Androgenic activity of effluent from forty-five municipal waste water treatment plants in Victoria, Australia

It is well known that waste water treatment plant (WWTP) effluents are estrogenic. There has been much less consideration of the androgenic activity of WWTP effluents. To partly address the shortage of information on androgens in Australian WWTP effluents, in August 2006, and again in 2007, we collected discharges from up to 45 Victorian WWTPs (~25% of all WWTPs in Victoria), grouped by treatment process, i.e. activated sludge, extended aeration, and lagoon based treatment, and measured the total estrogenic, androgenic, retinoic acid, and aromatic hydrocarbon hydrogenase activity of the effluents using a hybrid yeast bioassay. This paper will concentrate on the androgenic activity and male hormone concentrations.

Innovative reuse options for water treatment plant sludges

Reuse options were investigated for drinking water sludge. Research found sludges could be included with raw materials in brick and cement manufacturing with minimal impact. Poly-aluminium chloride sludge was found to an excellent adsorbent of phosphorus from wastewaters thus indirectly reducing potential algal blooms in our rivers.

Urban stormwater inputs to an adapted coastal wetland : role in water treatment and impacts on wetland biota

The Lake Pertobe wetland system is a semi-natural wetland that has been modified primarily for recreational use. However, this lake system receives stormwater from much of the central business district of Warrnambool City (Victoria, Australia) and serves as a buffer zone between the stormwater system and the Merri River and Merri Marine Sanctuary. This work considers the impact of stormwater inputs on Lake Pertobe and the effectiveness of the lake in protecting the associated marine sanctuary. Sediment contaminants (including heavy metals and polycyclic aromatic hydrocarbons (PAHs)) and water quality parameters within the lake, groundwater and stormwater system were measured. Water quality parameters were highly variable between stormwater drains and rain events. Suspended solids rapidly settled along open drains and shortly after entering the lake. Groundwater inputs increased both salinity and dissolved nitrogen in some stormwater drains. Some evidence of bioaccumulation of metals in the food chain was identified and sediment concentrations of several PAHs were very high. The lake acted as a sink for PAHs and some metals and reductions in Escherichia coli, biological oxygen demand and total phosphorus were observed, affording some protection to the associated marine sanctuary. Nutrient retention was inadequate overall and it was identified that managing the lake primarily as a recreational facility impacted on the effectiveness of stormwater treatment in the system.

The use of artificial biofilms to strip nutrients from an industrial smelters waste water under conditions of low temperature and high pH

The Victorian Environment Protection Authority (EPA) has identified Alcoa’s Point Henry aluminium smelter as being a major source of recognized pollutant input due to its disposal of effluent into Corio Bay. Historically, the water quality parameters that have most often exceeded Point Henry’s EPA limits have been pH and suspended solids from the smelter’s discharge points. These waste water discharges also experience high nitrogen and phosphorus concentrations which result in algal blooms that occur at the onset of warm weather. The main hypothesis of this study was that “prevention of algal blooming with the onset of warm weather by removal of nutrients during the cooler months, and continued removal thereafter, is better than curing the problems chemically”. Biofilms have been used to remove nutrients from waste waters, but not under the conditions experienced at Point Henry. The aim of this study, therefore, was to determine if significant biofilm growth would be observed on floating structures suspended in the Point Henry waste water stream during the cooler, winter months of the year. Statistically significant biofilm growth occurred on all suspended structures in all discharge ponds during the winter and early spring of 2000. The use of suspended structures, such as AquaMatTM, as an artificial substrate to attract and support periphyton and bacterial communities (biofilms), which are then able to out-compete phytoplankton communities for available nutrients, is therefore a viable option for the Point Henry smelter. However, further research on the competitive performance of biofilms in the Point Henry ponds during the summer months is required before adequate biofilm management strategies can be developed.

An investigation into the ion-exchange properties of chemically modified wool for use in water treatment and chromatography

This study was undertaken to investigate the suitability of natural and chemically treated wool fibres for use in water treatment and in the separation of constituents for monitoring contaminants in water.

Experimental work was carried out to determine the ability of natural and treated wool fibres to remove these constituents from water,

This study provided information on the characteristics of the wool fibre as a medium in water treatment.

Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe(2+) dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation.

