Synthesis of Eichhornia crassipes Biochar: Sustainable Efficient Adsorbent for Reducing Cr (VI) Metal Ion

Abstract

Chromium (Cr) is the most widely used metal in industrial activities and is the most toxic heavy metal ion found in waters. Utilization of Eichhornia crassipes as a Sustainable Efficient Adsorbent of heavy metal Cr (VI) is one of the innovations and alternative technologies that are very beneficial for society and the environment. The synthesis of Eichhornia crassipes biochar in this study employed the hydrothermal method. Hydrothermal temperature variations used in biochar synthesis were 220 C/240 C/260 C/280 C. Eichhornia penetrated biochar with H2O2 to the Cr (VI) metal adsorption capacity. The synthesis of biochar Eichhornia crassipes has the characteristics of combining hydroxyl, carbonyl, carboxyl, and amine functional groups. The surface morphology in the Eichhornia crassipes biochar modification term is rougher and irregular compared to Eichhornia crassipes biochar without modification. The modification of Eichhornia crassipes biochar using H2O2 showed an increase in oxygen composition in terms of modified biochar so that it increased the adsorption capacity of Cr (VI) metal ion. The best value of adsorption capacity in Eichhornia crassipes biochar terms modified with a hydrothermal temperature of 240 C that is equal to 30.2156 mg/g.