Abstract
The objective of this study was to investigate the influence of calcium ions（Ca2＋）on the fouling propensity of a thin-film composite reverse osmosis（RO）membrane by alginate. Under the experimental conditions investigated in this study, an increase in Ca2＋ of up to 0.2 mmol/L accelerated the fouling of the RO membrane. However, the fouling propensity was not influenced by concentrations of Ca2＋ above 0.2 mmol/L. This result could be explained by the content of Ca2＋ in the fouling layer, which increased when the concentration of Ca2＋ in the feed water was 0.25 mmol/L or less and reached a plateau above 0.25 mmol/L.
