. (2016). Removal of volatile organic compounds (VOCs) from groundwater by reverse osmosis and nanofiltration. Journal of Water Process Engineering, 9 9-21. Removal of volatile organic compounds (VOCs) from groundwater by reverse osmosis and nanofiltration AbstractA comprehensive study was conducted to examine the removal of volatile organic compounds (VOCs) which exist in groundwater at Southlands-Botany Bay (Sydney region). The ability of nanofiltration (NF) and reverse osmosis (RO) as advanced treatments was investigated using two commercially available NF or RO membranes. Laboratory-scale tests were used with cross-flow; tests were conducted with 16 ubiquitous compounds that represented the significant volatile organic compounds found in the contaminated groundwater. The results reported in this study indicate that the removal efficiency of reverse osmosis (RO) was better than NF in rejecting the VOCs detected in groundwater. This study revealed that the performance of NF and RO membranes in rejecting hydrophilic volatile organic compounds was higher than that for hydrophobic compounds and the highest rejection achieved by NF and RO membranes amounted 98.4% and 100%, respectively. Hydrophilic compounds can be effectively rejected by NF/RO membranes using the size exclusion mechanism (steric hindrance), whereas hydrophobic compounds can be adsorbed into NF/RO membranes and then diffuse through the dense polymeric matrix, resulting in the lower removal for these compounds compared to hydrophilic compounds. Keywords:Volatile organic compounds (VOCs) Reverse osmosis (RO) Nanofiltration (NF) Botany Bay ABSTRACT A comprehensive study was conducted to examine the removal of volatile organic compounds (VOCs) which exist in groundwater at Southlands-Botany Bay (Sydney region).The ability of nanofiltration (NF) and reverse osmosis (RO) as advanced treatments was investigated using two commercially available NF or RO membranes. Laboratory-scale tests were used with cross-flow; tests were conducted with 16 ubiquitous compounds that represented the significant volatile organic compounds found in the contaminated groundwater.The results reported in this study indicate that the removal efficiency of reverse osmosis (RO) was better than NF in rejecting the VOCs detected in groundwater. This study revealed that the performance of NF and RO membranes in rejecting hydrophilic volatile organic compounds was higher than that for hydrophobic compounds and the highest rejection achieved by NF and RO membranes amounted 98.4 % and 100 %, respectively. Hydrophilic compounds can be effectively rejected by NF/RO membranes using the size exclusion mechanism (steric hindrance), whereas hydrophobic compounds can be adsorbed into NF/RO membranes and then diffuse through the dense polymeric matrix, resulting in the lower removal for these compounds compared to hydrophilic compounds.

The distribution of trace metals (spatial and temporal) and sedimentary fractions were investigated to identify the concentrations and sources of trace metals within Kogarah Bay, NSW, Australia. A total of 59 surface sediments and six subsurface samples from core of the sediment were collected. The contamination factor and pollution load index indices used to evaluate environmental effects of trace metals. The study area was found to be uncontaminated with Cr and Ni, moderately contaminated with As and considerably contaminated with Cu, Zn and Pb. The concentrations of Cr and Ni were below both effect range low and effect range median, while As, Cu, Zn and Pb were slightly above effect range low. The highest concentrations of these trace metals such as Cu, Zn and Pb were found in the north, northwest and southeast of the bay, close to discharge points, stormwater outlets and around boatyards and watercrafts. The spatial distributions of metals were strongly related to muddy particles and organic matter. The temporal sediments of metals declined with increased sediment depth, which reflects accumulation of trace metals since European settlement in this area. Furthermore, the source of the trace metals was found to be stormwater outlets, gasoline fumes, boatyards and other human activities. AbstractThe distribution of trace metals (spatial and temporal) and sedimentary fractions were investigated to identify the concentrations and sources of trace metals within Kogarah Bay, NSW, Australia. A total of 59 surface sediments and six subsurface samples from core of the sediment were collected. The contamination factor and pollution load index indices used to evaluate environmental effects of trace metals. The study area was found to be uncontaminated with Cr and Ni, moderately contaminated with As and considerably contaminated with Cu, Zn and Pb. The concentrations of Cr and Ni were below both Effect Range Low and Effect Range Median, while As, Cu, Zn and Pb were slightly above Effect Range Low. The highest concentrations of these trace metals such as Cu, Zn and Pb were found in the north, north west and south east of the bay, close to discharge points, stormwater outlets and around boatyards and watercrafts. The spatial distributions of metals were strongly related to muddy particles and organic matter. The temporal sediments of metals declined with increased sediment depth, which reflects accumulation of trace metals since European settlement in this area. Furthermore, the source of the trace metals was found to be stormwater outlets, gasoline fumes, boatyards and other human activities.

