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1.
Int J Environ Health Res ; : 1-13, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36641808

RESUMO

Selecting an appropriate sanitation option involves multiple stakeholders with often conflicting objectives. A multiple criteria decision analysis (MCDA) framework was developed to inform decision makers on selecting appropriate sanitation options for rural communities. Criteria established from literature were evaluated and weighted on-line by stakeholders. A performance matrix was developed by assigning weights to criteria and scoring alternatives. Selection of alternatives was based on a composite appropriateness index from a rank using the simple multi-attribute ranking technique. The framework was evaluated by verification, validation and sensitivity analysis. Five alternatives were evaluated on 14 decision criteria. The first preferred alternative was the urine diverting dry toilet (72.54) then the Blair ventilated improved pit latrine (67.10). The framework was commented as reasonable and robust. A simple and transparent MCDA framework was developed considering local conditions in a participatory manner to select appropriate alternatives for rural sanitation where a single option is encouraged.

2.
Sci Total Environ ; 858(Pt 3): 160128, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36370789

RESUMO

Persulfate (PS)-based technologies have been demonstrated as efficient methods for enhancing the performance of waste activated sludge (WAS) anaerobic fermentation. Except for volatile fatty acids (VFAs), however, some exogenous substances would be also released during this process, which might affect its application as a carbon source for sewage treatment. To fill this knowledge gap, the feasibility of sludge fermentation liquid regulated by Fe/persulfate (PS) (PS-FL) as a carbon source for sewage treatment was investigated in this study. Results indicated that PS-FL exhibits distinct effects on the pollutants removal compared with commercial sodium acetate. It facilitates PO43--P removal but slightly inhibited COD removal & denitrification, and sludge settleability was also decreased. The mechanistic analysis demonstrated that PS-FL could stimulate the enrichment of phosphorus-accumulating bacteria (i.e. Candidatus Accumulibacter) and the enhancement of their metabolic activities (i.e. PKK), thereby enhancing the biological PO43--P removal. Moreover, Fe ions in PS-FL could combine with PO43--P to form a precipitate and thus further contributed to PO43--P removal. Conversely, the sulfate reduction process induced by SO42- in PS-FL inhibits denitrification by reducing the abundance of denitrifying bacteria (i.e. Dechloromonas) and metabolic activities (i.e. narG). Additionally, PS-FL also decreased the abundance of flocculation bacteria (i.e. Flavobacterium) and down-regulated the expression of functional genes responsible for COD removal, by which it exhibited certain negative effects on COD removal and sludge settleability. Overall, this work demonstrated that PS-FL can re-circulation as a carbon source for sewage treatment, which provides a new approach to recovering valuable carbon sources from WAS.


Assuntos
Poluentes Ambientais , Microbiota , Esgotos , Carbono
3.
J Hazard Mater ; 443(Pt A): 130200, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36274548

RESUMO

In this study, a suite of Fe-rich biochars derived from Fenton-like treated digestate (Fe-BC) were fabricated under different pyrolysis temperatures (300, 500, and 800 °C), which were firstly utilized as peroxymonosulfate (PMS) activators for promoting digestate dewaterability with wide applicability. Results showed that compared to the Fe-BC300/Fe-BC500 + PMS treatments, Fe-BC800 + PMS process performed superior digestate dewaterability in which specific resistance to filtration reduction and water content reduction improved by > 12.5% and > 130%, respectively, under the optimal conditions. Mechanistic results demonstrated that in Fe-BC800 + PMS system, HO• and SO4•- oxidation played a pivotal role on promoted digestate dewaterability, while HO• and 1O2 oxidation was dominated in Fe-BC300/Fe-BC500 + PMS treatments. Fe-BC800 containing higher Fe and CO contents could efficiently interact with PMS to generate numerous HO• and SO4•- via iron cycle. These highly reactive oxygen species proficiently reduced the hydrophilic biopolymers, protein molecules, and amino acids in extracellular polymeric substances, leading to remarkable decrease in particle size, hydrophilicity, adhesion, network strength, and bound water of digestate. Consequently, the flowability and dewaterability of digestate could be significantly enhanced. The cost-benefit result indicated the Fe-BC + PMS treatment possessed desirable reusability, applicability, and economic viability. Collectively, the Fe-BC + PMS is a high-performance and eco-friendly technique for digestate dewatering, which opens a new horizon towards a closed-loop of digestate reutilization.


