Impacts of quicklime (CaO) on the toxicity of copper (CuSO4, 5H2O) to fish and fish food organisms

Static bioassays of 96 h duration were conducted in the laboratory using fry of common carp (Cyprinus carpio), adult tubificid worm (Branchiura sowerbyi) and adult copepod plankton (Cyclops viridis) to determine LC50 values of Cu and CaO to these organisms and effects of interaction between Cu and CaO. Ninety-six hour LC(50) values of Cu to fry of common carp, worm and copepod were found to be 1.40 mgl(-1), 0.08 mgl(-1) and 0.03 mgl(-1) respectively. CaO up to 500 mgl(-1) did not produce any mortality of the fry of common carp up to 96 h. But 96 h LC50 values of CaO to worm and copepod were 83.00 mgl(-1) and 27.80 mgl(-1) respectively. When common carp fry, worm and the copepod were exposed to respective LC50 dose of Cu in presence of varying concentration of CaO, mortality of the organisms significantly reduced and was found inversely correlated with the doses of CaO [y = 48.36-0.807x, r = -0.99 (n = 7) for fish; y = 44.46-0.146x, r = -0.97 (n = 7) for worm; y = 49.46-0.66x, r = -0.99 (n = 7) for the copepod]. The present results indicate that CaO is non-toxic to fish and is capable of reducing the toxicity of Cu to fish while CaO and Cu are antagonistic to each other for the worm and the copepod. Potential of using CaO as antitoxic agent for Cu in water is discussed.     

Oxidation of SO2 in Clouds at Whiteface Mountain

In-cloud oxidation of SO₂ byH₂O₂ was investigated using a tracertechnique based on SO^2– ₄/Se ratios atWhiteface Mountain, New York during summer months from1990 to 1998. Cloud water samples collected at themountain's summit (1.5 km above mean sea level) andaerosols at a below cloud site (Lodge) located at 0.6km amsl and in cloud interstitial air at the summitwere analyzed for SO^2– ₄ and selectedtrace elements. Gaseous SO₂ andH₂O₂were measured in realtime. Cloud water pH wasgenerally below 5.0 with a mean value of 3.6. Theresults show that significant in cloud oxidation occursin clouds during summer months varying from belowdetection to 62% with on average approximately 24% ofthe cloud water SO^2– ₄ produced from in-situ SO₂ oxidation. During summer the clouds wereoxidant limited for approximately one third of thetime.     

Comparative studies on biomass productivity and lipid content of a novel blue-green algae during autotrophic and heterotrophic growth

Environmental Science and Pollution Research - Algae have long been acclaimed as the attractive renewable source for generating third-generation biofuels, particularly biodiesel. Under the present...     

A comparative study on the decomposition of edible and non-edible oil cakes in the Gangetic alluvial soil of West Bengal

An experiment has been conducted under laboratory conditions to investigate the effect of decomposition of two edible oil cakes, viz. mustard cake (Brassica juncea L) and groundnut cake (Arachis hypogaea L), and two non-edible oil cakes, viz. mahua cake (Madhuca indica Gmel) and neem cake (Azadirachta indica Juss), at the rate of 5.0 t ha^?1 on the changes of microbial growth and activities in relation to transformations and availability of some plant nutrients in the Gangetic alluvial (Typic Haplustept) soil of West Bengal, India. Incorporation of oil cakes, in general, highly induced the proliferation of total bacteria, actinomycetes, and fungi, resulting in greater retention and availability of oxidizable C, N, and P in soil. As compared to untreated control, the highest stimulation of total bacteria and actinomycetes was recorded with mustard cake (111.9 and 84.3 %, respectively) followed by groundnut cake (50.5 and 52.4 %, respectively), while the fungal colonies were highly accentuated due to the incorporation of neem cake (102.8 %) in soil. The retention of oxidizable organic C was highly increased due to decomposition of non-edible oil cakes, more so under mahua cake (14.5 %), whereas edible oil cakes and groundnut cake in particular exerted maximum stimulation (16.7 %) towards the retention of total N in soil. A similar trend was recorded towards the accumulation of available mineral N in soil and this was more pronounced with mustard cake (45.6 %) for exchangeable NH₄ ⁺ and with groundnut cake (63.9 %) for soluble NO₃ ^?. The highest retention of total P (46.9 %) was manifested by the soil when it was incorporated with neem cake followed by the edible oil cakes; while the available P was highly induced due to the addition of edible oil cakes, the highest being under groundnut cake (23.5 %) followed by mustard cake (19.6 %).     

