The study demonstrates the unprecedented ability of UV-C integrated surface dielectric barrier discharge (photo-SDBD) in the rapid removal of azo (brilliant red X3B), direct (direct yellow - 44), and reactive dyes (turquoise blue H5G) in textile wastewater. The degradation mechanisms of these dyes were studied using a high-resolution mass spectrometer (HRMS), and a step-by-step reaction pathway was proposed. The BR-X3B and DY-44 dyes undergo azo bond dissociation followed by functional group rearrangement, ring opening, and formation of open chain intermediates.
View Article and Find Full Text PDFThe study describes developing an energy-efficient and scalable alternative to conventional non-thermal plasma systems by integrating surface dielectric barrier discharge (SDBD) and UV-C radiation sources. The unprecedented enhancement in the mineralisation rate of an azo dye (brilliant red 5B) by the hybrid reactor (photo-SDBD) is demonstrated thoroughly as a function of dye concentrations, pH, and background salts. The photo-SDBD is 1.
View Article and Find Full Text PDFDissolved uranium in groundwater at high concentrations is an emerging global threat to human and ecological health due to its radioactivity and chemical toxicity. Uranium can enter groundwater by geochemical reactions, natural deposition from minerals, mining, uranium ore processing, and spent fuel disposal. Although much progress has been made in uranium remediation in recent years, most published reviews on uranium treatment have focused on specific methods, particularly adsorption.
View Article and Find Full Text PDFThe world has witnessed several incidents of epidemics and pandemics since the beginning of human existence. The gruesome effects of microbial threats create considerable repercussions on the healthcare systems. The continually evolving nature of causative viruses due to mutation or re-assortment sometimes makes existing medicines and vaccines inactive.
View Article and Find Full Text PDFThis paper describes the synthesis and performance evaluation of a granular solid desiccant composite synthesized through a sol-gel process at atmospheric pressure and ambient temperature. The composite desiccant essentially comprises of a biopolymer template, chitosan, and nanoscale boehmite particles embedded on the fibrils of the biopolymer. The chitosan fibers not only help in the formation of boehmite nanoparticles but also act as a reinforcing agent and enable the formation of sand like granules upon aging and drying.
View Article and Find Full Text PDFThis paper describes a labour efficient and cost-effective strategy to prepare few-layered of reduced graphene oxide like (RGOL) sheets from graphite. The self-propagated combustion route enables the bulk production of RGOL sheets. Microscopic and spectroscopic analyses confirmed the formation of few-layer graphene sheets of an average thickness of ∼3 nm and the presence of some oxygen functional groups with a C/O ratio of 8.
View Article and Find Full Text PDFThis paper reports dehalogenation of various organohalides, especially aliphatic halocarbons and pesticides at reduced graphene oxide-silver nanocomposite (RGO@Ag). Several pesticides as well as chlorinated and fluorinated alkyl halides were chosen for this purpose. The composite and the products of degradation were characterized thoroughly by means of various microscopic and spectroscopic techniques.
View Article and Find Full Text PDFCreation of affordable materials for constant release of silver ions in water is one of the most promising ways to provide microbially safe drinking water for all. Combining the capacity of diverse nanocomposites to scavenge toxic species such as arsenic, lead, and other contaminants along with the above capability can result in affordable, all-inclusive drinking water purifiers that can function without electricity. The critical problem in achieving this is the synthesis of stable materials that can release silver ions continuously in the presence of complex species usually present in drinking water that deposit and cause scaling on nanomaterial surfaces.
View Article and Find Full Text PDFAn in situ strategy for the preparation of graphene immobilized on sand using asphalt, a cheap carbon precursor is presented. The as-synthesized material was characterized in detail using various spectroscopic and microscopic techniques. The presence of G and D bands at 1578 cm(-1) and 1345 cm(-1) in Raman spectroscopy and the 2D sheet-like structure with wrinkles in transmission electron microscopy confirmed the formation of graphenic materials.
View Article and Find Full Text PDFUnprecedented adsorption of chlorpyrifos (CP), endosulfan (ES), and malathion (ML) onto graphene oxide (GO) and reduced graphene oxide (RGO) from water is reported. The observed adsorption capacities of CP, ES, and ML are as high as ~1200, 1100, and 800 mg g(-1) , respectively. Adsorption is found to be insensitive to pH or background ions.
View Article and Find Full Text PDFThis paper describes a green method for the synthesis of graphenic material from cane sugar, a common disaccharide. A suitable methodology was introduced to immobilize this material on sand without the need of any binder, resulting in a composite, referred to as graphene sand composite (GSC). Raman spectroscopy confirmed that the material is indeed graphenic in nature, having G and D bands at 1597 and 1338 cm(-1), respectively.
View Article and Find Full Text PDFACS Appl Mater Interfaces
February 2012
A highly luminescent freestanding film composed of the quantum cluster, Au(15), was prepared. We studied the utility of the material for specific metal ion detection. The sensitivity of the red emission of the cluster in the composite to Cu(2+) has been used to make a freestanding metal ion sensor, similar to pH paper.
View Article and Find Full Text PDFWe describe a novel combustion synthesis for the preparation of Nanomagnesia (NM) and its application in water purification. The synthesis is based on the self-propagated combustion of the magnesium nitrate trapped in cellulose fibers. Various characterization studies confirmed that NM formed is crystalline with high phase purity, and the particle size varied in the range of 3-7nm.
View Article and Find Full Text PDFIn this study, adsorption potential of a new sorbent manganese-oxide-coated alumina (MOCA) was investigated for defluoridation of drinking water using batch and continuous mode experiments. The effects of different parameters such as pH, initial fluoride concentration and co-existing ions (usually present in groundwater sample) were studied to understand the adsorption behavior of the sorbent under various conditions. Optimum removal of fluoride ions occurred in a pH range of 4-7.
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