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Seawater intrusion and submarine groundwater discharge along the Indian coast Texte intégral
2019
Manivannan, Vengadesan | Elango, Lakshmanan
Intrusion of seawater into the coastal aquifers is a major concern as it affects the quality of groundwater. The objective of this study is to delineate the extent of seawater intrusion in the Indian coast based on previous studies and estimate the area as well as locations of seawater intrusion and submarine groundwater discharge based on the groundwater level of the years 2007 and 2017. Several researchers have reported seawater intrusion in the coastal regions of India by different methods of investigation. These studies indicate that the east coast of India is affected greater than the west coast by seawater intrusion. The maximum extent (about 14 km) of seawater intrusion in India is reported in regions north of Chennai. It is estimated that around 7% of the total coastal area is affected by seawater intrusion, where groundwater is below mean sea level. Around 57% of the coastal area of India has groundwater level in the range from 0 to 10 m msl. Future research needs to focus on the areas where seawater intrusion and submarine groundwater discharge were identified based on this study.
Afficher plus [+] Moins [-]Buccal micronucleus assay in human populations from Sicily (Italy) exposed to petrochemical industry pollutants Texte intégral
2019
Federico, Concetta | Vitale, Valeria | La Porta, Noemi | Saccone, Salvatore
Petroleum refinery workers are potentially exposed to a wide range of petrochemical industry pollutants (PIP), such as benzene and 1,3-butadiene, cancer-related compounds classified as carcinogenic to humans. The aim of this study was to evaluate the cytogenetic effects of exposure to PIP from two industrialised areas in South/East Sicily (Italy) using a micronucleus (MN) assay and other nuclear anomalies (ONA) on exfoliated buccal cells. Results highlighted not only a statistically significant high level of increase of MN in petroleum refinery (PR) workers, but also in the subjects not working in PR but living in the industrialised area. The ONA analysis showed a highly significant increase in karyolytic cells in exposed vs unexposed subjects, in contrast to a decrease in differentiated cells. These results suggest the presence of a cytotoxic effect in the oral mucosa cells, probably related to the pollutant compounds present in the environment close to the petrochemical industries. Our data confirm that the analysis of exfoliated buccal cells is a useful and simple non-invasive method to evaluate the genotoxic/cytotoxic effects of pollutants in a specific area. To avoid confounding factors due to the different lifestyles of the human subjects, the above assays could be better applied on farm animals, which have a relatively consistent lifestyle and, in some cases, a very low genetic heterogeneity.
Afficher plus [+] Moins [-]Adsorption mechanism of Pb2+ ions by Fe3O4, SnO2, and TiO2 nanoparticles Texte intégral
2019
Rehman, Mahfooz-ur | Rehman, Wajid | Waseem, Muhammad | Hussain, Shahzad | Haq, Sirajul | Rehman, Muhammad Anees-ur
Nanosized sorbents for the removal of heavy metal ions are preferred due to high surface area, smaller size, and enhanced reactivity during adsorbate/adsorbent interactions. In the present study, Fe₃O₄, SnO₂, and TiO₂ nanoparticles were prepared by microemulsion-assisted precipitation method. The particles were characterized by BET surface area, X-rays diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, transmittance electron microscopy (TEM), and X-ray photoelectron (XPS) spectroscopy. The respective particle sizes calculated from TEM were 7 nm (± 2), 10 nm (± 2), and 20 nm (± 3) for Fe₃O₄, SnO₂, and TiO₂. The adsorbents were employed for the adsorption of Pb²⁺ ions from the aqueous solutions. The respective maximum adsorption capacity for Fe₃O₄, SnO₂, and TiO₂ nanoparticles was 53.33, 47.21, and 65.65 mg/g at 313 K. Based on the exchange reaction taking place on the surfaces of Fe₃O₄, SnO₂, and TiO₂, it is concluded that Pb²⁺ ions are adsorbed in hydrated form. The X-ray photoelectron spectroscopy (XPS) studies also support the exchange mechanism and confirmed the presence of elements like Fe, Sn, Ti, Pb, and O and their oxidation states. Both Langmuir and Freundlich models in non-linear form were applied, however, based on RL values, the Langmuir model fits well to the sorption data. Moreover, adsorption parameters were also determined by using non-linear form of the Langmuir model along with statistical approaches to remove error. The qₘ and Kb values confirm better adsorption capacity and binding strength for Pb²⁺ ions as compared to the values reported in the literature.
