Suvendu Manna

The emergence of the pandemic around the world owing to COVID-19 is putting the world into a big threat. Many factors may be involved in the transmission of this deadly disease but not much-supporting data are available. Till now no proper evidences has been reported supporting that temperature changes can affect COVID-19 transmission. This work aims to correlate the effect of temperature with that of Total Cases, Recovery, Death, and Critical cases all around the globe. All the data were collected in April and the maximum and minimum temperature and the average temperature were collected from January to April (i.e the months during which the disease was spread). Regression was conducted to find a non-linear relationship between Temperate and the cases. It was evident that indeed temperature does have a significant effect on the total cases and recovery rate around the globe. It was also evident from the study that the countries with lower temperatures are the hotspots for COVID-19....

Fluoride has both detrimental and beneficial effects on living beings depending on the concentration and consumption periods. The study presented in this article investigated the feasibility of using neem oil phenolic resin treated lignocellulosic bio-sorbents for fluoride removal from water through fixed bed column study. Results indicated that treated bio-sorbents could remove fluoride both from synthetic and groundwater with variable bed depth, flow rate, fluoride concentration and column diameter. Data obtained from this study indicated that columns with the thickest bed, lowest flow rate, and fluoride concentration showed best column performance. Bio-sorbents used in this study are regenerable and reusable for more than five cycles. The initial materials cost needed to remove one gram of fluoride also found to be lower than the available alternatives. This makes the process more promising candidate to be used for fluoride removal. In addition, the process is also technically ad...

Possibility of removing fluoride present in water using inexpensive, plant-based biosorbents has been studied. The data indicate that untreated and transesterified jute could be effectively used as biosorbents for removing fluoride. In essence, the process is an endothermic and spontaneous physical adsorption driven by hydrogen bonding, protonation and van der Waals forces. Relevant batch study results indicate that up to 98 % of F− present in distilled water spiked with 5 mg/L NaF could be removed using only 0.8 g of transesterified jute biosorbent. In comparison, untreated jute could remove only 42 % of F− . Although the process efficiency was higher at pH of about 5, transesterified jute biosorbent was found capable of removing F− at a pH between 3 and 8. The F− removal efficiency of the transesterified jute was found to be 1.8 times higher than that of untreated jute and 2.3 times that of activated alumina. The biosorbents could be regenerated by washing with mild acid solution ...

ABSTRACT Waterborne fluoride is usually removed from water by coagulation, adsorption, ion exchange, electrodialysis or reverse osmosis. These processes are often effective over narrow pH ranges or they have the potential to release ions considered hazardous to human health or produce large volumes of toxic sludge, which is difficult to handle and dispose. Although plant matters have been shown to remove waterborne fluoride, they suffer from poor removal efficiency. Following from the insight that interaction between microbial carbohydrate biopolymers and anionic surfaces is often facilitated by lipids an attempt has been made to enhance fluoride adsorption efficiency of jute by grafting the lignocellulosic fiber with fatty acyl chains found in vegetable oils. Fluoride removal efficiency of the grafted jute was found to be comparable or higher than those of alternative defluoridation processes. Infrared and X-ray photoelectron spectroscopic evidence indicated that hydrogen bonding, protonation and C-Fbonding were responsible for fluoride accumulation on grafted jute. Adsorption based on grafted jute fibers appears to be an economical, sustainable and eco-friendly alternative technique for removing waterborne fluoride.

The susceptibility and characteristics of biological degradation of lignocellulosic fibers, such as sisal fibers, are presented in this study using a modified soil burial test (SBT) protocol. The biodegradation profile of untreated sisal fibers as well as of fibers treated with an alkaline emulsion of neem oil and phenolic resin was evaluated by estimating the enzymatic activities during the exposure of fibers to a soil/compost mix. Observation of the results indicated that biodegradation of the fibers was predominated by enzymatic hydrolysis of amorphous materials followed by degradation of crystalline cellulose. It was also evident that “oil-resin” treatment makes the fibers more resistant to biodegradation owing to the removal of amorphous materials, enhanced hydrophobicity, and possible chemical alteration of the surface hydroxyl groups of the fiber surface. This research aims to establish a systematic knowledge on the biodegradation profile of fiber components using a state-of-...

Abstract A process for transesterifying jute fibers or textiles using reagents largely derived from natural sources has been developed for enhancing the long-term tensile strength and water repellence of fiber or textile samples. Geotextiles woven from treated jute fibers (JG1) and geotextiles treated at the fabric level (JG2) using the process developed in this study were found to retain 50% of their initial tensile strengths after remaining immersed in aqueous solutions with pH between 4 and 9 for 120 days.

Three medicinal plants Ocimum sanctum, Ocimum bacilicum and Leucas aspera were screened to study endophytic diversity of the plants. Altogether 103 fungal endophytes belonging to fourteen genera were isolated. Leaves of all three medicinal plants were colonized by a great number of endophytic fungi. Leaves of O. sanctum were colonized by the most, that is, eleven endophytes. Highest Shannon-Wiener index (2.256) was exhibited by O.

Abstract A bio-catalyzed process has been developed for treating jute fibers to enhance their tensile strength and resistance against biodegradation. Lipolytic bacteria were used in the process to transesterify jute fibers by replacing hydrophilic hydroxyl groups within cellulose chains with hydrophobic fatty acyl chains. Transesterification of some of the hydroxyl groups within the fiber was confirmed with FTIR, UV-vis spectroscopy, 13 C solid state NMR, gas chromatography and analytical determination of ester content.

This work was aimed to isolate, purify and characterize an extracellular polysaccharide (EPS) produced by a freshwater dynamic sediment-attached micro-organism, Bacillus megaterium RB-05, and study its emulsifying potential in different hydrocarbon media. Bacillus megaterium RB-05 was found to produce EPSs in glucose mineral salts medium, and maximum yield (0.864 g l(-1) ) was achieved after 24-h incubation. The recovery rates of the polysaccharide material by ion-exchange and gel filtration chromatography were around 67 and 93%, respectively. As evident from HPLC and FT-IR analyses, the polysaccharide was found to be a heteropolymer-containing glucose, galactose, mannose, arabinose, fucose and N-acetyl glucosamine. Different oligosaccharide combinations namely hexose(3), hexose(4), hexose(5) deoxyhexose(1) and hexose(5) deoxyhexose(1) pentose(3) were obtained after partial hydrolysis of the polymer using MALDI-ToF-MS. The polysaccharide with an average molecular weight of 170 kDa and thermal stability up to 180°C showed pseudoplastic rheology and significant emulsifying activity in hydrocarbon media. Isolated polysaccharide was found to be of high molecular weight and thermally stable. The purified EPS fraction was composed of hexose, pentose and deoxyhexose sugar residues, which is a rare combination for bacterial polysaccharides. Emulsifying property was either better or comparable to that of other commercially available natural gums and polysaccharides. This is probably one of the few reports about characterizing an emulsifying EPS produced by a freshwater sediment-attached bacterium. The results of this study contribute to understand the influence of chemical composition and material properties of a new microbial polysaccharide on its application in industrial biotechnology. Furthermore, this work reconfirms freshwater dynamic sediment as a potential habitat for bioprospecting extracellular polymer-producing bacteria. This study will improve our knowledge on the exploitation of a nonconventional renewable resource, which also seems to be ecologically significant.