Influence of operating parameters on clay fouling of a RO membrane

Effect of operating parameters on permeate flux due to clay fouling on a reverse osmosis membrane in a laboratory scale plate and frame membrane module is discussed. Bentonite clay was used as the model foulant. No steady state conditions were observed even after 24 hrs of operation. The flux-time curves obtained could be generalized into three categories. In the short term, the application of higher pressure leads to higher initial permeate flux. However, this effect has a negative effect on the long term flux by the formation of a more dense and a less porous cake layer on the membrane. Particle concentration plays a more dominant role in flux reduction. The results show that an increase in particle concentration from 100 to 300 mg/l could lead to an increase in the flux decline between 15.9 to 47.7 percent. For the tested conditions, crossflow velocity did not have much of an impact on the permeate flux.