Improving Membrane Treatment Energy Efficiency through Monitoring the Removal of Colloidal Particle Foulants

Measuring Colloidal Particles Prior to Membrane Treatment Can Reduce Energy and Cost for Water Reclamation

Kennedy/Jenks Consultants


Irvine, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Result

Project is complete. Results indicate that the fouling potential for the microfiltration (MF) membranes tested at Orange County Water District (OCWD) was mitigated through use of targeted chemical addition. Test results show that fouling is reduced by 60% compared to the no coagulant addition. Energy and economic evaluation at OCWD indicated that the approach can reduce energy consumption due to MF by 28% and can result in 2,940 MWh/year savings. OCWD staff has made internal presentation of the project findings to its management. Recipient has presented the project results at five conferences attended by water/wastewater treatment plant staff, regulators and vendors. This project will be published in 'Water World'; either as a podcast/article.

The Issue

Membrane treatment processes are highly energy intensive due to the fouling of the membranes over time. The high energy demand of low pressure membranes is caused by the accumulation of colloidal particles in the feedwater inside the membrane pores which increases the transmembrane pressure. There are no techniques to measure the levels of colloidal particles directly in wastewater, and minimize their deposition in membrane pores. As a result, many utilities do not pretreat the entering wastewater prior to membrane treatment. This results in membrane fouling and high energy use.

Project Innovation

The project demonstrated an online monitoring technology for wastewater treatment plants to directly measure colloidal particle concentrations in order to lower membrane fouling and reduce energy use and maintenance costs. Direct detection of colloidal particles will help determine the optimal pretreatment needed to minimize deposition of colloidal particles in membrane pores.

Project Goals

Identify optimal settings for the process control system for integration of instrument with the pretreatment process.
Demonstrate the ability of the instrument to measure colloidal particles under dynamic flow conditions.
Obtain reliable capital and operations and maintenance (O&M) cost data, including energy efficiency and ROI.
Lower the energy demand of low-pressure membrane treatment by 20%.
Lower overall O&M cost of membrane treatment by 10%.

Project Benefits

Nationwide there are over 100 microfiltration/ultrafiltration treatment plants and there are over 100 reverse osmosis facilities in California using membranes. Membrane treatment for wastewater treatment is very energy intensive due to fouling of membranes over time. This project could overcome the barriers to use of membrane treatment by demonstrating a technology that can detect colloidal particles in membrane feed water. This can facilitate an optimal pretreatment process for their removal and reduce membrane fouling and energy costs.

Lower Costs


The project reduced the frequency of cleaning and membrane replacement, energy use, and wastewater treatment plant operating costs by reducing the build-up in membrane pores and removing colloidal particles in the feed water duri

Key Project Members

Ganesh Rajagopalan

Ganesh Rajagopalan

Manager - Applied Research Group
Alan Bracewell

Alan Bracewell

Staff Engineer
Kennedy Jenks Consultants



Southern California Edison Company


Match Partners


Orange County Water District


West Basin Municipal Water District


Evoqua Water Technologies




Contact the Team