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541.
542.
Journal of Polymers and the Environment - This research is an effort towards the synthesis of a novel Guar Gum (GG) based flocculant by grafting it with Itaconic Acid (IA) using microwave...  相似文献   
543.
Aquatic biodiversity is one of the most essential characteristics of the aquatic ecosystem formaintaining its stability and a means of coping with any environmental change. The entire stretch of the Mothronwala swamp has rich riparian vegetation for providing conducive environment for the growth of aquatic organisms. The present work has been undertaken to study the bio-physico-chemical characteristics of the swamp. The data on physico-chemical environmental variables (temperature, total dissolved solutes, size and composition of substratum, pH, dissolved oxygen, alkalinity chlorides, and hardness) have been given under the present contribution. A total of 16 genera of aquatic insects belonging to orders Trichoptera, Coleoptera, Hemiptera, Ephemeroptera, Odonata and Phylum Mollusca represented the macroinvertebrates of Mothronwala swamp. The fresh water swamp of Mothronwala is under threat due to human interference and other anthropogenic activities. Some of the natural and anthropogenic environmental problems of the Mothronwala swamp have been identified and the ameliorative measures for the protection of aquatic environment and the conservation measures for the swamp have been suggested. The qualitative study revealed the present status of the aquatic biodiversity of the swamp and also about the physico-chemical parameters, which would be very helpful for policy makers to take precautionary measures to save the swamp.  相似文献   
544.
The effluent from a Lucknow- based distillery (Mohan Meakin Distillery) was analyzed for physico-chemical and biological parameters of pollution and concentration of potentially toxic heavy metals (Cd, Cr, Ni and Zn) and the effect of the distillery effluent, as such and on 50% dilution with tap water was studied on seed germination and seedling growth of maize (Zea mays L.) and rice (Oryza sativa L.). The effluent was wine red in colour and highly acidic (pH approximately 55) and possessed decaying alcoholic smell. The effluent contained high values of different pollution parameters, particularly total solids, 3450 mgl(-1) (soluble plus suspended solids), alkalinity 1500 mgl(-1), biological oxygen demand (BOD, 1649 mgl(-1)) and chemical oxygen demand (COD, 2036 mgl(-1)). It had very low values of dissolved oxygen (DO, 0.34 mgl(-1)). The heavy metals (Cd, Cr, Ni and Zn) content, particularly the nickel concentration (0.029 mg l(-1)) was high. Use of the distillery effluent, even on 1:1 dilution with tap water inhibited germination and early seedling growth of maize and rice. In both maize and rice, more so in the former germination % of seeds, length of radicle and plumule and the fresh and dry weight of the seedlings were significantly reduced. The emerging leaves of the seedlings also developed visible effects of toxicity some of which resembled the symptoms of nickel toxicity. Our observations suggest that the effluent, as discharged from the distillery carry a heavy load of pollutants. Its discharge into the river Gomti poses a potential threat to the aquatic life, perticularly during the summer months when the water flow in the river is drastically reduced. The distillery effluentis also harmful for irrigating crops grown along the drain carrying it.  相似文献   
545.
546.
The objective of this study was to use the freshwater food fish, Heteropneustes fossilis, as a model to evaluate the concentration-dependent effects of LAS on the testicular structure through short-term static bioassays. Concentration mediated histopathological leisions were observed in testis of H. fossilis, treated with four different concentrations of LAS for 24, 48, 72 and 96 hr Inference drawn from the study is that the cytotoxic damage is more pronounced in fish exposed to higher concentrations of LAS for shorter durations than lower concentrations of LAS for longer durations. Gross damage of germinal epithelium, inflammatory response, intertubular vacuolations and contraction and condensation in the cells of tubules under all sets of intoxication and exposures are quite suggestive of reproductive impairment leading to delayed gonadal maturity.  相似文献   
547.