Afficher plus [+] Moins [-]Adsorption of CO2 on amine-functionalized green metal-organic framework: an interaction between amine and CO2 molecules Texte intégral
2019
Rehman, Ayesha | Farrukh, Sarah | Hussain, Arshad | Fan, Xianfeng | Pervaiz, Erum
The efficient capture of CO₂ is a critical problem for porous adsorbents. The inadequacy of conventional adsorbents has low adsorption capacity towards CO₂ removal. Metal organic frame work has been considered as very effective for CO₂ adsorption as it shows higher rate of CO₂ adsorption at room temperature. In conventional amine processes, a comparatively high energy penalty is required, whereas a novel class of metal-organic framework by the combination of amine solvent have improve the potential of adsorption process and also the efficiency of separation. Amine-functionalized MOFs become more fascinated due to strong interaction between carbon dioxide and amine-functionalized MOF. A renewable green γCD-MOF was synthesized by using vapor diffusion method. Post-synthetic modification of γCD-MOF was done with piperazine and analyzed to expose its crystalline structure, morphology, and porous structure. The main aim of this paper is to enhance the CO₂ adsorption by functionalization of inexpensive, green, nanoporous γCD-MOF and also to highlight the effects of amine-based functionalization towards potential application. Gravimetric CO₂ adsorption isotherms for γCD-MOF, pip-γCD-MOF are reported up to 60 °C and found to follow a pseudo-second-order reaction. The pip-γCD-MOF confirms comparatively increased rapid adsorption rate of CO₂ than that of γCD-MOF and desorption of CO₂, and need less energy for regeneration. These results are the complete evidence of piperazine as an efficient amine group for increasing the CO₂ adsorption uptake capacity.
Afficher plus [+] Moins [-]Butyrylcholinesterase—a potential plasma biomarker in manganese-induced neurobehavioral changes Texte intégral
2019
Anjum, Adiba | Biswas, Sheta | Rahman, Mizanur | Rahman, Atiqur | Siddique, Abu Eabrahim | Karim, Yeasir | Aktar, Sharmin | Nikkon, Farjana | Haque, Azizul | Himeno, Seiichiro | Hosāina, Khāleda | Saud, Zahangir Alam
Groundwater particularly drinking water contamination with metals has created an environmental disaster in Bangladesh. Manganese (Mn), an essential trace element, plays a key role in the development and function of the brain. Excess Mn exposure is reported to be associated with complex neurological disorders. Here, we have found a notably large extent of Mn above the permissive limit in the tube-well water of Rajshahi and Naogaon districts in Bangladesh. Higher levels of Mn in hair and nail samples, and a decreasing level of butyrylcholinesterase (BChE) activity were detected in plasma samples of the human subjects recruited from Naogaon district. Mn concentrations in water, hair, and nails were negatively correlated with the plasma BChE levels in Mn-exposed populations. To compare and validate these human studies, an animal model was used to determine the in vivo effects of Mn on neurobehavioral changes and blood BChE levels. In elevated plus maze, the time spent was significantly reduced in open arms and increased in closed arms of Mn-exposed mice compared to control group. The mean latency time to find the platform was declined significantly in control mice compared to Mn-treated group during 7 days in Morris water maze test, and Mn-exposed group also spent significantly less time in the desired quadrant as compared to the control group in probe trial. BChE activity was significantly reduced in Mn-exposed mice compared to control mice. Taken together, these results suggest that plasma BChE levels may serve as reliable biomarker of Mn-induced neurotoxicity related to behavioral changes.
Afficher plus [+] Moins [-]Human health risk exposure with respect to particulate-bound polycyclic aromatic hydrocarbons at mine fire-affected coal mining complex Texte intégral
2019
Roy, Debananda | Seo, Yong-Chil | Sinha, Sweta | Bhattacharya, Abir | Singh, Gurdeep | Biswas, Pallab Kr
Particulate-bound poly-aromatic hydrocarbons (PAHs) are of great concern due to their mutagenicity and carcinogenicity effect on human health. In this context, identification, quantification and inhalation cancer risk (ICR) assessment due to PM₁₀- and PM₂.₅-bound PAHs has been carried out at six monitoring stations in a critically polluted Jharia coalfield/Dhanbad City. Identification of pollution sources at study area has been performed by using PCA statistical methods. Air quality index (AQI) and air quality health index (AQHI) were calculated based on the concentration levels of PM₁₀. Location-wise direct comparison between AQI, AQHI and ICR was performed to analyse the risk levels. Consequently, maximum concentration levels of particulate (PM₂.₅ and PM₁₀)-bound total PAHs (400 and 482 ng/m³) were recorded at the monitoring station Lodna Thana, followed by Bank More and Sijua Stadium, respectively. It was also observed that mine fire-affected station Lodna Thana was exaggerated with presence of PAHs due to wood and open coal burning activities. Moreover, about 1000 and 889 cases of inhalation cancer risk were estimated due to direct exposure of PM₁₀- and PM₂.₅-bound PAHs in the study area, respectively. Active mine fire-affected station Lodna Thana was recorded with maximum probability of lung tumour due to inhalation cancer risk. This study has reported higher AQHI at station Dugdha Basti, Lodna Thana and Bank More, which results increased number of tumours due to ICR. This result concludes that Jharia coalfield/Dhanbad City are not only critically polluted area but it is also an inhalation cancer prone area due to direct exposure of active mine fire.
