Our Research High-efficiency chemical-free backwash strategy for reverse osmosis membrane antifouling

Challenge:

Membrane fouling in reverse osmosis (RO) desalination leads to high energy consumption and cost and requires chemical additives for cleaning.  Is there a cost efficient, chemical-free answer? 

Research Strategy

  • Study the fouling process of RO membranes to understand how contaminants adhere 
  • Engineer a physical membrane fouling mitigation process such as vibration that is targeted, chemical-free, and energy efficient 

Project description

Reverse osmosis (RO) technology has attracted great academic and industrial interest due to the increasing demand for clean water in various aspects of our life and society. However, membrane fouling, or the accumulation of foulants on the RO membrane, inevitably leads to a decrease in membrane permeability, higher energy consumption and cost. The conventional method of mitigating fouling is to add chemicals such as chloramine to the feed solution, which is costly, time- and energy-inefficient, and environmentally undesirable.

In this project, the research team is developing new chemical-free fouling mitigation strategies with low cost and a reduced energy consumption to achieve high-efficiency RO membrane antifouling. The research objectives include: i) studying the fouling process during RO membrane operation and characterizing the adhesion between fouling film and RO membrane; ii) understanding new foulant-detaching mechanisms based on mechanical methods.

The significance and impact of the proposed project is two-fold: i) it will provide fundamental understanding of foulant detaching mechanisms; and ii) based on this understanding, it will result in the development of a high-efficiency, chemical-free antifouling strategy for RO systems. Whereas existing studies on membrane fouling and antifouling have not incorporated a deep understanding of solid mechanics; the proposed work is creating a new collaboration between experts in soft material mechanics (Zhao lab) and experts in RO membrane fouling (Lienhard lab) to develop targeted, efficient, chemical-free membrane fouling mitigation protocols.

Outcomes

  • Designed and constructed flow setups to deploy physical cleaning methods as alternatives to chemicals in mitigating fouling in RO membranes.
  • Investigated the effectiveness of osmotically-induced cleaning (OIC) and applicability in the presence of spacers for brackish water desalination
  • Evaluated the potential of OIC on biofilms for desalination applications

Publications

Additional Details

Impact Areas

  • Water

Research Themes

  • Water Purification & Desalination
  • Technology & Commercialization

Year Funded

  • 2017

Grant Type

  • Seed Grant

Status

  • Completed