Assuntos
Ferro , Eliminação de Resíduos Líquidos , Ferro/química , Eliminação de Resíduos Líquidos/métodos , Esgotos/química , Anaerobiose , Peróxidos/química , Oxirredução , Água/química
4.
Environ Sci Technol ; 57(1): 626-634, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36511650

RESUMO

Conventional Fenton treatment is fundamentally impractical for large-scale applications, as the consumption of Fe(II), H2O2, and pH regulators and the accumulation of iron hydroxide sludge are very costly. This paper describes a new method for Fenton treatment of complex wastewater without additional dosing of Fe(II) and H2O2, without iron-sludge accumulation, and with less consumption of pH regulators, using a novel bioelectrode system. Our new system includes a novel three-chamber microbial electrolysis unit and Fenton reaction unit, where Fenton reagents are generated by biotic and abiotic cathodes, while the bioanode simultaneously degrades biodegradable organics from the wastewater. The system's self-alkalinity buffering also waives the need for pH regulators. Dissolved organic carbon and 22 specific recalcitrant organics were removed by 99% and between 78 and 100%, respectively. The bioelectrode system generated 13 ± 3 mg/L dissolved Fe(II) and 5 ± 0.4 mg/L H2O2 for the Fenton reaction unit. The closed iron cycle avoided iron loss and iron sludge accumulation during operation. The pH regulator dosage and operating costs were just 9.7 and 1.4%, respectively, of what is required by classic Fenton. The low operating cost and reduction in chemical usage make it an efficient, sustainable alternative to the conventional treatment processes currently used for complex wastewater.


Assuntos
Poluentes Químicos da Água , Esgotos , Peróxido de Hidrogênio , Oxirredução , Ferro , Compostos Ferrosos , Eliminação de Resíduos Líquidos
5.
Sci Total Environ ; : 160491, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36455745

RESUMO

BACKGROUND: Dengue fever is a tropical disease and a major public health concern, and almost half of the world's population lives in areas at risk of contracting this disease. Climate change is identified by WHO and other international health authorities as one of the primary factors that contribute to the rapid spread of dengue fever. METHODS: We evaluated the effect of sanitation on the cross-correlation between rainfall and the first symptoms of dengue in the city of Mato Grosso do Sul, which is in a state in the Midwest region of Brazil, and employed the time-lagged detrended cross-correlation analysis (DCCAC) method. RESULTS: Co-movements were obtained through the time-phased DCCAC to analyze the effects of climatic variables on arboviruses. The use of a time-lag analysis was more robust than DCCAC without lag to present the behavior of dengue cases in relation to accumulated precipitation. Our results show that the cross-correlation between rain and dengue increased as the city implemented actions to improve basic sanitation in the city. CONCLUSION: With climate change and the increase in the global average temperature, mosquitoes are advancing beyond the tropics, and our results show that cities with improved sanitation have a high correlation between dengue and annual precipitation. Public prevention and control policies can be targeted according to the period of time and the degree of correlation calculated to structure vector control and prevention work in places where sanitation conditions are adequate.

6.
Tegucigalpa; OPS; 2022-12-14. (OPS/HND/22-0002).
em Espanhol | PAHO-IRIS | ID: phr2-56858

RESUMO

El 2 de diciembre de 1902 los países de América reunidos en Washington D.C. en la I Convención Sanitaria Internacional y a solicitud de la II Conferencia Internacional Americana, se crea un organismo promotor y coordinador de esfuerzos para combatir enfermedades, prolongar la vida y estimular el mejoramiento físico y mental de los habitantes del mundo que fue bautizado con el nombre de Oficina Sanitaria Internacional, nombre que conservó hasta el año 1923 cuando se le cambia a Oficina Sanitaria Panamericana. En la 15ª. Conferencia Sanitaria Panamericana celebrada en la Habana Cuba, el 14 de noviembre de 1924, se adoptó el nombre de Organización Panamericana de la Salud (OPS) y se publicó el Código Sanitario Panamericano que aún se mantiene vigente y sirve como catalizador de las actividades sanitarias de la región. Detrás de esta efeméride existe un interesante y ejemplar historial. La OPS es la agencia de salud pública más antigua del mundo, miembro desde el año 1948 del Sistema de Naciones Unidas. Como una de las actividades de celebración del 120 aniversario de la OPS, la Representación en Honduras ha realizado una selección de fotografías que muestran el trabajo de la Organización y algunos de los hitos más significativos en la historia de la salud pública del país, con el objetivo de dejar evidencia del camino que se ha recorrido en la búsqueda de la salud universal. Este es un libro fotográfico que muestra imágenes del trabajo de la Organización Panamericana de la Salud desde su fundación hasta la fecha actual, haciendo un especial énfasis en la cooperación brindada a Honduras, un país prioritario con el cual reiteramos nuestro compromiso para seguir contribuyendo al fortalecimiento de su sistema nacional de salud, con el objetivo de que todas las personas tengan acceso y cobertura universal de salud, de una manera equitativa, multicultural y sin dejar a nadie atrás.


