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Trace metal exposure and health concerns in Bangladeshi rivers: a seasonal comparison of the Buriganga, Shitalakhya, Meghna, Karnaphuli, and Padma rivers' water, sediment, and fish Texto completo
2024
Hasan, Nahid Bin | Fahad, Md. Abu | Zahid, Abdullah-Al | Hasan, Mahadi | Rahaman, Ashiqur | Hossain, Sakhawat | Sarker, Tama Rani | Hossain, Mohammad Nazmul | Khatun, Nazma
We determined the levels of nine heavy elements in water, sediment, and the edible tissues of three frequently eaten fish species collected from the five polluted rivers in different divisions of Bangladesh. These samples were randomly taken from five rivers and analyzed by Flame Atomic Absorption Spectroscopy. We found seasonal fluctuations in the hierarchy of mean concentration for different heavy metals in five rivers’ fish, water, and sediments. In the water, the concentrations of Cd, Cr, Cu, Fe, Mn, Pb, Zn, Ni, and Hg ranged from 0.010-0.081, 0.016-5.531, 0.013-2.445, 0.860-22.924, 0.043-1.424, 0.015-0.933, 0.091-1.451, 0.012-2.888, and 0.010-0.032 mg/l where in the sediment the concentrations ranged from 0.1-1.47, 4.21-284.1, 0.12-28.46, 1860-14971.33, 122.1-480.8, 0.84-42.15, 2.14-210.35, 15.3-30.4, and 0.17-10.44 mg/kg. For fishes concentrations ranging from BDL-0.78, 0.04-86.45, 0.01-1.67, 4.19-102, 0.08-0.94, 0.01-0.99, 0.08-9.56, 0.01-4.56, and BDL-0.2 mg/kg were reported for the above metals order respectively. The highest concentration (mean) of Cr and Fe in waters and sediments was 1023 times and 13020.72 % higher than WHO’s standard and Toxicity Reference Values (TRV), respectively. Besides, the bioaccumulation factors (BAF) of the selected elements for the studied fishes were found to be between 0.036-626.25, where the pollution load index (PLI) for the five rivers ranged from 0-0.95 and the concentration factor (CF) found between 0.02-4.03. Estimated daily Intake (EDI) as well as Target hazard quotients (THQs) analyses revealed potential risks for fish consumers, particularly the level of some metals exceeding the WHO/FAO's tolerable limit, which indicates that the rivers' water and fish are dangerous to humankind.
Mostrar más [+] Menos [-]A comparison between two polychaete species; Marphysa gravelyi and Dendronereis aestuarina in terms of heavy metal accumulation from three differently polluted mangrove ecosystems of Northern Kerala, India. Texto completo
2024
Jithin, Kothalil | Dinesh, Kaippilly
Three separate mangrove ecosystems in Kerala's Kannur district were examined for trace metal build-up in sediment and two polychaete species, Marphysa gravelyi and Dendronereis aestuarina. By classifying the areas according to the intensity of anthropogenic activity, metal deposition in polychaete tissue was investigated. ICP-MS was used to assess the heavy metal load and the accumulation of metals in sediment in the range of, Zn 24.37-59 mg/kg, Ni 23.67- 59.25 mg/kg, Cu 11.27- 38.6 mg/kg, Pb 4.5- 16.4 mg/kg, Cd 0.1-1.8 mg/kg, Fe 1.25- 3.67 %, and Al 0.65-2.43 %. The soil sample's Zn concentration was at its highest and heavy metals accumulated in the pattern Zn˃Ni˃Cu˃Pb˃Cd. By just switching the concentrations of Ni and Cu, polychaetes' trace metal concentrations follow the same pattern as those found in soil, however, M. gravelyi was discovered to have larger amounts of accumulation when compared to D. aestuarina, mostly for metals like Zn and Pb. Based on data compiled from all stations, the average concentration of accumulation for Zn was 62.34 mg/kg & 43.45 mg/kg, and for Pb, it was 6.59 mg/kg & 1.86 mg/kg in M. gravelyi and D. aestuarina, respectively. Most metal buildup is found in mangrove soil, which has higher levels of organic carbon and clay particles. The findings imply that D. aestuarina is an organism that is sensitive to pollution and that M. gravelyi is a species that is extremely tolerant of pollution, suggesting that the species can be used to anticipate the state of its surrounding environment.
