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Gajanan K. Khadse Morami Kalita Sarika N. Pimpalkar Pawan K. Labhsetwar 《Environmental monitoring and assessment》2011,178(1-4):401-414
To ascertain the quality of drinking water being supplied, water quality monitoring and surveillance was conducted in Gangtok city at various treatment stages, service reservoirs, distribution network, public standposts, and households. No significant change in raw water quality was observed on day-to-day basis. Residual chlorine was found in the range of nil to 0.2 mg/l in the sump water/finished water. Throughout the year (i.e., during summer, winter, and monsoon seasons), the total coliform and fecal coliform counts were ranged from nil to 7 CFU/100 ml and nil to 3 CFU/100 ml, respectively, in sump water of Selep and VIP complex water treatment plant; however, at consumer end, those were observed as nil to 210 CFU/100 ml and nil to 90 CFU/100 ml, respectively. These variations in bacterial counts among the different service reservoirs and consumer ends may be attributed to the general management practices for maintenance of service reservoirs and the possibility of enroute contamination. Evaluation of the raw water quality indicates that the water is suitable for drinking after conventional treatment followed by disinfection. The finished water quality meets the level of standards described as per Bureau of Indian Standard specifications (BIS:10500 1991) for potability in terms of its physicochemical characteristics. 相似文献
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Research to alter crops for their better performance involving modern technology is underway in numerous plants, and achievements
in transgenic plants are impacting crop improvements in unparalleled ways. Striking progress has been made using genetic engineering
technology over the past two decades in manipulating genes from diverse and exotic sources, and inserting them into crop plants
for inducing desirable characteristics. RNA interference (RNAi) has recently been identified as a natural mechanism for regulation
of gene expression in all higher organisms from plants to humans and promises greater accuracy and precision to plant improvement.
The expression of any gene can be down-regulated in a highly explicit manner exclusive of affecting the expression of any
other gene by using RNAi technologies. Additional research in this field has been focused on a number of other areas including
microRNAs, hairpin RNA, and promoter methylation. Manipulating new RNAi pathways, which generate small RNA molecules to amend
gene expression in crops, can produce new quality traits and having better potentiality of protection against abiotic and
biotic stresses. Nutritional improvement, change in morphology, or enhanced secondary metabolite synthesis are some of the
other advantages of RNAi technology. In addition to its roles in regulating gene expression, RNAi is also used as a natural
defense mechanism against molecular parasites such as jumping genes and viral genetic elements that affect genome stability.
Even though much advancement has been made on the field of RNAi over the preceding few years, the full prospective of RNAi
for crop improvement remains to be fully realized. The intricacy of RNAi pathway, the molecular machineries, and how it relates
to plant development are still to be explained. 相似文献
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Sun Hui Zhang Hengyuan Mao Huimin Yu Bin Han Jian Bhat Gajanan 《Environmental Chemistry Letters》2019,17(2):1091-1096
Environmental Chemistry Letters - Dyeing wastewaters present high hazards for the environment and human health. Advanced dye removal may be achieved by magnetic metal–organic frameworks... 相似文献
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Knowledge of climate change vulnerability and impacts is a prerequisite for formulating locally relevant climate change adaptation policies. A participatory approach has been used in this study to determine climate change vulnerability, impacts and adaptation aspects for the Kangsabati River basin, India. The study approach involved engaging with stakeholders representing state (sub-national), district and community levels, through an interactive brainstorming method, to understand stakeholder perceptions regarding (a) local characteristics which influence vulnerability, (b) climate change impacts and (c) relevant adaptation options. The study reveals that vulnerability varies across upstream, midstream and downstream sections of the river basin. Suggested adaptation options, in this predominantly agricultural basin, are found to be applicable across spatial scales. Stakeholder perceptions, regarding vulnerability and impacts, vary with the level of interaction, academic background and type of experience. Interaction confirms the notion that stakeholders have inherent knowledge regarding adaptation, reveals their preferences and ability to think unconventionally. We discuss limitations of the approach while demonstrating its ability to deliver locally relevant and acceptable adaptation options, which could facilitate implementation. We conclude that engaging stakeholders at multiple levels was highly effective in assessing locally relevant aspects of climate change vulnerability, impacts and applicable adaptation options in the Kangsabati River basin. Based on this assessment, a sub-basin scale is recommended for evaluating these aspects, especially for water resources and agricultural systems, through multi-level stakeholder input. 相似文献
