Effects of hydrocarbon fouling on reverse osmosis membranes

TD Environmental technology. Sanitary engineering;GE Environmental Sciences

Owadally, M. Hassan ; Hodgkiess, Trevor

University:University of Glasgow

Department:School of Engineering

关键词: Reverse Osmosis, Seawater, Brackish water, fouling, Hydrocarbon;   

Others  :  http://theses.gla.ac.uk/754/1/2009OwadallyMSc.pdf

来源: University of Glasgow

【 摘 要 】

Organic fouling in reverse osmosis (RO) has been studied using model hydrocarbons such as hexane and diesel. A large number of countries that use reverse osmosis to obtain drinking water also are producers and exporters of hydrocarbons. This makes seawater RO units particularly susceptible to damage from oil spills.This project is focused on the repercussions of such an incident on the performance of the above-mentioned modules. The study has concentrated on the lower molecular weight hydrocarbons present in contaminated seawater feed as it can be safely assumed that organics of higher molecular weight will have already been dealt by passage through the RO pre-treatment processes.The organic foulants chosen for investigation are: diesel (a likely constituent arising from spillages) and hexane (chosen as a model low-molecular-weight hydrocarbon). The study has investigated the effects of the presence of these contaminants in both water-soluble and emulsion form. The membranes tested are brackish water membranes and seawater membranes of different structures polyamide based and CTA (cellulose triacetate). These membranes were tested in saline water mainly at the salinity, 5500 ppm NaCl.The performance of the RO unit, in terms of salt passage and permeate flux through the membranes, were assessed before and after fouling. These results have been correlated with microscopic examinations of the surface of the membranes. Substantially different effects of exposure to hydrocarbons have been monitored between different membranes and also in terms of the active and support layers of a particular membrane.