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Monitoring of Phenol in Wastewater Bioremediation by HPLC 总被引:1,自引:0,他引:1
KC Ng G Poi CM Puah V De Castro PL Rogers 《Environmental monitoring and assessment》1997,44(1-3):433-436
Bioremediation emphasizes the detoxification and destruction of toxic substances by microorganisms. Wastewater obtained from an industrial concern was solvent extracted with methyl alcohol and dichloromethane and analysed by GC/MS. Besides phenol, a large variety of organic compounds were detected. Under controlled laboratory conditions, the wastewater was innoculated with a mixed culture of microorganisms specially selected for their abilities to degrade phenol. Samples were collected at regular intervals from the stirred tank bioreactor and analysed for phenol by reverse phase HPLC with a C18 column. Results shows that from an initial phenol concentration of 987 ppm, slightly more than 50% was destroyed within 163 hours. The dry weight of the microorganisms and the plate count (CFU/ml) shows a steady increase from 0.5238 gms to 0.5355 gms and from 1.1E+9 to 1.94E+13 respectively over the same period. This suggested that the phenol was consumed by the microorganisms as the sole carbon source. 相似文献
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Food surveys for levels of toxic chemicals frequently report the levels on an uncooked basis. It is known that cooking may in some conditions decrease the amount of dioxins and related chemicals in food. Surveys of polybrominated diphenyl ether (PBDE) levels in food to date show data from uncooked food only. In this article, it was shown that broiling, with fat dripped from the foods reported here, ground beef, ground lamb, catfish, trout, and salmon, reduces the amount of PBDEs in these foods. This suggests that calculations of food intake need to take into consideration levels in the cooked food rather than in the uncooked food. 相似文献
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Vijetha Ponnam Naresh Kumar Katari Ramesh Naidu Mandapati Satyasree Nannapaneni Subbaiah Tondepu 《Journal of environmental science and health. Part. B》2020,55(4):396-405
AbstractBentazone is one of the toxic insecticides used to control forest tent caterpillar moths, boll weevils, gypsy moths, and other types of moths in various field crops. We report the efficacy of biochar prepared from the Azardirachta Indica waste biomass as adsorbent for removal of Bentazone. Biochar material was prepared by pyrolysis process under limited oxygen conditions. Biochar material was characterized by proximate and ultimate analysis, SEM analysis, FTIR analysis and TG/DTA analyses. The Bentazone adsorption capacity by biochar from aqueous solutions was assessed. Effect of time, adsorbent dosage, insecticide concentration and pH on the adsorption characteristics of the biochar were evaluated. Adsorption parameters were obtained at equilibrium contact time of 150?min, with biochar dosage of 0.5?g at pH 8. From the optimization studies, desirability of 0.952 was obtained with response (adsorption uptake) of 79.40?mg/g, for initial concentration of insecticide (50?mg/L), adsorbent dosage (0.448?g), time 30.0?min and pH 2. The adsorption isotherm data for the removal of Bentazone fitted well with the Freundlich isotherm. This study indicates that the biochar produced from the bark of Azardirachta Indica biomass could be employed as a potential adsorbent for removal of synthetic organic pollutants from the water streams. 相似文献
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Khan Anoar Ali Mukherjee Shraboni Mondal Madhumanti Boddu Sumalatha Subbaiah Tondepu Halder Gopinath 《Environmental science and pollution research international》2022,29(41):61856-61869
Environmental Science and Pollution Research - The current investigation focuses on a systematic study of application of two dried algal biomass (i.e., Nostoc sp. and Turbinaria vulgaris) in... 相似文献
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The volatile organic pollutants from direct vehicular exhaust were trapped with activated charcoal, desorbed with carbon disulphide and analysed by GC/MS with tert-butyl benzene as an internal standard. A comparative study was made from the exhaust of 1000 cc, 1300 cc, 1600 cc cars, pickup, lorry(diesel), 125 cc and 70 cc motorbikes. The level of pollutants emitted were in the following order, motorbike(petrol) car(petrol) pickup(petrol) lorry(diesel). The range of highest emission (125 cc motorbike) to the lowest emission (lorry(diesel)) was of the order of 102 for benzene, 6×102 for ethyl benzene, 5×102 for toluene and 3×102 for xylenes. Among cars, those fitted with catalytic convertors emitted a lower level of benzene (2 to 3 times) when compared with those without catalytic convertors. Similar studies on the air in air-conditioned buses, non air-conditioned buses and three metres from the edge of the road shows that they have the same pollutant level. The level of these pollutant as compared to those from direct car exhaust are of the order of 102 times less for benzene, xylene and toluene and 103 times less for ethylbenzene. The levels of benzene, toluene, ethylbenzene and xylenes by the road side and in the buses were found to be lower than the exposure limits of ACGIH, OSHA and EH40. 相似文献
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Krishna Bahadur KC Laxmi Prasad Pant Evan D. G. Fraser Pratap Kumar Shrestha Dinesh Shrestha Anga Lama 《Regional Environmental Change》2016,16(5):1239-1251
