AWWA ACE68820

This powerpoint presentation begins by providing a brief overview of the project objective of examining the effect of algogenic organic matter (AOM) on reverse osmosis(RO) membranes during desalination. RO experiments were performed on a semi-automatedbench-scale system. A test of algal-laden "red tide" seawater resulted insignificant flux decline. It was determined that unicellular marine dinoflagellate algae are the cause ofred tide events. Fluorescence microscopy can be used to evaluate andcount algal cells. A set of AOM fractionation experiments wasperformed. Experimental results have the following implications for full-scaleoperation, including:fairly high levels of organic matter causeonly minor short-term flux decline;AOM does accumulate in thick layers;membrane resistance is much higher thancake-layer resistance;bench-scale tests should include autopsy;frequent cleanings are suggested even whenperformance is steady; shearing of algal cells releases dissolvedAOM; and,inlet structures and pretreatment technologiesshould be designed for low shear if possible. Techniques developed during this research could bevaluable for future work, including the following:fluorescence measurements of foulantscould help distinguish between algogenicand bacterial fouling;the dichotomy of algae and bacteria canbe explored; and,pretreatment strategies can be developedto remove algal cells and minimize AOMrelease. Includes figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

28

File Size:

1 file , 3.3 MB