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High-efficiency Pb2+ removal by hydroxy-sodalite for point-of-use drinking water purification
Qian Zheng1, Ziwei Wang1, Zhouyang Tian2
1College of Resources and Environment, Huazhong Agricultural University, Wuhan, China.
Journal of Hazardous Materials
|January 15, 2025
Summary
This study developed a cost-effective hydroxy-sodalite (HySOD) material from kaolinite for lead (Pb) removal. The new material efficiently purifies drinking water, offering a vital solution for public health.
Area of Science:
- Materials Science
- Environmental Science
- Chemistry
Background:
- Lead (Pb) contamination in drinking water poses a significant public health risk, particularly in underdeveloped regions.
- Cost-effective point-of-use (POU) water purification devices are crucial for mitigating lead exposure.
- Natural kaolinite is an abundant and inexpensive material with potential for water treatment applications.
Purpose of the Study:
- To develop a novel, cost-effective material for efficient lead (Pb) removal from drinking water.
- To investigate the synthesis, adsorption properties, and removal mechanisms of the developed material.
- To demonstrate the efficacy of the material in a simplified point-of-use (POU) water purification device.
Main Methods:
- Kaolinite was transformed into hydroxy-sodalite (HySOD) using a hydrothermal process.
- Adsorption experiments were conducted to determine Pb2+ adsorption capacity and selectivity in single and multi-cation systems.
- Mechanism studies involved analyzing the phase change and surface interactions during Pb2+ adsorption.
- Continuous filtration tests were performed using a HySOD-loaded POU device to treat Pb-contaminated water.
Main Results:
- The hydrothermal process yielded HySOD with an impressive 91.5% efficiency.
- HySOD exhibited a high Pb2+ adsorption capacity (476 mg/g) and selectivity, with a distribution coefficient of 5.0 × 10^7 mL/g in multi-cation systems.
- Pb2+ removal was attributed to chemisorption and cation exchange leading to a spontaneous phase change.
- The POU device effectively reduced Pb2+ concentration from 200 μg/L to below 10 μg/L at a high water flux.
Conclusions:
- Hydroxy-sodalite (HySOD) derived from kaolinite is a highly effective and selective adsorbent for lead (Pb) removal.
- The material's performance in a POU device demonstrates its significant potential for safe drinking water purification.
- This research offers a promising solution for addressing lead contamination in drinking water, especially in resource-limited settings.
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