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201.
Manchar Lake is the largest natural freshwater lake in Pakistan. The Lake has received less fresh water in past few years.
In addition, drainage water is being discharged in the Lake through Main Nara Valley Drain (MNVD) since many years. Consequently,
concern has grown regarding the water quality of the Lake. The aim of this study was to assess the water quality of Manchar
Lake and MNVD and the objectives were to determine physiochemical properties and the concentrations of common cations and
anions as well as seven trace metals i.e. Cu, Ni, Zn, Co, Fe, Pb and Cd. The concentration of the trace metals were determined
by simultaneous preconcentration and solvent extraction using flame atomic absorption spectrometer. Results of physicochemical
parameters of Manchar Lake water samples showed mean pH 8.4 (±0.2), conductivity 2,310.3 (±581.3) μS cm−1 and hardness (as CaCO3) 213.1 (±62.3) mg l−1. Mean concentrations of cations and anions were Na 521.5 (±49.7), Cl− 413.6 (±225.7), Ca 70.7 (±12.9), Mg 56.2 (±28.9), K 17.6 (±6.5), 0.34 (±0.2) and 0.02 (±0.01) mg l−1. Mean concentrations of trace metals were Zn 15.7 (±1), Fe 12 (±3.5), Pb 9 (±2.7), Cu 8.9 (±7.7), Ni 4.3 (±3.4), Co 4 (±3.4)
and Cd 1.1 (±1) μg l−1. MNVD water samples showed mean pH 8.9 (±0.8), conductivity 1,735.7 (±567.8) μS cm−1 and hardness (as CaCO3) 184.8 (±32.4) mg l−1. In MNWD, the mean concentrations of cations and anions were Na 482.7 (±11.7), Cl− 395.7 (±271.5), Ca 79.1 (±23.5), Mg 54.2 (±28.1), K 26.2 (±21.3), NO−3 0.5 (±0.3) and 0.1 (±0.1) mg l−1. Mean concentrations of trace metals observed in MNWD water were Fe 14.9(±3.5), Cd 8.3 (±9.4), Pb 6.9 (±2.4), Cu 6.6 (±3.1),
Zn 6.2 (±1.8), Co 4.5 (±2.7), and Ni 3.5 (±2.9) μg l−1. The pH of both Manchar Lake and MNVD waters and concentration of Pb in Manchar Lake and concentration of Cd in MNVD water
were higher than the World Health Organisation’s guideline values for the drinking water quality. The water quality of Manchar
Lake was found degraded. 相似文献
202.
203.
Shah MH Shaheen N Jaffar M Khalique A Tariq SR Manzoor S 《Journal of environmental management》2006,78(2):128-137
Spatial variations in total suspended particulate matter (TSP) were investigated for distribution of metals and particle size fractions in the urban and rural atmosphere of Islamabad, Pakistan. The metals Na, K, Fe, Mn, Pb, Cd, Cr, Zn, Ni and Co, and the particle fractions <2.5, 2.5-10, 10-100 and >100 microm were included in the study. TSP samples were trapped on glass fibre filters using high volume samplers and quantification of metals was done using Atomic Absorption Spectrometry employing HNO(3) based wet digestion. At the urban site, Na was dominant at 2.384 microg/m(3) followed by K, Fe and Zn with 0.778, 0.667 and 0.567 microg/m(3) as mean concentrations, respectively. The metal levels for the rural site ranged from 0.002 microg/m(3) for Cd to 1.077 microg/m(3) for Na. However, compared with the urban site, mean Pb concentration showed an almost two-fold enhancement, i.e., 0.163 Vs. 0.327 microg/m(3). Metals and particle size source identification was done using Principal Component Analysis and Cluster Analysis. Five sources were traced out for the urban site: industrial, soil, automobile emissions, metallurgical industries and excavation activities. For the rural site, four sources were recorded: agricultural, automotive emissions, excavation activities and metallurgical units. Collectively, for both the sites, PM(10-100) emerged as a major contributor to TSP, followed by PM(2.5-10), PM(<2.5) and PM(>100) in that order. The metals showed in general positive relationship with fine particulate fractions (PM(2.5-10), PM(<2.5)), and negative correlation with coarse fractions (PM(10-100), PM(>100)). Comparison with the corresponding data from various Asian sites revealed that the levels of Na, K, Fe, Mn, Co and Ni for the present study were lower than those reported for grossly polluted cities of the world. 相似文献
204.
