Water Flux Prediction in Direct Contact Membrane Distillation Subject to Inorganic Fouling.

Area of Science:

• Water Treatment Technologies
• Chemical Engineering
• Materials Science

Background:

• Freshwater scarcity necessitates advanced water purification and reuse technologies.
• Membrane distillation (MD) is a promising desalination technology.
• Membrane fouling significantly degrades MD performance.

Purpose of the Study:

• To develop a mathematical model predicting distillate fluxes in direct-contact MD with inorganic fouling.
• To validate the model against experimental data.
• To understand the factors influencing inorganic membrane fouling in MD.

Main Methods:

• A mathematical model integrating heat and mass transfer with cake-filtration theory was employed.
• The model predicts steady-state distillate fluxes before and after fouling onset.
• Experimental data from direct-contact MD experiments were used for validation.

Main Results:

• The model accurately predicted distillate fluxes, with root-mean-square errors below 1.4 kg m⁻² h⁻¹.
• Cake-filtration theory effectively represents flux decline due to inorganic fouling.
• Fouling onset was consistent, influenced by feed-membrane interactions; flux decline depended on flow and precipitate.

Conclusions:

• The developed mathematical model is a reliable tool for predicting water flux in MD with inorganic fouling.
• Cake-filtration theory provides a valid framework for understanding inorganic fouling in MD.
• Further research is needed to extend the model's applicability to diverse conditions and fouling types.