Performance of Modified Biochar Derived from Ziziphus Jujube Seeds for Hexavalent Chromium Removal

Abstract

The removal of hexavalent chromium (Cr(VI)) from aqueous solutions, a newlinepressing environmental concern due to its high toxicity and persistence, was newlinesystematically investigated using biochar derivatives derived from Ziziphus Jujube Seeds newline(ZJS). Four types of biochar namely unmodified ZJS biochar (ZJSB), activated biochar newline(ZJSAB), magnetic biochar (MB), and activated magnetic biochar (MAB)were newlinesynthesized and evaluated for their efficiency in Cr(VI) removal under various newlineexperimental conditions. The characterization study evaluated the physicochemical newlineproperties of biochars derived from Ziziphus Jujube Seeds (ZJS). Unmodified biochars, newlineZJSB400 and ZJSB500, were analysed using proximate, elemental, and functional group newlineanalysis, surface area measurements, and thermogravimetric analysis (TGA). ZJSB500 newlineshowed superior thermal stability and adsorption potential due to enhanced structural newlineintegrity and carbon content from higher pyrolysis temperatures. Activated biochar newline(ZJSAB) exhibited increased active sites and adsorption efficiency, while magnetic newlinebiochar (MB1) demonstrated advanced features, including a larger surface area, welldefined newlinecrystalline structure, and strong magnetic properties. These characteristics newlineenabled MB1 to achieve high Cr(VI) removal efficiency. The study underscores the newlineinfluence of pyrolysis, activation, and magnetization processes on biochar properties, newlineidentifying MB1 as the most effective for water treatment applications due to its superior newlineadsorption performance and reusability newline