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81.
Aerosol size distribution and mass concentration measurements in various cities of Pakistan 总被引:1,自引:0,他引:1
Alam K Blaschke T Madl P Mukhtar A Hussain M Trautmann T Rahman S 《Journal of environmental monitoring : JEM》2011,13(7):1944-1952
During March and April 2010 aerosol inventories from four large cities in Pakistan were assessed in terms of particle size distributions (N), mass (M) concentrations, and particulate matter (PM) concentrations. These M and PM concentrations were obtained for Karachi, Lahore, Rawalpindi, and Peshawar from N concentrations using a native algorithm based on the Grimm model 1.109 dust monitor. The results have confirmed high N, M and PM concentrations in all four cities. They also revealed major contributions to the aerosol concentrations from the re-suspension of road dust, from sea salt aerosols, and from vehicular and industrial emissions. During the study period the 24 hour average PM(10) concentrations for three sites in Karachi were found to be 461 μg m(-3), 270 μg m(-3), and 88 μg m(-3), while the average values for Lahore, Rawalpindi and Peshawar were 198 μg m(-3), 448 μg m(-3), and 540 μg m(-3), respectively. The corresponding 24 hour average PM(2.5) concentrations were 185 μg m(-3), 151 μg m(-3), and 60 μg m(-3) for the three sites in Karachi, and 91 μg m(-3), 140 μg m(-3), and 160 μg m(-3) for Lahore, Rawalpindi and Peshawar, respectively. The low PM(2.5)/PM(10) ratios revealed a high proportion of coarser particles, which are likely to have originated from (a) traffic, (b) other combustion sources, and (c) the re-suspension of road dust. Our calculated 24 hour averaged PM(10) and PM(2.5) concentrations at all sampling points were between 2 and 10 times higher than the maximum PM concentrations recommended by the WHO guidelines. The aerosol samples collected were analyzed for crustal elements (Al, Fe, Si, Mg, Ca) and trace elements (B, Ba, Cr, Cu, K, Na, Mn, Ni, P, Pb, S, Sr, Cd, Ti, Zn and Zr). The averaged concentrations for crustal elements ranged from 1.02 ± 0.76 μg m(-3) for Si at the Sea View location in Karachi to 74.96 ± 7.39 μg m(-3) for Ca in Rawalpindi, and averaged concentrations for trace elements varied from 7.0 ± 0.75 ng m(-3) for B from the SUPARCO location in Karachi to 17.84 ± 0.30 μg m(-3) for Na at the M. A. Jinnah Road location, also in Karachi. 相似文献
82.
Mucus released by scleractinian corals can act as an important energy and nutrient carrier in coral reef ecosystems, and a
distinct isotopic signature would allow following the fate of this material. This study investigates the natural C and N stable
isotopic signatures of mucus released by four scleractinian coral genera (Acropora, Fungia, Pocillopora and Stylophora) in comparison with those of suspended particulate organic matter (POM) in seawater of a Northern Red Sea fringing coral
reef near Aqaba, Jordan. The natural δ13C and δ15N signatures of coral mucus differed significantly from seawater POM for the majority of seasonal comparisons, but were inappropriate
for explicit tracing of mucus in the coral reef food web. Thus, a labeling technique using stable isotope tracers (13C and 15N) was developed that produced δ13C values of up to 122 ± 5‰ (mean ± SE) and δ15N of up to 2,100 ± 151‰ in mucus exuded by Fungia corals. 13C and 15N-enriched compounds were rapidly (within 3 h) and light-dependently transferred from the endosymbiotic zooxanthellae to the
mucus-producing coral host. The traceability of 15N-labeled mucus was examined by evaluating its uptake and potential utilization by epizoic acoelomorph Waminoa worms naturally occurring on a range of scleractinian coral taxa. This tracer experiment resulted in uptake of coral mucus
by the coral-associated acoelomorphs and further demonstrated the possibility to trace stable isotope-labeled coral mucus
by revealing a new trophic pathway in coral reef ecosystems. 相似文献
83.
Mangroves forests are facing serious stresses which jeopardize their sustainability and their existence in Pakistan. Theses
coastal forests are found in the Indus delta in Sindh and the coastal areas of Sonmiani, Kalmat and Gawatar bay in Balochistan.
A significant reduction in the fresh water supply and increased marine water pollution in from industries as well as over
harvesting of mangroves and fishes by the local peoples, sedimentation, population stress and coastal erosion are usually
considered to be the immediate causes of mangrove loss in Pakistan. Various Projects have been under taken in the past and
in current scenario to conserve the resources of mangrove areas. Strong planning with the collaboration of the local institutes
at the grass-root levels will be helpful to strengthen their capacity and to achieve the targets easily, and they will also
help in achieving the conservation goals in a sustainable manner. It is predictable that large-scale plantation of this mangroves
species in these areas would increase the resources in coastal areas, resulting economic benefit to the local people. 相似文献
84.
