Strong Adsorption of Phosphorus by ZnAl-LDO-Activated Banana Biochar: An Analysis of Adsorption Efficiency, Thermodynamics, and Internal Mechanisms | JoVE Visualize

Strong Adsorption of Phosphorus by ZnAl-LDO-Activated Banana Biochar: An Analysis of Adsorption Efficiency, Thermodynamics, and Internal Mechanisms

Anyu Li¹, Hua Deng¹, Yuqing Wu¹

¹College of Environment and Resources, Guangxi Normal University, Guilin 541006, China.

ACS Omega|March 29, 2021

View abstract on PubMed

Summary

A novel Zn-Al layered bimetallic composite derived from banana straw (ZnAl-LDO-BC) efficiently removes phosphorus. This biochar-based adsorbent exhibits a high adsorption capacity and follows pseudo-second-order kinetics and Langmuir adsorption isotherms.

Area of Science:

Environmental Chemistry
Materials Science
Green Chemistry

Background:

Phosphorus pollution poses a significant threat to aquatic ecosystems.
Developing efficient and sustainable adsorbents for phosphorus removal is crucial.
Bio-based materials offer a promising avenue for environmental remediation.

Purpose of the Study:

To synthesize a novel Zn-Al layered bimetallic composite adsorbent (ZnAl-LDO-BC) from banana straw.
To investigate the adsorption kinetics, thermodynamics, and mechanism of phosphorus removal by ZnAl-LDO-BC.
To evaluate the potential of ZnAl-LDO-BC as a green technology for addressing phosphorus pollution.

Main Methods:

Preparation of Zn-Al layered bimetallic composites using banana straw via ethanol strengthening and co-precipitation.
High-temperature calcination to obtain the ZnAl-LDO-BC adsorbent.
Adsorption experiments to study kinetics, thermodynamics, and the influence of competing anions.
Characterization using SEM-EDS, FTIR, and XRD to elucidate the adsorption mechanism.

Main Results:

The adsorption process follows pseudo-second-order kinetics and the Langmuir model.
The theoretical maximum adsorption capacity is 111.11 mg/g at 45 °C and 500 mg/L initial phosphorus concentration.
The adsorption efficiency is influenced by anions in the order: CO3^2- > SO4^2- > NO3-.
Characterization confirmed efficient phosphorus adsorption via surface complexation, precipitation, biochar surface adsorption, and interlayer adsorption.

Conclusions:

ZnAl-LDO-BC is a highly efficient phosphorus adsorbent derived from sustainable biomass.
The adsorption mechanism involves multiple interactions, including surface complexation and precipitation.
This study presents a novel green technology for effective phosphorus removal from contaminated water sources.