Fabrication of agro–waste lotus leaf–derived adsorbent for effective removal of organic pollutants from water

Abstract

Full utilization of agricultural waste (agro–waste)–derived adsorbents for water purification is favorably sustainable. Herein, adsorbents obtained from the local lotus leaves are employed to remove the organic pollutants from water. The local lotus–leaf–derived adsorbent followed by 2 g of ZnCl2 activation at 1173 K (LAC–2–1173) exhibits a maximum adsorption capacity of 91.7 mg∙g−1 for norfloxacin at 298 K due to its larger specific surface area and hydrophobicity. Meanwhile, LAC–2–1173 possesses a superior adsorption performance of methylene blue and methyl orange with the maximum adsorption capacity of 176.7 mg∙g−1 and 246.5 mg∙g−1, respectively. The pollutants’ adsorption over LAC–2–1173 is exothermic and spontaneous, and the adsorption kinetic behavior and adsorption isotherms are well in line with the pseudo–second–order equation and Langmuir model, respectively. This work provides some insight into the fabrication and utilization of local agro–wastes–derived materials for environmental remediation.