The pond water is used by a variety of animals i.e. mammals, birds, duck, and fish. Sediments play a significant role in determining the overall environmental quality for the living organism. Therefore, in this work, ...The pond water is used by a variety of animals i.e. mammals, birds, duck, and fish. Sediments play a significant role in determining the overall environmental quality for the living organism. Therefore, in this work, chemical characterization of pond water and sediment in the largest coal burning basin of India i.e. Korba basin is described. Elements i.e. C, O, S, F, Cl, Na, Mg, Al, Si, P, K, Ca, Ti, Fe, As, Cr, Cu, Zn, Cd, Pb, and Hg were quantified. Toxic metals i.e. As, Cd, Hg, and Pb were highly enriched in the sediments, ranging from 36 - 154, 0.14 - 1.19, 0.12 - 0.82 and 26 - 127 mg/kg with mean value (p = 0.05) of 95 ± 12, 0.62 ± 0.11, 0.35 ± 0.08 and 75 ± 13 mg/kg, respectively. The concentration variations, pollution indices and sources of elements in water and sediment are discussed.展开更多
Atmospheric fine particulate matters (PM2.5) were collected with an Envirotech Instrument (Model APM 550) at the roof of Khundkur Mukarram Hussain Science Building, University of Dhaka, Bangladesh between January and ...Atmospheric fine particulate matters (PM2.5) were collected with an Envirotech Instrument (Model APM 550) at the roof of Khundkur Mukarram Hussain Science Building, University of Dhaka, Bangladesh between January and February, 2013. PM2.5 samples were collected on Quartz fiber filters during day and night time. Water soluble ions (sulfate, nitrate, phosphate, chloride, bromide, sodium, potassium and calcium) were analyzed with Ion Chromatography (Model 881, Metrohm Ltd., Switzerland) and Flame photometer (Model PFP7, Jenway, UK). Average PM2.5 mass was 136.1 μg·mDž during day time and 246.8 μg·mDž during night time with a total average of 191.4 μg·mDž. Nighttime PM2.5 concentration was about double compared than that of daytime presumable due to the low ambient temperatures with high emissions from heavy duty vehicles. The 24-hour average PM2.5 mass (average of day and night) was about eight times higher than WHO (25.0 μg·mDž) and about three times higher than DoE, Bangladesh (65.0 μg·mDž) limit values. The total average concentrations of sulfate, nitrate, phosphate, bromide, chloride, sodium, potassium and calcium were 5.30, 7.75, 0.62, 0.16, 1.19, 1.30, 8.11, and 3.09 μg·mDž, respectively. The concentrations of the water soluble ions were much higher during nighttime than daytime except nitrate, bromide and potassium. Excellent correlations were observed between sulfate and nitrate, sodium and chloride, bromide and phosphate indicating joint sources of origin. Potassium, sulfate, nitrate and calcium are the most dominant species in PM2.5. Water soluble ionic components in Dhaka contributed about 15% mass of the PM2.5. Ratio analysis showed that sodium and chloride were from mainly sea salt. Potassium has varieties of sources other than biomass burning. Sulfate and nitrate are mainly from fossil fuel origin. This is the first study of the day and night variation of the water soluble ionic species at the fine particulate matters (PM2.5) in Bangladesh.展开更多
Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electrom...Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electromagnetic fields is discussed.Air/water/soil contains ions and the energy transfer for living organisms takes place by ion exchange processes.Ions are affected by electric/magnetic fields.Many investigators展开更多
Atmospheric particulate samples were collected from four densely populated places in a university,and then the concentration levels of indoor particulates were analyzed.Water-soluble cations and anions in the indoor p...Atmospheric particulate samples were collected from four densely populated places in a university,and then the concentration levels of indoor particulates were analyzed.Water-soluble cations and anions in the indoor particles were analyzed through ultrasonic extraction and ion chromatography(IC),and total organic carbon(TOC)content was analyzed by using a TOC analyzer.Organic compounds in the indoor particles were analyzed through ultrasonic extraction and GC-MS.The results showed that among the water-soluble ions,the mass concentration of SO2-4in indoor particles was the highest,so it was the main contributor of water-soluble anions,indicating that combustion of fossil fuels and industrial discharge were main sources of indoor particles at the four sampling points.Water-soluble organic carbon was the main component of water-soluble carbon in indoor particles.Among the four sampling points,the mass concentrations of the 18 organic compounds except for glycerol and phthalic acid were the highest in the cafeteria,so organic components in indoor atmospheric particles were mainly from food sources.展开更多
In this work, Coffee husk (CH) was used as a solid phase extractor (SPE) for removal and/or minimization of Zn2+ and Ni2+ ions in aqueous media. XRD, FESEM and FTIR analysis of the SPE were performed for surface morph...In this work, Coffee husk (CH) was used as a solid phase extractor (SPE) for removal and/or minimization of Zn2+ and Ni2+ ions in aqueous media. XRD, FESEM and FTIR analysis of the SPE were performed for surface morphology and function groups characterisation. Batch mode adsorption studies were performed by varying the operational parameters such as adsorbent dose, solution pH, initial analyte concentration and contact time. The equilibrium data of both analytes was found a better fit with the Langmuir and Freundlich isotherm models. The qm of Langmuir for Zn2+ and Ni2+ ions were 12.987 and 11.11 mg/g, respectively. The adsorption capacities of the CH adsorbent towards Zn2+ and Ni2+ resulted of 12.53 and 10.33 mg/g, respectively. In addition, the kinetic data of Zn2+ and Ni2+ ions uptake revealed that the present system fitted well with pseudo-second-order kinetic model (R2 > 0.99). Thermodynamic studies showed that the retention step was exothermic, and spontaneous in nature. The results indicated that the coffee husk provides an effective and economical approach in highly reducing or almost eradication of both metals Zn2+ and Ni2+ from the aqueous solution.展开更多
文摘The pond water is used by a variety of animals i.e. mammals, birds, duck, and fish. Sediments play a significant role in determining the overall environmental quality for the living organism. Therefore, in this work, chemical characterization of pond water and sediment in the largest coal burning basin of India i.e. Korba basin is described. Elements i.e. C, O, S, F, Cl, Na, Mg, Al, Si, P, K, Ca, Ti, Fe, As, Cr, Cu, Zn, Cd, Pb, and Hg were quantified. Toxic metals i.e. As, Cd, Hg, and Pb were highly enriched in the sediments, ranging from 36 - 154, 0.14 - 1.19, 0.12 - 0.82 and 26 - 127 mg/kg with mean value (p = 0.05) of 95 ± 12, 0.62 ± 0.11, 0.35 ± 0.08 and 75 ± 13 mg/kg, respectively. The concentration variations, pollution indices and sources of elements in water and sediment are discussed.
