Sulfamic acid modified hydrochar derived from sawdust for removal of benzotriazole and Cu(II) from aqueous solution: Adsorption behavior and mechanism

A novel hydrochar adsorbent derived from sawdust (SAHC) was prepared for highly efficient simultaneous removal of benzotriazole (BTA) and Cu(II) from aqueous solution. The prepared adsorbent was characterized by several methods such as SEM, FTIR, and XPS. Batch adsorption experiments showed that the maximum adsorption capacity of SAHC for BTA and Cu(II) was 159.91 and 298.86 mg/g, respectively. Additionally, the study of competitive adsorption showed that the adsorption of Cu(II) was barely affected by the existence of BTA while the BTA adsorption was significantly improved with the coexistence of Cu(II). The study of adsorption mechanism found that Cu(II) could chelate with BTA to form complex, and the complexing-bridging interaction improved BTA adsorption. SAHC exhibited high adsorption ability after six adsorption cycles, which indicated excellent stability and regeneration performance of SAHC. All the results suggested that SAHC could be a promising adsorbent for simultaneous removal of BTA and Cu(II) from wastewater.