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91.
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93.
Ali Duran Mustafa Tuzen Mustafa Soylak 《Environmental monitoring and assessment》2014,186(7):4619-4628
Regular consumption of fish has been widely recommended by health authorities. However, it is known that some species accumulate high levels of contaminants including heavy metals (e.g., Hg, Cd, Pb, and As). In this study, Cu, Pb, Co, Ni, Cr, Mn, Cd, and Fe were determined in the muscle tissue of 11 commercially available fish species (Sparus auratus, Dicentrarchus labrax, Mullus barbatus, Belone belone, Psetta maxima, Epinephelus aeneus, Salmothymus, Soleidae, Pomatomus saltatrix, Engraulis encrasicolus, and Sarda sarda) supplied from retailers in Kayseri, Turkey. Determinations were carried out by flame atomic absorption spectrometry after the wet digestion method. The average metal concentrations of the 11 species were determined in the range of 0.54–1.79, 0.82–1.40, 2.38–4.54, 1.23–3.67, 5.01–5.97, 0.77–3.59, 0.48–1.06, and 5.05–122.8 μg/g wet weight for Cu, Pb, Co, Ni, Cr, Mn, Cd, and Fe, respectively. The permissible tolerable daily intake (PTDI) and calculated daily intake (CDI) values were compared, and the calculated daily intake values of the samples were found to be below the established values. Correlations between the metal contents in samples were investigated by performing correlation tests with SPSS 13.0 for windows. 相似文献
94.
Kabir Ahmad Azizullah Azizullah Shama Shama Muhammad Nasir Khan Khattak 《Environmental monitoring and assessment》2014,186(11):7357-7366
The present study was conducted to investigate the contamination of water, sediments, and fish tissues with heavy metals in river Panjkora at Lower Dir, Khyber Pakhtunkhwa, Pakistan. Water, sediments, and fish (Shizothorax plagiostomus) samples were collected from September 2012 to January 2013 at three different sites (upstream site at Sharigut, sewage site at Timergara, and downstream site at Sadoo) of river Panjkora. The concentrations of heavy metals in water were in the order Zn?>?Cu?≈?Pb?>?Ni?≈?Cd with mean values of 0.30, 0.01, 0.01, 0.0 and 0.0 mg/l, respectively, which were below the maximum permissible limits of WHO for drinking water. In sediments, heavy metals were found in the order Cu?>?Zn?>?Ni?>?Pb?>?Cd with mean concentrations of 50.6, 38.7, 9.3, 8, and 0.4 mg/kg, respectively. Ni and Cd were not found in any fish tissues, but Zn, Cu, and Pb were detected with the mean concentration ranges of 0.04–1.19, 0.03–0.12, and 0.01–0.09 μg/g, respectively. The present study demonstrates that disposal of waste effluents causes a slight increase in the concentration of heavy metals in river Panjkora as revealed by variation in metal concentrations from upstream to downstream site. Sewage disposal was also found to change physicochemical characteristics of Panjkora water. At present, water and fish of river Panjkora are safe for human consumption, but the continuous sewage disposal may create problems in the future. 相似文献
95.
Muhammad BG Jaafar MS Abdul Rahman A Ingawa FA 《Environmental monitoring and assessment》2012,184(8):5043-5049
Soil serves as a major reservoir for contaminants as it posseses an ability to bind various chemicals together. To safeguard the members of the public from an unwanted exposure, studies were conducted on the sediments and soil from water bodies that form the major sources of domestic water supply in northern peninsular Malaysia for their trace element concentration levels. Neutron Activation Analysis, using Nigeria Research Reactor-1 (NIRR-1) located at the Centre for Energy Research and Training, Zaria, Nigeria was employed as the analytical tool. The elements identified in major quantities include Na, K, and Fe while As, Br, Cr, U, Th, Eu, Cs, Co, La, Sm, Yb, Sc, Zn, Rb, Ba, Lu, Hf, Ta, and Sb were also identified in trace quantities. Gamma spectroscopy was also employed to analyze some soil samples from the same area. The results indicated safe levels in terms of the radium equivalent activity, external hazard index as well as the mean external exposure dose rates from the soil. The overall screening of the domestic water sources with relatively high heavy metals concentration values in sediments and high activity concentration values in soil is strongly recommended as their accumulation overtime as a consequence of leaching into the water may be of health concern to the members of the public. 相似文献
96.