No abstract

No abstract

Measurement of elevated trace elements is an important component of environmental assessment and management of estuarine marine sediments in systems adjacent to concentrated human activity. The present study surveys the estuarine sediments in selected tributary bays, creeks, and the upper segments of the Georges River system, NSW, Australia, which flows into the Tasman Sea through Botany Bay. A total of 146 surface sediment samples were analysed by X-ray fluorescence. Potential pollution of sediments was evaluated using potential load index, modified degree of contamination, and potential ecological risk index. The spatial distribution of trace elements varies between sites. Variable sources of contamination, including runoff from catchment areas, and emissions from watercraft and boatyards are contributing sources. Bay morphologies and their interactions with catchment and tidal flows play significant roles in the distribution of trace elements. The greatest concentration of trace elements occurs around discharge points and in the inner parts of bays that have high percentages of mud particles and organic matter. The lowest contamination by trace elements was found in sandy sediments along the shoreline and edges of the bays. Trace element distributions decline in concentration in residential-free areas and reach background levels in deeper sediment cores. The concentrations of trace elements were controlled by discharge points from the catchment area, marine boat activities, bay morphology, and sediment types (sand, silt, and clay). The highest pollutant concentrations are the result of past legal, but uncontrolled, discharge of waste from manufacturing into Salt Pan Creek. Creek.

A combination of geochemical analysis and hydrodynamic measuring has been established in order to provide an explanation for the spatial distribution of both sediment particles and trace element pollution Gunnamatta Bay, NSW, Australia. Fifty nine samples of surface sediment were collected to determine the spatial concentrations of trace elements in the bay. Moreover, current track pathways and velocities have been measured in the bay. The distribution of trace elements such as chromium, nickel, copper, zinc, arsenic and lead had similar patterns in surface sediments. Trace element pollution is concentrated along the current trajectory in the inner part of the bay, which has deeper sites and higher percentages of mud particles. The highest concentrations of these metals were found to be in sample GU55 from the northeast of the bay, which is close to a surface discharge point and moored boats. concentrations of these metals were found to be in sample GU55 from the northeast of the bay, which is close to a surface discharge point and moored boats.

Anthropogenic lead has been released into environmental ecosystems via human activities; essentially from mining, smelting of lead, leaded gasoline and industrial activities. In order to explore the source apportionment and historic record of lead pollution in the marine sediments, concentration of lead was determined from the Botany Bay and Port Hacking estuaries, south of Sydney, Australia. Areas with the highest concentrations of lead in the sediment samples were analysed by inductively coupled plasma-mass spectrometry (ICP-MS) for lead isotopes to effectively identify the metal contamination source. In addition, other sediment samples were collected from cores at 40 cm depth to represent the natural background composition. The study found that the total lead in the tested marine sediments varied from 75.6 mg/kg to 582.2 mg/kg. The 206Pb/204Pb showed a decline towards the current surface sediment. Assuming that the natural background source of lead remains the same in terms of both isotopic signature and accumulation rate, the decline in 206Pb/204Pb indicated a rise in the contribution of old lead to the sediment, mainly from gasoline fumes (car and boat exhausts) and paint. This is because the samples came from close to water discharge points which have concentrated the catchment lead via stormwater runoff. Pb indicated a rise in the contribution of old lead to the sediment, mainly from gasoline fumes (car and boat exhausts) and paint. This is because the samples came from close to water discharge points which have concentrated the catchment lead via stormwater runoff.

No abstract