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Geochemical study of groundwater from a structurally deformed granitic terrain near Hyderabad (India) was carried out to understand
and evaluate the hydrogeochemical processes and quality of groundwater. Several trace elements (Fe, Mn, Be, Al, V, Cr, Co,
Ni, Cu, Zn, As, Sr, Mo, Cd, Sb, Ba, Pb, U) along with major ions and minor elements were precisely estimated in shallow and
drilled wells to know the suitability of water for drinking and irrigation purposes. Analytical data shows that pH and major
ion chemistry in dug wells and bore wells do not vary significantly, while some trace elements (Fe, Mn, Al, Be, Co, Pb, U
and Zn) vary in dug wells and bore wells, which can be attributed to differential mineral weathering and dissolution/precipitation
reactions along fractures/joints. Although the water is not potable, it was found to be suitable for irrigation with little
danger in the development of harmful level of exchangeable sodium. It is inferred that the chemical composition of the groundwater
in this region is likely to have its origin from silicate weathering reactions and dissolution/precipitation processes supported
by rainfall and groundwater flow. 相似文献
3.
2,4-Dichlorophenol (2,4-DCP) is known as an important chemical intermediate and an environmental endocrine disruptor. There is no paper dealing with the predicted no-effect concentration (PNEC) of 2,4-DCP, mainly due to shortage of chronic and site-specific toxicity data. In the present study, toxicity data was obtained from the tests using six Chinese native aquatic species. The HC5 (hazardous concentration for 5% of species) was derived based on the constructed species sensitivity distribution (SSD), which was compared with that derived from literature toxicity data of non-native species. For invertebrates, the survival no-observed effect concentrations (NOECs) were 0.05 and 1.00 mg L−1 for Macrobrachium superbum and Corbicula fluminea, respectively. NOECs based on fishes’ growth were 0.10, 0.20 and 0.40 mg L−1 for Mylopharyngodon piceus, Plagiognathops microlepis and Erythroculter ilishaeformis, respectively. For aquatic plant Soirodela polyrhiza, NOEC based on concentration of chlorophyll was 1.00 mg L−1. A final PNEC calculated using the SSD approach with a 50% certainty based on different taxa ranged between 0.008 and 0.045 mg L−1. There is no significant difference between HC5 derived from native and that from non-native taxa. 相似文献
4.
Satyanarayanan Raghavan Shreyes Melkote Fukuo Hashimoto 《Journal of Manufacturing Processes》2013,15(3):318-328
Cost-effective machining of hardened steel components such as a large wind turbine bearing has traditionally posed a significant challenge. This paper presents an approach to machine hardened steel parts efficiently at higher material removal rates and lower tooling cost. The approach involves a two-step process consisting of laser tempering of the hardened workpiece surface followed by conventional machining at higher material removal rates with lower cost ceramic tools to efficiently remove the tempered material. The laser scanning parameters that yield the highest depth of tempered layer are obtained from a kinetic phase change model. Machining experiments are performed to demonstrate the possibility of higher material removal rates and improved tool wear behavior compared to the conventional hard turning process. Tool wear performance, cutting forces, and surface finish of Cubic Boron Nitride (CBN) tools as well as low cost ceramic tools are compared in machining of hardened AISI 52100 steel (~63 HRC). In addition, cutting forces and surface finish are compared for the laser tempering based turning and conventional hard turning processes. Experimental results show the potential benefits of the laser tempering based turning process over the conventional hard turning process. 相似文献
5.
