Phytochemical screening, antioxidant activity, antimicrobial activity and heavy metal quantification of Chrysophyllum albidum fruit extract (sapotaceae)

Background: Chrysophyllumalbidum (Sapotaceae) is a forest fruit tree described by the Scottish botanist George Don. It is commonly found throughout tropical Africa with the common name “white star apple”. Chrysophyllumalbidumis popularly called Agbalumo in the Southwestern region of Nigeria andclosely related to the African star apple (Chrysophyllumafricanum).Objectives: This study aims to determine the phytochemical constituents of the Chrysophyllumalbidum fruits, quantify its heavy metals composition and also determine the antioxidant and antimicrobial activity of the fruit.Material and Methods: Phytochemical screening of the fruit extract was carried out using standards methods while the antioxidant activity was done using DPPH (2, 2-Diphenyl-1-picrylhydrazyl). Atomic absorption spectrophotometer was used to detect and quantify the level of some toxic metal (Cadmium, Lead, Iron, Copper, Chromium, Zinc) contamination of the fruit. Antibacterial assay was carried out using disc diffusion method with measured zones of inhibition.Results: Results obtained reveal the presence of flavonoids, indicative of its antioxidant potentials, tannins and saponin. Heavy metals were also found to exist in varying amount in the fruit with the conspicuous absence of Cadmium. The antimicrobial assay showed increasing activities with increasing concentrations.Conclusion: The fruit of C. albidum, thus possesses antibacterial and antioxidant activities and are so beneficial for consumption. However stringent environmental control needs to be put in place to minimise the level of soil contamination with heavy metals through various human explorative activities.Keywords: Heavy metal, Antioxidant, Antimicrobial, Chrysophyllumalbidu

Biosorption of Cadmium (II) and Chromium (VI) from Aqueous Solution by Chemically Modified Tithonia Diversyfolia Biomass

Staff PublicationThe search for alternative and innovative treatment technologies for the effective removal of heavy metals from aqueous wastes has been a research of concerted effort due to the inherent limitations exhibited by the conventional methods such as less efficiency, sensitive operating conditions, energy requirements and generation of toxic sludge or other waste products. Biosorption, the passive uptake of heavy metals by biomaterials has been studied recently because of its high efficiency and cost effectiveness. Therefore, the biosorption capacity of Tithonia diversyfolia biomass chemically modified with sodium hydroxide for the removal of cadmium and chromium ions from aqueous solution was investigated. The effects of temperature, contact time, initial concentration of metal ions, adsorbent dosage and pH on the biosorption of Cd2+ and Cr6+ ions were assessed. Thermodynamic parameters such as free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) during the biosorption were evaluated. The results showed that the biosorption process of Cd2+ and Cr6+ by chemically modified Tithonia diversyfolia (CMTD) biomass was feasible and exothermic under the studied conditions. The equilibrium process was well described by the Langmuir isotherm model, with a maximum biosorption capacity of 46.75mg/g and 48.00mg/g for Cadmium and Chromium ions, respectively. Kinetic studies indicated that the biosorption of metal ions followed a pseudo-second order equation