RESUMO
Stress factors such as climate change and drought may switch the role of temperate peatlands from carbon dioxide (CO2 ) sinks to sources, leading to positive feedback to global climate change. Water level management has been regarded as an important climate change mitigation strategy as it can sustain the natural net CO2 sink function of a peatland. Little is known about how resilient peatlands are in the face of future climate change scenarios, as well as how effectively water level management can sustain the CO2 sink function to mitigate global warming. The authors assess the effect of climate change on CO2 exchange of south Swedish temperate peatlands, which were either unmanaged or subject to water level regulation. Climate chamber simulations were conducted using experimental peatland mesocosms exposed to current and future representative concentration pathway (RCP) climate scenarios (RCP 2.6, 4.5 and 8.5). The results showed that all managed and unmanaged systems under future climate scenarios could serve as CO2 sinks throughout the experimental period. However, the 2018 extreme drought caused the unmanaged mesocosms under the RCP 4.5 and RCP 8.5 switch from a net CO2 sink to a source during summer. Surprisingly, the unmanaged mesocosms under RCP 2.6 benefited from the warmer climate, and served as the best sink among the other unmanaged systems. Water level management had the greatest effect on the CO2 sink function under RCP 8.5 and RCP 4.5, which improved their CO2 sink capability up to six and two times, respectively. Under the current climate scenario, water level management had a negative effect on the CO2 sink function, and it had almost no effect under RCP 2.6. Therefore, the researchers conclude that water level management is necessary for RCP 8.5, beneficial for RCP 4.5 and unimportant for RCP 2.6 and the current climate.
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Dióxido de Carbono , Mudança Climática , Sequestro de Carbono , Ecossistema , ÁguaRESUMO
Water purification is one of the most essential services provided by wetlands. A lot of concerns regarding wetlands subjected to climate change relate to their susceptibility to hydrological change and the increase in temperature as a result of global warming. A warmer condition may accelerate the rate of decomposition and release of nutrients, which can be exported downstream and cause serious ecological challenges; e.g., eutrophication and acidification. The aim of this study is to investigate the effect of climate change on water quality in peatland and constructed wetland ecosystems subject to water level management. For this purpose, the authors simulated the current climate scenario base on the database from Malmö station (Scania, Sweden) for 2016 and 2017 as well as the future climate scenarios for the last 30 years of the century based on the Representative Concentration Pathway (RCP) and different regional climate models (RCM) for a region wider than Scania County. For future climate change, the authors simulated low (RCP 2.6), moderate (RCP 4.5) and extreme (RCP 8.5) climate scenarios. All simulations were conducted within climate chambers for experimental peatland and constructed wetland mesocosms. Our results demonstrate that the effect of climate scenario is significantly different for peatlands and constructed wetlands (interactive effect) for the combined chemical variables. The warmest climate scenario RCP 8.5 is linked to a higher water purification function for constructed wetlands, but to a lower water purification function and a subsequent deterioration of peatland water qualities, even if subjected to water level management. The explanation for the different response of constructed wetlands and peatlands to climate change could be due to the fact that the substrate in the constructed wetland mesocosms and peatlands was different in terms of the organic matter quality and quantity. The utilization of nutrients by the plants and microbial community readily exceed the mineralization under a limited nutrient content (as we had in constructed wetland) when the temperature rises. However, concerning the extreme scenario RCP 8.5, the peatlands have shown a tendency to have reverse processes.
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Ecossistema , Áreas Alagadas , Mudança Climática , Suécia , Qualidade da ÁguaRESUMO
Climate change is identified as a major threat to wetlands. Altered hydrology and rising temperature can change the biogeochemistry and function of a wetland to the degree that some important services might be turned into disservices. This means that they will, for example, no longer provide a water purification service and adversely they may start to decompose and release nutrients to the surface water. Moreover, a higher rate of decomposition than primary production (photosynthesis) may lead to a shift of their function from being a sink of carbon to a source. This review paper assesses the potential response of natural wetlands (peatlands) and constructed wetlands to climate change in terms of gas emission and nutrients release. In addition, the impact of key climatic factors such as temperature and water availability on wetlands has been reviewed. The authors identified the methodological gaps and weaknesses in the literature and then introduced a new framework for conducting a comprehensive mesocosm experiment to address the existing gaps in literature to support future climate change research on wetland ecosystems. In the future, higher temperatures resulting in drought might shift the role of both constructed wetland and peatland from a sink to a source of carbon. However, higher temperatures accompanied by more precipitation can promote photosynthesis to a degree that might exceed the respiration and maintain the carbon sink role of the wetland. There might be a critical water level at which the wetland can preserve most of its services. In order to find that level, a study of the key factors of climate change and their interactions using an appropriate experimental method is necessary. Some contradictory results of past experiments can be associated with different methodologies, designs, time periods, climates, and natural variability. Hence a long-term simulation of climate change for wetlands according to the proposed framework is recommended. This framework provides relatively more accurate and realistic simulations, valid comparative results, comprehensive understanding and supports coordination between researchers. This can help to find a sustainable management strategy for wetlands to be resilient to climate change.