Assessment of source water contamination by estrogenic disrupting compounds in China 总被引:2,自引:0,他引:2
Weiwei Jiang Ye Yan Mei M Donghong Wang Qian Luo Zijian Wang Senthil Kumaran Satyanarayanan 《环境科学学报(英文版)》2012,24(2):320-328
Detection of estrogenic disrupting compounds (EDCs) in drinking waters around China has led to rising concerns about health risks associated with these compounds. There is, however, a paucity of studies on the occurrence and identification of the main compounds responsible for this pollution in the source waters. To fill this void, we screened estrogenic activities of 23 source water samples from six main river systems in China, using a recombinant two-hybrid yeast assay. All sample extracts induced significant estrogenic activity, with E2 equivalents (EEQ) of raw water ranging from 0.08 to 2.40 ng/L. Additionally, 16 samples were selected for chemical analysis by gas chromatography-mass spectrometry. The EDCs of most concern, including estrone (E1), 17βup-estradiol (E2), 17αup-ethinylestradiol (EE2), estriol (E3), diethylstilbestrol (DES), estradiol valerate (EV), 4-t-octylphenol (4-t-OP), 4-nonylphenols (4-NP) and bisphenol A (BPA), were determined at concentrations of up to 2.98, 1.07, 2.67, 4.37, 2.52, 1.96, 89.52, 280.19 and 710.65 ng/L, respectively. Causality analysis, involving comparison of EEQ values from yeast assay and chemical analysis identified E2, EE2 and 4-NP as the main responsible compounds, accounting for the whole estrogenic activities (39.74% to 96.68%). The proposed approach using both chemical analysis and yeast assay could be used for the identification and evaluation of EDCs in source waters of China. 相似文献
6.
Kumaran S Deivasigamani B Alagappan KM Sakthivel M 《Journal of environmental biology / Academy of Environmental Biology, India》2010,31(4):539-541
Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio sp. Fish disease will be controlled by proper vaccination trials and maintenance of fish form. Pathogenicity for Asian seabass (Lates calcarifer) against V anguillarum results in necrosis and haemorrhagic areas near the base of fins, exopthalmia and ulcers on the skin surface. Around 50, 100, 200 microl of formalin killed bacterial cells were injected (Intraperitoneal) to three different size (5-10, 20-30, 35-50 g) of seabass fishes respectively and control sere as saline were maintained separately. The Relative Percentage Survival (RPS) for vaccinated fishes was 60, 75, and 62.5 respectively and the vaccinations for 20-30 g fishes stay alive. These results stated that the vaccination for fishes with 20-30 g size may fabricate good immune response. 相似文献
7.
Estrogen-related receptor
disruption of source water and drinking water
treatment processes extracts
Na Li Weiwei Jiang Kaifeng Rao Mei M Zijian Wang Satyanarayanan Senthik Kumaran 《环境科学学报(英文版)》2011,23(2):301-306
Environmental chemicals in drinking water can impact human health through nuclear receptors. Additionally, estrogen-related
receptors (ERRs) are vulnerable to endocrine-disrupting e ects. To date, however, ERR disruption of drinking water potency has
not been reported. We used ERR
two-hybrid yeast assay to screen ERR
disrupting activities in a drinking water treatment plant
(DWTP) located in north China and in source water from a reservoir, focusing on agonistic, antagonistic, and inverse agonistic activity
to 4-hydroxytamoxifen (4-OHT). Water treatment processes in the DWTP consisted of pre-chlorination, coagulation, coal and sand
filtration, activated carbon filtration, and secondary chlorination processes. Samples were extracted by solid phase extraction. Results
showed that ERR
antagonistic activities were found in all sample extracts, but agonistic and inverse agonistic activity to 4-OHT
was not found. When calibrated with the toxic equivalent of 4-OHT, antagonistic e uent e ects ranged from 3.4 to 33.1 g/L. In the
treatment processes, secondary chlorination was e ective in removing ERR
antagonists, but the coagulation process led to significantly
increased ERR
antagonistic activity. The drinking water treatment processes removed 73.5% of ERR
antagonists. To our knowledge,
the occurrence of ERR
disruption activities on source and drinking water in vitro had not been reported previously. It is vital, therefore,
to increase our understanding of ERR
disrupting activities in drinking water. 相似文献
8.
