Diatomite Composited with a Zeolitic Imidazolate Framework for Removing Phosphate from Water

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Phosphate pollution is a significant environmental concern, necessitating effective wastewater treatment methods.
• Adsorption technology using various adsorbents is a widely adopted approach for phosphate removal.
• Developing novel, efficient, and eco-friendly adsorbents is crucial for sustainable water management.

Purpose of the Study:

• To develop a novel composite adsorbent material for efficient phosphate removal from water.
• To investigate the adsorption performance and mechanism of the composite adsorbent under various conditions.
• To evaluate the potential of the novel adsorbent as a sustainable solution for wastewater treatment.

Main Methods:

• A composite adsorbent, diatomite composited with ZIF-8 (CZD), was synthesized using chitosan as a modifier.
• Phosphate adsorption experiments were conducted to study the effects of adsorption time, temperature, pH, and competitive ions.
• Adsorption isotherms, kinetics, and thermodynamic parameters were analyzed to understand the adsorption mechanism.

Main Results:

• The composite adsorbent CZD exhibited rapid phosphate adsorption, achieving 85% removal within 10 minutes.
• The maximum adsorption capacities were 13.46, 13.55, and 13.95 mg/g at 25, 35, and 45 °C, respectively.
• Removal efficiencies exceeded 98%, reaching 100% at 45 °C, with electrostatic attraction identified as the primary removal mechanism.

Conclusions:

• The developed CZD adsorbent demonstrates high efficiency and rapid kinetics for phosphate removal from water.
• The adsorption process is physical, endothermic, and well-described by the Langmuir isotherm and pseudo-second-order kinetic models.
• CZD presents a promising, eco-friendly alternative for effective phosphate management in wastewater treatment.