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Mudança Climática , Áreas Alagadas , Sequestro de Carbono , Ecossistema , HidrologiaRESUMO
In developing countries, there is often a lack of a comprehensive data set that supports the development of coherent policies on resource recovery from wastewater treatment. This paper aims to contribute to the elaboration of resource recovery projects by providing accurate and updated data from wastewater treatment plants such as those located in the region of the Macrometropolis of Sao Paulo. The authors discuss possibilities of improvement of resource recovery for this illustrative example. Comprehensive analyses were performed based on data from 143 municipal wastewater treatment plants to understand the situation regarding resource recovery implementation in this region. The results show that just 26% of the plants perform at least one resource recovery practice. The predominant resource recovery practice is internal water reuse, and recovery is concentrated more in large plants than in medium and small ones. The sludge is disposed in landfills except for three plants, which perform sludge recycling for compost. Some plant managers reported interest in recovering energy from biogas, in expanding water reuse and in recovering sludge for fertilizer production or for building materials. Several aspects that have been regarded as relevant to the implementation of resource recovery processes in previous literature are discussed, such as the size of the plant, related legislation as well as treatment technologies and configurations. Finally, the authors propose a generic framework with several steps that can help to achieve resource recovery implementation. Therefore, the results can provide support for planning of resource recovery projects for large cities in developing countries.
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Eliminação de Resíduos Líquidos , Águas Residuárias , Cidades , Países em Desenvolvimento , EsgotosRESUMO
The aim of this paper is to provide guidance in selecting phosphorus recovery options within the municipal wastewater treatment sector regarding developing countries. This critical review includes a brief contextualization of the resource-oriented sanitation paradigm, the discussion of processes for phosphorus recovery based on methods at full-scale, pilot-scale and laboratory-scale, and a concise discussion of the environmental impacts and benefits associated with phosphorus recovery strategies. Finally, the main challenges related to the implementation of resource recovery strategies, especially for phosphorous, were identified and discussed. According to the results, some of the main drivers for phosphorus recovery are the limited availability of phosphorus, increasing cost of phosphate fertilizers and reduction of maintenance costs. Currently, most of the operational processes are based on crystallization or precipitation from the digester supernatant. Struvite is the most common recovered product. The recovery rate of phosphorus from the liquid phase is lower (10-60% from wastewater treatment plant influent), than from sludge (35-70%) and from sludge ashes (70-98%). Phosphorus recovery remains challenging, and some barriers identified were the integration between stakeholders and institutions, public policies and regulations as well as public acceptance and economic feasibility. In developing countries, the implementation of nutrient recovery systems is challenging, because the main concern is on the expansion of sanitation coverage. Resource recovery approaches can provide benefits beyond the wastewater treatment sector, not only improving the sustainability of wastewater treatment operations, but generating revenue for the utility provider.