Tahir MW Mumtaz MW Tauseef S Sajjad M Nazeer A Farheen N Iqbal M 《Environmental monitoring and assessment》2012,184(8):4879-4888
The present study describes the estimation of particulate matter (cotton dust) with different sizes, i.e., PM(1.0), PM(2.5), PM(4.0), and PM(10.0 μm) in small-scale weaving industry (power looms) situated in district Hafizabad, Punjab, Pakistan, and the assessment of health problems of workers associated with these pollutants. A significant difference was found in PM(1.0), PM(2.5), PM(4.0), and PM(10.0) with reference to nine different sampling stations with p values <0.05. Multiple comparisons of particulate matter with respect to size, i.e. PM(1.0), PM(2.5), PM(4.0), and PM(10.0), depict that PM(1.0) differs significantly from PM(2.5), PM(4.0), and PM(10.0), with p values <0.05 and that PM(2.5) differs significantly from PM(1.0) and PM(10.0), with p values <0.05, whereas PM(2.5) differs non-significantly from PM(4.0), with a p value >0.05 in defined sampling stations on an average basis. Majority of the workers were facing several diseases due to interaction with particulate matter (cotton dust) during working hours. Flue, cough, eye, and skin infections were the most common diseases among workers caused by particulate matter (cotton dust). 相似文献
97.
Ghumman AR Ahmad MM Hashmi HN Kamal MA 《Environmental monitoring and assessment》2012,184(5):3153-3163
Hill torrents cause a lot of environmental and property damage in Pakistan every year. Proper assessment of direct runoff in the form of hill torrents is essential for protection of environment, property, and human life. In this paper, direct surface runoff hydrograph (DSRH) was derived for a large catchment using the geomorphologic instantaneous unit hydrograph concept. The catchment with hill torrent flows in semi-arid region of Pakistan was selected for this study. It was divided into series of linear cascades and hydrologic parameters required for Nash's conceptual model, and were estimated using geomorphology of the basin. Geomorphologic parameters were derived from satellite images of the basin and ERDAS and ArcGIS were used for data processing. Computer program was developed to systematically estimate the dynamic velocity, its related parameters by optimization and thereby to simulate the DSRH. The data regarding rainfall-runoff and satellite images were collected from Punjab Irrigation and Power Department, Pakistan. Model calibration and validation was made for 15 rainfall-runoff events. Ten events were used for calibration and five for validation. Model efficiency was found to be more than 90% and root mean square error to be about 5%. Impact of variation in model parameters (shape parameter and storage coefficient) on DSRH was investigated. For shape parameter, the number of linear cascades varied from 1 to 3 and it was found that the shaper parameter value of 3 produced the best DSRH. Various values of storage coefficient were used and it was observed that the value determined from geomorphology and the dynamic velocity produced the best results. 相似文献
98.
Ali Naderi Beni Michael Kühn Robert Meyer Christoph Clauser 《Environmental Modeling and Assessment》2012,17(4):337-351
We study opportunities for CO2 sequestration in geological formations of the state North Rhine Westphalia in Germany. Simulations are performed for evaluating a potential site within the Bunter sandstone formation near the town of Minden in a depth?of around 3,000 m using the numerical simulator TOUGHREACT. Our focus is on three CO2 storage mechanisms: (1) hydrodynamic trapping, (2) dissolution trapping, and (3) mineral trapping. The results show that due to buoyancy the injected CO2 phase initially migrates towards the top of the reservoir and is hydrodynamically trapped beneath the confining layer of the cap rock. Then, the CO2 spreads laterally and dissolves partially in the formation water. The dissolution of CO2 results in an increase of the density of the brine causing a downward migration until it settles after 10,000 years at the bottom of the reservoir. The simulations indicate that after 10,000 years, 15% (17 Mt) from a total of 114 Mt injected CO2 are trapped hydrodynamically, 20% (23 Mt) are trapped by dissolution, and 65% (74 Mt) are fixed in newly formed carbonates such as dawsonite, ankerite, and siderite. Within our study pressure increases near the injection well by a factor of 1.1 which is lower than the upper limit usually accepted in gas storage operations. The mineral reactions cause a net decrease of porosity and in turn a decrease of permeability down to 9% of the initial value in parts of the reservoir. 相似文献
99.
