Department of Physical Sciences

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Start date: 2020End date: 2021

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    Adsorption evaluation of selected heavy metal ions by aminofunctionalized low-cost adsorbents. A Review
    (Global Scientific, 2021-07) T, Nyahanga; N, Ndung’u Samuel; N, Wanjau Ruth; W, Nthiga Esther
    Presence of heavy metals in drinking water has significant adverse effects on human wellbeing due to their toxicity nature. Several techniques have been employed to reduce their concentration to permissible levels. In recent years, adsorption has been widely investigated from low-cost adsorbents due to their cost effectiveness and easy in design. The application of amino-functionalized adsorbents for decontamination of wastewater have been reported. Generally, chemical modification of adsorbents has proved to have a higher adsorption capacity. Numerous amino- compounds such as ethylenediamine, 3-aminopropyl triethoxysilane, Triethylenetetramine, Sodium paminobenzoate, Acrylonitrile, Diethylenetriaminepentaacetic dianhydride, Polyaniline, Nitrilotriacetic acid, 3aminopyrazole, N,N - dimethyl benzal aniline, Di (2-picolyl) amine, Ethylenediaminetetraacetic acid etc. grafted on adsorbents in studying equilibrium, kinetic and thermodynamics has been reported. These adsorbents are applied extensively in the removal of heavy metal ions such as Cu2+, Cd2+, Pb2+, Ni2+, Cr3+, Co2+, As5+ among others. The paper reviews the applicability of vast amino-functionalized adsorbents in the study of equilibrium, kinetics and thermodynamic adsorption studies of heavy metal ions from aqueous solutions
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    A Gold Nanoparticle-Based Colorimetric Probe for Detection of Gibberellic Acid Exuded by Ralstonia solanacearum Pathogen in Tomato (Solanum lycopersicum L.)
    (International Journal of Horticultural Science and Technology, 2021-01-27) Aoko, Ivy Lynn; Ondigo, Dezzline; Kavoo, Agnes Mumo; Wainaina, Cornelius; Kiirika, Leonard
    We report a simple colorimetric probe based on gold nanoparticles (AuNPs) for detecting Ralstonia solanacearum. The AuNPs were synthesized through reduction with citrate ion and characterized by ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The freshly synthesized AuNPs were brick red due to an intense surface plasmon absorption band at 520 nm. Upon interaction with synthetic gibberellic acid (GA3), a bathochromic shift occurred in the surface plasmon resonance (SPR) peak of AuNPs to higher wavelengths. The 'eye-ball' limit of detection was 0.2 ppm. This shift was accompanied by a change in the color of the AuNPs from brick red to purple. Soil samples were collected from the rhizosphere of tomato plants, exhibiting bacterial wilt symptoms and pure cultures of Ralstonia solanacearum isolated using a modified Kelman’s TZC medium. Gibberellins (GA) were extracted from the culture of R. solanacearum using ethyl acetate and characterized using fourier transform infrared spectroscopy (FT-IR). AuNP solution aggregation was induced by GA-mediated R. solanacearum. A color change from brick red to purple was also observed. The results illustrated the use of both SPR wavelength-shift sensing and visual color change to detect molecules of biological relevance
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    To Investigate the Effect of Microwaves Irradiated Water and Feeds On The Broilers.
    (UGC Care listed, 2020-02) Kihiko, J. M.; Azhar, Shaikh Mohd.; Makena, Linet; Rabbani, Gulam
    In electromagnetic spectrum, microwaves radiation spans a range from 300 MHz to 300 GHz. These radiationshave been used in many devices that are used by humanbeings.They may be very harmful for living organisms. Bad effects of microwaves have also been investigated for several crops. This work investigates the effect of microwaves treated water and microwaves warmedfeeds to thebroiler chicken. 1100 Watt and 2450MHz power microwaveoven was used to irradiate chicken’s drinking water and feeds.During investigations, many parameterssuch as temperature, humidity, quality of water and food were well maintained.In conclusion, measuring body weight may be a useful tool to estimate growth potential rather than using body height and length. The broilerused microwavedradiated water and feeds shows better growth rate as compared to others that used normal water and feeds and that used boiled water and warmed feeds.
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