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Mangifera indica L. as Airborne Metal Biomonitor for Regions of the State of Espírito Santo (Brazil) Full text
2020
Inorganic pollutants are continuously introduced into the atmosphere. Bioindicators present an alternative method of monitoring air quality. This work proposes to evaluate the Mangifera indica L. leaves as a biomonitor for air quality. Quantification of aluminum (Al), barium (Ba), calcium (Ca), chromium (Cr), copper (Cu), iron (Fe), potassium (K), manganese (Mn), magnesium (Mg), sodium (Na), nickel (Ni), sulfur (S), strontium (Sr), titanium (Ti), and zinc (Zn) were determined in leaves of M. indica using optical emission spectrometer inductively coupled plasma (ICP-OES). The correlogram analyses demonstrated a strong positive correlation between Al and Fe. Contamination of the soil by vehicles and agricultural chemicals, in synergy with the influence of the winds, may be considered as a source of contamination. Enrichment factor (EF) index was used to distinguish between natural and anthropogenic sources. Detection of Mn and Cu could be associated with anthropogenic influence, demonstrating M. indica as a feasible tool to biomonitor air quality.
Show more [+] Less [-]Measuring education sector resilience in the face of flood disasters in Pakistan: an index-based approach Full text
2020
School resilience is characterized as risk management techniques to build a safe environment for students. Recognizing the need of building disaster resilience for the education sector, this study is aimed at assessing flood disaster resilience of elementary schools in four extremely vulnerable districts of Khyber Pakhtunkhwa province of Pakistan. This paper established the assessment tool by incorporating climate resilience indices and 16 tasks of the Hyogo Framework for action designed for the education sector. It discusses four dimensions: physical conditions of elementary schools, human resources, institutional issues, and external relationships, each with three parameters and five variables. The data were obtained for 60 variables from 20 randomly selected elementary schools. Indicators of resilience were identified, and an index-based approach was used to get the composite values of the four dimensions of resilience. Correlations between the dimensions, components, and indicators were also checked in the current study. Results show that schools in Nowshera, followed by Charsadda, Peshawar, and Dera Ismail Khan, are the most resilient to flood disasters. For all 12 parameters under 4 dimensions, the relative resilience of study districts is the same. The findings further indicated that there is a strong correlation between the pairs of human resources and institutional issues as well as institutional issues and external relationships that can also enhance human resources and external relationships. Furthermore, institutional issues are also correlated with external relationships and human resources, which indicate that there is a triangular relationship among human resources, institutional issues, and external relationships. The findings would encourage policymakers and practitioners to develop an effective plan to improve the resilience of schools using the overall resilience situation. In short, education sector disaster resilience can be achieved by integrated planning and implementation approach. In this respect, disaster managers, public and private education sectors, school staff, students, and parents need to establish synergies to devise a comprehensive plan of action to enhance disaster education.
Show more [+] Less [-]Sediment distribution on the continental shelf in relation to stream inputs and contamination: hydrodynamic, chemical, mineralogical, and sedimentological characteristics (Ligurian Sea, Italy) Full text
2020
River estuaries, continental shelf, and sediment contamination are closely linked from the point of view of sediment transport and diffusion that is governed by different factors such as sea waves and currents, river flows and floods, and sediment characteristics. Taking these factors into consideration, we have examined marine environmental and marine bottom sediments off the mouth of a stream to highlight the main ways of sediment and contaminant transport and diffusion on the continental shelf. For this purpose, we followed a multidisciplinary approach, studying circulation of water masses, hydrological characteristics of water column, distribution and main characteristics of sediment grain size, sediment mineralogical composition, and metal concentrations of bottom sediments. Our results allowed identifying the presence of preferential ways of sediment deposition and areas of sediment spread for the Entella Stream, as well as the origin of some metals.
Show more [+] Less [-]Multi-model ensemble simulated non-point source pollution based on Bayesian model averaging method and model uncertainty analysis Full text
2020
Watershed models are cost-effective and powerful tools for evaluating and controlling non-point source pollution (NPSP), while the reliability of watershed models in a management context depends largely on inherent uncertainties in model predictions. The objective of this study is to present the use of multi-model ensemble applied to streamflow, total nitrogen (TN), and total phosphorus (TP) simulation and quantify the uncertainty resulting from model structure. In this study, three watershed models, which have different structures in simulating NPSP, were selected to conduct watershed monthly streamflow, TN load, and TP load ensemble simulation and 90% credible intervals based on Bayesian model averaging (BMA) method. The result using the observed data of the Yixunhe watershed revealed that the coefficient of determination and Nash–Sutcliffe coefficient of the BMA model simulate streamflow, TN load, and TP load were better than that of the single model. The higher the efficiency of a single model is, the greater the weight during the BMA ensemble simulation is. The 90% credible interval of BMA has a high coverage of measured values in this study. This indicates that the BMA method can not only provide simulation with better precision through ensemble simulation but also provide quantitative evaluation of the model structure through interval, which could offer rich information of the NPSP simulation and management.
