Use of UF-PAC for removing humic materials from drinking water sources
Journal
Water Supply
Journal Volume
17
Journal Issue
3-4
Pages
157-162
Date Issued
1999
Author(s)
Huang Y.-J.
Abstract
It has been recognized that dissolved natural organic matters (NOM) are potential precursors for producing disinfection by products (DBP) during the chlorination process. As a result, removal of NOM and subsequently elimination of DBPs are of importance in the water supply industry. There are many approaches to minimize the formation of DBPs, including a variety of chemical processes, e.g., activated carbon and ozone oxidation. However, the membrane process has received considerable attention lately to minimize DBPs, due to its simplicity of operation, development of higher flux membranes, and decreased membrane costs. Unfortunately, membrane fouling, resulting in lower flux and deteriorated water quality, is one of the major problems limiting the wide application of different membrane processes. This study addresses the effects of NOM molecular size of humic material in water and the addition of powdered activated carbon (PAC) on the fouling of ultrafiltration (UF) membranes. Using the gel filtration chromatography method, the humic acid portion of one particular water supply source was fractionated into four groups of molecular size: 180-650, 650-2200, 2200-6500, and 6500-22,600 daltons. Under constant humic acid concentration conditions in a recirculation mode of operation, the decline of the UF permeate flux is significantly affected by the smallest molecular fractions. The hybrid process of combined UF and PAC processes reduces TOC as well as trihalomethane formation potential. However, the extent of operation time and degree of fouling were not improved with the hybrid process. On the contrary, organic matter remaining after PAC adsorption caused further decline in permeate flux, due to its role as foulant.
Subjects
Humic acid; Natural organic matter; PAC; Ultrafiltration
SDGs
Other Subjects
activated carbon; drinking water; organic matter; ozone; trihalomethane; activated carbon; drinking water; fouling; membrane; particle size; ultrafiltration; chlorination; conference paper; cost; disinfection; gel filtration chromatography; humic substance; membrane; molecular size; oxidation; powder; total organic carbon; ultrafiltration; water quality; water supply; water treatment
Type
conference paper