Shah Md.Atiqul Haq 《中国人口.资源与环境(英文版)》2009,7(3):83-88
Now environment is an important topic in academic field. Many researches focus on the negative outcomes of nature which are being continually created by human and much attention has been paid to how the environment is protected through integrated research, movement and policy. But few studies are concentrated on population and environment and are to find out the interconnectivity and underlying mechanism that have an effect on people's preferring additional children and perception to environment. Many researchers claim that population growth is a great problem for environment but they do not provide the indepth integrated knowledge and mechanism that influence fertility trend and environmental problems. It is very crucial to develop practical and concrete initiatives to confirm a transition to reduce population growth and redirect the perception on population and environment. 相似文献
205.
Airborne particulate matter (PM) collected from two sampling stations in Islamabad, Pakistan, was analyzed for lead content and size gradation. A high volume air sampler was used to trap particulates on glass fiber filters for 8-12 h on a daily basis. Lead was estimated using a nitric acid digestion based AAS method on 44 samples from station 1 and 61 samples from station 2. Particle size fractions were categorized as <2.5, 2.5-10, 10-100 and >100 microm. The correlation between lead concentration and particle size was investigated. The results from two stations indicated average airborne lead concentrations of 0.505 and 0.185 microg/m3. Enhanced levels of lead were measured at a maximum of 4.075 microg/m3 at station 1 and 4.000 microg/m3 at station 2. PM < 2.5 and PM > 100 were found to constitute the local atmosphere in comparable proportions. A comparison of the lead levels is made with the existing permissible levels of this element laid down by different international agencies. 相似文献
206.
Chao He Yunshan Ge Jianwei Tan Kewei You Xunkun Han Junfang Wang Qiuwen You Asad Naeem Shah 《Atmospheric environment (Oxford, England : 1994)》2009,43(24):3657-3661
The characteristics of carbonyl compounds emissions were investigated on a direct injection, turbocharged diesel engine fueled with pure biodiesel derived from soybean oil. The gas-phase carbonyls were collected by 2,4-dinitrophenylhydrazine (DNPH)-coated silica cartridges from diluted exhaust and analyzed by HPLC with UV detector. A commercial standard mixture including 14 carbonyl compounds was used for quantitative analysis. The experimental results indicate that biodiesel-fueled engine almost has triple carbonyls emissions of diesel-fueled engine. The weighted carbonyls emission of 8-mode test cycle of biodiesel is 90.8 mg (kW h)?1 and that of diesel is 30.7 mg (kW h)?1. The formaldehyde is the most abundant compound of carbonyls for both biodiesel and diesel, taking part for 46.2% and 62.7% respectively. The next most significant compounds are acetaldehyde, acrolein and acetone for both fuels. The engine fueled with biodiesel emits a comparatively high content of propionaldehyde and methacrolein. Biodiesel, as an alternative fuel, has lower specific reactivity (SR) caused by carbonyls compared with diesel. When fueled with biodiesel, carbonyl compounds make more contribution to total hydrocarbon emission. 相似文献
207.
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
208.
Hussain Sajjad Mubeen Muhammad Ahmad Ashfaq Akram Waseem Hammad Hafiz Mohkum Ali Mazhar Masood Nasir Amin Asad Farid Hafiz Umar Sultana Syeda Refat Fahad Shah Wang Depeng Nasim Wajid 《Environmental science and pollution research international》2020,27(32):39676-39692
Environmental Science and Pollution Research - Land use/land cover (LULC) change has serious implications for environment as LULC is directly related to land degradation over a period of time and... 相似文献
209.
Kihombo Shauku Saud Shah Ahmed Zahoor Chen Songsheng 《Environmental science and pollution research international》2021,28(37):51149-51159
Environmental Science and Pollution Research - Earth is in the Anthropocene era and humankind deteriorates the global environment; thus, there is a dire need for sustainable policies at all levels.... 相似文献
210.
Khalid Sana Shahid Muhammad Natasha Shah Ali Haidar Saeed Farhan Ali Mazhar Qaisrani Saeed Ahmad Dumat Camille 《Environmental science and pollution research international》2020,27(32):39852-39864
Environmental Science and Pollution Research - The presence of toxic substances in aquifers, particularly potentially toxic heavy metals, is an important environmental and social concern worldwide.... 相似文献