Assessment of the fouling potential of wastewater treatment plant effluent using a modified capillary suction time measurement.
A new technique was developed to measure membrane fouling, which is derived from the capillary suction time (CST)--a parameter often used to indicate the dewaterability of sludge--and which is called the modified CST (CSTm). The results indicate a good repeatability and reproducibility of the test. Spiking tests with suspended solids and humic acid, which have a high fouling potential, resulted in a significant rise of the CSTm value, indicating a sensitive assessment of these fouling components. However, the CSTm measurement is mainly indicative for the colloidal fouling of the sample.