Bio-mediated silver nanoparticle synthesis: mechanism and microbial inactivation

Even though plenty of literature is available on the biosynthesis of metal nanoparticles, there are serious lacunae on the mechanisms of their formation. In the present study, the mechanism of formation of mono-crystalline silver nanoparticles using a fruit extract of the ornamental tree Thevetia peruviana is emphasized, i.e. how the pH of the reaction mixture affected reaction kinetics and size of the nanoparticles. The facilitation of formation of Ag₂O at higher pH resulted in a faster rate of particle formation. The diameter of the bare particles at neutral pH determined by field emission scanning electron microscopy and the hydrodynamic diameter determined by dynamic light scattering were 53 and 104 nm, respectively. The silver nanoparticles exhibited good inactivation of Escherichia coli due to participation of free radicals as evidenced by electron spin resonance spectroscopy.     

Monitoring and evaluating the spatiotemporal variations of the water quality of a stretch of the Bhagirathi-Hugli River,West Bengal,India, using geospatial technology and integrated statistical methods

Environmental Science and Pollution Research - Water quality is a critical environmental issue because all forms of life depend on the water. The present study primarily focused on the...     

Food selectivity and reproductive biology of small indigenous fish Indian river shad,Gudusia chapra (Hamilton, 1822) in a large tropical reservoir

Environmental Science and Pollution Research - Assessment of life history strategies of economically important small indigenous fishes (SIF) which are rich in nutritive values is essential and...     

Interaction effects of elevated CO2 and temperature on microbial biomass and enzyme activities in tropical rice soils

The impacts of elevated CO(2) and temperature on microbial biomass and soil enzyme activities in four physicochemically different types of tropical rice soils (Aeric Endoaquept, Aeric Tropoaquept, Ultic Haplustalf and Udic Rhodostalf) were investigated in a laboratory incubation study. Soil samples were incubated under 400, 500 and 600 μmol mol(-1) CO(2) concentration at 25°C, 35°C and 45°C for 2 months. Elevated CO(2) significantly increased the mean microbial biomass carbon (MBC) content, across the soils, over control by 6.2%, 38.0% and 49.2% at 400, 500 and 600 μmol mol(-1) CO(2) concentration, respectively. Soil enzyme activities (fluorescein diacetate hydrolase, dehydrogenase, β-glucosidase, urease, alkaline and acid phosphatases) also increased significantly ranging from 1.3% (urease) to 53.2% (alkaline phosphatase) under high CO(2) in the soils studied. Both MBC and soil enzyme activities were further stimulated at high temperatures suggesting elevated CO(2) and high temperature interaction accelerated the general turnover of the organic C fractions of the soil and through increase in microbially mediated processes.     

Detection and enumeration of colonic mucosal cells in amniotic fluid using a colon epithelial-specific monoclonal antibody

Since its introduction, prenatal diagnosis of chromosomal and metabolic disorder by mid-trimester amniocentesis has relied upon the use of a mixture of fetal cells obtained from amniotic fluid. Little knowledge has been gained in the sorting of these cells for diagnosis of tissue-specific disorders. In an attempt to determine the contribution of fetal colonic mucosal cells to the overall amniocyte population, we used the colonic epithelial-specific monoclonal antibody (MC-Ab) 7E₁₂H₁₂, IgM isotype. Specimens of the small intestine, colon, buccal mucosa, kidney, urinary bladder, and umbilical cord were obtained from electively aborted normal fetuses of 12–28 weeks' gestation. All of these specimens were examined with 7E₁₂H₁₂ by the immunoperoxidase technique. The MC-Ab reacted with the colonic epithelial cells but not with any of the other tissues. In addition, 40 amniotic fluid samples obtained from women between 16 and 18 weeks of gestation, who underwent amniocentesis because of advanced maternal age, were tested using a fluorescent activated cell sorter. Among the amniotic fluid specimens examined, 18·4 ± 10·3 percent cells reacted with 7E₁₂H₁₂. Double immunofluorescence studies revealed that all Mc-Ab-stained cells contained secretory component, confirming that they were epithelial in origin. All fetuses whose amniotic fluid was analysed had normal karyotypes and amniotic fluid alpha-fetoprctein levels that were also normal. This study demonstrates that cell-specific Mc-Ab can be used to detect colon cells in the amniotic fluid and that colon cells contribute significant numbers in the mixture of amniotic fluid cells. This technique could be helpful in the prenatal diagnosis of disorders in which the flow of amniotic fluid through the fetal intestine is impaired, such as cystic fibrosis, imperforate anus, Hirschsprung aganglionic megacolon, and intestinal atresia.