AWWA MTC69694

The performance of the reverse osmosis (RO) membrane when reclaiming high fouling produced water at an elevated pH and temperature is distinctive from more common municipal wastewaters. This unique process offers an opportunity to better understand RO membrane salt passage and durability, as well as RO element and system design, at more extreme conditions. This paper discusses the characteristics of the RO membrane in a system reclaiming high pH/high temperature produced water from the oil and gas extraction process. This characterization is based on laboratory studies, pilot studies, and actual plant performance. In addition to understanding salt passage when treating high pH water, a better understanding of membrane longevity is necessary considering the high pH and high temperature operation associated with this process. Operation at high pH can mitigate organic fouling of the RO and act as a kind of continuous cleaning, but exposure to high pH can also adversely affect the integrity of the membrane's polyester support. An analysis of flow, salt passage, and strength was performed to characterize the effects of long term exposure of the membrane to these extreme conditions. Includes 6 references, tables, figures.