Haflong Government College, established in 1961, is a general degree college situated at Haflong town of Dima Hasao district, Assam. This college is affiliated with the Assam University..
Water plays a pivotal role as a resource for ecological sustenance. Escalating concerns about water scarcity have intensified research and scientific focus on next-generation water-treatment methods. Solar-driven water purification offers a sustainable pathway to reclaim freshwater resources and alleviate shortages. This review paper critically examines carbon dot (CD)-integrated hydrogel systems for solar water evaporation, emphasizing materials design, photothermal mechanisms and recent performance advances. First, the mechanism of solar water evaporation is discussed, followed by the photothermal properties of carbon dots, thereby highlighting recent developments in carbon dot-based solar water evaporators. Next, the various characteristics of hydrogels including their photothermal properties are elaborated. While reviewing the advantages of hydrogel-based solar water evaporators as well as the synergistic effects of carbon dot (CD)-based hydrogel composites, the recent advancements in CD–hydrogel composites are also overviewed. The key points on challenges in achieving long-term durability, multi-functional pollutant removal and prevention of salt crystallization are summarized, along with recommended future research directions. Efficient energy confinement facilitated by solar vapor generation can progress with updated designs, which can turn out to be evolutionary towards sustainability.
Croton joufra is a well-established anthelmintic used in Assam, India. However, reports of its possible toxicity, genotoxic potentials and the phyto-compounds it possesses which could be the reason for its efficacy and toxicity are lacking. This study evaluates its toxic potentials in rodents treated with the extract for 28 days. In addition to blood biochemical and haematological parameters, the liver and kidney tissues were studied for any toxic effects. The presence of toxic heavy metals in the extract was also assessed. Treated animals showed an elevation in the neutrophil and RBC counts. Electron microscopy study of the liver revealed normal architecture in liver and kidney tissues. Elemental analysis showed high levels of cobalt (0.61 ± 0.04 mg/kg) which was above the permissible limits. However, genotoxicity assessment did not reveal any abnormalities. All the chromosomes appeared normal. GC-MS study revealed the presence of about 18 different compounds of which, Phytol, n-Hexadecanoic acid, 9,12,15-Octadecatrienoic acid, (Z,Z,Z)-, 2-(1-Cyclopentenyl)furan, Squalene were in abundance and these could be responsible for its efficacy and toxicity. The study reveals that C. joufra is capable of causing mild toxicity in its long-term use which could be attributed to the bioactive compounds present in it.
Water pollution by dye-containing industrial effluent emerged as an environmental challenge due to its toxicity and persistence in the aquatic system. Tea polyphenol-coated magnetite (Fe3O4) nanoparticles were synthesized by a modified coprecipitation method, and their photocatalytic performance was evaluated through the degradation of a cationic dye (methylene blue) under simulated sunlight irradiation. Structural analysis of the samples was carried out by using an X-ray diffractometer and a transmission electron microscope, which revealed the formation of predominantly single-phase magnetite with a particle size 7–10 nm. Application of tea extract (Camellia sinensis) as a source of tea polyphenol reduces the particle size and suppresses agglomeration. The co-existence of Fe2 + /Fe3+ states and the role of polyphenol in stabilizing the Fe2+ ions was confirmed by the X-ray photoelectron spectroscopy technique. The effect of polyphenol content on the magnetic samples was reflected in the EPR spectra. The nanoparticles were found to be ferrimagnetic at low temperature (77 K) and superparamagnetic at room temperature. The moderate polyphenol-coated sample showed the highest magnetic moment (MS= 57 emug−1 at room temperature) among the samples under study due to reduced hematite impurities and balanced particle size effects (10 nm). Zeta potential measurements revealed enhanced colloidal stability and increasingly negative surface charge with higher polyphenol content, which promotes a strong electrostatic interaction with the cationic dyes. Moreover, increasing polyphenol coating on magnetite nanoparticles significantly enhanced dye removal efficiency (up to 92%) in. This study highlights the effectiveness of an eco-friendly and simple synthesis route for developing highly efficient, magnetically recoverable photo-catalysts for sustainable wastewater treatment applications.
Plastic-based food packaging poses serious environmental and health risks due to its non-biodegradability and potential release of toxic substances. These concerns have intensified the search for sustainable and functional alternatives, bringing bacterial nanocellulose (BNC) into focus as a renewable biomaterial for food packaging. However, successful application of BNC critically depends on the selection of bacterial strains capable of efficient cellulose production and the formation of films with suitable packaging properties. This study reports the isolation and characterization of a novel BNC-producing strain, Novacetimonas hansenii BIK1, from Kombucha prepared with Assam orthodox black tea. Under optimized static culture conditions in HS media, N. hansenii BIK1 exhibited high productivity, forming uniform BNC films. Structural analysis using X-ray diffraction (XRD) revealed a cellulose Iα structure, while Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of functional groups characteristic of pure cellulose. The mechanical properties of the BNC films produced by N. hansenii BIK1 were noteworthy, with a tensile strength of 4.33 MPa, Young’s modulus of 274 MPa, elongation at break of 80.4
Psilorhynchus nahlongthai, a new psilorhynchid fish, is described from the Diyung River, a tributary to the Kopili River (itself a southern tributary of the Brahmaputra drainage) in Assam, northeast India. It is placed in the Psilorhynchus balitora species group and can be easily distinguished from all other members of this group by a combination of the following characters: dense and prominent tuberculation on the head region; thick and long pre- and post-epiphyseal fontanelles on the neurocranium; 9 + 8 caudal-fin rays; and 34 (24 + 10) vertebrae. Genetic divergence between P. nahlongthai and members of the P. balitora species group from the Brahmaputra and neighbouring drainages, with K2P distances ranging 3.7%-14.7% and 7.4%-20.7% in the mitochondrial COI and cyt b gene datasets respectively, support its report as a new species.
