Assessment of water treatment processes: detailed organic matter characterisation and membrane fouling indices at the Loddon Water Treatment Plant, Victoria, Australia

Abstract

Recent advances in membrane technology have led to its broad application, and reverse osmosis (RO) systems now represent the fastest growing segment of the desalination market. Its performance is hindered by membrane fouling. In this study pre-treatment methods to reduce RO fouling were investigated including flocculation, adsorption and ion exchange. Detailed organic characterisations were made in terms of florescence spectroscopy excitation emission matrix (EEM), UV254 absorbance and liquid chromatography-organic carbon detection (LCOCD). The different pre-treatment methods were assessed in terms of the fouling potential. This was quantified in terms of the modified fouling index measured using a dead-end cell micro-filtration (MF) unit. The existing pre-treatment of granular activated carbon (GAC) filter led to a good organic removal. Among the pre-treatment methods tested in the laboratory, purolite ion exchange/adsorption was found to be better than FeCl3 flocculation in terms of the amount as well as the wide range of organics removal. A pre-treatment of flocculation with Poly-ferric-silicate (PFSi) as flocculent gave a higher removal of organic matter compared to other pre-treatments tested. DOC was reduced from 11.5 to 4.25 mg/L, and it removed mostly the humic type substances.

Effective Decolorization and Turbidity Removal of Canal Water using Activated Carbon Prepared from Local Agricultural Wastes

“…Moreover, Hatt et al could achieve up to 95 % of turbidity removal by using the AC [7]. Accordingly, several reports introduced the AC as effective material to reduce the modified fouling index (MFI) for different wastewater sources [8,9]. Adsorption process is a very effective method in wastewater treatment because of its simple operation, economic, low secondary pollution and environmental protection [10].…”