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Fósforo , Águas Residuárias , Países em Desenvolvimento , Esgotos , Eliminação de Resíduos LíquidosRESUMO
The present study highlights microbial assimilation of carbon (glucose) and nitrogen (NH3-N) from wastewater using heterotrophic bioconversion process. Experiments were conducted to study the role of heterotrophic microbes towards removal of carbon and nitrogen at varying initial concentrations of carbon (COD, 533 to 1600 mg/l) and nitrogen (NH3-N, 73 to 249 mg/l) keeping the initial biomass of microorganisms constant. Removal of COD and ammonia from wastewater represented a first-order rate reaction, upon analysis of kinetics, indicating that the rate of reaction is dependent on the initial concentration of nutrients available. Rate equations were developed using the Monod model, and the maximum specific consumption rate (k4) and half saturation constant (Ks) values for NH3-N and COD were found to be 2.59 mg/l/h and 64.13 mg/l/h and 38.46 mg/l and 2162.69 mg/l, respectively. Assimilation of NH3-N followed the Freundlich isotherm model. The mass transfer coefficient for COD and NH3-N were found to be 0.13 h-1 and 0.81 h-1 respectively. The NH3-N is converted to N2O during nitrification, and observed values of N2O coincided with the empirically predicted values indicating the activity of heterotrophic nitrifiers. The regeneration/doubling time of heterotrophic microbial biomass varied from 26 to 121 h. Statistical techniques, viz. analysis of variance, multi-linear regression analysis and principal component analysis, validated the results.
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Carbono/metabolismo , Nitrogênio/metabolismo , Eliminação de Resíduos Líquidos , Bactérias/metabolismo , Biomassa , Processos Heterotróficos , Cinética , Nitrificação , Águas ResiduáriasRESUMO
Attapulgite (or palygorskite) is a magnesium aluminium phyllosilicate. Modified attapulgite-supported nanoscale zero-valent iron (NZVI) was created by a liquid-phase reduction method and then applied for nitrate-nitrogen (NO3-N) removal (transformation) in simulated groundwater. Nanoscale zero-valent iron was sufficiently dispersed on the surface of thermally modified attapulgite. The NO3-N removal efficiency reached up to approximately 83.8% with an initial pH values of 7.0. The corresponding thermally modified attapulgite-supported nanoscale zero-valent iron (TATP-NZVI) and NO3-N concentrations were 2.0â¯g/L and 20â¯mg/L respectively. Moreover, 72.1% of the water column NO3-N was converted to ammonium-nitrogen (NH4-N) within 6â¯h. The influence of environmental boundary conditions including dissolved oxygen (DO) concentration, light illumination and water temperature on NO3-N removal was also investigated with batch experiments. The results indicated that the DO concentration greatly impacted on NO3-N removal in the TATP-NZVI-contained solution, and the NO3-N removal efficiencies were 58.5% and 83.3% with the corresponding DO concentrations of 9.0 and 0.3â¯mg/L after 6â¯h of treatment, respectively. Compared to DO concentrations, no significant (pâ¯>â¯0.05) effect of light illumination on NO3-N removal and NH4-N generation was detected. The water temperature also has great importance concerning NO3-N reduction, and the removal efficiency of NO3-N at 25⯰C was 1.25 times than that at 15⯰C. For groundwater, therefore, environmental factors such as water temperature, anaerobic conditions and darkness could influence the NO3-N removal efficiency when TATP-NZVI is present. This study also demonstrated that TATP-NZVI has the potential to be developed as a suitable material for direct remediation of NO3-N-contaminated groundwater.
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Desnitrificação , Água Subterrânea/química , Ferro , Compostos de Magnésio , Nitratos/isolamento & purificação , Nitrogênio , Compostos de Silício , Poluentes Químicos da ÁguaRESUMO
Precipitated sludge (ochre) obtained from a mine water treatment plant was considered as an adsorbent substance for pollutants, since ochre is relatively free from problematic levels of toxic elements, which could impair on the quality of water to be treated. Artificially created ochre pellets from mixing Portland cement with raw ochre sludge were utilised to remediate either high (HC) or low (LC) contaminated synthetic greywater (SGW) in mesocosm-scale stabilisation ponds at 2-day and 7-day contact times under real weather conditions in Salford. After a specific retention time, treated SGW was agitated before sampling to evaluate pollutant removal mechanisms (other than sedimentation) such as adsorption by ochre pellets, before replacing the treated water with new inflow SGW. The results showed that cement-ochre pellets have a high ability to adsorb ortho-phosphate-phosphorous (PO4-P) significantly (p < 0.05) by 70.7% and 56.0% at 7-day contact time for HC-SGW and LC-SGW, respectively. After the experiment, an analysis revealed that elements such as boron (B), cadmium (Cd), magnesium (Mg), manganese (Mn), nickel (Ni) and zinc (Zn) accumulated significantly (p < 0.05) within the ochre pellets. The notable accumulation of Cd within ochre pellets reflects the significant (p < 0.05) remediation of greywater during the first 35 and 20 successive times of treatment for HC-SGW at 2- and 7-day contact times, respectively. Cadmium was still adsorbed significantly (p < 0.05) during the treatment of LC-SGW. However, the calcium (Ca) content decreased significantly (p < 0.05) within ochre pellets treating both types of greywaters due to mobilisation. The corresponding increases of Ca in greywater were significant (p < 0.05).
