New insights into the interactions between Pb(II) and fruit waste biosorbent

TY - JOUR

T1 - New insights into the interactions between Pb(II) and fruit waste biosorbent

AU - Wang, Qian

AU - Wang, Yunlong

AU - Tang, Junjie

AU - Yang, Zi

AU - Zhang, Li

AU - Huang, Xiaowu

PY - 2022/5/22

Y1 - 2022/5/22

N2 - Fruit waste is a sustainable biosorbent for heavy metal removal from wastewater. Elucidation of adsorption mechanism is imperative for the process control and development of effective adsorbents. In this study, watermelon rind (WR) exhibited selective and efficient Pb(II) adsorption with a maximum uptake of 230.5 mg/g at pH 5.0. The WR-packed bed column showed high Pb(II) uptake and robust durability over 10 adsorption-desorption cycles with long breakthrough time of 8–13 h (89–144 bed volume), and 95% of sequestered Pb(II) was rapidly desorbed in 1–2 h by 0.05 M HCl. Spectroscopic characterization by FTIR and XPS identified hydroxyl, carboxyl, amine, and ether groups as the binding sites for Pb(II) via the binding force of complexation. Physicochemical analysis showed that ion exchange with Mg2+ and Ca2+ accounted for 19% of Pb(II) adsorption by WR; electrostatic attraction and microprecipitation jointly contributed. Quantum chemistry simulation verified the interactions between Pb(II) and binding sites and revealed carboxyl was the preferential functional group. The findings corroborate the applicability of WR in scale-up Pb(II) removal/recovery from wastewater and elaborate the mechanisms of Pb(II) adsorption by the WR-biosorbent. This also provides insights into the behavior of heavy metals in other liquid/solid interfaces.

AB - Fruit waste is a sustainable biosorbent for heavy metal removal from wastewater. Elucidation of adsorption mechanism is imperative for the process control and development of effective adsorbents. In this study, watermelon rind (WR) exhibited selective and efficient Pb(II) adsorption with a maximum uptake of 230.5 mg/g at pH 5.0. The WR-packed bed column showed high Pb(II) uptake and robust durability over 10 adsorption-desorption cycles with long breakthrough time of 8–13 h (89–144 bed volume), and 95% of sequestered Pb(II) was rapidly desorbed in 1–2 h by 0.05 M HCl. Spectroscopic characterization by FTIR and XPS identified hydroxyl, carboxyl, amine, and ether groups as the binding sites for Pb(II) via the binding force of complexation. Physicochemical analysis showed that ion exchange with Mg2+ and Ca2+ accounted for 19% of Pb(II) adsorption by WR; electrostatic attraction and microprecipitation jointly contributed. Quantum chemistry simulation verified the interactions between Pb(II) and binding sites and revealed carboxyl was the preferential functional group. The findings corroborate the applicability of WR in scale-up Pb(II) removal/recovery from wastewater and elaborate the mechanisms of Pb(II) adsorption by the WR-biosorbent. This also provides insights into the behavior of heavy metals in other liquid/solid interfaces.

KW - Fruit waste

KW - Heavy metal

KW - Adsorption mechanism

KW - Column study

KW - Circular economy

U2 - 10.1016/j.chemosphere.2022.135048

DO - 10.1016/j.chemosphere.2022.135048

M3 - 文章

C2 - 35613637

SN - 0045-6535

JO - Chemosphere

JF - Chemosphere

ER -