Show more [+] Less [-]Distribution and correlation of radon and uranium and associated hydrogeochemical processes in alluvial aquifers of northwest India Full text
2020
The spatial and vertical distributions of radon and uranium are evaluated in relation to the hydrogeology, geomorphology, and hydrochemistry of southwest Punjab. Radon activity of the groundwater ranges from 580 to 3633 Bq/m³ (shallow groundwater 580 to 2438 Bq/m³ and deep groundwater 964 to 3633 Bq/m³), and uranium concentration varies from 24.4 to 253 μg/L (shallow groundwater 24.4 to 253 μg/L and deep groundwater 27.6 to 76.3 μg/L). Shallow groundwater shows higher U concentration compared with deeper ones, which can be attributed to the presence of dissolved oxygen (DO) and NO₃⁻ as oxidants and HCO₃⁻ as stabilizing agent in shallow zone. Unlike uranium, the radon activities were found to be similar in both shallow and deep groundwater. Rnₑₓcₑₛₛ over secular equilibrium was used to confirm the possibility of additional sources of radon, such as secondary minerals present in the subsurface. Surface manifestations show significant influence on radon and uranium distributions in the shallow zone but not in deep zone due to limited hydraulic connectivity. Depth profiles and correlations of radon and uranium with trace elements and hydrochemical parameters indicate that groundwater exhibits different redox characteristics in shallow (younger and oxidizing) and deep zones (older and reducing). The present study provides critical information that can be helpful for planning sustainable groundwater development in this region and other similar regions without contaminating the relatively safer deep aquifers.
Show more [+] Less [-]A Novel Solid Platform–Based Ag Nanoparticles Chemically Impregnated Activated Carbon for Selective Separation of Tungstate Species in Water: Kinetics and Thermodynamic Study Full text
2020
The level of tungstate in freshwater is disturbing due to its toxicity and its impact to human health. Thus, the current study explores the use of Ag nanoparticle (AgNP)–treated activated carbon (AgNPs/AC) nanocomposite as solid phase extractor (SPE) for removal of trace levels of tungstate ions in water. The AgNPs/AC was synthesized by chemical binding of Ag nanoparticles onto AC. The microstructure image indicated that the AgNPs were uniformly dispersed on AC surface and thus maintaining high surface area. Scanning electron micrographs of AgNPs/AC revealed a three-dimensional structure which is suitable as SPE. The AgNPs/AC nanocomposite was used as a low-cost and effective SPE for tungstate removal from water. Adsorption of tungstate from aqueous media reached maximum at pH ≈ 4 and reached equilibrium in < 20 min. Tungstate sorption followed pseudo-second-order kinetic with an overall rate constant (k) of 0.72 min.⁻¹ The negative values of ΔH and ΔG are interpreted as exothermic and spontaneous reaction of tungstate sorption by the adsorbent, respectively. The positive value of ΔS (R² = 0.999) reflected good absorption and/or adsorption of the oxyanion [WO₄]²⁻ as an ion associate with the bulky cations and the surface area available in the nanocomposite. The sorbent AgNPs/AC was also packed column for preconcentration of trace levels of tungstate in tap water samples. Tungstate species were satisfactorily recovered with NaOH (1.0 mol L⁻¹) and subsequently ICP-OES analyzed.
Show more [+] Less [-]Selective Adsorption Capacity of Grape Marc Hydrogel for Adsorption of Binary Mixtures of Dyes Full text
2020
In this work, an aqueous solution containing industrial dyes consisting of methylene blue (MB), and methyl red (MR) was treated with bio-oxidize grape marc entrapped or not in calcium alginate hydrogels. Experiments were carried out in batch, a room temperature using different concentration of adsorbents and dyes. When dyes were evaluated separately, non-immobilized grape marc hydrogel was unable to remove any MR, whereas when the bioadsorbent was immobilized in calcium alginate beads the removal of MR was around 88%. Contrarily, 98% of MB was removed with both, non-entrapped or entrapped grape marc. Regarding binary mixtures, it was observed that the adsorption of MR was not affected by the presence of MB, whereas the adsorption of MB decreased in high extend on non-entrapped grape marc when MR was present.Adsorption conditions were optimized for binary mixtures using a Box-Behnken factorial design, obtaining theoretical equations that allowed to calculate the removal percentage and capacity of calcium alginate-grape marc hydrogel depending on the concentration of dyes (40–100 mg/L), ratio between bioadsorbent and water stream (0.6–1.2) and adsorption time (10–60 min). The equations obtained revealed that grape marc hydrogel is able to remove 100.0–93.3% of MB and 78.72–57.80% of MR in 10 min in the range of dye and bioadsorbent stablished in the experimental design, being the extraction time the less significant variable. Additionally, the kinetic study showed that pseudo-second-order was the model that better explained the bioadsorption process for both dyes in binary mixtures onto grape marc hydrogel.
