Ultrafiltration of distinct natural waters: correlation of fouling resistances with water constituents

摘要

This paper was to explore the correlation of fouling reversibility with raw water qualities by investigating the ultra filtration (UF) fouling resistance of distinct surface waters (lake water, campus water, river water and reservoir water) and by analyzing these water characteristics. Ultra filtration performance revealed that the order of different natural waters was lake campus > river > reservoir according to their impact on trans-membrane pressure (TMP) increase. Hydraulically reversible fouling resistance (R-re) was largely responsible for the sharply elevated TMP in lake water, while hydraulically irreversible fouling resistance (R-ir) contributed much to the increased TMP of the other three waters. High performance size exclusion chromatography (HPSEC) coupled with peak-fitting indicated that biopolymers (BP) fractions were mainly retained by UF membrane, while a small quantity of low molecular weight (LMW) and humic substances (HS) were held back. Principal component analysis (PCA) method was also used to identify fouling reversibility associated with water constituents. Results manifested that BP as well as fulvic-acid-like substances were the main components of hydraulically reversible foulants, while LMW contributed greatly to the hydraulically irreversible foulants. The proposed PCA method has the potential for diagnosing and controlling the predominant foulants present in natural waters.