Afficher plus [+] Moins [-]Metal distribution in sediments of a drinking water reservoir: influence of reservoir morphometry and hydrodynamics Texte intégral
2019
Zhu, Lin | Wang, Tianxiang | Liu, Jianwei | Xu, Shiguo | Chen, Xiaoqiang | Jiang, Xin
Metal(loid)s in the reservoir sediment tend to be released into the water column when encountering disturbances and thus pose threats to the aquatic system. In this study, sediment and pore water samples collected from eight cross sections in the Biliu River Reservoir (Dalian, China) were analyzed to determine the spatial distributions of six metal(loid)s and their associations with reservoir morphometry and hydrodynamics. The results show that total metal concentrations of the sediments are higher at the sites with greater water depths and are influenced by the reservoir morphometry. Mn is of great concern with respect to its increasing total concentration from the upstream sites to the dam sites. According to the improved BCR sequential extraction procedure, the acid-soluble fraction of Mn increases along the thalweg to the dam, implying the soluble Mn²⁺ in the upstream hypolimnion, and sediment is possible to be transported longitudinally by water currents. For Fe, Mn, Pb, Cu, and Zn, the reducible fraction accounts for more than 15% of the total metal concentration, which suggests that Fe–Mn (hydr)oxides could be important in scavenging these metals. High Mn concentrations in pore waters close to the dam, with an average value of more than 40 mg/L, give rise to significant Mn diffusive flux up to 296.1 mg/m²/day.
Afficher plus [+] Moins [-]Correction to: Efficient removal of dyes from dyeing wastewater by powder activated charcoal/titanate nanotube nanocomposites: adsorption and photoregeneration Texte intégral
2019
Lin, Yingchao | Ma, Jun | Liu, Wen | Li, Zeyu | He, Kai
The original publication of this paper contains a mistake. The published Fig. 8 does not cite the related reference, and several grammar errors has been found in the image. The improved version of Fig. 8 and its caption is shown in this correction. These errors do not change the conclusions
Afficher plus [+] Moins [-]Management of green transportation: an evidence-based approach Texte intégral
2019
Shouket, Bilal | Zaman, Khalid | Nassani, Abdelmohsen A. | Aldakhil, Abdullah Mohammed | Abro, Muhammad Moinuddin Qazi
The objective of the study is to examine the impact of air-railways transportation on environmental degradation in the form of high mass carbon emission, natural resource depletion and forest depletion in the context of Pakistan by using an annual time series data from 1975 to 2016. The results show that railway passengers carried increases carbon emissions while air-railways transportation and travel services degrade environment in the form of natural resource depletion. The study verified “pollution haven hypothesis” where trade liberalization policies increases carbon emissions; however, “population genius” principle is hold where population growth conserve natural resources and environment through affluence and technology. The study concluded that government should take serious action to re-define transportation infrastructure in order to promote environmental sustainability agenda by introducing green vehicles and green transportation system, which is imperative for country’s long-term sustainable development.
Afficher plus [+] Moins [-]Heavy metal exposure through artificial diet reduces growth and survival of Spodoptera litura (Lepidoptera: Noctuidae) Texte intégral
2019
Ali, Sajjad | Ullah, Muhammad Irfan | Saeed, Muhammad Farhan | Khalid, Samina | Saqib, Muhammad | Arshad, Muḥammad | Afzal, Muhammad | Damalas, Christos A.
Insect physiology is affected by the presence of toxins in the surrounding environment of insects as well as their food sources. The objective of this study was to determine the effect of heavy metal exposure to two low concentrations (50 μg/g and 150 μg/g) of lead (Pb) and zinc (Zn) through artificial diet to the larvae on biological parameters of Asian armyworm (Spodoptera litura Fabricius) (Lepidoptera: Noctuidae). Both Pb and Zn, even at low concentrations, had relatively high toxic effects on S. litura larvae (P < 0.01). S. litura larval weight and length suffered the maximum reduction when the larvae were fed on diet mixed with the high Pb concentration (150 μg/g) tested compared to the other treatments. At the same Pb concentration (150 μg/g), values of larva growth index, pupa growth index, immature growth index, standardized growth index, and fitness index were 4.66, 7.33, 7.82, 5.35, and 10.00 times lower, respectively, than those of control. At the same Zn concentration (150 μg/g), values of larval growth index, pupal growth index, immature growth index, standardized growth index, and fitness index were 5.61, 3.00, 3.04, 3.23, and 9.24 times lower, respectively, than those of control. The survival rate of S. litura larvae was also lower (12.5%) when the larvae were fed on diet mixed with Pb at 150 μg/g after 10 days of observation. Overall, the presence of those heavy metals in the environment, even at low concentrations, would exert an adverse impact on larvae development of this insect. From this point of view, findings could provide a basis for long-term evaluation of heavy metal risk and its impact on populations of important agricultural pests.
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