posted on 2024-02-07, 21:30authored byXi Liu, Yili Tang, Xianguang Wang, Muhammad Tariq Sarwar, Xiaoguang Zhao, Juan Liao, Jun Zhang, Huaming Yang
In recent decades,
the tetracycline (TC) concentration
in aquatic
ecosystems has gradually increased, leading to water pollution problems.
Various mineral adsorbents for the removal of tetracyclines have garnered
considerable attention. However, efficient adsorbents suitable for
use in a wide pH range environment have rarely been reported. Herein,
a phytolith-rich adsorbent (PRADS) was prepared by a simple one-step
alkali-activated pyrolysis treatment using phytolith as a raw material
for effectively removing TC. PRADS, benefiting from its porous structure,
which consists of acid- and alkali-resistant, fast-adsorbing macroporous
silica and mesoporous carbon, is highly desirable for efficient TC
removal from wastewater. The results indicate that PRADS exhibited
excellent adsorption performance and stability for TC over a wide
pH range of 2.0–12.0 under the coexistence of competing ions,
which could be attributed to the fact that PRADS has a porous structure
and contains abundant oxygen-containing functional groups and a large
number of bonding sites. The adsorption mechanisms of PRADS for TC
were mainly attributed to pore filling, hydrogen bonding, π–π
electron-donor–acceptor, and electrostatic interactions. This
work could offer a novel preparation strategy for the effective adsorption
of pollutants by new functionalized phytolith adsorbents.