Increasing on-farm crop diversity is one agroecological approach to enhancing food self-sufficiency that helps small-scale farmers keep their food systems stable by reducing risks associated with stressors, such as a pest outbreaks or droughts. But understanding how crop diversity and food self-sufficiency are related is unknown. To explore this complex relation, this study presents household data (n = 1664) from Nepal to test the hypothesis that families with high crop diversity enjoy greater household food self-sufficiency. Data are presented for three districts that are representative of three distinct agroecological regions of the country: (1) Sarlahi, which is affluent, market-oriented, and on the plains; (2) Makwanpur District in the hills, which has well-developed integrated farm production; and (3) the mountainous District of Humla, which has the poorest quality environment and is the most remote. Results show that in the Humla District, families with greater crop diversity were more self-sufficient. In contrast, farmers in Makwanpur, who have already established a high degree of crop diversity based on vegetable production, do not benefit from additional crop diversity in terms of their ability to provide for themselves. Finally, data from Sarlahi show that families’ food self-sufficiency benefits from crop diversification. We conclude that boosting crop diversity is a viable strategy for maintaining stability in food systems, but this varies depending on the accessibility of a farm and, in particular, access to markets. 相似文献
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Both cooperation and conflict between the sexes are commonplace in monogamous mating systems. However, little is known about
how cooperation and competition varies seasonally in monogamous species that maintain permanent territories. We presented
territorial pairs of male and female New Zealand robins (Petroica australis) with a large supply of insect prey at monthly intervals for 2 years. Behavioural observations after food presentation were
then made to quantify seasonal and sexual differences in aggressive interactions over prey, prey acquisition rates, mate provisioning,
offspring provisioning, selfish food hoarding and cache retrieval. Data were used to evaluate sex-specific behavioural strategies
of mediating competition for food. Results showed that males aggressively excluded females from experimental food sources
year-round. Females only accessed food sources when males left them unattended. Consequently, females acquired fewer prey
than males. After controlling for differences in prey acquisition, both sexes consumed similar amounts of prey in the non-breeding
season. Even though males aggressively excluded females from accessing food sources directly, males fed large amounts of prey
to females during the breeding season. Both sexes provisioned young at similar rates. Males cached less prey than females
in the breeding season but more prey than females in the non-breeding season. Females showed similar caching intensities year-round.
Although males tried to defend their hoards, females frequently retrieved male-made caches. Overall, results showed that although
New Zealand robins cooperate to raise offspring during the breeding season, conflict between the sexes occurs year-round.
Males and females display different behavioural strategies to gain access to experimental food sources, which appear to lessen
male–female competition for food and evenly distribute food resources between the sexes. 相似文献
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Subbaiah KC Raniprameela D Visweswari G Rajendra W Lokanatha V 《Die Naturwissenschaften》2011,98(12):1019-1026
The aim of the present study was to investigate the effect of vitamin E on pro/anti-oxidant status in the liver, brain and
heart of Newcastle disease virus (NDV) infected chickens. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione
peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and the levels of reduced glutathione and malonaldehyde were estimated in selected tissues of uninfected,
NDV-infected and NDV + vit. E-treated chickens. A significant increase in MDA levels in brain and liver (p < 0.05) was observed in NDV-infected chickens when compared to controls. The activities of SOD, CAT, GPx, GR, GST and levels
of GSH were significantly (p < 0.05) decreased in brain and liver of NDV-infected chickens over controls. On the other hand, a significant decreased MDA
levels and enhanced antioxidant enzyme activity levels were observed in NDV + vit. E-treated animals compared to NDV-infected
chickens. Histopathological studies revealed that liver of NDV infected chicken shows focal coagulation and infiltration of
hepatocytes, whereas neuronal necrosis and degeneration of Purkinje cells were observed in brain and moderate infiltration
of inflammatory cells was observed in heart. However such histological alterations were not observed in NDV + vit. E-treated
animals. The results of the present study, thus demonstrated that antioxidant defense mechanism is impaired after the induction
of NDV, suggesting its critical role in cellular injury in brain and liver. Further, the results also suggest that vitamin
E treatment will ameliorate the antioxidant status in the infected animals. The findings could be beneficial to understand
the role of oxidative stress in the pathogenesis of NDV and therapeutic interventions of antioxidants. 相似文献
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