Dynamic adsorption of Cd²⁺ from aqueous solution using biochar of pine-fruit residue

Pristine biochar performance investigation to remove metals in primary and secondary treated municipal wastewater for groundwater recharge application

“…As influent concentration increased to 5 mg/L, breakthrough time was reduced in single and mixed-metal solutions as the metal ions occupy the binding sites faster on the biochar which are easily accessible as shown Table 2 and S1 Fig . The breakthrough curves extended with the increased mass transfer rates which lead to higher removal efficiencies for the lower influent concentrations [ 54 ]. For 2.5 mg/L initial metal ion concentration, the highest average metal ion uptakes and removal rates were observed as: 9.21 mg/g (52.14%) for Cu 2+ , 9.82 mg/g (56.90%) for Fe 2+ , 6.66 mg/g (45.87%) for Zn 2+ , 4.82 mg/g (35.50%) for Ni 2+ in single-metal solutions; 4.25 mg/g (35.60%) for Cu 2+ , 5.67 mg/g (50.00%) for Fe 2+ , 2.78 mg/g (26.76%) for Zn 2+, 1.09 mg/g (12.05%) for Ni 2+ in mixed-metal solutions as shown in Table 2 .…”

“…Steeper breakthrough curves and decreased exhaustion times were observed at higher flow rate (20 mL/min) for both single- and mixed-metal solutions due to internal mass transfer which increases the diffusion of metal ions [ 54 , 56 ]. The highest average metal ion uptakes and removal rates for the lower flow rate (10 mL/min) were 5.30 mg/g (39.06%) for Cu 2+ , 8.91 mg/g (43.69%) for Fe 2+ , 4.58 mg/g (34.94%) for Zn 2+ , 1.21 mg/g (10.92%) for Ni 2+ in single-metal solutions; 3.34 mg/g (23.10%) for Cu 2+ , 3.48 mg/g (23.38%) for Fe 2+ , 1.91 mg/g (17.87%) for Zn 2+, 1.03 mg/g (10.67%) for Ni 2+ in mixed-metal solutions as shown in Table 2 and S1 Fig .…”