This paper has studied the environmental deterioration due to copper mining in Malanjkhand at Central-east India. No data is available on environmental degradation at the studied site although geological aspects are well studied. Mine drainage from the mines is definitively toxic. The site is also undergoing various stages of acid mine drainage (AMD) particularly from the heap leaching sites and the tailing area. AMD impacted water steam and sediment were also analysed. Results show substantial level of contamination of almost all segments of environment. Presence of elevated level of other heavy metal viz. Au, Ag, Pb, Cr, Cd, Fe, Cu and base metals like Na, K in AMD impacted water and sediments is due to metal leaching effect of AMD. Bio monitoring with the help of benthic macro invertebrates and metal accumulation in plants was also carried to know the impact of the toxic drainage. Results prove a very significant impact on the environmental health.  相似文献   
548.
Several studies on the presence and ecology of various Vibrio sp have been reported in coastal and estuarine waters throughout the world, but there is trifling information available on the distribution of this organism of colossal pathogenic potential in the fresh water riverine environment. Thus, we conducted a multiyearenvironmental study to scrutinize the occurrence of members of genus Vibrio in the largest west flowing river of the Indian subcontinent, which is also the largest river of central India, the Narmada. Statistical analysis was done to reveal major environmental factors controlling the presence of Vibrio sp in the river Narmada. Monthly field samplings were conducted between January 2002 and December 2003 at four different sites in Jabalpur (MP), India. At each site, water samples were taken and physicochemical and bacteriological parameters were measured. The identity of the isolates was confirmed by employing 16S rRNA analysis. The organisms were found to be widely distributed in the river with regular seasonal variations. The density of Vibrio was found to be correlated with temperature, coliforms and other heterotrophic bacteria. Water temperature accounted for most of the variability in the concentration of Vibrio spAs typical fecal pollution indicators may not access public health risk from potential pathogens such as vibrios, hence special monitoring programme for vibrios may adequately be included in the water quality management.  相似文献   
549.
Ferrate(VI): green chemistry oxidant for degradation of cationic surfactant   总被引:1,自引:0,他引:1  
Eng YY  Sharma VK  Ray AK 《Chemosphere》2006,63(10):1785-1790
Iron in its familiar form exists in the +2 and +3 oxidation states, however, higher oxidation state of iron +6, ferrate(VI) (Fe(VI)O(4)(2-)) can be obtained. The high oxidation power of ferrate(VI) can be utilized in developing cleaner ("greener") technology for remediation processes. This paper demonstrates the unique property of ferrate(VI) to degrade almost completely the cationic surfactant, cetylpyridinium chloride (C(5)H(5)N(+)(CH(2))(15)CH(3).H(2)O Cl(-), CPC). The Rate law for the oxidation of CPC by ferrate(VI) at pH 9.2 was found to be: -d[Fe(VI)]/dt = k[Fe(VI)][CPC](2). Ferrate(VI) oxidizes CPC within minutes and molar consumption of ferrate(VI) was nearly equal to the oxidized CPC. The decrease in total organic carbon (TOC) from CPC was more than 95%; suggesting mineralization of CPC to carbon dioxide. Ammonium ion was the other product of the oxidation. This is the first report in which Fe(VI)O(4)(2-) ion opens the pyridine ring and mineralizes the aliphatic chain of the organic molecule giving inorganic ions.  相似文献   
550.
Scanning electron microscopic (SEM) study of gills of Catla catla catla (17-day-old) exposed to UV-B radiation (145?µW?cm?2 at the water surface) for three different exposure times: 5, 10 and 15?min was conducted. Fish without UV-B exposure served as control. UV-B radiation damaged both gill filaments and lamellae. The intensity of damage was minimal in 5?min exposed fish, followed by 10?min exposed fish and maximal in 15?min. The gill epithelium was severely damaged in 15?min irradiated fish compared to control. Pavement cells (PVCs) were damaged and the numbers of microridges within PVCs decreased. The deep boundary of PVC was not clear. In some area of gill epithelium, PVCs were destroyed and mitochondrion-rich cells (MRCs) were exposed. The 5?min exposure reduced the number of microridges in the PVCs, but the boundary of PVCs was still visible. MRCs in the gill epithelium were not exposed in 5?min exposed fish. The damage to PVCs and subsequent exposure of MRCs in UV-B irradiated fish may hamper respiratory functions and disturb osmoregulation in catla.  相似文献   
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