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Dengue fever is a life-threatening illness in humans caused by the dengue virus belonging to Flaviviridae, affecting mainly in tropical and subtropical countries. The spread of this disease is through the dengue vector Aedes aegypti. Development of biodegradable, environmentally safe, low-cost larvicides is essential to overcome the resurgence effects of chemical insecticides. The present study included the development of bioformulations from larvicidal polar solvent extracts of the plant leaves. The solvents used for the extractions were ethyl acetate for Aloe vera (A), ethanol for Carica papaya (B), and methanol for Parthenium hysterophorous (C). Bioformulations in different combinations like A, B, C, A+B, B+C, C+A, and A+B+C with the concentrations of 50ppm, 100ppm, 150ppm, 200ppm, 250ppm and 300ppm were tested against the IVth instar larvae of Aedes aegypti and the results were recorded for every 24h 48h and 72h . The bioformulation extracts B+C (300ppm) showed 90 percent mortality of larvae after 72 h of treatment. It was concluded that the larvae's mortality was caused by the presence of bioactive compounds of B+C extracts. This formulation can be considered an effective biopesticide for the dengue vector Ae. aegypti IVth instar larvae.

Textile industries are hailed as one of the major environmental polluters in the world, owing to their release of undesirable dye effluents. Synthetic dyes do not adhere to fabric firmly and are released into the aquatic ecosystem as effluent. Consequently, the consistent release of wastewater from numerous textile industries without previous treatment has detrimental effects on the ecosystem and human health. Treatment methods currently being used fail to degrade the dye effluents and have their own shortcomings. Immobilized nanoparticles have been extensively studied for dye remediation because of their many advantages over conventional methods. The present study aimed to compare the efficiency of two different carrier matrices [namely Poly(vinylidene fluoride) and Polyurethane] for iron nanoparticle and their decolorization activity on an azo dye (RED ME4BL). Scanning Electron Microscopy was carried out to show the deposition of iron nanoparticles on the membrane. The reaction kinetics of the bare nanoparticles were compared with that of the immobilized nanoparticles, and all were found to follow pseudo-second-order kinetics. Polyurethane immobilized iron nanoparticles showed a significant degradation of RED ME4bl than the Poly(vinylidene fluoride) immobilized iron and bare nanoparticles. This paper also demonstrates a relatively newer method for nanoparticle immobilisation using the synthetic polyurethane form.