Authors:Anuradha Baghel; Beer - Singh Abstract: The objective of our study was to develop and explore the appropriate adsorbents for the removal of toxicants such as heavy metals, CN¯, E. coli, and chemical warfare agents (nerve agents and sulphur mustard) from water. The presence of toxicants in drinking water causes severe threats for living beings. Therefore, many adsorbents such as activated carbon, impregnated carbon, activated carbon spheres, bentonite loaded fabric strips, ion exchange resins, and molecularly imprinted polymers were studied for the elimination of toxicants dissolved in water. Out of them activated carbon and impregnated carbons are highly porous material and having high surface area in comparison to others while molecularly imprinted polymers show high selectivity towards imprinted ions. Stirring time, adsorbent amount and initial concentration of toxicants also affect their removal from water. Pb(II) adsorption on carbon obeyed first order in starting then followed pseudo second order kinetics. While SM adsorption on carbon from a mixture of methanolic water (1 : 1) was pseudo first order with 5.04 X 10–3 min-1 rate constant and half life of adsorption reaction was 137.5 minutes. . PubDate: Fri, 21 Oct 2016 07:33:20 +053
Authors:Lokesh Kumar Pandey; Uma Pathak Abstract: This review delineates the development of novel reagents and methods for synthetic transformation of organosulfur compounds. The first chapter is devoted to the literature information available on various aspects of organosulfur compounds related to their properties, applications and various methodologies employed for their synthesis. The second chapter deals with thionation of carbonyl compounds. This chapter focused mainly on the development of novel reagent and procedure for thioamide preparation. Fourth chapter is concerned with the development of solid supported reagents for organosulfur transformation. Fifth chapter includes the preparation of few important bio-active compounds. PubDate: Tue, 26 Jul 2016 07:31:01 +053
Authors:J. Praveen Kumar; Gangavarapu Krishna Prasad, B Singh Abstract: Objective of our study was to explore and evaluate the novel and alternative reactive sorbent decontaminants based on nanoporous materials to the existing ones such as fuller’s earth for the use in personal decontamination kits and spray devices against chemical weapons. Nanoporous materials have exceptional capacity to adsorb wide range of chemical weapons on their large internal as well as external surface and also in the nanometer sized pore space. They can be spread or sprayed on contaminated surfaces to help in decontamination by adsorptive removal of chemical weapons. After adsorption, they participate in chemical reactions with chemical weapons and decontaminate them owing to the wealth of active sites on their surface. Subsequently, after wiping off the used reactive sorbent decontaminant the surfaces are rendered safe for normal operations. PubDate: Thu, 23 Jun 2016 09:01:14 +053
Authors:Gangavarapu Krishna Prasad; Beer Singh Abstract: Filtration systems containing impregnated carbons have been used for the removal of persistent as well as non persistent chemical warfare agents from the contaminated air in order to provide breathable air to the user. Non persistent chemical warfare agents are removed by filtration systems by means of chemical reactions, however, persistent chemical warfare agents are removed by mainly physical adsorption. Once the life of filtration is consumed, its disposal and handling becomes more important and raises concerns over safety. There shall be cross contamination due to desorption when it is disposed off improperly after its use. To overcome these problems a suitable carbon with the efficient capability to take part in in situ degradation of physisorbed toxic chemicals becomes indispensible. To meet this requirement, a study was undertaken to develop suitable reactive carbon for in situ degradation of sulphur mustard when used in nuclear, biological, and chemical filtration systems. PubDate: Mon, 06 Jun 2016 21:15:44 +053
Authors:Valsa Remony Manoj Abstract: Sustainable Aquaculture development in India warrants Environmentally Sustainable Recirculating aquaculture systems which can lower environmental impact and conserve water. However, such technologies are not popular since majority of brackishwater shrimp aquaculture is still practiced as semi-intensive enterprise. An important challenge in biological aquaculture wastewater treatment in recirculating units is accumulation of nitrate nitrogen of upto 500 mg/L, which is reported to be toxic to fish at levels of 20 mg of NO3 -N/L. Biological denitrification using attached growth is a suitable method; but is in want of cheaper materials to be used as bacterial support medium. The present study evaluated indigenously available coconut coir fibre compared to commercially available synthetic Fujino spirals for denitrification of nitrate laden synthetic aquaculture wastewater in upflow anaerobic packed bed column bioreactors. In the experiments, maximum nitrate removal (99%) was achieved using coconut coir fibre as the bacterial support medium. The performance of coconut coir fibre was comparable to that of Fujino spirals. Physical and biochemical tests results further compounded it’s resilience , structural integrity. PCR analysis confirmed presence of Denitrifying genes. Subsequent application of support medium with coconut coir fibre anaerobic baffled reactor obtained maximum COD removal of 96 % and 95 % . Post aeration using cascading method removed residual ammonia and restored dissolved oxygen. A conceptual model for the integration of anaerobic and aerobic processes in the treatment of nitrate laden aquaculture wastewater has been developed based on the findings. PubDate: Fri, 25 Sep 2015 10:29:51 +053
