Combined Toxicity and Bioconcentration of Fluoride and Arsenic in African Catfish Clarias gariepinus (Burchell, 1822)

Laboratory experiments were performed to examine the combined toxic effects of two important aquatic contaminants viz., arsenic and fluoride on African catfish, Clarias gariepinus. Additionally, the bio concentration factors (BCFs) of the two contaminants in tissues and blood of catfish were also determined. The LC50 for sodium fluoride and arsenic trioxide were determined to be 619.3 mg L-1, 30.3 mg L-1, respectively. Erratic swimming movements with hyperactivity, loss of equilibrium, augmented air gulping and decreased food consumption were observed in the experimental groups. In co-exposure groups of arsenic and fluoride, the concentration of fluoride in fish tissues increased with increasing water fluoride concentration in the test aquaria with significant differences (

Mercury spillage through smoke-stakes of an integrated steel plant: Effects on soil and ground water

49-52<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Massive coal consumption has been shown by steel industries. Mercury emission from the stacks of steel industries was reported earlier. The respective samples of soil, ground water and pond water were collected from the susceptible and non-susceptible sites around the steel plant within a distance of 10 km. Samples were analyzed for the presence of mercury by mercury analyzer. Mercury concentration more than 1:0 ppm was observed in soils of high susceptible Sites. Mercury concentration in the range of 0.5-1.0 ppm was observed in the east and west direction of the plant upto a distance of 7 km. In case of ground water and pond water contamination, mercury concentration was found to be more than 10.0 ppb upto a distance of 10 km at high susceptible sites. Concentration range of 10.0 ppb-1.0 ppb was observed within the distance of 7 km at less susceptible sites. Concentration below the permissible limits for drinking water (1.0 ppb) was observed beyond the distance of 7 km at less susceptible sites.</span

Modeling of degraded composite beam due to moisture absorption for wave based detection

In this paper, wave propagation is studied in degraded composite beam due to moisture absorption. The obtained wave responses are then used for diagnosis of the degraded zone. Moisture absorption causes an irreversible hygrothermal deterioration of the material. The change in temperature and moisture absorption changes the mechanical properties. Thus this affects the structure in dimensional stability as well as material degradation due to reduction in mechanical properties. Here, the composite beam is modeled as Timoshenko beam using wavelet based spectral finite element (WSFE) method. The WSFE technique is especially tailored for simulation of wave propagation. It involves Daubechies scaling function approximation in time and spectral finite element approach. The simulated wave responses are then used as surrogate experimental results to predict degradation using a measure called damage force indicator (DFI). Numerical experiments are presented for moisture absorbed composite beam due to modulated sinusoidal excitation. The responses are studied for different environmental conditions in term of relative humidity and at a temperature

Temporal and spatial variations of PM2.5 organic and elemental carbon in Central India

This study describes spatiotemporal patterns from October 2015 to September 2016 for PM2.5 mass and carbon measurements in rural (Kosmarra), urban (Raipur), and industrial (Bhilai) environments, in Chhattisgarh, Central India. Twenty-four-hour samples were acquired once every other week at the rural and industrial sites. Twelve-hour daytime and nighttime samples were acquired either a once a week or once every other week at the urban site. Each site was equipped with two portable, battery-powered, miniVol air samplers with PM2.5 inlets. Annual average PM2.5 mass concentrations were 71.8 +/- 27 mu gm(-3) at the rural site, 133 +/- 51 mu gm(-3) at the urban site, and 244.5 +/- 63.3 mu gm(-3) at the industrial site,similar to 2-6 times higher than the Indian Annual National Ambient Air Quality Standard of 40 mu gm(-3). Average monthly nighttime PM2.5 and carbon concentrations at the urban site were consistently higher than those of daytime from November 2015 to April 2016, when temperatures were low. Annual average total carbon (TC = OC + EC) at the urban (46.8 +/- 23.8 mu gm(-3)) and industrial (98.0 +/- 17.2 mu gm(-3)) sites also exceeded the Indian PM2.5 NAAQS. TC accounted for 30-40% of PM2.5 mass. Annual average OC ranged from 17.8 +/- 6.1 mu gm(-3) at the rural site to 64 +/- 9.4 mu gm(-3) at the industrial site, with EC ranging from 4.51 +/- 2.2 to 34.01 +/- 7.8 mu gm(-3). The average OC/EC ratio at the industrial site (1.88) was 18% lower than that at the urban site and 52% lower than that at the rural site. OC was attributed to 43.0% of secondary organic carbon (SOC) at the rural site, twice that estimated for the urban and industrial sites. Mortality burden estimates for PM2.5 EC are 4416 and 6196 excess deaths at the urban and industrial sites, respectively, during 2015-2016