A framework for dissolved oxygen (DO) modeling of the Ravi River has been developed based on a combination of laboratory measurements
and field and monitoring data. Both the classical Streeter-Phelps (CSP) and the modified Streeter-Phelps (MSP) models are
used for DO simulations. The MSP model considers the carbonaceous biochemical oxygen demand (CBOD) and nitrogenous biochemical
oxygen demand (NBOD) separately, whereas the CSP model is evaluated considering only the CBOD and NBOD is incorporated in
the overall BOD utilization rate. CBOD, NBOD and BOD rates have been determined through long-term BOD analysis of five main
wastewater outfalls and two surface drains discharging into the Ravi River over a 98 km stretch. Analysis by Thomas Method
manifests strong coefficient of determination “R2” between 0.72 and 0.98 for all the three types of BOD rates. Sensitivity analyses have also been carried out to find out
a suitable reaeration rate formula for highly variable flows in the Ravi River. The CSP model results based on classical approach
of considering only CBOD show significant difference between the model predictions and field measurements suggesting that
NBOD needs to be incorporated for the model development. The dissolved oxygen values calculated using the MSP model and the
CSP model based on overall BOD rate are in close agreement with field measurements and are thus suitable to model DO levels
in the Ravi River. 相似文献
100.
When agricultural lands are no longer used for agriculture and allowed to recover its natural vegetation, soil organic carbon
can accumulate in the soil. Measurements of soil organic carbon and aggregate stability changes under various forms of land
use are needed for the development of sustainable systems. Therefore, comparison of soil samples taken from both agricultural
and nearby area close to land-mined fields where no agricultural practices have been done since 1956 can be a good approach
to evaluate the effects of tillage and agriculture on soil quality. The objective of this study was to compare tillage, cropping
and no tillage effects on some soil-quality parameters. Four different locations along the Turkey–Syria border were selected
to determine effects of tillage and cropping on soil quality. Each location was evaluated separately because of different
soil type and treatments. Comparisons were made between non-tilled and non-cropped fallow since 1956 and adjacent restricted
lands that were tilled about every 2 years but not planted (T) or adjacent lands tilled and planted with wheat and lentil
(P). Three samples were taken from the depths of 0–20 and 20–40 cm each site. Soil organic carbon (SOC), pH ,electrical conductivity,
water soluble Ca++, Mg++, CO3-2{\rm CO}_{3}^{-2} and HCO3-{\rm HCO}_{3}^{-}, extractable potassium (K+) and sodium (Na+), soil texture, ammonium (NH4+{\rm NH}_{4}^{+}–N) and nitrate (NO3–N), extractable phosphorous and soil aggregate stability were determined. While the SOC contents of continuous tillage without
cropping and continuous tillage and cropping were 2.2 and 11.6 g kg−1, respectively, it was 30 g kg−1 in non-tilled and non-planted site. Tillage of soil without the input of any plant material resulted in loss of carbon from
the soil in all sites. Soil extractable NO3−N contents of non-tilled and non-cropped sites were greatest among all treatments. Agricultural practices increased phosphorus
and potassium contents in the soil profile. P2O5 contents of planted soils were approximately 20 to 39 times greater than those of non-tilled and non-cropped soils at different
sites. FTIR spectra showed that never tilled sites had greater phenol, carboxylic acid, amide, aromatic compounds, polysaccharide
and carbohydrates than other treatments. 相似文献