Authors:Vishnu Murthy; Narayana Reddy Abstract: This work review is structured in three different parts. The first part includes total synthesis of 14-membered macrolides (S)-zearalenone and zeralenone through the application of Diels-Alder reaction, Jacobsen kinetic resolution, Mitsunobu coupling, Ring-closing metathesis, and hydrogenation as key steps. The second part discusses a convenient and metal-free protocol for the preparation of α,β-unsaturated ketones from alkynes and aldehydes using Amberlyst-15®. The third part describes the preparation of β-butynyloxy enones through the 2:1 coupling of homopropargyl alcohol and aldehydes using Amberlyst-15® as a heterogeneous solid acid. PubDate: Fri, 07 Nov 2014 07:17:10 +053
Authors:Rachna Ahlawat Abstract: The present research work deals with synthesis of Y2O3:SiO2 and Gd2O3:SiO2 nanocomposites around moderate annealing temperature and their optical properties were also investigated. Monitoring of shape, size, crystallinity and densification of the samples were demonstrated by multi-step annealing schedule. Precursors were refluxed by using sol-gel technique and dried samples were sintered at different temperatures and incubated for few hours. The main objectives of this thesis are to demonstrate the synthesis and phase evolution of the prepared binary oxides. PubDate: Wed, 16 Apr 2014 11:00:53 +053
Authors:Ramacharyulu V R K Peesapati; G.K. Prasad, K. Dwivedi Abstract: Objective of this study was to develop an advanced sorbent decontamination system for the cleansing of surfaces contaminated with chemical, and biological warfare agents. This study employs conventional energy sources like natural sunlight, and a nontoxic solid based on nano titania. The catalyst is intended to be sprayed on the contaminated surfaces, which adsorbs toxic chemicals due to higher surface area. After adsorption, the toxic chemical undergoes photocatalytic degradation on the surface of nano titiania in the presence of ecological sunlight and was degraded into non-toxic products. Resultant sorbent is wiped off to obtain cleaned surfaces. PubDate: Sun, 23 Feb 2014 00:00:00 +053
Authors:Randhir Kumar Bharti Abstract: A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. ISTD04 by 16S rRNA sequencing. The bacterium was tested for product formation in form of calcite crystals in presence of 5% CO2. Carbon dioxide sequestering capacity of bacterium was detected by 14C labeling and purification of carbonic anhydrase enzyme and RuBisCO. 14C labeling analysis revealed that the rate of assimilation of CO2 by the strain is 0.756 x 10-9 μmol CO2 fixed cell-1 h-1. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials. The bacterium produced 0.647 mg mg-1 per unit cell dry weight of lipids. After transesterification of lipids, the total saturated and unsaturated FAME was found to be 51% and 49% respectively. The major FAME contained in the biodiesel was C16:0, C18:1 and C19:1. PubDate: Tue, 11 Feb 2014 00:00:00 +053
Authors:Bhupendra Koul; Devendra V. Amla, Indraneel Sanyal Abstract: The work is structured into four different parts. The first part is dedicated to computational analysis of six variants of Bt-cry1A genes to generate an idea of their integrity and stability. The second part includes optimization of Agrobacterium-mediated tomato transformation procedure using vegetative leaf disc-explants with p35SGUS-INT and validation of the procedure using five different genes of diverse origin. The third part deals with a comparative analysis of constitutive promoter DECaMV35S and synthetic promoter Pcec (complete expression cassette) with defined regulatory sequences to enhance the expression and efficacy of Bt-cry1Ac gene against Helicoverpa armigera in transgenic tomato. Finally, the fourth part discusses molecular characterization and comparative expression analysis of transgenic tomato transformed with modified full-length and truncated version of cry1Ac genes. It also includes the performance and efficacy of truncated cry1Ab gene against Helicoverpa armigera and Spodoptera litura, in transgenic tomato. The higher level of Cry1Ab toxin (≈ 0.47 ± 0.01% TSP) did not show any detrimental effect on in vitro regeneration, plant development and efficacy against target pests in transgenic line Ab25E, contrary to the earlier reports with Cry1Ac toxin. The full-length cry1Ac gene can be redesigned for higher expression and performance in dicots. PubDate: Wed, 01 Jan 2014 00:00:00 +053
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