Visible and UV functionality of TiO2 ternary nanocomposites on cotton

This research intends to increase the photocatalytic efficiency of cotton fabrics coated with TiO2-based nanocomposites under illumination particularly visible light. The fabrics were functionalized using a low-temperature sol-gel method of TiO2/Metal/SiO2 nanocomposite systems. Integrating silica and noble metals into TiO2 sol was put forth for boosting its functionality. Three noble metals (gold (Au), platinum (Pt) and silver (Ag)) with four different concentrations were employed. The photocatalytic activity of the functionalized fabrics was assessed through coffee stain-removal test and photodecomposition of methylene blue (MB) under UV and visible light. The impact of coating layers on fabrics' hydrophilicity was analyzed through measuring the water contact angle as well as the water absorption time. The fabrics were characterized using XRD, SEM and EDS. It was corroborated that the presence of silica enhanced the self-stain-removal capability of fabrics under UV. Moreover, the self-cleaning property of fabrics improved under both UV and visible light after integrating the metals into the colloids. In the same line, the self-cleaning activity threshold of fabrics was shifted to visible region.

Towards integrated anti-microbial capabilities: Novel bio-fouling resistant membranes by high velocity embedment of silver particles

Biofilm formation on membranes during water desalination operation and pre-treatments limits performance and causes premature membrane degradation. Here, we apply a novel surface modification technique to incorporate anti-microbial metal particles into the outer layer of four types of commercial polymeric membranes by cold spray. The particles are anchored on the membrane surface by partial embedment within the polymer matrix. Although clear differences in particle surface loadings and response to the cold spray were shown by SEM, the hybrid micro-filtration and ultra-filtration membranes were found to exhibit excellent anti-bacterial properties. Poly(sulfone) ultra-filtration membranes were used as for cross-flow filtration of Escherichia coli bacteria solutions to investigate the impact of the cold spray on the material[U+05F3]s integrity. The membranes were characterized by SEM-EDS, FT-IR and TGA and challenged in filtration tests. No bacteria passed through the membrane and filtrate water quality was good, indicating the membranes remained intact. No intact bacteria were found on hybrid membranes, loaded with up to 15. wt% silver, indicating the treatment was lysing bacteria on contact. However, permeation of the hybrid membranes was found to be reduced compared to control non-modified poly(sulfone) membranes due to the presence of the particles across the membrane material. The implementation of cold spray technology for the modification of commercial membrane products could lead to significant operational savings in the field of desalination and water pre-treatments.

Detection of endocrine disrupting chemicals in aerial invertebrates at sewage treatment works

Endocrine disrupting chemicals (EDCs) constitute a diverse group of chemical compounds which can alter endocrine function in exposed animals. Whilst most studies have focussed on exposure of wildlife to EDCs via aquatic routes, there is the potential for transfer into the terrestrial food chain through consumption of contaminated prey items developing in sewage sludge and waste water at sewage treatment works. In this study, we determine levels of EDCs in aerial insects whose larval stages develop on percolating filter beds at sewage treatment works. We compare absolute concentrations of known EDCs with those collected from aquatic environments not exposed to sewage effluent outflow. Our findings document for the first time that aerial invertebrates developing on sewage filter beds take up a range of chemicals thought to be incorporated from the sewage effluent, which act as endocrine disruptors. For two synthetic chemicals (17α-ethinylestradiol and butylated hydroxy aniline), concentrations were significantly higher in insects captured around percolating filter beds than sites over 2 km from the nearest sewage works. A number of species of insectivorous bats and birds, some of which are declining or threatened, use sewage works as principle foraging sites. We calculate approximate exposure levels for a species of bat known to forage within sewage works and suggest that further research is warranted to assess the ecological implications of consuming contaminated invertebrate prey

Effect of cold plasma pre-treatment on photocatalytic activity of 3D fabric loaded with nano-photocatalysts: response surface methodology

In this study, the physico-chemical effects occasioned by the cold plasma discharge (CPD) on the photo-decolorization of Reactive Orange 16 (RO16) by 3D fabrics (spacer fabrics) loaded with ZnO:TiO2 nano-photocatalysts (nphs) were optimized via response surface methodology (RSM). CPD was employed to improve the surface characteristics of the spacer fabrics for nphs loading. Surface morphology and color variation were studied utilizing scanning electron microscopy (SEM) and CIE-Lab system, respectively. The effect of CPD on the wetting ability of the spacer fabrics was examined using dynamic adsorption measurement (DAM). Also, X-ray fluorescence (XRF) was utilized to investigate the durability of the nphs on the spacer fabrics. All the experiments were implemented in a Box-Behnken design (BBD) with three independent variables (CPD treatment time, dye concentration and irradiation time) in order to optimize the decolorization of RO16. The anticipated values of the decolorization efficiency were found to be in excellent agreement with the experimental values (R2 = 0.9996, Adjusted R2 = 0.9992). The kinetic analysis demonstrated that the photocatalytic decolorization followed the Langmuir-Hinshelwood kinetic model. In conclusion, this heterogeneous photocatalytic process is capable of decolorizing and mineralizing azoic reactive dye in textile wastewater. Moreover, the results confirmed that RSM based on the BBD was a suitable method to optimize the operating conditions of RO16 degradation.