Persistent Organochlorine Pesticide Residues in Soil and Surface Water of Northern Indo-Gangetic Alluvial Plains

This study reports the concentration levels and distribution pattern of the organochlorine pesticide (OCPs) residues in the soil and surface water samples collected from the northern Indo-Gangetic alluvial plains. A total of 31 soil and 23 surface water samples were collected from the study region in Unnao district covering an area of 2150 km² and analyzed for aldrin, dieldrin, endrin, HCB, HCH isomers, DDT isomers/metabolites, endosulfan isomers (α and β), endosulfan sulfate, heptachlor and its metabolites, α-chlordane, γ-chlordane and methoxychlor. In both the soil and surface water samples β- and δ-isomers of HCH were detected most frequently, whereas, methoxychlor was the least detected pesticide. The results showed contamination of soil and surface water of the region with several persistent organic pesticides. The total OCPs level ranged from 0.36–104.50 ng g^–1 and 2.63–3.72 μg L^–1 in soil and surface water samples, respectively.     

Hydrochemistry of Wet Atmospheric Precipitation Over an Urban Area in Northern Indo-Gangetic Plains

Rain water samples were collected to study the chemical composition of wet atmospheric precipitation (first event) over the Lucknow city in the northern Indo-gangetic alluvial plains. The samples were collected in the month of July, 2005 from different sites. The wet precipitation samples were analyzed for pH, EC, major ions (, Cl⁻, , , , F⁻, Na⁺, K⁺, Ca²⁺, Mg²⁺, ) and heavy metals (As, Cd, Al, Co, Cr, Cu, Fe, Mn, Mo, Ni, Hg, Pb, Se, Sn, Ti, V, Zn). The pH values of wet precipitation samples ranged between 6.5 and 8.7. The analysis of linear regression applied to the set of studied variables and computation of neutralization factors showed that neutralization occurred in precipitation samples and Ca²⁺ had the maximum neutralization capacity. It was found that Cl⁻, , Ca²⁺, Mg²⁺, Na⁺ and K⁺ in the precipitation samples originated mainly from crustal/anthropogenic sources in the region. On an average Fe, and Al accounted for >72% of the total concentration of trace metals in the wet precipitation samples followed by Zn (>10%). Enrichment factors calculated for heavy metals over reference background level in seawater and Earth’s crust showed relatively higher enrichment of Zn. The principal component analysis (PCA) identified the possible sources of ionic species and heavy metals in the wet precipitation samples.     

Fungicidal elements accumulated in Cryptothecia punctulata (Ascomycetes lichen) of an arecanut orchard in South India

Different nutrient elements were analyzed in the lichen Cryptothecia punctulata collected from the arecanut trees which were exposed to several sprays of a fungicide Bordeaux mixture. The study revealed the accumulation of fungicidal elements such as Cu, Ca and S in higher concentration of 575.4, 10,000 and 21,000 microg g(-1), respectively.     

Membrane technology for water purification

Managing higher water demands is a grand challenge of the twenty-first century due to pollution and climate change that are decreasing the amount of drinkable water. There is therefore a need for improved techniques to purify contaminated waters. Nanotechnology provides materials of unprecedented properties, which can be used to clean water. This article reviews recent developments in nanotechnology for wastewater treatment using novel polymeric membrane materials. The use of polymeric membrane materials and polymer brushes are discussed.     

Ovarian development in Labeo dyocheilus (McClelland) during active reproductive phase under captive and wild conditions

Ovarian development in Labeo dyocheilus was assessed during active reproductive phase under ambient environmental conditions in captivity and wild. Increasing day length and water temperature seemed favourable for ovarian development in female L. dyocheilus under both conditions. Gonadosomatic index (GSI) was lower in May and higher in July in captivity (6.168 and 13.366) and wild (5.798 and 16.166) respectively Ovarian development started little bit in advance in captivity with late yolk vesicle stage oocyte in May when yolk globule stage oocytes were prominent in wild. Fully grown oocytes with germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) stages were observed in July in both conditions. Degree of transformation of developing oogonials into advance stage oocytes was observed to be better in wild fish compared to captivity reared ones. The histophysiological changes in liver corresponded well to the progression of ovarian development. Successive granulation and vacuolization of hepatocyte cytoplasm were indicative of augmented synthetic activity and probably mobilization of energy content for oocyte growth. These observations indicated that normal ovarian development of L. dyocheilus under captivity in Tarai region of Uttarakhand would be useful for success of its seed production in captivity for stock augmentation in wild or species diversification in aquaculture.     

Experimental Methodology to Assess Contaminant Diffusion in Rock Mass

Monitoring changes in electrical conductivity (EC) of aqueous phase, due to contaminant diffusion through porous media, is one of the techniques followed by researchers to understand the migration mechanism. However, the contaminant diffusion in the rock mass is a slow process and hence detecting small changes in conductivity with the help of conventional laboratory conductivity meters is quite difficult. With this in view, an experimental methodology to monitor diffusion of contaminant(s) through the intact and fractured rock mass, with the help of a USDTS (Ultra-Sensitive Devices and Technical Services) conductivity meter, has been developed. Results have been validated with those obtained from the ion chromatograph (IC) technique and a good agreement has been noted. The study demonstrates usefulness of the proposed methodology for online monitoring of contaminant migration through the porous media.     

Uptake and accumulation of potentially toxic metals (Zn, Cu and Pb) in soils and plants of Durgapur industrial belt

Uptake and accumulation of metals in crops may cause possible health risks through food chain. A field survey was conducted to investigate the accumulation of potentially toxic metals contamination in soil and plants irrigated with complexed industrial effluents. Concentration of Zn, Cu and Pb was 205-255,101-130,118-177 microg g(-1) in rhizosphere soils and 116-223, 57-102 and 63-95 microg g(-1) d. wt. in root and 95-186, 44-75 and 27-58 microg g(-1) d. wt. in shoot, respectively. The trend in Cu and Pb was in the order: soil > root > shoot > seed while in Zn it was soil > root > seed > shoot. Roots accumulated a larger fraction of soil Cu (70%) > Zn (67%) > Pb (54%). Bioaccumulation coefficient of soil to root ranged from 51-98 for Zn, 54-85 for Cu and 43-63 for Pb.Analysis of variance showed marginal change in bioaccumulation coefficient, noticed between plants (p > 0.05) while it varied significantly (p < 0.01) between tissues and metals. It increased from root to seed/fruit (root > shoot > seed/fruit) while decreased between metals from Zn to Pb (Zn > Cu > Pb). Out of the three, two Cu and Pb accumulated to phyotoxic levels while Zn was within threshold limit of phytotoxicity.     

Salicylic acid to decrease plant stress

Pollution and climate change degrade plant health. Plant stress can be decreased by application of salicylic acid, an hormone involved in plant signaling. Salicylic acid indeed initiates pathogenesis-related gene expression and synthesis of defensive compounds involved in local resistance and systemic acquired resistance. Salicylic acid may thus be used against pathogen virulence, heavy metal stresses, salt stress, and toxicities of other elements. Applied salicylic acid improves photosynthesis, growth, and various other physiological and biochemical characteristics in stressed plants. Salicylic acid antagonizes the oxidative damaging effect of metal toxicity directly by acting as an antioxidant to scavenge the reactive oxygen species and by activating the antioxidant systems of plants and indirectly by reducing uptake of metals from their medium of growth. We review here the use of exogenous salicylic acid in alleviating bacterial, fungal, and viral diseases, heavy metal toxicity, toxicity of essential micronutrients, and salt stress.