文摘Atmospheric fine particulate matters (PM2.5) were collected with an Envirotech Instrument (Model APM 550) at the roof of Khundkur Mukarram Hussain Science Building, University of Dhaka, Bangladesh between January and February, 2013. PM2.5 samples were collected on Quartz fiber filters during day and night time. Water soluble ions (sulfate, nitrate, phosphate, chloride, bromide, sodium, potassium and calcium) were analyzed with Ion Chromatography (Model 881, Metrohm Ltd., Switzerland) and Flame photometer (Model PFP7, Jenway, UK). Average PM2.5 mass was 136.1 μg·mDž during day time and 246.8 μg·mDž during night time with a total average of 191.4 μg·mDž. Nighttime PM2.5 concentration was about double compared than that of daytime presumable due to the low ambient temperatures with high emissions from heavy duty vehicles. The 24-hour average PM2.5 mass (average of day and night) was about eight times higher than WHO (25.0 μg·mDž) and about three times higher than DoE, Bangladesh (65.0 μg·mDž) limit values. The total average concentrations of sulfate, nitrate, phosphate, bromide, chloride, sodium, potassium and calcium were 5.30, 7.75, 0.62, 0.16, 1.19, 1.30, 8.11, and 3.09 μg·mDž, respectively. The concentrations of the water soluble ions were much higher during nighttime than daytime except nitrate, bromide and potassium. Excellent correlations were observed between sulfate and nitrate, sodium and chloride, bromide and phosphate indicating joint sources of origin. Potassium, sulfate, nitrate and calcium are the most dominant species in PM2.5. Water soluble ionic components in Dhaka contributed about 15% mass of the PM2.5. Ratio analysis showed that sodium and chloride were from mainly sea salt. Potassium has varieties of sources other than biomass burning. Sulfate and nitrate are mainly from fossil fuel origin. This is the first study of the day and night variation of the water soluble ionic species at the fine particulate matters (PM2.5) in Bangladesh.
文摘Man made activities are changing environment of our planet earth.Various methods are used to reduce the environmental pollution.In this paper the methods of air/water/soil pollution mitigation/reduction using electromagnetic fields is discussed.Air/water/soil contains ions and the energy transfer for living organisms takes place by ion exchange processes.Ions are affected by electric/magnetic fields.Many investigators
文摘Atmospheric particulate samples were collected from four densely populated places in a university,and then the concentration levels of indoor particulates were analyzed.Water-soluble cations and anions in the indoor particles were analyzed through ultrasonic extraction and ion chromatography(IC),and total organic carbon(TOC)content was analyzed by using a TOC analyzer.Organic compounds in the indoor particles were analyzed through ultrasonic extraction and GC-MS.The results showed that among the water-soluble ions,the mass concentration of SO2-4in indoor particles was the highest,so it was the main contributor of water-soluble anions,indicating that combustion of fossil fuels and industrial discharge were main sources of indoor particles at the four sampling points.Water-soluble organic carbon was the main component of water-soluble carbon in indoor particles.Among the four sampling points,the mass concentrations of the 18 organic compounds except for glycerol and phthalic acid were the highest in the cafeteria,so organic components in indoor atmospheric particles were mainly from food sources.
文摘In this work, Coffee husk (CH) was used as a solid phase extractor (SPE) for removal and/or minimization of Zn2+ and Ni2+ ions in aqueous media. XRD, FESEM and FTIR analysis of the SPE were performed for surface morphology and function groups characterisation. Batch mode adsorption studies were performed by varying the operational parameters such as adsorbent dose, solution pH, initial analyte concentration and contact time. The equilibrium data of both analytes was found a better fit with the Langmuir and Freundlich isotherm models. The qm of Langmuir for Zn2+ and Ni2+ ions were 12.987 and 11.11 mg/g, respectively. The adsorption capacities of the CH adsorbent towards Zn2+ and Ni2+ resulted of 12.53 and 10.33 mg/g, respectively. In addition, the kinetic data of Zn2+ and Ni2+ ions uptake revealed that the present system fitted well with pseudo-second-order kinetic model (R2 > 0.99). Thermodynamic studies showed that the retention step was exothermic, and spontaneous in nature. The results indicated that the coffee husk provides an effective and economical approach in highly reducing or almost eradication of both metals Zn2+ and Ni2+ from the aqueous solution.
