Development and application of an accelerated biofouling test in flat cell

Abstract

This paper discusses the steps followed to establish an accelerated reverse osmosis membrane biofouling test protocol. Easily bioassimilable nutrients were dosed into water from the Ebro River which was fed into a membrane flat cell pilot plant. The membrane biofouling results were determined by measuring adenosine triphosphate and total organic carbon extracted from the exposed membrane and feed spacer. This strategy was chosen because the equipment does not have pressure drop measurement capability and the observed change in flux or salt rejection was not significant under the testing conditions. The duration of the experiment was set to 3 d to enable rapid screening of different membrane types, yet enable a smooth evolution of biofilm. This study determined that achieving a similar amount of biofouling in each of the three cells was very sensitive to the level of bioassimilable nutrients were dosed to the water. For the Ebro River water, 0.2 mg/L of carbon, 0.04 mg/L of nitrogen, and 0.02 mg/L of phosphorous was determined to provide the best result.