Assuntos
Cobertura Universal de Saúde , Equidade no Acesso aos Serviços de Saúde , Saúde Pública , COVID-19 , Honduras
7.
Artigo em Inglês | MEDLINE | ID: mdl-36498112

RESUMO

The practical application of nanoscale zero-valent iron (NZVI) is restricted by its easy oxidation and aggregation. Here, sludge biochar (SB) was used as a carrier to stabilize NZVI for Cd2+ and Cu2+ removal. SB supported NZVI (SB-NZVI) was synthesized using the carbothermic method. The superior preparation conditions, structural characteristics, and performance and mechanisms of the SB-NZVI composites for the removal of Cd2+ and Cu2+ were investigated via batch experiments and characterization analysis. The optimal removal capacities of 55.94 mg/g for Cd2+ and 97.68 mg/g for Cu2+ were achieved at a Fe/sludge mass ratio of 1:4 and pyrolysis temperature of 900 °C. Batch experiments showed that the SB-NZVI (1:4-900) composite had an excellent elimination capacity over a broad pH range, and that weakly acidic to neutral solutions were optimal for removal. The XPS results indicated that the Cd2+ removal was mainly dependent on the adsorption and precipitation/coprecipitation, while reduction and adsorption were the mechanisms that play a decisive role in Cu2+ removal. The presence of Cd2+ had an opposite effect on the Cu2+ removal. Moreover, the SB-NZVI composites made of municipal sludge greatly reduces the leaching toxicity and bio-availability of heavy metals in the municipal sludge, which can be identified as an environmentally-friendly material.


Assuntos
Ferro , Poluentes Químicos da Água , Ferro/química , Cádmio , Esgotos , Poluentes Químicos da Água/análise , Adsorção
8.
Microorganisms ; 10(11)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36363709

RESUMO

Because of growing urbanization and lack of time to prepare meals at home, eating out or getting food delivered have become common trends for many people. The consumption of food from unknown sources may impose an increased chance of contamination with microbiological hazards, especially if sanitary conditions are not met. We evaluated data from health surveillance agencies and scientific articles on foodborne diseases (FBD) reported internationally according to the exposure sites. We observed that the data are influenced by cultural, political, and socioeconomic differences. For instance, in New Zealand, Australia, United States, Denmark and India, the occurrence of FBD outbreaks was greater from foods prepared in commercial establishments and street vendors than from households. Conversely, in China, countries of the European Union and Brazil, the results are the opposite. Additionally, the pandemic imposed new eating behavior patterns, increasing delivery services and foods prepared in so-called "Dark Kitchens". The underreporting and heterogeneity of data among countries prevented a precise conclusion to the question of whether homemade foods are inherently safer than foods prepared out. Nevertheless, a lower level of development in a country influences its sanitation conditions, as well as the number of street food vendors, the search for cheaper foods, and insufficient knowledge of the population on good hygiene practices, which can all increase the chances of FBD cases.

