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101.
Assessment of phenanthrene bioavailability in aged and unaged soils by mild extraction 总被引:2,自引:0,他引:2
Khan MI Cheema SA Shen C Zhang C Tang X Shi J Chen X Park J Chen Y 《Environmental monitoring and assessment》2012,184(1):549-559
It has become apparent that the threat of an organic pollutant in soil is directly related to its bioavailable fraction and
that the use of total contaminant concentrations as a measure of potential contaminant exposure to plants or soil organisms
is inappropriate. In light of this, non-exhaustive extraction techniques are being investigated to assess their appropriateness
in determining bioavailability. To find a suitable and rapid extraction method to predict phenanthrene bioavailability, multiple
extraction techniques (i.e., mild hydroxypropyl-β-cyclodextrin (HPCD) and organic solvents extraction) were investigated in soil spiked to a range of phenanthrene levels (i.e.,
1.12, 8.52, 73, 136, and 335 μg g − 1 dry soil). The bioaccumulation of phenanthrene in earthworm (Eisenia fetida) was used as the reference system for bioavailability. Correlation results for phenanthrene suggested that mild HPCD extraction
was a better method to predict bioavailability of phenanthrene in soil compared with organic solvents extraction. Aged (i.e.,
150 days) and fresh (i.e., 0 day) soil samples were used to evaluate the extraction efficiency and the effect of soil contact
time on the availability of phenanthrene. The percentage of phenanthrene accumulated by earthworms and percent recoveries
by mild extractants changed significantly with aging time. Thus, aging significantly reduced the earthworm uptake and chemical
extractability of phenanthrene. In general, among organic extractants, methanol showed recoveries comparable to those of mild
HPCD for both aged and unaged soil matrices. Hence, this extractant can be suitable after HPCD to evaluate risk of contaminated
soils. 相似文献
102.
Ghumman AR Ghazaw YM Hashmi HN Kamal MA Niazi MF 《Environmental monitoring and assessment》2012,184(3):1671-1681
Many drainage schemes and salinity control projects have been executed world wide. Pipe drainage has widely been used in Pakistan,
Egypt and India to control waterlogging. The impact of pipe drainage on land and water was evaluated in this paper using data
of three pipe drainage projects in Pakistan namely Khushab Salinity Control and Reclamation Project, Fourth Drainage Project
in Faisalabad and Swabi Salinity Control and Reclamation Project. Data by regular monitoring of these projects were collected.
The effect of pipe drainage on water table depth at these three locations has been compared. Water quality and soil salinity
improvement due to the pipe drainage has also been investigated. Data, related to water table depths and discharges from drain
pipes/wells, was collected. Observation wells, installed at various places by the Water and Power Development Authority, were
used for collection of this data. To evaluate the impact of the projects on salinity, soil samples from all the three locations
were tested. A questionnaire was prepared to get the view of the people about the projects. It was revealed that in these
areas, due to subsurface pipe drainage, the percentage of the abandoned land has been considerably decreased. Over drainage
was observed in a few places of the projects. The farmers at such places were asked to change their cropping patterns. Ultimately,
there has been an increase in area under cultivation, crop yields and cropping intensity in the projects’ area. 相似文献
103.
Removal of arsenic species from water by batch and column operations on bagasse fly ash 总被引:2,自引:0,他引:2
Imran Ali Zeid A. Al-Othman Abdulrahman Alwarthan Mohd Asim Tabrez A. Khan 《Environmental science and pollution research international》2014,21(5):3218-3229
Bagasse fly ash (BFA, a sugar industrial waste) was used as low-cost adsorbent for the uptake of arsenate and arsenite species from water. The optimum conditions for the removal of both species of arsenic were as follows: pH 7.0, concentration 50.0 μg/L, contact time 50.0 min, adsorbent dose 3.0 g/L, and temperature 20.0 °C, with 95.0 and 89.5 % removal of arsenate and arsenite, respectively. The Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich adsorption isotherms were used to analyze the results. The results of these models indicated single-layer uniform adsorption on heterogeneous surface. Thermodynamic parameters, i.e., ΔG°, ΔH°, and ΔS°, were also calculated. At 20.0 to 30.0 °C, the values of ΔG° lie in the range of ?4,722.75 to ?4,878.82 and ?4,308.80 to ?4,451.73 while the values of ΔH° and ΔS° were ?149.90 and ?121.07, and 15.61 and 14.29 for arsenate and arsenite, respectively, indicating that adsorption is spontaneous and exothermic. Pseudo-first-order kinetics was followed. In column experiments, the adsorption decreased as the flow rate increased with the maximum removal of 98.9 and 95.6 % for arsenate and arsenite, respectively. The bed depth service time and Yoon and Nelson models were used to analyze the experimental data. The adsorption capacity (N o) of BFA on column was 3.65 and 2.98 mg/cm3 for arsenate and arsenite, respectively. The developed system for the removal of arsenate and arsenite species is economic, rapid, and capable of working under natural conditions. It may be used for the removal of arsenic species from any contaminated water resources. 相似文献
104.