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Mineração , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água , Fósforo , Água , Purificação da ÁguaRESUMO
This study examines the benefits and risks associated with various types of wastewater recycled for vegetable garden irrigation and proposes the best water source in terms of its water quality impact on crop yields. The aim was to evaluate the usability of river, rain, gully pot, real grey and artificial grey waters to water crops. The objectives were to evaluate variables and boundary conditions influencing the growth of chillies (De Cayenne; Capsicum annuum (Linnaeus) Longum Group 'De Cayenne') both in the laboratory and in the greenhouse. A few irrigated chilli plants suffered from excess of some nutrients, which led to a relatively poor harvest. High levels of trace minerals and heavy metals were detected in river water, gully pot effluent and greywater. However, no significant differences in plant yields were observed, if compared with standards and other yields worldwide. The highest yields were associated with river water both in the laboratory and in the greenhouse. Plant productivity was unaffected by water quality due to the high manganese, potassium, cadmium and copper levels of the greywater. These results indicate the potential of river water and gully pot effluent as viable alternatives to potable water for irrigation in agriculture.
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Irrigação Agrícola/métodos , Capsicum/crescimento & desenvolvimento , Monitoramento Ambiental , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Agricultura/métodos , Cádmio , Produtos Agrícolas , Água Potável , Água Doce , Metais Pesados/análise , Chuva/química , Rios/química , Águas Residuárias/químicaRESUMO
Monitoring large-scale treatment wetlands is costly and time-consuming, but required by regulators. Some analytical results are available only after 5 days or even longer. Thus, adaptive neuro-fuzzy inference system (ANFIS) models were developed to predict the effluent concentrations of 5-day biochemical oxygen demand (BOD5) and NH4-N from a full-scale integrated constructed wetland (ICW) treating domestic wastewater. The ANFIS models were developed and validated with a 4-year data set from the ICW system. Cost-effective, quicker and easier to measure variables were selected as the possible predictors based on their goodness of correlation with the outputs. A self-organizing neural network was applied to extract the most relevant input variables from all the possible input variables. Fuzzy subtractive clustering was used to identify the architecture of the ANFIS models and to optimize fuzzy rules, overall, improving the network performance. According to the findings, ANFIS could predict the effluent quality variation quite strongly. Effluent BOD5 and NH4-N concentrations were predicted relatively accurately by other effluent water quality parameters, which can be measured within a few hours. The simulated effluent BOD5 and NH4-N concentrations well fitted the measured concentrations, which was also supported by relatively low mean squared error. Thus, ANFIS can be useful for real-time monitoring and control of ICW systems.
Assuntos
Monitoramento Ambiental/métodos , Lógica Fuzzy , Redes Neurais de Computação , Áreas Alagadas , Análise por Conglomerados , Modelos Biológicos , Qualidade da ÁguaRESUMO
Nitrogen (N) transformations and removal in integrated constructed wetlands (ICWs) are often high, but the contributions of various pathways, including nitrification/denitrification, assimilation by plants and sediment storage, remain unclear. This study quantified the contributions of different N removal pathways in a typical multi-celled ICW system treating domestic wastewater. Findings showed near complete average total N retention of circa 95% at 102.3 g m⻲ yr⻹ during the 4-year period of operation. Variations in total N and NH4-N removal rates were associated with effluent flow volume rates and seasons. According to the mass balance estimation, assimilation by plants and sediment/soil storage accounted for approximately 23% and 20%, respectively, of the total N load removal. These were the major N removal route besides microbial transformations. Thus, the combination of plants with high biomass production offer valuable opportunities for improving ICW performance. The retrieval and use of sequestered N in the ICW sediment/soils require coherent management and provide innovative and valuable opportunities.