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Hairong Zhang Jingchun Tang Lin Wang Juncheng Liu Ranjit Gajanan Gurav Kejing Sun 《环境科学学报(英文版)》2016,28(9):7-13
The present work aimed to develop a novel strategy to bioremediate the petroleum hydrocarbon contaminants in the environment. Salt tolerant bacterium was isolated from Dagang oilfield, China and identified as Corynebacterium variabile HRJ4 based on 16S rRNA gene sequence analysis. The bacterium had a high salt tolerant capability and biochar was developed as carrier for the bacterium. The bacteria with biochar were most effective in degradation of n-alkanes (C16, C18, C19, C26, C28) and polycyclic aromatic hydrocarbons (NAP, PYR) mixture. The result demonstrated that immobilization of C. variabile HRJ4 with biochar showed higher degradation of total petroleum hydrocarbons (THPs) up to 78.9% after 7-day of incubation as compared to the free leaving bacteria. The approach of this study will be helpful in clean-up of petroleum-contamination in the environments through bioremediation process using eco-friendly and cost effective materials like biochar. 相似文献
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To ascertain the quality of drinking water being supplied and maintained at Guwahati, the study was conducted on the status of water supply in city through surveillance of drinking water quality for consecutive 7 days at various treatment stages, distribution network and consumer ends. The performance of five water treatment plants (WTPs), viz. Panbazar WTP, Satpukhuri WTP, Kamakhya WTP, PHED WTP and Hegrabari WTP were assessed for summer, piost-post-monsoon and winter seasons. No significant change in raw water quality was observed on day-to-day basis. Residual chlorine was found in the range of nil to 0.2 mg/L in the treated water. During post-monsoon, winter, and summer seasons the thermotolerent TC and FC counts ranged between Nil to 168 CFU/100 ml and Nil to 84 CFU/100 ml; Nil to 3356 CFU/100 ml and Nil to 152 CFU/100 ml; and Nil to 960 CFU/100 ml and Nil to 108 CFU/100 ml respectively. There was variation in bacterial counts among the different service reservoirs and consumer ends, which may be attributed to the general management practices for maintenance of service reservoirs and the possibility of enroute contamination. Evaluation of the raw water quality indicate that the water is suitable for drinking after conventional treatment followed by disinfection. The finished water quality meets the level of standards described as per Bureau of Indian Standard specifications (BIS:10500 1991) for potability in terms of its physico-chemical characteristics. 相似文献
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Gajanan Bhat John Bergstrom R. Jeff Teasley J. M. Bowker H. Ken Cordell 《Environmental management》1998,22(1):69-77
/ This paper describes a framework for estimating the economic value of outdoor recreation across different ecoregions. Ten ecoregions in the continental United States were defined based on similarly functioning ecosystem characters. The individual travel cost method was employed to estimate recreation demand functions for activities such as motor boating and waterskiing, developed and primitive camping, coldwater fishing, sightseeing and pleasure driving, and big game hunting for each ecoregion. While our ecoregional approach differs conceptually from previous work, our results appear consistent with the previous travel cost method valuation studies.KEY WORDS: Recreation; Ecoregion; Travel cost method; Truncated Poisson model 相似文献
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In the present study, degradation of endosulfan by a mixed culture isolated from a pesticide-contaminated soil was studied in batch experiments. After two weeks of incubation, the mixed culture was able to degrade 73% and 81% of alpha and beta endosulfan respectively. Endodiol was identified by GC/MS as degradation intermediate. The toxicity studies of endosulfan before and after degradation were carried out using micronucleus assay on human polymorphonuclear cells. The findings suggested that the metabolism of endosulfan isomers by the mixed culture was accompanied by significant reduction in the toxicity. Studies were also carried out to quantify the degradation potential of the individual species in the mixed bacterial culture. Two cultures identified by 16S rRNA as Stenotrophomonas maltophilia and Rhodococcus erythropolis were found to be responsible for majority of the degradation by the mixed culture. S. maltophilia showed better degradation efficiency compared to that by R. erythropolis. This is the first report of endosulfan degradation using the above-mentioned organisms. 相似文献
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