Tabassum Riaz Ahmad Shahid Muhammad Dumat Camille Niazi Nabeel Khan Khalid Sana Shah Noor Samad Imran Muhammad Khalid Samina 《Environmental science and pollution research international》2019,26(20):20018-20029
Environmental Science and Pollution Research - Currently, several news channels and research publications have highlighted the dilemma of arsenic (As)-contaminated groundwater in Pakistan. However,... 相似文献
105.
Han Il Yoo Keunje Kang Bo Ram No Jee Hyun Wee Gui Nam Khan Muhammad Imran Jeong Tae Young Lee Tae Kwon 《Environmental geochemistry and health》2018,40(1):451-460
Environmental Geochemistry and Health - Improper decisions concerning animal carcass disposal sites pose grave threats to environmental biosecurity. However, only a few studies have focused on the... 相似文献
106.
Anjum Shakeel Ahmad Tanveer Mohsin Ashraf Umair Hussain Saddam Shahzad Babar Khan Imran Wang Longchang 《Environmental science and pollution research international》2016,23(17):17132-17141
Environmental Science and Pollution Research - Drought stress is one of the major environmental factors responsible for reduction in crop productivity. In the present study, responses of two maize... 相似文献
107.
Perspectives of using fungi as bioresource for bioremediation of pesticides in the environment: a critical review 总被引:1,自引:0,他引:1
Zahid Maqbool Sabir Hussain Muhammad Imran Faisal Mahmood Tanvir Shahzad Zulfiqar Ahmed Farrukh Azeem Saima Muzammil 《Environmental science and pollution research international》2016,23(17):16904-16925
Pesticides are used for controlling the development of various pests in agricultural crops worldwide. Despite their agricultural benefits, pesticides are often considered a serious threat to the environment because of their persistent nature and the anomalies they create. Hence removal of such pesticides from the environment is a topic of interest for the researchers nowadays. During the recent years, use of biological resources to degrade or remove pesticides has emerged as a powerful tool for their in situ degradation and remediation. Fungi are among such bioresources that have been widely characterized and applied for biodegradation and bioremediation of pesticides. This review article presents the perspectives of using fungi for biodegradation and bioremediation of pesticides in liquid and soil media. This review clearly indicates that fungal isolates are an effective bioresource to degrade different pesticides including lindane, methamidophos, endosulfan, chlorpyrifos, atrazine, cypermethrin, dieldrin, methyl parathion, heptachlor, etc. However, rate of fungal degradation of pesticides depends on soil moisture content, nutrient availability, pH, temperature, oxygen level, etc. Fungal strains were found to harbor different processes including hydroxylation, demethylation, dechlorination, dioxygenation, esterification, dehydrochlorination, oxidation, etc during the biodegradation of different pesticides having varying functional groups. Moreover, the biodegradation of different pesticides was found to be mediated by involvement of different enzymes including laccase, hydrolase, peroxidase, esterase, dehydrogenase, manganese peroxidase, lignin peroxidase, etc. The recent advances in understanding the fungal biodegradation of pesticides focusing on the processes, pathways, genes/enzymes and factors affecting the biodegradation have also been presented in this review article. 相似文献
108.