Assuntos
Nitrogênio/metabolismo , Plantas/metabolismo , Águas Residuárias/análise , Poluentes Químicos da Água/metabolismo , Purificação da Água/normas , Áreas Alagadas , Irlanda , Estações do AnoRESUMO
Sustainable drainage systems (SuDS) design and retrofitting is predominantly based on expert opinion supported by descriptive guidance documents. The aim of this paper is to develop an innovative rapid decision support tool based on novel ecosystem service variables for retrofitting of key SuDS techniques. This unique tool proposes the retrofitting of a SuDS technique that obtained the highest ecosystem service score for a specific urban site. This approach contrasts with methods based on traditional civil engineering judgement linked to standard variables based on community and environment studies. For a case study area (Greater Manchester), a comparison with the traditional approach of determining community and environment variables indicates that permeable pavements, filter strips, swales, ponds, constructed wetlands and below-ground storage tanks are generally less preferred than infiltration trenches, soakaways and infiltration basins. However, permeable pavements and belowground storage tanks also received relatively high scores, because of their great potential impact in terms of water quality improvement and flood control, respectively. The application of the proposed methodology will lead to changes of the sustainable drainage infrastructure in the urban landscape.
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Drenagem Sanitária , Áreas Alagadas , CidadesRESUMO
Despite the many articles about activated carbon with different precursors in adsorption process, no in-depth research has been carried out to understand the causes of the difference in surface adsorption characteristics of activated carbon with different precursors and different activation processes. In this work, the ability of two active carbon adsorbents made of walnut shell and peach kernel by two chemical and physical methods (totally 4 different types of activated carbon) in treatment of oily wastewater including diesel, gasoline, used oil or engine lubricant has been compared. The results show that the chemical activated peach carbon active with 97% hardness has provided the highest hardness and physical activated walnut carbon active has obtained the lowest hardness value (87%). It is also found that peach activated carbon has a higher iodine number than walnut activated carbon, and this amount can be increased using chemical methods; Therefore, the highest amount of Iodine Number is related to Peach activated carbon that is made by chemical method (1230 mg/g), and the lowest amount of iodine number is seen in walnut activated carbon that is made by physical method (1020 mg/g). moreover, the pore diameter of physical activated carbon is lower than chemical activated carbon in all cases. So that the pore diameter of chemical activated peach carbon active is equal to 22.08 µm and the measured pore diameter of physical activated peach carbon active is equal to 20.42 µm. These values for walnut are obtained as 22.74 µm and 21.86 µm, respectively. Furthermore, the temperature and pH effects on the adsorption of different synthesized oily wastewater was studied and it was found that a decrease in adsorption can be seen with an increase in temperature or decreasing the pH value, which can be referred to this fact that the process of adsorption is an exothermic process. Finally, to analyze the compatibility of adsorption isotherms with experimental data and to predict the adsorption process, three different isotherms named Langmuir, Temkin, and Freundlich isotherms were applied and their parameters were correlated. The correlation results show that the Langmuir isotherm had the best correlation in all cases compared to the Freundlich and Temkin isotherms, based on the correlation coefficient, and the calculated R2 values which was greater than 0.99 in all the studied cases.
Assuntos
Carvão Vegetal , Juglans , Prunus persica , Termodinâmica , Águas Residuárias , Juglans/química , Carvão Vegetal/química , Águas Residuárias/química , Prunus persica/química , Adsorção , Purificação da Água/métodosRESUMO
One of the direct and unavoidable consequences of global warming-induced rising temperatures is the more recurrent and severe heatwaves. In recent years, even countries like Malaysia seldom had some mild to severe heatwaves. As the Earth's average temperature continues to rise, heatwaves in Malaysia will undoubtedly worsen in the future. It is crucial to characterize and monitor heat events across time to effectively prepare for and implement preventative actions to lessen heatwave's social and economic effects. This study proposes heatwave-related indices that take into account both daily maximum (Tmax) and daily lowest (Tmin) temperatures to evaluate shifts in heatwave features in Peninsular Malaysia (PM). Daily ERA5 temperature dataset with a geographical resolution of 0.25° for the period 1950-2022 was used to analyze the changes in the frequency and severity of heat waves across PM, while the LandScan gridded population data from 2000 to 2020 was used to calculate the affected population to the heatwaves. This study also utilized Sen's slope for trend analysis of heatwave characteristics, which separates multi-decadal oscillatory fluctuations from secular trends. The findings demonstrated that the geographical pattern of heatwaves in PM could be reconstructed if daily Tmax is more than the 95th percentile for 3 or more days. The data indicated that the southwest was more prone to severe heatwaves. The PM experienced more heatwaves after 2000 than before. Overall, the heatwave-affected area in PM has increased by 8.98 km2/decade and its duration by 1.54 days/decade. The highest population affected was located in the central south region of PM. These findings provide valuable insights into the heatwaves pattern and impact.
