Controls on quartz silt formation by crystalline defects

Silt composed predominately of quartz occurs abundantly in the sedimentary material found in deposits worldwide. Its origin is still the subject of many debates, but one acknowledged source is due to glacial grinding. To examine this problem and test the apparent contradictory evidence in the literature, a series of experiments were performed. In these experiments, the Bromhead ring shear apparatus was used as it can simulate glacial grinding due to its uninterrupted shearing action; hence, it provides an effective reproduction of glacial grinding. Experiments conducted on unweathered sand-sized vein quartz produced little silt, while use of sand from a sedimentary deposit, Leighton Buzzard sand, produced plentiful silt. Experimental results suggest that there is an internal mineralogical control on the formation of quartz silt particles. It is argued that the processes involved in the formation of quartz introduce defects (Moss defects) into the low-quartz crystal structure, demonstrated by the presence of peaks in the particle size curve around 20 μm. This indicates that there is a lithological control for the silt yielded under weathering, and this could explain why a pronounced mode at around 20–60 μm is commonly observed in silts, such as loess.     

Light scattering from sea-salt aerosols at Interagency Monitoring of Protected Visual Environments (IMPROVE) sites

A method is described to estimate light scattering (Bsp) by sea-salt aerosols at coastal locations in the Interagency Monitoring of Protected Visual Environments (IMPROVE) network. Dry mass scattering efficiencies for fine and coarse sea-salt particles were based on previously measured dry sea-salt size distributions. Enhancement of sea-salt particle scattering by hygroscopic growth was based on NaCl water activity data. Sea-salt aerosol mass at the IMPROVE site in the Virgin Islands (VIIS) was estimated from strontium (Sr) concentrations in IMPROVE aerosol samples. Estimated Bsp, including contributions from sea-salt mass based on Sr, agreed well with measured Bsp at the VIIS IMPROVE site. On average, sea salt accounted for 52% of estimated Bsp at this site. Sea-salt aerosol mass cannot be reliably estimated from Sr unless its crustal enrichment factor exceeds 10. Sodium (Na) concentrations are not accurately determined by X-ray fluorescence analysis in IMPROVE samples. It is recommended that Na be measured in the fine and coarse modes by a more appropriate method, such as atomic absorption spectroscopy or ion chromatography, to account for scattering by sea-salt particles at IMPROVE sites where such contributions may be significant.     

Adsorption and desorption characteristics of hydrophobic pesticide endosulfan in four Indian soils

Adsorption and desorption characteristics of endosulfan in four Indian soils were studied extensively. The soils used were clayey soil (CL--lean clay with sand), red soil (GM--silty gravel with sand), sandy soil (SM--silty sand with gravel) and composted soil (PT--peat) as per ASTM (American Society for Testing and Materials) standards. Adsorption and desorption rates were calculated from kinetic studies. These values varied for alpha and beta endosulfan depending on the soil type. Maximum specific adsorption capacities (qmax) for different soils were calculated by Langmuir model. The values varied from 0.1 to 0.45 mg g(-1) for alpha endosulfan and 0.0942-0.2722 mg g(-1) for beta endosulfan. Maximum adsorption took place in clay soil followed by composted soil and red soil. Adsorptions of alpha and beta endosulfan were negligible in sand. The binding characteristics of various functional groups were calculated using Scatchard plot. Effect of functional groups was more predominant in clayey soil. Organic matter also played a significant role in adsorption and desorption of endosulfan. Endosulfan adsorption decreased drastically in clay soil when the pH was reduced. Desorption was higher at both acidic and alkaline pH ranges compared to neutral pH. Results indicated that alpha endosulfan is more mobile compared to beta endosulfan and mobility of endosulfan is maximum in sandy soil followed by red soil. It can be inferred that crystal lattice of the clay soil plays a significant role in endosulfan adsorption and desorption. Immobilization of endosulfan is more advisable in clay soil whereas biological and or chemical process can be applied effectively for the remediation of other soil types.     