Mostrar más [+] Menos [-]The geochemistry of strontium-90 in peatlands of the European Subarctic of Russia Texto completo
2024
Lukoshkova, Anna | Yakovlev, Evgeny | Orlov, Alexander
The subject of this research is the vertical migration of strontium-90 in peatlands of the European Subarctic region of Russia. The activity level of strontium-90 has been determined in peat samples, and the physicochemical parameters of peat deposits have been studied. The specific activity of the radionuclide has been determined using beta radiometric methods with radiochemical preparation according to the methodology. The physicochemical parameters of the peat have been determined using weight-based methods according to the specified procedures. The influence of physicochemical parameters on the vertical migration of the radionuclide in peatlands has been evaluated using correlation analysis. The results have shown that the specific activity of strontium-90 in peat deposits ranges from 0.25 to 7.7 Bq/kg. The results are consistent with typical values for all soils in Russia. The average value of the specific activity of strontium-90 in peat deposits is estimated to be 1.5±0.02 Bq/kg, which is below the established minimum values and average parameters for all soils in Russia. The pathways of vertical migration of strontium-90 in peat deposits demonstrate a downward direction with various trajectories. These pathways serve as a trace of past global atmospheric radioactive fallout. The vertical migration of strontium-90 in peat is associated with the organic matter content, ash content in peatlands, and recent local atmospheric fallout from nuclear fuel facilities. The research results provide valuable information for predicting the migration of strontium-90 into aquifers under changing environmental conditions due to the Arctic's rapid climate warming.
Mostrar más [+] Menos [-]Removal of Benzyl butyl phthalate by Polyetheretherketone/polyvinylalcohol nanocomposite Modified with Zinc oxide nanoparticles Adsorbent from Wastewater Texto completo
2024
Cheraghi, Reza | Abrishamkar, Maryam | Jalali Jahromi, Hossein | Hoseini, Farzaneh
The applicability of Polyetheretherketone/polyvinylalcohol nanocomposite modified with zinc oxide nanoparticles synthesis for the removal of benzyl butyl phthalate from wastewater. Identical techniques, including BET, FT-IR, XRD, and SEM, have to characterize this unknown material. The investigation shows the applicability of adsorbent PEEK/PVA/ZnONPs, as an available, suitable, and low-cost adsorbent for adequately removing the benzyl butyl phthalate from wastewater. The impacts of variables, including benzyl butyl phthalate concentration, adsorbent, pH, and time (15 mgL-1, 0.3 g, 5.0, and 60 min). Based on the received data, the adsorption of benzyl butyl phthalate on the PEEK/PVA/ZnONPs adsorbent agrees well with the Langmuir adsorption model isotherm (qm = 34.24 mgg-1). The results of the thermodynamic parameter showed a negative enthalpy (-77.0 KJ/mol), a negative Gibbs free energy (-11.7 KJ/mol), and negative entropy (-274.0 J/K.mol). This led to the conclusion that the adsorption process is energetically possible, and exothermic was also spontaneous. This work indicates that the PEEK/PVA/ZnONPs, used as an ecologically adapted, adsorbent holds promise for eliminating benzyl butyl phthalate from wastewater.
Mostrar más [+] Menos [-]A framework of Trapezoidal Fuzzy Best-Worst Method in Location Selection for Surface Water Treatment Plant Texto completo
2024
Debnath, Kalyani | Debnath, Piyali | Choudhury, Sudipa | Saha, Apu | Majumdar, Abhijit
Decision-making under uncertainty refers to a dilemma when a decision-maker is aware of a variety of potential natural states but lacks adequate information to assign any probabilities of occurrence to them. The uncertainty related to the input parameters is one of the main issues in the majority of decision-making situations. Uncertainty may produce some irrational results, which could make the decision-making process even more challenging. To overcome this challenge, a fuzzy extension of Best-Worst Method (BWM) has been proposed, using trapezoidal fuzzy sets, to combine the advantages of a reduced number of pair-wise comparisons and easy handling of ambiguity. The criteria and alternatives have been evaluated by the proposed Trapezoidal Fuzzy Best-Worst Method (TrFBWM), where the weight of each element is represented by a Trapezoidal Fuzzy Number (TrFN). To verify the coherence of judgment, the consistency ratio is evaluated for TrFBWM. The proposed method is then applied to the location selection of a water treatment plant along the bank of the Brahmaputra river in Assam. The obtained results are compared to one previous work and found that the outcomes of the proposed method indicate a good agreement with that. The outcomes of the study provide useful insights for selecting a suitable location for a surface water treatment plant which can also be extended to other service facilities.