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A sustainable and low-cost point-of-use household drinking water solar disinfection (SODIS) technology was successfully applied to treat microbiologically contaminated water. Field experiments were conducted to determine the efficiency of SODIS and evaluate the potential benefits and limitations of SODIS under local climatic conditions in Karachi, Pakistan. In order to enhance the efficiency of SODIS, the application of physical interventions were also investigated. Twenty per cent of the total samples met drinking water guidelines under strong sunlight weather conditions, showing that SODIS is effective for complete disinfection under specific conditions. Physical interventions, including black-backed and reflecting rear surfaces in the batch reactors, enhanced SODIS performance. Microbial regrowth was also investigated and found to be more controlled in reactors with reflective and black-backed surfaces. The transfer of plasticizer di(2-ethylhexyl)phthalate (DEHP) released from the bottle material polyethylene terephthalate (PET) under SODIS conditions was also investigated. The maximum DEHP concentration in SODIS-treated water was 0.38 µg/L less than the value of 0.71 µg/L reported in a previous study and well below the WHO drinking-quality guideline value. Thus SODIS-treated water can successfully be used by the people living in squatter settlements of mega-cities, such as Karachi, with some limitations.
Assuntos
Países em Desenvolvimento , Desinfecção , Luz Solar , Microbiologia da Água/normas , Poluentes Químicos da Água/química , Abastecimento de Água/normas , Cidades , Clima , Características da Família , Sedimentos Geológicos , Humanos , Paquistão , Fatores de Tempo , Purificação da Água/instrumentação , Purificação da Água/métodos , Abastecimento de Água/análise , Tempo (Meteorologia)RESUMO
The most significant operational cost in a treatment plant is related to the dewatering and disposal of sludge. In this research, different shapes of mixers (radial, axial, wheel, three-blade and magnetic) have been tested to assess their influence on sludge dewaterability testing. As well as the shape of mixers, different rapid mixing velocities, rapid mixing times and coagulants also have been used as test parameters. The capillary suction time (CST) test apparatus was used as a rapid measure to assess sludge dewaterability. Findings indicate that the use of magnetic stirrers leads to the lowest sludge dewaterability properties tested using the CST. The magnetic stirrer produced greater vortex and turbulence compared with other types of mixers, so rapid contact between the coagulant and the water occurred. The use of the other mixers produced similar results. However, the application of different coagulants results differently regarding the sludge dewaterability, when using different rapid mixing velocities. Different rapid mixing times did not lead to differences in the CST. During rapid mixing, Moringa oleifera produced the highest CST values followed by alum and ferric. This is likely due to the difference in sludge volume that is produced by each coagulant. Only M. oleifera produced contaminant agglomerates. In comparison, alum and ferric produced contaminant agglomerates and coagulant hydrolysis products.
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Dessecação/métodos , Esgotos/análise , Esgotos/química , Água/análise , Água/química , Desenho de Equipamento , Análise de Falha de Equipamento , ViscosidadeRESUMO
To accurately manage water resources, a precise prediction of reference evapotranspiration (ETref) is necessary. The best empirical equations to determine ETref are usually the temperature-based Baier and Robertson (BARO), the radiation-based Jensen and Haise (JEHA), and the mass transfer-based Penman (PENM) ones. Two machine learning (ML) models were used: least squares support vector regression (LSSVR) and ANFIS optimized using the particle swarm optimization algorithm (ANFPSO). These models were applied to the daily ETref at 100 synoptic stations for different climates of Iran. Performance of studied models was evaluated by the correlation coefficient (R), coefficient of determination (R2), mean absolute error (MAE), root mean square error (RMSE), scatter index (SI) and the Nash-Sutcliffe efficiency (NSE). The combination-based ML models (LSSVR4 and ANFPSO4) had the lowest error (RMSE = 0.34-2.85 mm d-1) and the best correlation (R = 0.66-0.99). The temperature-based empirical relationships had more precision than the radiation- and mass transfer-based empirical equations.