9.
Artigo em Inglês | MEDLINE | ID: mdl-36361004

RESUMO

COD is an arbitrary indicator of the content of organic and inorganic compounds in wastewater. The aim of this research was to determine the effect of COD of industrial wastewater on the nitrification process. This research covered wastewater from acrylonitrile and styrene-butadiene rubbers, emulsifiers, polyvinyl acetate, styrene, solvents (butyl acetate, ethyl acetate) and owipian® (self-extinguishing polystyrene intended for expansion) production. The volume of the analyzed wastewater reflected the active sludge load in the real biological treatment system. This research was carried out by the method of short-term tests. The nitrification process was inhibited to the greatest extent by wastewater from the production of acrylonitrile (approx. 51%) and styrene-butadiene (approx. 60%) rubbers. In these wastewaters, nitrification inhibition occurred due to the high COD load and the presence of inhibitors. Four-fold dilution of the samples resulted in a two-fold reduction in the inhibition of nitrification. On the other hand, in the wastewater from the production of emulsifiers and polyvinyl acetate, a two-fold reduction in COD (to the values of 226.4 mgO2·dm-3 and 329.8 mgO2·dm-3, respectively) resulted in a significant decrease in nitrification inhibition. Wastewater from the production of styrene, solvents (butyl acetate, ethyl acetate) and owipian® inhibited nitrification under the influence of strong inhibitors. Lowering the COD value of these wastewaters did not significantly reduce the inhibition of nitrification.


Assuntos
Acrilonitrila , Nitrificação , /química , Butadienos , Eliminação de Resíduos Líquidos/métodos , Óxido de Magnésio , Nitrogênio/química , Esgotos/química , Estirenos , Solventes , Reatores Biológicos
10.
BMJ Glob Health ; 7(11)2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36446446

RESUMO

INTRODUCTION: We comprehensively evaluate whether the Chinese Government's goal of ensuring Universal Health Coverage for essential health services has been achieved. METHODS: We used data from the 2008, 2013 and 2018 National Health Services Survey to report on the coverage of a range of Sustainable Development Goals (SDG) indicator 3.8.1. We created per capita household income deciles for urban and rural samples separately. We report time trends in coverage and the slope index (SII) and relative index (RII). RESULTS: Despite much lower levels of income and education, rural populations made as much progress as their urban counterparts for most interventions. Coverage of maternal and child health interventions increased substantially in urban and rural areas, with decreasing rich-poor inequalities except for antenatal care. In rural China, one-fifth women could not access 5 or more antenatal visits. Coverage of 8 or more visits were 34% and 68%, respectively in decile D1 (the poorest) and decile D10 (the richest) (SII 35% (95% CI 22% to 48%)). More than 90% households had access to clean water, but basic sanitation was poor for rural households and the urban poorest, presenting bottom inequality. Effective coverage for non-communicable diseases was low. Medication for hypertension and diabetes were relatively high (>70%). But adequate management, counting in preventive interventions, were much lower and decreased overtime, although inequalities were small in size. Screening of cervical and breast cancer was low in both urban and rural areas, seeing no progress overtime. Cervical cancer screening was only 29% (urban) and 24% (rural) in 2018, presenting persisted top inequalities (SII 25% urban, 14% rural). CONCLUSION: China has made commendable progress in protecting the poorest for basic care. However, the 'leaving no one behind' agenda needs a strategy targeting the entire population rather than only the poorest. Blunt investing in primary healthcare facilities seems neither effective nor efficient.


Assuntos
Cobertura Universal do Seguro de Saúde , Neoplasias do Colo do Útero , Gravidez , Criança , Feminino , Humanos , Detecção Precoce de Câncer , China , Cuidado Pré-Natal
11.
Environ Sci Technol ; 56(23): 17206-17214, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36409825

RESUMO

Renewable, low-carbon biofuels offer the potential opportunity to decarbonize marine transportation. This paper presents a comparative techno-economic analysis and process sustainability assessment of four conversion pathways: (1) hydrothermal liquefaction (HTL) of wet wastes such as sewage sludge and manure; (2) fast pyrolysis of woody biomass; (3) landfill gas Fischer-Tropsch synthesis; and (4) lignin-ethanol oil from the lignocellulosic ethanol biorefinery utilizing reductive catalytic fractionation. These alternative marine biofuels have a modeled minimum fuel selling price between $1.68 and $3.98 per heavy fuel oil gallon equivalent in 2016 U.S. dollars based on a mature plant assessment. The selected pathways also exhibit good process sustainability performance in terms of water intensity compared to the petroleum refineries. Further, the O and S contents of the biofuels vary widely. While the non-HTL biofuels exhibit negligible S content, the raw biocrudes via HTL pathways from sludge and manure show relatively high S contents (>0.5 wt %). Partial or full hydrotreatment can effectively lower the biocrude S content. Additionally, co-feeding with other low-sulfur wet wastes such as food waste can provide another option to produce raw biocrude with lower S content to meet the target with further hydrotreatment. This study indicates that biofuels could be a cost-effective fuel option for the marine sector. Marine biofuels derived from various feedstocks and conversion technologies could mitigate marine biofuel adoption risk in terms of feedstock availability and biorefinery economics.


