Surface modification of Trema orientalis wood biochar using natural coconut vinegar and its potential to remove aqueous calcium ions: column and batch studies

Recent investigations have revealed the harmful health effects of elevated calcium levels in drinking water. Chemically activated biochar is most popular option for low-cost cation adsorption. However, these chemicals are hardly available rural communities, corrosive, and difficult to handle by unskilled personnel. This study aimed determine ability natural coconut vinegar, a common mild acid, activate Trema orientalis wood pyrolyzed at 300˚C (BC) as facile, safe, approach aqueous ion (Ca2+) removal. Column tests showed two-fold increase Ca2+ adsorption capacity ten-fold retaining BC after activation with vinegar. The isotherm results were well correlated Langmuir model. maximum (BC-A) was 9.96 mg/g. amount determined using flame photometry. EDX analysis that O/C ratio increased from 0.07 0.13 activation. FTIR wettability studies oxygenated functional groups on BC-A surface. authors suggest possible acid-catalyzed hydration C-O-C bridges biochar, introducing new hydroxyl/carbonyl/ester/carboxylic/lactone surface due vinegar activation, enhancing through chemisorption.