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The impact of different climate scenarios, drought, and water level management on the outflow water quality of peatlands has been investigated. A mesocosm experiment has been conducted within climate control chambers to simulate current (2016-2019 real-time) and future representative concentration pathway (RCP) climate scenarios (RCP 2.6, 4.5 and 8.5). To assess the efficiency of a management strategy for improving peatland water quality, water level adjustment was applied to half of the system at the same time for each climate scenario. Furthermore, the mesocosm experienced the 2018 European drought during the simulation years, and the corresponding impact was analyzed. The results of this study revealed a substantial and favorable impact of water level management on water quality of peatlands under different climate scenarios. The effect of water level management was the largest for ammonium (NH4-N) and 5-day biochemical oxygen demand (BOD5), and the smallest for total phosphorus (TP). Drought had a strong impact on chemical variables, increasing their concentration and deteriorating the water quality of peatland outflow. However, water level management can stabilize the nutrient levels in peatland outflows, particularly during drought and under warmer climate scenarios, thus mitigating the adverse effects of climate change.
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Compostos de Amônio , Mudança Climática , Carbono/metabolismo , Secas , Oxigênio , Fósforo , Solo , Qualidade da ÁguaRESUMO
The healthcare sector throughout the world is identified for its outsized carbon footprint. Despite the mounting importance of employees' pro-environmental behavior (PEB) for decarbonization, the role of PEB in a healthcare context was less emphasized previously, especially in a developing country context. To address this knowledge gap, the current work was carried out to examine the relationship between a hospital's corporate social responsibility (CSR) initiatives and PEB with the mediating effect of environmental-specific transformational leadership (ESTL). At the same time, the conditional indirect effect of altruistic values (AV) was also considered in the above relationship. The data were collected through a questionnaire by employing a paper-pencil method from the hospital employees (n = 293). By considering the structural equation modeling, the hypothesized relationships were validated. The results indicated that CSR directly (ß1 = 0.411) and indirectly, via ESTL, (ß4 = 0.194) influenced the PEB of employees. It was also realized that A.V produced a conditional indirect effect in this relationship (ß5 = 0.268). This work tends to help a hospital to improve its environmental footprint through CSR and ESTL. Moreover, the current work also highlights the role of employees' values (e.g., A.V) to guide the environment-specific behavior of employees.
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Liderança , Organizações , Altruísmo , Hospitais , Responsabilidade SocialRESUMO
Non-steroidal anti-inflammatory drugs (NSAIDs) (concentration <µg/L) are globally acknowledged as hazardous emerging pollutants that pass via various routes in the environment and ultimately enter aquatic food chains. In this context, the article reviews the occurrence, transport, fate, and electrochemical removal of some selected NSAIDs (diclofenac (DIC), ketoprofen (KTP), ibuprofen (IBU), and naproxen (NPX)) using carbon-based anodes in the aquatic environment. However, no specific protocol has been developed to date, and various approaches have been adopted for the sampling and elimination processes of NSAIDs from wastewater samples. The mean concentration of selected NSAIDs from different countries varies considerably, ranging between 3992−27,061 µg/L (influent wastewater) and 1208−7943 µg/L (effluent wastewater). An assessment of NSAIDs removal efficiency across different treatment stages in various wastewater treatment plants (WWTPs) has been performed. Overall, NSAIDs removal efficiency in wastewater treatment plants has been reported to be around 4−89%, 8−100%, 16−100%, and 17−98% for DIC, KTP, NPX, and IBU, respectively. A microbiological reactor (MBR) has been proclaimed to be the most reliable treatment technique for NSAIDs removal (complete removal). Chlorination (81−95%) followed by conventional mechanical biological treatment (CMBT) (94−98%) treatment has been demonstrated to be the most efficient in removing NSAIDs. Further, the present review explains that the electrochemical oxidation process is an alternative process for the treatment of NSAIDs using a carbon-based anode. Different carbon-based carbon anodes have been searched for electrochemical removal of selected NSAIDs. However, boron-doped diamond and graphite have presented reliable applications for the complete removal of NSAIDs from wastewater samples or their aqueous solution.