Assuntos
Biocombustíveis , Eliminação de Resíduos , Esgotos , Esterco , Alimentos , Biomassa , Etanol
12.
BMC Public Health ; 22(1): 2142, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36414936

RESUMO

BACKGROUND: Clean water and sanitation are global public health issues. Safe drinking water and sanitation are essential, especially for children, to prevent acute and chronic illness death and sustain a healthy life. The UN General Assembly announced the 17 Sustainable Development Goals (SDGs) and 169 targets for the 2030 Agenda on 25 September 2015. SDG 6 is very important because it affects other SDG (1, 2,3,5,11,14 and 15). The present study deals with the national and state-wise analysis of the current status and to access deficiency of India's achievement towards SDG 6 (clean water and sanitation for all) for the 2030 agenda based on targets 6.1, 6.2,6.4,6.6 from 2012 to 2020. MATERIALS AND METHODS: Data of different indicators of SDG 6 are collected from different secondary sources-NSS 69th (2012) and 76th (2018) round; CGWB annual report 2016-2017 and 2018-2019; NARSS (2019-2020); SBM-Grameen (2020). To understand overall achievement towards SDG 6 in the 2030 agenda, the goal score (arithmetic mean of normalised value) has been calculated. MAJOR FINDINGS: According to NSS data, 88.7% of Indian households had enough drinking water from primary drinking water sources throughout the year, while 79.8% of households had access to toilet facilities in 2018. As per the 2019-2021 goal score for States and UTs in rural India based on SDG 6 indicator, SDG 6 achiever States and UTs (100%) are Sikkim, Himachal Pradesh, Andaman and Nicobar Islands. CONCLUSION: Drinking water and sanitation for all ensure a healthy life. It is a matter of concern for the government, policymakers, and people to improve the condition where the goal score and indicator value of SDG 6 are low.


Assuntos
Água Potável , Saneamento , Criança , Humanos , Desenvolvimento Sustentável , Abastecimento de Água , Características da Família
13.
Environ Health Insights ; 16: 11786302221133951, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36353216

RESUMO

Introduction: Food-borne disease is a major health problem especially in low-income countries like Ethiopia. This study aimed to assess the knowledge and practice of food handlers at student cafeteria of Kotebe Metropolitan University. Methods: A cross-sectional study design was conducted among 68 food handlers in student cafeteria of Kotebe Metropolitan University from May 30, 2018 to October 30, 2019. A structured questionnaire was used via face-to-face interviews to assess food handler's knowledge of food safety and practices food safety. Data were analyzed using Statistical Package for the Social Sciences window version 20 and presented in the form of frequency tables, percentages, and graphs. The association was tested using Pearson's chi-square, where P-value (<.05) was considered statistically significant. Results: The result showed that food handlers had good knowledge of food safety and good practice of food safety measured by the passing score of 40 (57.94%) and 48 (70.6%), respectively. Almost all food handlers were aware of the crucial role of knowledge of food safety and food safety practices in the student cafeteria. Accordingly, results of this work revealed that 67 (98.5%), 60 (88.2%), 65 (95.6%), and 56 (82.4%) of the subjects had food safety knowledge, always wash vegetables and fruits, had hand washing facilities with a supply of hot water, soap, and hand drying towel, had a hair mask or cloth during food preparation, and wore safety cloth during food preparation, respectively. Conclusion: The findings revealed significant relationship between food safety practices of food handlers and level of education, specifically regarding access to hand washing facilities, hand washing after a break and in the toilet, changing gloves between raw and ready-to-eat food, and drying and cleaning hands before handling food (P < .05). Additionally, Kotebe Metropolitan University should design food handling and safety guidelines and offer specific training for food handling workers.