Show more [+] Less [-]Water Quality Scenario of Kashmir Himalayan Springs—a Case Study of Baramulla District, Kashmir Valley Full text
2020
Bhat, Sami Ullah | Mushtaq, Suraya | Qayoom, Umara | Sabha, Inam
This article describes the water quality scenario of freshwater springs of Baramulla district of Kashmir Valley in light of pollution threats and predicted climate change consequences for Himalayan ecosystems. The study was designed to have insights to what extent the community is relying on the spring water and what policy initiatives and planning perspectives at the government level are currently in vogue for sustainable management of these freshwater springs. Our results indicated that the springs are mild hard water type with nitrate concentration, conductivity, and iron values ranging from 19 to 675 μg/L, 185 to 811 μS/cm, and 1 to 308 μg/L respectively. Water quality index (WQI) revealed that the majority of the springs have excellent to good water quality category, while as in few springs like Aboora (26), Harwan (27), Fugipora (29), and Goigam (30), it was falling under poor to very poor category. Principal component analysis (PCA) generated mainly three components (VF1, VF2, and VF3) with higher Eigen values of 2.0 or more (2.23–6) accounting for 56.92%, 28.85%, and 10.64% of the total variance respectively. The survey highlights revealed the dependence of a large proportion of population for drinking water besides other uses, but no signs of involvement from the government level. Keeping in view the importance of these springs, it is necessitated that this situation should catch the attention of government and policy makers for the management of freshwater springs which can play an important role in fulfilling the UN (United Nations) Sustainable Development Goal (SDG) of access to safe drinking water.
Show more [+] Less [-]Leaching Potential of Multi-metal-Contaminated Soil in Chelate-Aided Remediation Full text
2020
Park, Soyoung | Sung, Kijune
Chelates, used to increase the uptake of heavy metals in phytoremediation, can also increase the mobility of metals. If plants fail to uptake or stabilize all the mobilized metals, then subsurface soil or groundwater can be contaminated. Therefore, the type and concentration of chelate used and proper site management are important for chelate-aided phytoremediation. In this study, we evaluated potential metal leaching from the soil after applying three different chelates. The readily soluble and exchangeable metal (RSEM) and plant-available metal (PAM) of Pb, Zn, Cu, Cd, and Ni in soil amended with ethylene diamine tetra acetic acid (EDTA), ethylene diamine disuccinate (EDDS), or humic acid (HA) were analyzed, and the potential leaching factor (PLF) of the heavy metals was estimated. Results showed that the effects of chelates and their concentration on RSEM and PAM of heavy metal in soil were different. The addition of EDTA increased the CRSEM and CPAM of all heavy metals, although its effects varied with the concentration added. EDDS application increased CRSEM and CPAM of Cu, Ni, and Zn, but EDDS was more effective than EDTA for Cu and Ni. HA did not show a significant impact due to the short duration of the experiment. In most cases with chelates effects, the increase of RSEM was greater than PAM, and the potential of metal leaching increased. Therefore, application of chelates for remediation of metal-contaminated soil should consider not only the capacity of metal uptake in plants but also the potential metal leaching from the system. Additionally, this process should be accompanied by proper water management to minimize leachate in chelate-aided phytoremediation applications.
Show more [+] Less [-]Physiological response of the bioindicator Ramalina farinacea in relation to atmospheric deposition in an urban environment Full text
2020
Sujetovienė, Gintarė | Sališiūtė, Jotvilė | Dagiliūtė, Renata | Žaltauskaitė, Jūratė
Urban air pollution is one of the most important environmental problems. Lichens are good bioindicators in air pollution studies because of their dependence on the atmospheric deposition for nutrition. The present study focused on the effects of urbanization on the composition of atmospheric deposition inputs and physiological parameters of transplanted epiphytic lichen Ramalina farinacea. The status of lichens responded to urban pollutants related to vehicle and industrial activity (NO₃⁻, Ca²⁺, Mg²⁺, NO₂, PM₁₀). The content of chlorophyll and FV/FM were positively related to the amount of precipitation (mm) and the Normalized Difference Vegetation Index (NDVI). The increase in lipid peroxidation and electrolyte conductivity, indicating damage to the cell membrane, was found in lichens transplanted to the urban environment. The high variability in electrolyte conductivity indicated that cell membrane injuries were characteristics of the investigated study area.
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