Mostrar más [+] Menos [-]Purification of Heavy Metals Contaminated Groundwater by Electro-Coagulation Process Using Graphite Electrodes Texto completo
2024
Muhibbu-Din, Eniola Ismail | Jimoh, Heekmah Oiza | Kehinde, David Pelumi | Tinuoye, Ifeoluwa Agnes
The application of the electro-coagulation process to the identified contaminated groundwater at Abala community, a suburb of Ilorin metropolis in Kwara state, Nigeria, is the subject of this study. The groundwater samples were electro-coagulated in a batch reactor of 2.5L containing 1 litre volume of contaminated groundwater for 1 hour per run using a DC power supply ranging from 10v to 20v at constant current 5amp and 2amp to 6amp at constant voltage 10v using graphite electrodes. The results revealed that electro-coagulation process can reduce turbidity, TDS, Electrical Conductivity, BOD, TOC, COD, and color by 97.3 %, 91.2 %, 91.1 %, 96 %, 99.7%, 99.7%, 79.9%, and 82.96 %, respectively. Through Atomic Absorption spectroscopy analytical study, the process also shows removal efficiency of Manganese, Iron, and Zinc of 82.96 percent, 70.0 percent, and 95.30 percent, respectively. The outcome of the electro-coagulation process met the World Health Organization (WHO), the United States Environmental Protection Agency (USEPA), and the Water Environment Partnership In Asia (WEPA) criteria for both drinking water and general industrial wastewater discharge guidelines. The electro-coagulation treatment for contaminated groundwater was efficient and effective, therefore it is recommended in this study for Nigerians.
Mostrar más [+] Menos [-]Modeling Airflow in Urban High-Rise Building Areas and Climate Comfort Texto completo
2024
Zahedifar, Tahmineh | Darabi, Hassan
Urban morphology impacts micro-climates, solar energy absorption, air flow, wind patterns, energy consumption, and air pollution concentration. Temperature control in public spaces reduces heat island formation, while ventilation corridors potentially improve air quality. However, despite the literature on airflow and urban tall buildings providing valuable insights, further research is needed to understand the complex relationship between airflow patterns and urban high-rise buildings. This research should consider factors such as landscape types, building height, density, and orientation. This research aims to examine airflow patterns in high-rise buildings that are influenced by nearby land use, which can impact ventilation and climate comfort. To investigate these objectives, we utilized the Universal Thermal Climate Index (UTCI) and Predicted Mean Vote Index (PMV) by conducting simulations using ENVI-met software. The results revealed that buildings with narrower widths have better wind warded front conditions, while those with an unfavorable wind angle or a narrow facade are less comfortable. Public spaces that face the wind benefit from improved ventilation. It is essential to consider the optimal arrangement, ventilation, and height of buildings to ensure the favorable airflow. Factors such as the placement of trees, the use of porous walls, water features such as fountains and sprinklers, and the local climate all contribute to creating better wind conditions. Investigating the reciprocal interaction between the landscape, high-rise buildings, and climate comfort could be considered in future research.