14.
Antibiotics (Basel) ; 11(11)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36421249

RESUMO

Hand hygiene is the key factor to control and prevent the spread of infections, for example, hospital-acquired infections (HAIs). People commonly use alcohol-based hand sanitizers to assure hand hygiene. However, frequent use of alcohol-based hand sanitizers in a pandemic situation (e.g., COVID-19) was associated with serious drawbacks such as skin toxicity including irritation, skin dermatitis, and skin dryness or cracking, along with peeling, redness, or itching with higher possibility of infection. This demands the development of alternative novel products that are effective as alcohol-based hand sanitizers but have no hazardous effects. Zinc oxide nanoparticles (ZnO-NPs) are known to have broad-spectrum antimicrobial activity, be compatible with the biological system and the environment, and have applicable and economic industrial-scale production. Thus, ZnO-NPs might be a good candidate for hand sanitation. To the best of our knowledge, the antibacterial activity of ZnO-NPs in comparison to alcohol-based hand sanitizers has not yet been studied. In the present work, a comparative study of the antibacterial activity of ZnO-NPs vs. Sterillium, a commercial alcohol-based hand sanitizer that is commonly used in Egyptian hospitals, was performed against common microorganisms known to cause HAIs in Egypt, including Acinetobacter baumannii, Klebsiella pneumoniae,&nbsp;Methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus aureus. The safety profiles of ZnO-NPs and Sterillium were also assessed. The obtained results demonstrated the superior antibacterial activity and safety of ZnO-NPs compared to Sterillium. Therefore, ZnO-NPs could be a promising candidate for hand sanitation in comparison to alcohol-based hand sanitizers; however, several studies related to long-term toxicity and stability of ZnO-NPs and investigations into their antimicrobial activity and safety in healthcare settings are still required in the future to ascertain their antimicrobial activity and safety.

15.
Int J Mol Sci ; 23(21)2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36361844

RESUMO

The plant-microbe holobiont has garnered considerable attention in recent years, highlighting its importance as an ecological unit. Similarly, manipulation of the microbial entities involved in the rhizospheric microbiome for sustainable agriculture has also been in the limelight, generating several commercial bioformulations to enhance crop yield and pest resistance. These bioformulations were termed biofertilizers, with the consistent existence and evolution of different types. However, an emerging area of interest has recently focused on the application of these microorganisms for waste valorization and the production of "bio-organic" fertilizers as a result. In this study, we performed a bibliometric analysis and systematic review of the literature retrieved from Scopus and Web of Science to determine the type of microbial inoculants used for the bioconversion of waste into "bio-organic" fertilizers. The Bacillus, Acidothiobacillus species, cyanobacterial biomass species, Aspergillus sp. and Trichoderma sp. were identified to be consistently used for the recovery of nutrients and bioconversion of wastes used for the promotion of plant growth. Cyanobacterial strains were used predominantly for wastewater treatment, while Bacillus, Acidothiobacillus, and Aspergillus were used on a wide variety of wastes such as sawdust, agricultural waste, poultry bone meal, crustacean shell waste, food waste, and wastewater treatment plant (WWTP) sewage sludge ash. Several bioconversion strategies were observed such as submerged fermentation, solid-state fermentation, aerobic composting, granulation with microbiological activation, and biodegradation. Diverse groups of microorganisms (bacteria and fungi) with different enzymatic functionalities such as chitinolysis, lignocellulolytic, and proteolysis, in addition to their plant growth promoting properties being explored as a consortium for application as an inoculum waste bioconversion to fertilizers. Combining the efficiency of such functional and compatible microbial species for efficient bioconversion as well as higher plant growth and crop yield is an enticing opportunity for "bio-organic" fertilizer research.


Assuntos
Inoculantes Agrícolas , Eliminação de Resíduos , Fertilizantes/análise , Biomassa , Alimentos , Esgotos/microbiologia , Bibliometria , Solo
16.
Sci Rep ; 12(1): 17532, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36266312