Size fractionated speciation of nitrate and sulfate aerosols in a sub-tropical industrial environment

Size fractionated chemical speciation of acidic aerosols were performed for ammonium sulfate, other sulfates, ammonium nitrate and other nitrates in a sub-tropical industrial area, Bina, India during December 2003 to November 2004. Analysis of variance (ANOVA) revealed highly significant temporal variations (p > .001) in the concentrations of nitrate and sulfate aerosols in all the three size fractions (fine, mid-size and coarse). Winter demonstrated utmost concentrations of ammonium sulfate, which ranged from 3.2 to 26.4 microg m(-3) in fine particles and 0.20-0.34 microg m(-3) in coarse particles. Ammonium sulfate was chiefly in fine mode (43.77% of total particulate sulfate) as compared to coarse particles (28.60% of total particulate sulfate). The major fraction Ammonium sulfate existed in different forms in atmospheric aerosols, for example NH4Fe(SO4)2, (NH4)2SO4, (NH4)3H(SO4)2 in fine particles, and (NH4)4(NO3)SO4+ in coarse particles. Other sulfate concentrations were also higher during winter ranging from 1.89 to 14.3 microg m(-3) in fine particles and 0.12-0.65microg m(-3) in coarse particles. Ammonium nitrate constituted the major fraction of total particulate nitrate all through the year and was principally in fine particles (the highest concentration in January i.e. 14.2 microg m(-3)). Other nitrates were mainly distributed in the fine particles (highest concentration in January i.e. 11.2 microg m(-3)) All the sulfate and nitrate species were mainly distributed in fine mode and have significant impact on human health.     

Molluscicidal activity of Ferula asafoetida, Syzygium aromaticum and Carum carvi and their active components against the snail Lymnaea acuminata

The molluscicidal activity of dried root latex powder of Ferula asafoetida, flower-bud powder of Syzygium aromaticum and seed powder of Carum carvi against the snail Lymnaea acuminata was studied. The molluscicidal activity of all the three plant products was found to be both time and concentration dependent. The toxicity of S. aromaticum flower-bud powder (96 h LC(50):51.98 mg/l) was more pronounced than that of root latex powder of F. asafoetida (96 h LC(50):82.71 mg/l) and seed powder of C. carvi (96 h LC(50):140.58 mg/l). Ethanol extract was more toxic than other organic extracts. The ethanol extract of S. aromaticum (24h LC(50):83.53 mg/l) was more effective than that of F. asafoetida (24h LC(50):132.31 mg/l) and C. carvi (24h LC(50):130.61 mg/l) in killing the test animals. The 96 h LC(50) of column purified fraction of seed powder of C. carvi was 5.40 mg/l whereas those of flower-bud powder of S. aromaticum and dried root latex powder of F. asafoetida were 7.87 and 9.67 mg/l, respectively. The product of F. asafoetida, S. aromaticum and C. carvi may be used as potent molluscicides.     

Distribution of improved cook stoves: analysis of field experiments using strategic niche management theory

Close to three billion people globally and over 800 million in India are dependent on direct combustion of unprocessed solid biomass fuels in inefficient traditional mud stoves. Current cooking practices, besides causing serious health problems, are also being linked to emissions of climate change and pollution agents such as black carbon and ozone precursors. In India several initiatives have been taken up to tackle the problem but the present trajectory of limited technical and social change in cooking energy use is nonetheless persistent in rural areas. In order to develop and scale up alternative cooking technology options, we have analyzed, using the principles of strategic niche management, two projects implemented by The Energy and Resources Institute (TERI) in nine villages in India. The assessment, while highlighting reasons for stability of the current cooking regime, also points to triggers that can destabilize the regime. The focus is also on assessing the influence of protection in the form of subsidies on the process of transition. User preferences relating to social and technical aspects have been analyzed, pointing to forced draft cookstoves as the preferred option notwithstanding cost reductions to address affordability concerns. The assessment indicates that while it is critically important to understand and address the preferences of users and to improve the technology, scaling up will depend on stove cost reduction through further research. Creativity in effective financing schemes and support structures put in place by fostering public–private partnerships are also needed.     

Fertigation effect of distillery effluent on agronomical practices of Trigonella foenum-graecum L. (Fenugreek)

