Year

2015

Degree Name

Doctor of Philosophy

Department

School of Earth and Environmental Sciences

Abstract

The occurrence and fate of both organic and inorganic contaminants in the aquatic environment has been recognised as a critical issue of public health and environmental concern. Treated contaminated surface and groundwater is a valuable water source that can be reclaimed for diverse purposes. However, with the intention of minimizing health and environmental risks and maintaining sufficient levels of sustainable water sources, advanced treatment is required. Membrane technology can be used for better treatment of contaminated surface and groundwater and it can be said that membrane technology is a promising technology for removal of trace organic and inorganic contaminants for environmental friendly water reuse. A comprehensive study was conducted to examine the removal of two main contaminant groups that are of concern in aquatic resources namely volatile organic compounds (VOCs) and cations and anions which exist in surface and groundwater in the Illawarra and Sydney regions. The ability of nanofiltration (NF) or reverse osmosis (RO) and carbon nanotube (CNT) systems as advanced treatment was investigated using two commercially available NF or RO membranes and multiwalled carbon nanotube (MWNT) buckypapers. Laboratory-scale tests were used with both cross-flow cell and dead-end stirred-cell filtration; tests were conducted with 21 ubiquitous compounds that represented the significant volatile organic compounds and 10 inorganic compounds representing cations and anions commonly found in contaminated surface and groundwater.

The results reported in this study indicate that the removal efficiency of reverse osmosis (RO) was better than NF and MWNT in rejecting both organic and inorganic contaminants detected in surface and groundwater. This study revealed that the removal efficiency of RO in rejecting organic contaminants ranged between 43.4 - 100 %, whereas the removal efficiency of RO in rejecting inorganic contaminants ranged between 76 - 100 %. Also this study concluded that the removal efficiency of NF in rejecting organic contaminants ranged between 27.6 - 98.4%. In contrast, the removal efficiency of NF-90 in rejecting inorganic contaminants ranged between 60 - 100 %. It is notable that the removal efficiency of MWNT in rejecting organic and inorganic contaminants was the lowest compared to the removal efficiency of RO and NF. This study showed that the removal efficiency of MWNT in rejecting organic contaminants ranged between 33.1 - 88.5 %. On the other hand, the removal efficiency of MWNT in rejecting inorganic contaminants ranged between 1.3 - 69.2%. Consequently, it can be concluded that RO is considered the best and most effective system to retain contaminants from surface and groundwater.

Share

COinS