Feasibility of pre-treating wastewater/water to prevent/minimize reverse osmosis (RO) membrane biofouling using ozone process

Abstract

With an ever increasing world population, the demand for clean and safe drinking water also increases. As such, various disinfection techniques have been widely applied to tackle the problem of contaminated natural water sources and one such example is the use of membrane technology. However, membranes are prone to biofouling and biofouling can potentially affect the treatment process. To prevent biofouling of membranes, water/wastewater should be pre- treated. In this study, the efficiency of using ozone advanced oxidation process was investigated for potential treatment of water spiked with contaminant. The bacterium model used was the wild type Pseudomonas aeruginosa bacterial strain PA01. Experiments using 4 different rates of ozone generation (100 mg/h, 200 mg/h, 300 mg/h and 400 mg/h) to inactivate a PA01 concentration of 8×106 CFU/ml were conducted to determine the most effective ozone generation rate. The inactivation efficiency of the different rates of ozone generation was calculated and the ozone generation rate of 400 mg/h was found to be the most efficient as 100% inactivation was reached within the fastest time of 10s. Experiments using an ozone generation rate of 400 mg/h as a control were then conducted with varying concentrations of PA01 to investigate the duration needed to achieve 100% inactivation. It was also found out that as contact time increased, inactivation efficiency also increased because there were less living cells over time. Therefore, the inactivation of Pseudomonas aeruginosa was found to be dependent on the disinfectant concentration and contact time.