Household solid fuel burning emission characterization and activity levels in India

Emission factors (EFs) of PM2.5 carbon fractions, major ionic (K+, Ca2+, NH4+,SO42-, NO3- and Cl-) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g.kg(-1)) were: 34.16 +/- 10.1 for PM2.5 (CB), 14.18 = 5.8 for OC (CB), 2.33 +/- 1.4 for EC (DC), 1.03 +/- 02 for K+ (CR), 221 +/- 0.6 NH4+ (DC), 0.61 +/- 02 for NO3- (CB), 0.59 +/- 0.1 for SO42- (CB), 0.69 +/- 0.1 for Cl- (CR) among the fuels. Higher OC EFs for CB could be attributed to higher moisture content (>13%) in coal-powder that is used to handmade coal balls. It is observed that, in general, OC3 and EC1 were the dominant thermally evolved carbon mass fractions. The study averaged MCE values were in the range 0.93-0.98, which could be attributed to higher variability in flaming and smoldering episodes during the combustion of selected fuels. Sum of ionic EFs for emissions from DC, CR and MF were found to be higher than those observed for FW and CB. The K+/EC and Cl- /EC (similar to 1) ratios could be better indicators of CR fuels to differentiate it from 1W, whereas NH4+ EC (similar to 1) is suitable to indicate DC. Average annual emission estimates of PM2.5 (2.00 +/- 053 Tg.yr(-1)), OC (0.86 +/- 0.23 Tg.yr(-1)) and EC (0.11 +/- 0.02 Tg.yr(-1)) for tested fuels are evaluated to be contributing 27, 15 and 4% of total PM2.5, OC and EC, respectively, toward annual emission budget from different anthropogenic activities in India. (C) 2018 Elsevier B.V. All rights reserved

Household solid fuel burning emission characterization and activity levels in India

Emission factors (EFs) of PM2.5 carbon fractions, major ionic (K+, Ca2+, NH4+,SO42-, NO3- and Cl-) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g.kg(-1)) were: 34.16 +/- 10.1 for PM2.5 (CB), 14.18 = 5.8 for OC (CB), 2.33 +/- 1.4 for EC (DC), 1.03 +/- 02 for K+ (CR), 221 +/- 0.6 NH4+ (DC), 0.61 +/- 02 for NO3- (CB), 0.59 +/- 0.1 for SO42- (CB), 0.69 +/- 0.1 for Cl- (CR) among the fuels. Higher OC EFs for CB could be attributed to higher moisture content (>13%) in coal-powder that is used to handmade coal balls. It is observed that, in general, OC3 and EC1 were the dominant thermally evolved carbon mass fractions. The study averaged MCE values were in the range 0.93-0.98, which could be attributed to higher variability in flaming and smoldering episodes during the combustion of selected fuels. Sum of ionic EFs for emissions from DC, CR and MF were found to be higher than those observed for FW and CB. The K+/EC and Cl- /EC (similar to 1) ratios could be better indicators of CR fuels to differentiate it from 1W, whereas NH4+ EC (similar to 1) is suitable to indicate DC. Average annual emission estimates of PM2.5 (2.00 +/- 053 Tg.yr(-1)), OC (0.86 +/- 0.23 Tg.yr(-1)) and EC (0.11 +/- 0.02 Tg.yr(-1)) for tested fuels are evaluated to be contributing 27, 15 and 4% of total PM2.5, OC and EC, respectively, toward annual emission budget from different anthropogenic activities in India