Ahmad Kalbasi Ashtari Amir M. Samani Majd Gerald L. Riskowski Saqib Mukhtar Lingying Zhao 《Frontiers of Environmental Science & Engineering》2016,10(6):3
Slightly acidic solutions are a practical means of removing ammonia from air
Scrubbed NH3 accumulates in solution as NH4+ and should be an excellent fertilizer
Increased air velocity decreased NH3 removal and increased NH4+ collection
Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions would reduce corrosion, maintenance, and cost; however, designers may need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this study was to determine if a spray scrubber with slightly acidic and higher pH scrubbing solution (pH from 2 to 8) could effectively remove NH3 from NH3 laden air (such as animal building exhaust air), and also collect this valuable resource for later use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppmv NH3/air mixture in a countercurrent contact chamber. First, the solution pH was varied from 2 to 8 while maintaining constant air velocity at 1.3 m·s−1. Next, air velocity was increased (2 and 3 m·s−1) while solution pH remained constant at pH6. At 1.3 m·s−1, NH3 removal efficiencies ranged between 49.0% (pH8) and 84.3% (pH2). This study has shown that slightly acidic scrubbing solutions are a practical means of removing ammonia from air especially if the scrubber is designed to increase collisions between solution droplets and NH3 molecules. The NH3 removed from the air was held in solution as NH4+ and accumulates over time so the solution should be an excellent fertilizer. 相似文献
85.
Qian Guoqing Duanmu Chuansong Ali Nisar Khan Adnan Malik Sumeet Yang Yong Bilal Muhammad 《Environment, Development and Sustainability》2022,24(8):9731-9756
Environment, Development and Sustainability - There has been great concern about producing, converting, or disposing of the waste obtained from different sources. Waste production is a continuous... 相似文献
86.
Shabbir Malik Shahzad Wisdom Okere 《Environmental science and pollution research international》2020,27(32):39946-39957
Environmental Science and Pollution Research - The primary objective of this research is to ascertain the relationship between corporate social responsibility, environmental investments and... 相似文献
87.
Malik Bilal Ahmad Shah Mohammad Yousuf Sawant Vishwas A. 《Environmental science and pollution research international》2021,28(35):48274-48283
Environmental Science and Pollution Research - Micropiles, on account of their versatility, can serve as both a new foundation and a long-term option for prevailing foundations without disturbing... 相似文献
88.
B.S. Paul S.D. Singh J.K. Malik 《Journal of environmental science and health. Part. B》2013,48(1):111-122
Abstract The acute toxic effects of quinalphos (0,0‐diethyl 0–2‐quinoxalyl phosphorothioata) uere investigated in male buffalo calves. Quinalphos was administered in single oral doses of 5, 7.5, 8.5 and 10 mg/kg body wt. and its effects on erythrocyte and plasma cholinesterases, serum aspartate aminotransferase and blood glucose were studied at various time intervals. The lowest dose (5 mg/kg) produced no apparent toxic symptoms. All the animals given highest dose (10 mg/kg) died within 60–82 hours after dosing. Quinalphos at all the dose levels markedly inhibited the erythrocyte and plasma cholinesterases (68–100%) and significantly elevated the levels of serum aspartate aminotransferase and blood glucose. Seven days after the administration of quinalphos, the blood cholinesterases in survivors remained inhibited to the extent of 41–77% whereas the levels of serum aspartate aminotransferase and blood glucose were comparable to control values. 相似文献
89.
Anushree Malik Neena Singh Santosh Satya 《Journal of environmental science and health. Part. B》2013,48(4):453-469
Musca domestica L. (Diptera: Muscidae), commonly called the house fly, is a major domestic, medical and veterinary pest that causes irritation, spoils food and acts as a vector for many pathogenic organisms. In this paper, the social and health problems related to housefly are introduced with the associated need to control its population. Physical and chemical methods of house fly control are briefly discussed. The main focus of this review is on the biological control methods for house fly control, that comprise botanical, fungal, bacterial and parasitoid agents. Although several biocontrol agents are still in the nascent stage, some of them (especially fungal and parasitoid agents) have shown reliable field performance and seem to be suitable candidates for commercialization. However, the majority of these laboratory and field studies have been conducted in the temperate region. It remains to be seen whether the application of biocontrol agents would be feasible in tropical environments. The integrated pest management practices, which can provide more reliable field performance, have also been discussed. A multi-dimensional approach that exerts control on all the life stages of house fly, but simultaneously preserves the fly's natural enemies could be an ecologically sustainable way of maintaining the fly populations below maximally acceptable limits. 相似文献
90.
Concentration of ten metals (Cd, Cr, Co, Cu, Fe, Li, Mn, Ni, Pb and Zn) were analyzed in the egg contents, prey and soil samples of little egret (Egretta garzetta) and cattle egret (Bubulcus ibis) from two Headworks to determine habitat and species-specific differences; to assess the importance of prey and habitat contamination as an exposure source for heavy metals. Concentration of Cu, Mn, Cr and Pb in egg contents, Fe, Co, Cu, Mn, Zn in prey and Fe, Co, Cu, Ni, Li in surface soils were significantly different (P < 0.05). Mean metal concentrations of Cr, Pb and Cd were relatively higher in little egret whereas Cu and Mn were higher in the egg contents of cattle egret. The mean concentrations of Cu, Mn and Zn were higher in prey samples of cattle egrets and Cr, Cd and Pb in prey samples of little egrets. In soil samples collected from little egret heronries metal concentrations were higher except Cu and Ni. Correlation Analysis and Hierarchical Agglomerative Cluster Analysis (HACA) identified relatively similar associations of metals and their source identification. Metals such as Fe, Cu, Mn, and Li were related with geochemical origin from parent rock material as well as anthropogenic input whereas Cr, Cd, Pb, Ni, Co and Zn were associated mostly with anthropogenic activities. The study suggested that eggs are useful bio-monitor of local heavy metal contamination. 相似文献