Reddy MV Babu KS Balaram V Satyanarayanan M 《Environmental monitoring and assessment》2012,184(4):1991-2000
The surface water qualities of Hussainsagar, an eutrophic urban lake in the midst of twin cities of Hyderabad and Secunderabad
(India) receiving large quantities of external inputs—both untreated municipal sewage containing industrial effluents, and
treated sewage, a large number of annually immersed idols of God and Goddess, and intense boating activities were assessed
in relation to the concentration of elements including heavy metals of the water along the necklace road of the lake. Elemental
analyses of water using ICP-MS revealed 26 elements including heavy metals—As, Cd, Cr, Ni, Pb, Cu, Fe, Mn, Se, Ba, Zn, Mo,
V, Co, Ag, Sr, Rb, Mg, K, Ca, Al, Si, Sb, Na, Li, and B, in the surface water of the lake. Of these, the first 15 elements
were found in elevated concentrations in the water at the outfall point of the untreated municipal sewage (site 3), which
was the main dominating source of contamination of the lake water while Cu and Sb were recorded in higher concentrations at
the outfall of treated effluent from Sewage Treatment Plant, and three elements (Ba, Si, and B) were in higher concentration
at the sites of outfall of sewage flowing from an oxygenated pond (site 4), Ca, Zn, and Sr, at the site immersed with idols
(site 1), and Pb, Ag, and Al at the center of the lake (site 5) with intense boating activities. Concentrations of most of
these elements exceeded the maximum permissible limits of national (Indian Council Medical Research) standards for drinking
water. The concentrations of most of the elemental contaminants showed significant positive correlations between them. 相似文献
9.
Kamala C. T. Balaram V. Dharmendra V. Satyanarayanan M. Subramanyam K. S. V. Krishnaiah A. 《Environmental monitoring and assessment》2014,186(11):7097-7113
Recently introduced microwave plasma-atomic emission spectroscopy (MP-AES) represents yet another and very important addition to the existing array of modern instrumental analytical techniques. In this study, an attempt is made to summarize the performance characteristics of MP-AES and its potential as an analytical tool for environmental studies with some practical examples from Patancheru and Uppal industrial sectors of Hyderabad city. A range of soil, sediment, water reference materials, particulate matter, and real-life samples were chosen to evaluate the performance of this new analytical technique. Analytical wavelengths were selected considering the interference effects of other concomitant elements present in different sample solutions. The detection limits for several elements were found to be in the range from 0.05 to 5 ng/g. The trace metals analyzed in both the sectors followed the topography with more pollution in the low-lying sites. The metal contents were found to be more in ground waters than surface waters. Since a decade, the pollutants are transfered from Patancheru industrial area to Musi River. After polluting Nakkavagu and turning huge tracts of agricultural lands barren besides making people residing along the rivulet impotent and sick, industrialists of Patancheru are shifting the effluents to downstream of Musi River through an 18-km pipeline from Patancheru. Since the effluent undergoes primary treatment at Common Effluent Treatment Plant (CETP) at Patanchru and travels through pipeline and mixes with sewage, the organic effluents will be diluted. But the inorganic pollutants such as heavy and toxic metals tend to accumulate in the environmental segments near and downstreams of Musi River. The data generated by MP-AES of toxic metals like Zn, Cu, and Cr in the ground and surface waters can only be attributed to pollution from Patancheru since no other sources are available to Musi River. 相似文献
10.
Paruchuri YL Shivaraman N Kumaran P 《Environmental pollution (Barking, Essex : 1987)》1990,68(1-2):15-28
Thiocyanate is present in appreciable concentration in coal carbonization wastewater along with other toxicants like phenols, cyanide, sulphide and ammonia. This paper encompasses studies on biodegradation of thiocyanate by a microbial consortium obtained from a biological treatment plant receiving coal carbonization wastewater. Effects of secondary toxicants and growth stimulants on thiocyanate oxidation by the consortium, and thiocyanate transformation in actual and partially treated coal carbonization waste, have also been studied. Results indicate that the consortium can degrade thiocyanate up to 1400 mg litre(-1) in batch culture with 10 mg litre(-1) of initial inoculum within a period of 6 days. Phenol above 500 mg litre(-1) and cyanide at 10 mg litre(-1) completely inhibits thiocyanate oxidation. Sulphide at 32 mg litre(-1) and ammonia at 4000 mg litre(-1) at neutral pH prolongs thiocyanate oxidation from 3 to 6 days and from 4 to 7.5 days, respectively. These studies reveal that elimination of phenolics, their oxidized products, ammonia, cyanides and sulphides is a pre-requisite for effective thiocyanate removal from the waste by the consortium. Bacteria of the genera Pseudomonas and Bacillus dominate the consortium. 相似文献