Mostrar más [+] Menos [-]Enhanced Removal of Chromate from Aqueous Solution Using a Metal Oxide Nanocomposite Derived from Bimetallic Metal Organic Framework with Both Adsorption and Catalytic Properties Texto completo
2024
Salari, Hadi | Zeraatkar Moghaddam, Ali
Removing environmental pollutants and preserving the environment is an important issue and many efforts have been made in this regard in recent years. In the present work, chromate ions were removed from aqueous solutions by ZnO/CuO acting as both adsorbent and catalyst. Metal oxide fabrication from metal organic framework is one of the most important and interesting scientific issues for the synthesis of high surface area materials. Here, we demonstrate ZnO/CuO synthesis from bimetallic Zn-Cu metal-organic framework (Zn(50)-Cu(50)-BTC) using temperature-programmed oxidation method. The adsorptive and catalytic removal procedure were optimized in terms of its batch efficiency using experimental designs. The effect of hole scavenger type was investigated, and the relationships between the effective important removal procedure parameters and chromate removal efficiency were analyzed through the response surface methodology (RSM) based on central composite design (CCD). The correlation coefficient (R2) and F values were 0.9883 and 74.81, respectively. Finally, simplex non-linear optimization was carried out and the optimal pH, ZnO/CuO amount and contact time were determined to be 2, 20 mg, and 17.5 min. Under these conditions, the predicted removal efficiency of 50 ppm chromate at a 95% confidence level was 98.1 ± 2.4%, which was very close to the recorded response (i.e. 99.4 ± 1.9%). The kinetic and isothermal profiles of the proposed ZnO/CuO, were thoroughly investigated under optimal conditions. The adsorption isotherm follow the Langmuir model and kinetics were found to be pseudo-second-order.
Mostrar más [+] Menos [-]Performance of Natural Coagulant Extracted from Castanea Sativa Tree Leaves in Water Purification processes Texto completo
2024
Hasan, Manar | Hassan, Ahmad | Al-Tameemi, Israa M. | Hassan, Nawar
Numerous coagulants, including natural and chemical coagulants, have been examined in the context of water purification. The use of natural coagulants constitutes an affordable and eco-friendly method of purifying water. The main aim of the current study was represented by investigated the feasibility of coagulant extracted from Castanea Sativa Tree Leaves using three different salts and distilled water. The active coagulant component was extracted using 0.25, 0.5, and 1 M of NaCl and KCl, 0.025, 0.05, and 0.1 M of NaOH, and distilled water. Powdered Castanea Sativa Tree Leaves was also used as a coagulant. Jar tests were performed using synthetic turbid water, a turbidity level of 35 NTU to investigate the coagulants’ activity. The pH was measured to study the influence of a range of different pHs, coagulant doses and initial turbidity were also investigated to optimize the coagulation process. The highest level of activity was achieved using 0.5 ml/l of coagulant extracted with 0.5 M NaCl at pH level 8. Coagulant extracted using 0.05 M NaOH demonstrated the second highest level of activity. Poor coagulant activity was observed for the powdered Castanea Sativa Tree Leaves and distilled water extract. The protein content of the extracted coagulant was 0.322, 0.283, and 0.274 mg/ml using 0.05 M NaCl, 0.5 M NaOH, and 0.5 M KCl, respectively. The use of this natural coagulant was also found to moderately increase organic matter content in the treated water, which was proportional to protein contents of the extracts. Coagulation results were statistically examined using SigmaPlot 12.5 software.
Mostrar más [+] Menos [-]Removal of Congo Red by Waste Fish Scale: Isotherms, Kinetics, Thermodynamics and Optimization Studies Texto completo
2024
Roy, Tapas | Mondal, Anupam | Mondal, Naba Kumar
Cong-red dye is a precursor of various products of cotton industry and its toxicity in the aquatic environment is a great concern. Present study was highlighted on the efficacy of the fish scale char (FSC) towards removal of congo red from aqueous solution. The prepared FSC was characterized by zero point charge (pHZPC), scanning electron micrograph with elemental analysis (SEM-EDX) and fourier transform infrared (FTIR). Based in the equilibrium and kinetic study, the Langmuir (R2 = 0.967) and Pseudo-second-order (R2 = 1.00) models are appropriate to describe the dye adsorption process. The randomness and exothermic nature of the system were confirmed by the negative values of both entropy and enthalpy, respectively. Finally, optimization by Response Surface Methodology (RSM) study revealed that the experimental data were nicely fitted with central composite design with very high F value (F = 1596.24, p < 0.0001). Perturbation plot suggested that congo-red dye removal is more sensitive with respect to biosorbent dose, pH and initial concentration. The exhausted adsorbent was regenerated with 0.5(M) NaOH solution. Therefore, it can be concluded that fish scale char could be a valuable materials towards purification of industrial effluent.
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