-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27232416

RESUMO

A novel vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet (VSLLME-SFO) was developed for the fast, simple and efficient determination of cadmium (Cd) in water samples followed by flame atomic absorption spectrometry (FAAS). In the VSLLME-SFO process, the addition of surfactant (as an emulsifier), could enhance the mass transfer from the aqueous solution into the extraction solvent. The extraction solvent could be dispersed into the aqueous phase under vigorous shaking with the vortex. In this paper, we investigated the influences of analytical parameters, including pH, extraction solvent type and its volume, surfactant type and its volume, concentration of chelating agent, salt effect and vortex time, on the extraction efficiency of Cd. Under the optimized conditions, the limit of detection was 0.16 µg/L. The analyte enrichment factor was 37.68. The relative standard deviation was 3.2% (10 µg/L, n = 10) and the calibration graph was linear, ranging from 0.5 to 30 µg/L. The proposed method was successfully applied for the analysis of ultra-trace Cd in river water and wastewater samples.


Assuntos
Cádmio/análise , Microextração em Fase Líquida/métodos , Espectrofotometria Atômica/métodos , Poluentes Químicos da Água/análise , Quelantes , Água Doce/análise , Tensoativos , Águas Residuárias/análise
11.
Analyst ; 141(7): 2313-8, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26911625

RESUMO

In this work, a new, rapid and reliable method for the determination of boron in water samples by dispersive liquid-liquid microextraction based on the solidification of a floating organic drop (DLLME-SFO) prior to fluorescence spectra analysis was developed. As a result of its complexation with boric acid, the method relies on the enhancement of the fluorescence (λex = 350 nm, λem = 373 nm) of chromotropic acid. The influences of DLLME-SFO parameters, including the extraction solvent type and its volume, pH, the disperser solvent type and its volume, and salt effects were investigated. Under the optimized conditions, the limit of detection was 0.11 ng L(-1), with a preconcentration factor of 86 times. The calibration curve was linear in the range of 0-40 nM. The proposed method has also been successfully applied to analyze real water samples and the relative recoveries of water samples ranged from 86.9 to 93.2%.

12.
J Sep Sci ; 39(7): 1258-65, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26888089

RESUMO

A novel dispersive solid-phase extraction combined with vortex-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplet was developed for the determination of eight benzoylurea insecticides in soil and sewage sludge samples before high-performance liquid chromatography with ultraviolet detection. The analytes were first extracted from the soil and sludge samples into acetone under optimized pretreatment conditions. Clean-up of the extract was conducted by dispersive solid-phase extraction using activated carbon as the sorbent. The vortex-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplet procedure was performed by using 1-undecanol with lower density than water as the extraction solvent, and the acetone contained in the solution also acted as dispersive solvent. Under the optimum conditions, the linearity of the method was in the range 2-500 ng/g with correlation coefficients (r) of 0.9993-0.9999. The limits of detection were in the range of 0.08-0.56 ng/g. The relative standard deviations varied from 2.16 to 6.26% (n = 5). The enrichment factors ranged from 104 to 118. The extraction recoveries ranged from 81.05 to 97.82% for all of the analytes. The good performance has demonstrated that the proposed methodology has a strong potential for application in the multiresidue analysis of complex matrices.

13.
J AOAC Int ; 99(1): 260-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26823154

RESUMO

A low-toxic dispersive liquid-liquid microextraction (DLLME) combined with inductively coupled plasma-MS was used for preconcentration and determination of Cu, Cr, Cd, Ni, Mn, and Pb in real-water samples. In traditional DLLME analysis, chlorinated solvents have been widely used as extraction solvents. However, these solvents are not environmentally friendly. To overcome this problem, we used a low-toxic bromosolvent (1-bromo-3-methylbutane; lethal concentration, 50%, 6150 mg/kg) as the extraction solvent. To study the effects of different parameters on the extraction efficiency, an orthogonal array experimental design with an L16(4(5)) matrix was used. Under the best experimental conditions (i.e., concentration of complexing reagent 1-(2-pyridylazo)-2-naphthol, 1.5 × 10(-3) mol/L; pH, 7.0; volume of acetone, 0.5 mL; volume of 1-bromo-3 methylbutane, 30 µL; and without salt addition), the enhancement factor ranged from 34 to 40. The linear dynamic range was 1-1000 µg/L with r(2) values of 0.9984-0.9999, and the LODs were between 0.042 and 0.53 µg/L. RSDs (at metal ion concentrations of 20 µg/L, n = 6) were 2.12 to 3.42%. The developed method was successfully applied to the extraction and determination of the mentioned metal ions in real-water samples, and satisfactory results were obtained.


