Assessing PAC contribution to the NOM fouling control in PAC/UF systems
Margarida Campinas1, Maria João Rosa
1University of Algarve, Gambelas Campus, 8005-139 Faro, Portugal. mgd.campinas@gmail.com
Water Research
|December 1, 2009
Summary
Powdered activated carbon (PAC) controls irreversible membrane fouling in hybrid processes, reducing cleaning needs. It also improves removal of certain organic matter but doesn't impact permeate flux or reversible fouling.
Area of Science:
- Water treatment technologies
- Membrane science
- Environmental engineering
Background:
- Natural organic matter (NOM) causes membrane fouling in ultrafiltration (UF) processes.
- Powdered activated carbon (PAC) is used in water treatment, but its role in PAC/UF hybrid fouling control needs clarification.
Purpose of the Study:
- To investigate PAC's contribution to fouling control by NOM in a PAC/UF hybrid process.
- To evaluate the foulant behavior of PAC itself during ultrafiltration.
Main Methods:
- Permeation of NOM surrogates (humic acids, tannic acid) and algogenic organic matter (AOM/EOM) through a UF membrane.
- Assessment of PAC's impact on permeate flux, rejection rates, and fouling under various conditions.
Main Results:
- Polysaccharide-like EOM combined with ions caused the most significant flux reduction and poorest rejection.
- PAC did not affect permeate flux or reversible fouling, irrespective of NOM characteristics or water inorganics.
- PAC effectively controlled irreversible fouling, minimizing chemical cleaning frequency and enhancing rejection of specific organic compounds.
Conclusions:
- PAC is a valuable component for mitigating irreversible fouling in PAC/UF hybrid systems.
- PAC improves the removal of certain organic matter fractions, contributing to overall water quality enhancement.
- PAC's effectiveness varies with the type of organic matter present, showing limitations with highly hydrophilic EOM compounds.
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