Since the wide range of industrial, medicinal, and therapeutic uses, gold nanoparticles (AuNPs) have sparked a lot of interest in the rapid development of nanotechnology. In this study, AuNPs were synthesized using the green approach with Pista (SH-1), Badam (SH-2), Walnut (SH-3), Groundnut (SH-4), and Tamarind (SH-5) nutshell extract in this work. Preliminary confirmation of the AuNPs production was attained by a visual color change from light brown to violet color. The UV Vis spectroscopic study of the AuNPs stability indicates the highest stability in Walnut SH-3 and Tamarind SH-5 up to 37th day at pH 7. UV- Visible Spectroscopy, Energy-dispersive X-ray spectroscopy (EDX) and Transmission electron microscope (TEM) were used to characterize the synthesized AuNPs. Physiochemical characterization of AuNPs exhibited absorbance at 550 nm for synthesized AuNPs nearly for all the extracts used, TEM image revealed that the obtained AuNPs are spherical and EDX analysis showed that obtained AuNPs were in pure form. We performed growth assessment on zebra fishes for up to 5 d by monitoring weight at various concentrations of AuNPs of walnut SH-3. It showed no histological abnormalities at organ levels in adult zebrafish up to 16 days. Our findings provided there is no notable cytotoxic evidence found in the synthesized AuNPs.

This study was conducted to study Bioremediation of Municipal Wastewater using Consortium of Chlorogium sp, Chlorella sorokiniana and Microcystis aeriginosa from River Ginzo Municipal wastewater of Katsina Metropolis using standard methods and procedures. Waste water samples were collected between May and June 2020. Agar plating was used for the isolation of individual species and BG-11 media were used for the culture of isolated microalgae. Twelve flasks 100 ml wastewater samples in 250 ml conical flasks) were prepared. Each of the twelve flasks was inoculated with 10 ml of cultured individual microalgae suspensions. Samples were analyzed every week. Results showed pH remaining around neutral values and indicated increases in dissolved oxygen (DO) on both species; Also both of the species indicated potentials in the reduction of physico-chemical parameters; Chologonium sp  (total dissolved solid 57.7%, nitrate 99.96%, phosphorus 100%, ammonium 99.98%, potassium 91.65%, zinc 87.03%, manganese 90.63%, iron 79.44%, copper 50.62%, nickel 30.10%. Chlorella sorokiniana (total dissolved solid 76.63%, nitrate 100%, phosphorus 97.39%, ammonium 99.46%, potassium 100%, zinc 96.29%, manganese 78.81%, iron 90.03%, copper 100%, nickel 4. 83%). Microcystis aeruginosa (total dissolved solid 34.85%, nitrate 75.73%, phosphorus 92.73%, ammonium 93.03%, potassium 99.53%, zinc 75.92%, manganese 85.57%, iron 98.92%, copper 6.87%, nickel 71.76%). Bioremediation uses naturally occurring microorganisms and other aspects of the natural environment to treat wastewater of its nutrients Therefore remediation of diverse wastewater is possible using (Chlorella sorokiniana, Chlorogonium sp and Microcystis aeruginosa).