Hassan Younas Ishtiaq A. Qazi Imran Hashmi M. Ali Awan Asif Mahmood Hafiz Adil Qayyum 《Environmental science and pollution research international》2014,21(1):740-752
The UN estimated about five million deaths every year due to water-borne diseases, accounting from four billion patients. Keeping in view, the ever increasing health issues and to undermine this statistics, a reliable and sustainable water-treatment method has been developed using visible light for water treatment. titania nanoparticles (NPs) have been synthesized successfully by a more applicable method Viz: liquid impregnation (LI) method. The bacterial death rate by photocatalysis under visible light was studied by employing a typical fluorescent source and was found to follow pseudo first-order reaction kinetics. The nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy to deduce their size range, surface morphology, and elemental compositions, respectively. Among all the prepared grades, 1 % Ag–TiO2 was found to be a very effective photocatalytic agent against Escherichia coli. The resulted photoinactivated data were also evaluated by different empirical kinetic models for bacterial inactivation. Hom, Hom-power, Rational, and Selleck models were not able to explain the disinfection kinetics but modified-Hom model fitted best with the experimentally obtained data by producing a shoulder, log-linear, and a tail region. 相似文献
109.
Tasneem G. Kazi Faheem Shah Haffeezur Rehman Shaikh Hassan Imran Afridi Afzal Shah Naeemullah Sadaf Sadia Arain 《Environmental science and pollution research international》2014,21(4):3021-3030
Prenatal and early-life exposure to lead (Pb) is hypothesized to have adverse effects on childhood health. The aim of this study was to evaluate the prenatal exposure to Pb and its adverse effects on mothers and their infants who are residents of industrial (exposed) and domestic areas (referents) in Karachi, Pakistan. The biological samples (scalp hair and blood) of mother–infants pairs were analyzed for Pb levels by atomic absorption spectrometry after microwave-assisted acid digestion method. The Pb levels in scalp hair and blood samples of exposed mothers were found in the range of 7.52–8.70 μg/g and 115–270 μg/L, respectively, which were significantly higher than those values obtained for referent mothers (p?<?0.001). The Pb levels in the blood (umbilical cord) and hair of neonates of exposed mother that were found in the range of 83–178 μg/L and 4.95–7.23 μg/g, respectively, were significantly higher than the obtained values of referent neonates (p?>?0.001). The correlation between maternal and cord blood of both groups was found in the range of 0.708–0.724 (p?<?0.01). It was observed that there were higher Pb burdens in exposed mothers and their infants as compared to referent mothers–neonates. 相似文献
110.
Surface runoff and nitrogen (N) loss in a bamboo (Phyllostachys pubescens) forest under different fertilization regimes 总被引:2,自引:1,他引:1
Qichun Zhang Imran Haider Shamsi Jinwen Wang Qiujin Song Qiaoyun Xue Yan Yu Xianyong Lin Sayed Hussain 《Environmental science and pollution research international》2013,20(7):4681-4688
Nitrogen (N) losses from agricultural fields have been extensively studied. In contrast, surface runoff and N losses have rarely been considered for bamboo forests that are widespread in regions such as southern China. The thriving of bamboo industries has led to increasing fertilizer use in bamboo forests. In this study, we evaluated surface runoff and N losses in runoff following different fertilization treatments under field conditions in a bamboo (Phyllostachys pubescens) forest in the catchment of Lake Taihu in Jiangsu, China. Under three different fertilization regimes, i.e., control, site-specific nutrient management (SSNM), and farmer's fertilization practice (FFP), the water runoff rate amounted to 356, 361, and 342 m3?ha?1 and accounted for 1.91, 1.98, and 1.85 % of the water input, respectively, from June 2009 to May 2010. The total N losses via surface runoff ranged from 1.2 to 1.8 kg?ha?1. Compared with FFP, the SSNM treatment reduced total nitrogen (TN) and dissolved nitrogen (DN) losses by 31 and 34 %, respectively. The results also showed that variations in N losses depended mainly on runoff fluxes, not N concentrations. Runoff samples collected from all treatments throughout the year showed TN concentrations greater than 0.35 mg?L?1, with the mean TN concentration in the runoff from the FFP treatment reaching 8.97 mg?L?1. The loss of NO3 ?–N was greater than the loss of NH4 +–N. The total loss of dissolved organic nitrogen (DON) reached 23–41 % of the corresponding DN. Therefore, DON is likely the main N species in runoff from bamboo forests and should be emphasized in the assessment and management of N losses in bamboo forest. 相似文献