Synergistic Adsorption-Membrane Distillation for Heavy Metal Extraction and Water Reclamation from Saline Waste...

Area of Science:

• Environmental science
• Chemical engineering
• Materials science

Background:

• Membrane distillation (MD) effectively treats saline water but struggles with complex solutions like heavy metal-laden wastewater.
• Industrial processes generate saline wastewater contaminated with heavy metals, posing environmental and resource challenges.

Purpose of the Study:

• To develop and demonstrate a coupled adsorption-membrane distillation (MD) process for selective heavy metal removal and saline water concentration.
• To investigate the treatment of lead(II) and sodium chloride (Pb(II)/NaCl) mixed solutions.

Main Methods:

• Fabrication of an iron oxyhydroxide@polyvinylidene fluoride (FeOOH@PVDF) adsorptive membrane for Pb(II) ion adsorption.
• Utilizing an omniphobic membrane for the membrane distillation (MD) process to concentrate Pb(II)-removed saline solution.

Main Results:

• The FeOOH@PVDF membrane exhibited selective chemical adsorption for Pb(II) ions.
• The MD process achieved a water flux of 16.12 kg·m⁻²·h⁻¹ at a concentration factor of 7.7.
• The coupled process successfully separated purified water and concentrated brine, removing heavy metal ions.

Conclusions:

• The proposed adsorption-MD coupling process offers a novel approach for treating complex saline wastewater containing heavy metals.
• This method enables effective water source recovery and utilization from industrial effluents.