RESUMO

This study focused on the hydrothermal treatment (HTC) of coal tailings (CT) and coal slurry (CS) and the co-hydrothermal treatment (Co-HTC) of CT, CS and sewage sludge to assess the potential for increasing the carbon content of the hydrochar produced as an enabler for a sustainable carbon economy. The optimal combination methodology and response surface methodology were used to study the relationship between the important process parameters, namely temperature, pressure, residence time, the coal-to-sewage-sludge ratio, and the carbon yield of the produced hydrochar. The optimized conditions for hydrochar from coal tailing (HCT) and hydrochar from coal slurry (HCS) (150 °C, 27 bar, 95 min) increased fixed carbon from 37.31% and 53.02% to 40.31% and 57.69%, respectively, the total carbon content improved from 42.82 to 49.80% and from 61.85 to 66.90% respectively whereas the ash content of coal discards decreased from 40.32% and 24.17% to 38.3% and 20.0% when compared CT and CS respectively. Optimized Co-HTC conditions (208 °C, 22.5bars, and 360 min) for Hydrochar from the blend of coal discards and sewage sludge (HCB) increased the fixed carbon on a dry basis and the total carbon content from 38.67% and 45.64% to 58.82% and 67.0%, when compared CT and CS respectively. Carbonization yields for HCT, HCS, and HCB were, respectively, 113.58%, 102.42%, and 129.88%. HTC and Co-HTC increase the calorific value of CT and CS, to 19.33 MJ/kg, 25.79 MJ/kg, respectively. The results further show that under Co-HTC conditions, the raw biomass undergoes dehydration and decarboxylation, resulting in a decrease in hydrogen from 3.01%, 3.56%, and 3.05% to 2.87%, 2.98%, and 2.75%, and oxygen from 8.79%, 4.78, and 8.2% to 5.83%, 2.75%, and 6.00% in the resulting HCT, HCS, and HCB, respectively. HTC and Co-HTC optimal conditions increased the specific surface area of the feedstock from 6.066 m2/g and 6.37 m2/g to 11.88 m2/g and 14.35 m2/g, for CT and CS, respectively. Total pore volume rose to 0.071 cm3/g from 0.034 cm3/g, 0.048 cm3/g, and 0.09 cm3/g proving the ability of HTC to produce high-quality hydrochar from coal discards alone or in conjunction with sewage sludge as precursors for decontamination of polluted waters, soil decontamination applications, solid combustibles, energy storage, and environmental protection.


Assuntos
Carbono , Esgotos , Carbono/química , Carvão Mineral , Hexaclorobenzeno , Temperatura , Hidrogênio , Solo , Oxigênio
17.
Sci Rep ; 12(1): 17766, 2022 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-36273077

RESUMO

Heavy metals are present in wastewater generated by industrial sectors, posing a threat to the environment, including surface and groundwater resources. With this in mind, there is a growing interest in finding alternative yet effective methods of removing heavy metal ions from industrial wastewater. Sorption is one of the techniques being readily applied due to the simplicity, high efficiency, production of small amounts of sludge, low investment, and the feasibility of the process over a wide range of pH and temperature. This paper deals with the treatment of industrial wastewater from electropolishing of stainless steel containing high concentrations of metal ions Fe(III), Cr(III), Ni(II), and Cu(II). Taking into account the effectiveness, availability and applicability of biosorbents for acidic wastewater, orange peels, algae, Eclipta alba, and eggshells were selected for the study. Sorption tests were carried out for Eclipta alba and the results obtained showed a best fit for the second-order kinetic model (R2 > 0.99) and the Langmuir isotherm model (R2 > 0.99). Maximum adsorption capacity was 17.92 mg/g for mixture of metal ions. The potential use of dried and calcinated eggshells was established. Both materials achieved a high removal rate of over 95%. Iron and chromium are removed from the solution first (about 100% and 90%, respectively), followed by nickel and copper ions. FT-IR and SEM with EDS measurements used to characterize materials, together with laboratory tests using real industrial effluent, made it possible to determine their mechanism of action. Specific surface area was determined for all tested materials and the values were: 1.63, 0.15 and 5.15 m2/g for Eclipta alba, dried eggshells and calcinated eggshells, respectively. The results provide grounds for optimism in the application of selected materials for industrial wastewater treatment.


Assuntos
Metais Pesados , Poluentes Químicos da Água , /química , Cobre/química , Níquel/química , Esgotos , Espectroscopia de Infravermelho com Transformada de Fourier , Aço Inoxidável , Compostos Férricos , Concentração de Íons de Hidrogênio , Metais Pesados/análise , Adsorção , Cromo , Íons/química , Cinética , Ferro , Poluentes Químicos da Água/análise
18.
Environ Monit Assess ; 194(12): 867, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36221011

