Removing DOM from chloride modified hydrochar could improve Cu²⁺ adsorption capacity from aqueous solution

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment

Background:

• Hydrochar-based dissolved organic matter (DOM) behavior and composition influence copper (Cu) removal efficiency in wastewater adsorption.
• Understanding these interactions is crucial for developing effective water treatment strategies.

Purpose of the Study:

• To investigate the effect of chloride modifications (ZnCl2, FeCl3, SnCl4) on hydrochar properties and their subsequent impact on Cu2+ adsorption.
• To analyze the release dynamics and composition of DOM from modified hydrochars.

Main Methods:

• Hydrochar production from reed using chloride salts (ZnCl2, FeCl3, SnCl4) and subsequent DOM removal to obtain washed hydrochars (WHCs).
• Analysis of DOM release dynamics and characterization of hydrochar properties (porosity, SSA, functional groups).
• Investigation of Cu2+ adsorption on pristine hydrochars (PHCs) and WHCs using adsorption experiments and XPS analysis.

Main Results:

• Chloride modifications improved WHC porosity, specific surface area (SSA), and functional groups.
• DOM quantity and composition (Ar-P, Fa-L) were significantly affected by chloride modifications and release time.
• Cu2+ adsorption capacity on WHCs increased significantly compared to PHCs, correlating with SSA and DOM release (Fa-L, Ar-P).

Conclusions:

• Hydrochar-based DOM content and composition are key drivers for Cu2+ adsorption efficiency.
• Chloride-modified hydrochars offer enhanced performance for Cu2+ removal from wastewater.
• The study highlights the potential of tailored hydrochar modifications for effective heavy metal remediation.