AWWA ACE60016

The influence of surface characteristics and natural organic matter (NOM) on membrane performance issignificant but not well understood. This study investigated the impact of membrane surface characteristics andNOM on membrane performance for varying pretreatment andmembranes. Surface charge, hydrophobicity and roughness variedsignificantly among the four membranes used in the study. The membranes were testedin parallel following two different pretreatment processes, an enhanced Zenonultrafiltration process (ZN) and a compact CSF process (Superpulsator (SP)) prior to reverse osmosis (RO)membrane treatment for a total of eight integrated membrane systems. All membranesystems were exposed to the similar temperature, recovery and flux as well as chemicaldosage. The feed water qualities were identical following ZN pretreatment and SPpretreatment except for NOM concentration. Membrane surface characteristics, NOMand SUVA measurements were used to describe mass transfer in a low pressure ROintegrated membrane system. Solute and water mass transfer coefficients weresystematically investigated for dependence on membrane surface properties and NOMmass loading.Inorganic MTCs were accurately described by a Gaussian distribution curve.Water productivity, NOM rejection and inorganic rejection increased as membranesurface charge and NOM loading increased. Inorganic MTCs were also correlated tosurface hydrophobicity and surface roughness. The permeability change of identicalmembranes was related to NOM loading, hydrophobicity and roughness. Organic foulingas measured by water, organic and inorganic mass transfer was less for membranes withhigher hydrophilicity and roughness. Includes 19 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2004

Number of Pages:

18

File Size:

1 file , 1 MB