Assuntos
Hidrocarbonetos Bromados/química , Microextração em Fase Líquida , Metais Pesados/análise , Solventes/química , Poluentes Químicos da Água/química , Espectrometria de Massas
14.
Arch Environ Contam Toxicol ; 70(3): 607-14, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26614355

RESUMO

A low toxic solvent-based vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction (LT-VSLLME) combined with graphite furnace atomic absorption spectrometry was developed for the extraction and determination of lead (Pb) in water samples. In the LT-VSLLME method, the extraction solvent was dispersed into the aqueous samples by the assistance of vortex agitator. Meanwhile, the addition of a surfactant, which acted as an emulsifier, could enhance the speed of the mass-transfer from aqueous samples to the extraction solvent. The influences of analytical parameters, including extraction solvent type and its volume, surfactant type and its volume, pH, concentration of chelating agent, salt effect and extraction time were investigated. Under the optimized conditions, a good relative standard deviation of 3.69% at 10 ng L(-1) was obtained. The calibration graph showed a linear pattern in the ranges of 5-30 ngL(-1), with a limit of detection of 0.76 ng L(-1). The linearity was obtained by five points in the concentration range of 5-30 ngL(-1). The enrichment factor was 320. The procedure was applied to wastewater and river water, and the accuracy was assessed through the analysis of the recovery experiments.


Assuntos
Monitoramento Ambiental/métodos , Chumbo/análise , Poluentes Químicos da Água/análise , Calibragem , Quelantes , Grafite/química , Limite de Detecção , Microextração em Fase Líquida , Espectrofotometria Atômica , Tensoativos
15.
J Sep Sci ; 38(24): 4204-10, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26475036

RESUMO

A novel low-density solvent-based vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with the solidification of floating organic droplet method coupled with high-performance liquid chromatography was developed for the determination of 3,5,6-trichloro-2-pyridinol, phoxim and chlorpyrifos-methyl in water samples. In this method, the addition of a surfactant could enhance the speed of the mass transfer from the sample solution into the extraction solvent. The extraction solvent could be dispersed into the aqueous by the vortex process. The main parameters affecting the extraction efficiency were investigated and the optimum conditions were established as follows: 80 µL 1-undecanol as extraction solvent, 0.2 mmol/L of Triton X-114 selected as the surfactant, the vortex time was fixed at 60 s with the vortex agitator set at 3000 rpm, the concentration of acetic acid in sample solution was 0.4% v/v and 1.0 g addition of NaCl. Under the optimum conditions, the enrichment factors were from 172 to 186 for the three analytes. The linear ranges were from 0.5 to 500 µg/L with a coefficient of determination (r(2) ) of between 0.9991 and 0.9995. Limits of detections were varied between 0.05 and 0.12 µg/L. The relative standard deviations (n = 6) ranged from 0.26 to 2.62%.

16.
J Sep Sci ; 38(20): 3487-93, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26257135

RESUMO

Vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with UV detection was applied to determine Isocarbophos, Parathion-methyl, Triazophos, Phoxim and Chlorpyrifos-methyl in water samples. 1-Bromobutane was used as the extraction solvent, which has a higher density than water and low toxicity. Centrifugation and disperser solvent were not required in this microextraction procedure. The optimum extraction conditions for 15 mL water sample were: pH of the sample solution, 5; volume of the extraction solvent, 80 µL; vortex time, 2 min; salt addition, 0.5 g. Under the optimum conditions, enrichment factors ranging from 196 to 237 and limits of detection below 0.38 µg/L were obtained for the determination of target pesticides in water. Good linearities (r > 0.9992) were obtained within the range of 1-500 µg/L for all the compounds. The relative standard deviations were in the range of 1.62-2.86% and the recoveries of spiked samples ranged from 89.80 to 104.20%. The whole proposed methodology is simple, rapid, sensitive and environmentally friendly for determining traces of organophosphorus pesticides in the water samples.