RESUMO

Correct and effective performance evaluation of wastewater treatment plants is a tough task because of the complex biological, physico-chemical, and biochemical processes and associated variables affecting their performance. Conventionally, the efficiency of sewage treatment plants (STPs) are obtained using some index relating pollutant removal efficiency with energy used or costs. These indicators consider only one variable at a time. This leads to incorrect assessment of efficiency, which in turn could adversely affect decision-making of the regulatory authorities. The data envelope analysis (DEA) method utilizes a Linear programming technique which can handle multiple input/output variables without requiring the cost function. This makes it an appropriate tool for assessing the relative efficiency of treatment plants. The present study assess the efficiency of 30 STPs in Delhi, India, using the tolerance-based DEA model utilizing the variable return of scale (VRS). The uncertainty was incorporated into the model using the tolerance measure. The model is solved using the "Add on" option in spreadsheet toolbox of excel solver. Results reveal that out of the 30 plants considered for the study, 6 are performing well (20%). Further, it was observed that a slight change in the input data leads to instability of the efficiency results. Lastly, the ranking is used to determine the treatment plant with best efficiency under all scenarios for the larger period of the year. Such studies will help in chalking out the best management practices that could be adopted by other regulatory authorities.


Assuntos
Poluentes Ambientais , Purificação da Água , Eficiência , Monitoramento Ambiental , Índia , Esgotos , Eliminação de Resíduos Líquidos/métodos
19.
Artigo em Inglês | MEDLINE | ID: mdl-36232171

RESUMO

The operational costs of wastewater treatment plants (WWTPs) are mainly driven by electric power consumption, making the energy-efficient operation an all-time present target for engineers and operators. A well known approach to reduce the demand for purchased electricity is the operation of an anaerobic sludge stabilisation process. Although anaerobic digesters make it possible to recover large quantities of energy-rich methane gas, additional strategies are required to handle the increased internal return flow of nitrogen, which arises with the sludge dewatering effluent (SDE). SDE treatment increases the oxygen demand and in turn the energy required for aeration. In this study, different SDE treatment processes were compared with regard to the treatment in mainstream, sidestream nitritation, as well as nitritation combined with anammox for two-stage and single-stage WWTPs. Although SDE treatment in sidestream nitritation was found to have no effect on the energy demand of single-stage WWTPs, this concept allows the treatment capacity in the activated sludge tank to be raised, while contributing to a high nitrogen removal under carbon limitation. In contrast, SDE sidestream treatment showed great potential for saving energy at two-stage WWTPs, whereby sidestream nitritation and the further treatment in the first stage was found to be the most efficient concept, with a savings of approx. 11% of the aeration energy.


Assuntos
Reatores Biológicos , Esgotos , Carbono , Metano , Nitrogênio , Oxirredução , Oxigênio
20.
Artigo em Inglês | MEDLINE | ID: mdl-36232283

RESUMO

Sewage sludge (SS) has been connected to a variety of global environmental problems. Assessing the risk of various disposal techniques can be quite useful in recommending appropriate management. The preparation of sewage sludge biochar (SSB) and its impacts on soil characteristics, plant health, nutrient leaching, and greenhouse gas emissions (GHGs) are critically reviewed in this study. Comparing the features of SSB obtained at various pyrolysis temperatures revealed changes in its elemental content. Lower hydrogen/carbon ratios in SSB generated at higher pyrolysis temperatures point to the existence of more aromatic carbon molecules. Additionally, the preparation of SSB has an increased ash content, a lower yield, and a higher surface area as a result of the rise in pyrolysis temperature. The worldwide potential of SS output and CO2-equivalent emissions in 2050 were predicted as factors of global population and common disposal management in order to create a futuristic strategy and cope with the quantity of abundant global SS. According to estimations, the worldwide SS output and associated CO2-eq emissions were around 115 million tons dry solid (Mt DS) and 14,139 teragrams (Tg), respectively, in 2020. This quantity will rise to about 138 Mt DS sewage sludge and 16985 Tg CO2-eq emissions in 2050, a 20% increase. In this regard, developing and populous countries may support economic growth by utilizing low-cost methods for producing biochar and employing it in local agriculture. To completely comprehend the benefits and drawbacks of SSB as a soil supplement, further study on long-term field applications of SSB is required.


Assuntos
Gases de Efeito Estufa , Esgotos , Agricultura , Carbono , Dióxido de Carbono/análise , Carvão Vegetal , Estudos de Viabilidade , Hidrogênio , Solo
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