The fertigation effect of distillery effluents concentrations such as 5%, 10%, 25%, 50%, 75% and 100% were studied on Trigonella foenu-graecu (Pusa early bunching) along with control (bore well water). On irrigation of soil with different effluents up to 90 days of harvesting, it was observed that there was a significant effect on moisture content (P < 0.001), EC, pH, Cl⁻, total organic carbon (TOC), HCO₃^-_{3}^{-}, CO₃^-2_{3}^{-2}, Na⁺, K⁺, Ca^2 +, Mg^2 +, Fe^2 +, TKN, NO₃^2-_{3}^{2-}, PO₄^3-_{4}^{3-}, and SO₄^2-_{4}^{2-} (P < 0.0001) and insignificant effect on WHC and bulk density (P > 0.05).There was no significant change in the soil texture of the soil. Among various concentrations of effluent irrigation, the irrigation with 100% effluent concentration decreased pH (16.66%) and increased moisture content (30.82%), EC(84.13%), Cl⁻ (292.37%), TOC (4311.61%), HCO₃^-_{3}^{-} (27.76%), CO₃^-2_{3}^{-2} (32.63%), Na⁺ (273%), K⁺ (31.59%), Ca^2 + (729.76%), Mg^2 + (740.47%), TKN (1723.32%), NO₃^2-_{3}^{2-} (98.02%), PO₄^3-_{4}^{3-} (337.79%), and SO₄^2-_{4}^{2-} (77.78%), Fe^2 + (359.91%), Zn (980.48%), Cu (451.51%), Cd (3033.33%), Pb (2350.00%), and Cr (2375.00%) in the soil. The agronomical parameters such as shoot length, root length, number of leaves, flowers, pods, dry weight, chlorophyll content, LAI, crop yield, and HI of T. foenum-graecum were recorded to be in increasing order at low concentration of the effluent, i.e., from 5% to 50% and in decreasing order at higher effluent concentration, i.e., from 75% to 100% as compared to control. The enrichment factor of various heavy metals was ordered for soil Cd>Cr> Pb>Zn>Cu>Fe and for T. foenum-graecum plants Pb>Cr>Cd>Cu>Zn>Fe after irrigation with distillery effluent.     

Biodegradation of C.I. Acid Red 1 by indigenous bacteria <Emphasis Type="Italic">Stenotrophomonas</Emphasis> sp. BHUSSp X2 isolated from dye contaminated soil

A significant proportion of xenobiotic recalcitrant azo dyes are being released in environment during carpet dyeing. The bacterial strain Stenotrophomonas sp. BHUSSp X2 was isolated from dye contaminated soil of carpet industry, Bhadohi, India. The isolated bacterial strain was identified morphologically, biochemically, and on the basis of 16S rRNA gene sequence. The isolate decolorized 97 % of C.I. Acid Red 1 (Acid RED G) at the concentration of 200 mg/l within 6 h under optimum static conditions (temperature ?35 °C, pH 8, and initial cell concentration 7?×?10⁷ cell/ml). Drastic reduction in dye degradation rate was observed beyond initial dye concentration from 500 mg/l (90 %), and it reaches to 25 % at 1000 mg/l under same set of conditions. The analysis related to decolorization and degradation was done using UV-Vis spectrophotometer, HPLC, and FTIR, whereas the GC-MS technique was utilized for the identification of degradation products. Phytotoxicity analysis revealed that degradation products are less toxic as compared to the original dye.     

Effects of silver nanoparticles on stress biomarkers of Channa striatus: immuno-protective or toxic?

Environmental Science and Pollution Research - Nanotechnology is a novel arena with promising applications in the field of medicine, industry, and agriculture including fisheries....     

Does Globalisation Worsen Environmental Quality in Developed Economies?

We examine the causal relationship between globalisation and CO₂ emissions for 25 developed economies in Asia, North America, Western Europe and Oceania using both time series and panel data techniques, spanning the annual data period of 1970–2014. Because of the presence of cross-sectional dependence in the panel, we employ Pesaran’s Journal of Applied Econometrics 22, 265–312 (2007) cross-sectional augmented panel unit root (CIPS) test to ascertain unit root properties. The Westerlund Oxford Bulletin of Economics and Statistics 69, 709–748 (2007) cointegration test is also used to ascertain the presence of a long-run association between globalisation and carbon emissions. The long-run heterogeneous panel elasticities are estimated using the Pesaran Econometrica, 74(4), 967–1012 (2006) common correlated effect mean group (CCEMG) estimator and the Eberhardt and Teal Productivity analysis in global manufacturing production (2010) augmented mean group (AMG) estimator. The causality between the variables is examined by employing the Dumitrescu and Hurlin Economic Modelling, 29, 1450–1460 (2012) and Emirmahmutoglu and Kose Economic Modelling, 28, 870–876 (2011) Granger causality tests. The empirical results reveal that globalisation increases carbon emissions, and thus, the globalisation-driven carbon emission hypothesis is valid. This empirical analysis suggests insightful policy guidelines for policy makers using ‘globalisation’ as an economic tool for better long-run environmental policy.