17.
J Air Waste Manag Assoc ; 65(1): 11-26, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25946954

RESUMO

The management of waste electronic and electrical equipment (WEEE) is a major challenge in developing and transition countries. The paper investigates recent strategies to manage this waste stream in an environmentally sound way. Obsolete electrical and electronic equipment (EEE) are a complex waste category containing both hazardous and valuable substances. Many countries and regions in the world are undertaking extensive scientific research to plan and develop effective collection and treatment systems for end-of-life EEE. In developing countries such as Botswana, effective strategies that cover all stages throughout the lifecycle of products, particularly at the end-of-life, still lag behind. Infrastructure, pre-processing, and end-processing facilities and innovative technologies for end-of-life management of e-waste are noticeably absent due to lack of investment and high costs of its management. The objective of the paper is to present the e-waste situation in Botswana, highlighting (a) measures taken in the form of legislative and policy regulations; (b) existing practices to manage e-waste; and (c) effective solutions for e-waste management in emerging economies. Studies from other countries on e-waste management issues provided insights on the "best" technical and logistical pre-processing and end-processing strategies to treat hazardous waste. The paper also highlights key societal factors that affect successful implementation of cost-effective collection and value recovery of end-of-life EEE. These include unavailability of national "e-waste policy," absence of formal take-back system, absence of financing and subsidies, inadequate source separation programmes, absence of technical and logistical integration of pre-processing and end-processing facilities, and limited infrastructure and access to technologies and investment. Effective strategies such as an "integrated approach" (mixed options), access to technologies, establishment of pre-processing and end-processing facilities and optimization of logistics, optimizing diversion of e-waste from disposal sites, and investment in e-waste are suggested to manage this complex waste stream in an environmentally sound way.


Assuntos
Países em Desenvolvimento , Resíduo Eletrônico , Gerenciamento de Resíduos/métodos , Botsuana , Gerenciamento de Resíduos/legislação & jurisprudência
18.
Waste Manag Res ; 32(12): 1158-68, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25432741

RESUMO

Hazardous and toxic waste is a complex waste category because of its inherent chemical and physical characteristics. It demands for environmentally sound technologies and know-how as well as clean technologies that simultaneously manage and dispose it in an environmentally friendly way. Nevertheless, Botswana lacks a system covering all the critical steps from importation to final disposal or processing of hazardous and toxic waste owing to limited follow-up of the sources and types of hazardous and toxic waste, lack of modern and specialised treatment/disposal facilities, technical know-how, technically skilled manpower, funds and capabilities of local institutions to take lead in waste management. Therefore, because of a lack of an integrated system, there are challenges such as lack of cooperation among all the stakeholders about the safe management of hazardous and toxic waste. Furthermore, Botswana does not have a systematic regulatory framework regarding monitoring and hazardous and toxic waste management. In addition to the absence of a systematic regulatory framework, inadequate public awareness and dissemination of information about hazardous and toxic waste management, slower progress to phase-out persistent and bio-accumulative waste, and lack of reliable and accurate information on hazardous and toxic waste generation, sources and composition have caused critical challenges to effective hazardous and toxic waste management. It is, therefore, important to examine the status of hazardous and toxic waste as a waste stream in Botswana. By default; this mini-review article presents an overview of the current status of hazardous and toxic waste management and introduces the main challenges in hazardous and toxic waste management. Moreover, the article proposes the best applicable strategies to achieve effective hazardous and toxic waste management in the future.


Assuntos
Substâncias Perigosas/antagonistas & inibidores , Gerenciamento de Resíduos/normas , Botsuana , Resíduos Perigosos/análise
19.
Environ Monit Assess ; 184(6): 3731-48, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21755426

RESUMO

Jialing River is the largest tributary in the catchment area of Three Gorges Reservoir, and it is also one of the important areas of sediment yield in the upper reaches of the Yangtze River. In recent years, significant changes of water and sediment characteristics have taken place. The "Long Control" Project implemented since 1989 had greatly changed the surface appearance of the Jialing River Watershed (JRW), and it had made the environments of the watershed sediment yield and sediment transport change significantly. In this research, the Revised Universal Soil Loss Equation was selected and used to predict the annual average amount of soil erosion for the special water and sediment environments in the JRW after the implementation of the "Long Control" Project, and then the rainfall-runoff modulus and the time factor of governance were both considered as dynamic factors, the dynamic sediment transport model was built for soil erosion monitoring and forecasting based on the average sediment yield model. According to the dynamic model, the spatial and temporal distribution of soil erosion amount and sediment transport amount of the JRW from 1990 to 2007 was simulated using geographic information system (GIS) technology and space-grid algorithm. Simulation results showed that the average relative error of sediment transport was less than 10% except for the extreme hydrological year. The relationship between water and sediment from 1990 to 2007 showed that sediment interception effects of the soil and water conservation projects were obvious: the annual average sediment discharge reduced from 145.3 to 35 million tons, the decrement of sediment amount was about 111 million tons, and decreasing amplitude was 76%; the sediment concentration was also decreased from 2.01 to 0.578 kg/m(3). These data are of great significance for the prediction and estimation of the future changing trends of sediment storage in the Three Gorges Reservoir and the particulate non-point source pollution load carried by sediment transport from watershed surface.


Assuntos
Sedimentos Geológicos/química , Fenômenos Geológicos , Chuva/química , Solo/química , China , Simulação por Computador , Monitoramento Ambiental , Sistemas de Informação Geográfica , Cinética , Tempo , Movimentos da Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...