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.

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.

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.

Integrated system for high quality water recovery and wastewater treatment

This thesis unveils an integrated system that once applied, could standardise and simplify the processes used for high quality water recovery and wastewater treatment. It forsees lower prices of desalinated and recovered water, in a streamlined and more efficient water industry, by departing from today's thinking of conventional wastewater treatment.

Ranking of pre-treatment technologies for reverse osmosis for water recovery

Agro-industries are a life-line for sustainable future of human kind. However, the wastewater generated by agro-industries poses direct threat to the same sustainable future by polluting the freshwater sources when discharged into those freshwater sources. Thus, we need both advanced treatment technologies to treat those wastewater streams generated and better reuse practices for the treated effluents. Reverse osmosis (RO) is one of the advanced treatments to treat dissolved solids that are present in agricultural wastewater streams. But, RO is very sensitive to suspended solids (SS) present in the wastewater streams. Those SS can foul the RO membrane and make it ineffective in producing treated effluent at desired rates. Therefore, suitable pre-treatment scheme is necessary to treat the agro-wastewater streams before passing through RO. This study focuses on the qualitative and quantitative ranking of the available conventional and modern pre-treatment technologies as pre-treatment for RO. This study considers wastewater that has been treated through a secondary treatment system for example activated sludge process as the target water that needs pre-treatment. Based on qualitative ranking of conventional pre-treatment options, the Lime clarification/Granular Media filtration (GMF) option is ranked as the best; whereas finescreens/ micro-screens option ranked as the least preferred option based on the scores they attained in treating the water quality parameters that are considered essential. Based on the quantitative ranking, the low pressure membrane technology such as ultra-filtration (UF) stood first and microfiltration (MF) stood last.

Application of floating medium filters for aquaculture wastewater treatment

Filtration is an effective process in removing particles of various nature and sizes that are present in water and wastewater. It has been used as a final clarifying step in water treatment since the19th century. It is becoming increasingly important in the tertiary treatment step of wastewater to produce effluent of superior quality for the purpose of reuse. Filtration is particularly applied when high flow rates of water with relatively low contents of suspended solids have to be treated. In a conventional water or wastewater treatment system, the filters are usually placed after sedimentation units to remove suspended particles, which escape without settling in the sedimentation units. When chemically pretreated and flocculated water is applied to a filter without a prior-solid liquid separation it is called direct filtration.

Fouling in reverse osmosis (RO) membrane in water recovery from secondary effluent : a review

Reverse osmosis (RO) is the most preferable process for water recovery from secondary effluent (SE) because of its higher rejection of impurities with lower associated cost and higher quality of product. Fouling still is a major challenge during the water recovery due to higher contaminant loadings in SE and high rejection capability of this membrane. The presence of suspended solids, colloidal and organic matters, and high level of biological activities in SE further elevate fouling potentiality. This review was performed to identify major foulants causing hindrance in sustainable application of reverse osmosis and to present available pre-treatment options for these foulants. There are four fouling types present in RO namely; bio-fouling, inorganic/scaling, organic, and particulate fouling. Among them; bio-fouling is less understood but dominant since the pre-treatment options are not well developed. Other fouling mechanisms have been overcome by well developed pre-treatments. The major foulants for RO are dissolved and macromolecular organic substances, sparingly soluble inorganic compounds, colloidal and suspended particles, and micro-organisms. Some of these potential fouling water quality parameters (PFWQPs) are interrelated with each others such as electrical conductivity is a surrogate measure of total dissolved solids with established stable relationship. Most of these PFWQPs such as total suspended solids, turbidity, chemical oxygen demand can be removed by conventional pre-treatment; some such as colloidal particles and micro-organisms by modern options and even others such as endocrine disrupting compounds, pharmaceutical and personal care products are still challenging for current pre-treatments. These foulants need to be identified properly to integrate appropriate pre-treatments for minimizing fouling potentiality to increase water recovery at minimal costs.

Corrosion impact on drinking water distribution systems : a review and future research direction

At present water treatment and distribution is of high priority to ensure that communities have access to safe and affordable drinking water. Current information states that in the United States a total annual cost of $36 billion (US) is spent replacing aging infrastructure, lost water from unaccounted-for leaks, corrosion inhibitors, internal mortar linings, external coatings, and cathodic protection as a result of corrosion. In order to reduce the cost incurred as a result of corrosion in the water distribution industry, it is essential that better corrosion management and preventative strategies are implemented. However through investigation of research previously undertaken by others, it was found that there was a lack of study of corrosion within distribution systems in the tropics taking into account the related seasonal temperature variations. To assist in the development of management strategies to improve the outcomes of drinking water distribution systems, the authors propose to implement a pilot study involving the installation of a corrosion reactor based on standard corrosion assessment technologies in a water distribution system located in the tropics.

Modeling bacterial growth in drinking water : effect of nutrients

This article presents a model of growth of naturally occurring heterotrophic bacteria in the bulk water phase in the absence of disinfectant. The model considers growth with carbon, phosphorus, and nitrogen balance, death and lysis of bacteria, and conversion of less biodegradable organic carbon to assimilable organic carbon. Experimental data from two raw and two treated waters were used to test the model. The model describes the increase of live and dead bacterial cells in the water phase, and its output closely matches the experimental data. Such a model has the ability to characterize water nutrient status as well as to predict behavior of indigenous heterotrophic bacteria. The ability to predict bacterial population dynamics with respect to nutrients is beneficial for water treatment optimization. The model, based on microbiological measurements, helps to characterize treated water quality and project performance in terms of water quality into a distribution system.

Sydney 1998 - lessons from a drinking water crisis

From July to September 1998, high concentrations of Cryptosporidium and Giardia were detected episodically in the water supply and distribution systems of Sydney, Australia. The resulting drinking water crisis triggered three consecutive boil-water advisories and a government inquiry into the management of the water supply. The episodic nature of the detections focused attention on the veracity of the laboratory results and triggered an investigation of the transport of these pathogens in Sydney's water supply system. This article provides information submitted to the Sydney Water Inquiry that explains the episodic occurrence of pathogens in the reticulated water supply, attributing it to rapid fluctuations in the quality of the water reaching the water treatment plant