Recent developments in carbon nanotube membranes for water purification and gas separation

Carbon nanotubes (CNTs) are nanoscale cylinders of graphene with exceptional properties such as high mechanical strength, high aspect ratio and large specific surface area. To exploit these properties for membranes, macroscopic structures need to be designed with controlled porosity and pore size. This manuscript reviews recent progress on two such structures: (i) CNT Bucky-papers, a non-woven, paper like structure of randomly entangled CNTs, and (ii) isoporous CNT membranes, where the hollow CNT interior acts as a membrane pore. The construction of these two types of membranes will be discussed, characterization and permeance results compared, and some promising applications presented.

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.

Performance evaluation and improved risk control philosophies for drinking water systems

World-wide, water is the single most used substance by humans every day. Water is also the major cause of illness and death in many countries including the affluent nations. Through this research, new risk control philosophies from catchment to consumers are highlighted. This thesis is about identifying the hazards, evaluating the risks and implementing controls to protect public health from drinking water.

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.

Alternative water strategies in public domains : innovative strategies in progress along North Terrace, Adelaide

Water sensitive design on our urban threshold is increasingly becoming topical. In Adelaide it is being driven by stormwater management strategies and economic efficiencies in a city that is beginning to embrace its Mediterranean environment, low water sustainability, and whether our showpiece public domains in Adelaide can afford large expanses of manicured lawns.

This paper reviews four projects in progress along the North Terrace in Adelaide. The first involves a major redesign of First Creek as it traverses Adelaide Botanic Garden to address stormwater management issues. The redesign includes strategies to control flash flooding, to cleanse stream water from pollutants, and to carefully incorporate a wetland system as an integral botanical and horticultural feature of a botanic garden. Further down North Terrace, the University of Adelaide is evaluating a scenario that will totally redesign Goodman Crescent, its picture-postcard promenade lawn. The scenario is to host an integrated water retention and water purification and cleansing system that will service independently of mains water an irrigation system and a waterfall. The proposal draws upon a similar strategy recently adopted by the South Australian Museum to capture and cleanse surface and roof water but place the installation and process on display as part of its overall biodiversity museum display that will unfold over the next five years under director Tim Flannery. The fourth example, in process at present, is to devise an integrated water system that may enable the Government House grounds to remove itself from dependence upon costly mains water to totally sustain its extensive gardens and lawns.

Importantly each project has similar threads: creative water maximization and purification use, and a desire to place these ‘installations’ on display as public statements of their commitment to water sustainability in Adelaide. But radically, here are four prominent cultural institutions readily willing to redefine the notion and traditional visual imagery of a ‘wetland’ on what is the main cultural boulevard of a capital city.

Template-free synthesis of functional 3D BN architecture for removal of dyes from water.

Three-dimensional (3D) architectures are of interest in applications in electronics, catalysis devices, sensors and adsorption materials. However, it is still a challenge to fabricate 3D BN architectures by a simple method. Here, we report the direct synthesis of 3D BN architectures by a simple thermal treatment process. A 3D BN architecture consists of an interconnected flexible network of nanosheets. The typical nitrogen adsorption/desorption results demonstrate that the specific surface area for the as-prepared samples is up to 1156 m(2) g(-1), and the total pore volume is about 1.17 cm(3) g(-1). The 3D BN architecture displays very high adsorption rates and large capacities for organic dyes in water without any other additives due to its low densities, high resistance to oxidation, good chemical inertness and high surface area. Importantly, 88% of the starting adsorption capacity is maintained after 15 cycles. These results indicate that the 3D BN architecture is potential environmental materials for water purification and treatment.

Solar photocatalytic oxidation system for colour removal in dyeing effluent

The effectiveness of various photocatalysts including titanium dioxide and other oxidants was investigated in a solar powered UV photocatalytic oxidation system for colour removal in dyeing effluent. A semi-empirical constant model and guidelines were developed to assist the design and to evaluate the full scale of the system.

Improved extraction of heavy metal ions using membrane technology

Investigates tha application of polymer membranes in industrial wastewater treatment. Several novel membrane systems have been developed. The new systems overcome the problems of low extractant capacity and slow rate of extraction of the traditional membrane system. These new systems offer significant scope for the treatment of industrial wastewater containing heavy metal ions.

Biobsorbent properties of biosolids for aqueous zinc, manganese and cyanide removal

Biosolids were used to remove zinc, manganese and cyanide from mining wastewaters. The effect of aqueous parameters and reaction variables on contaminant biosorption was quantified. The mechanism of removal was adsorption onto amine and carboxyl functional groups. Immobilisation was investigated to overcome problems of swelling and disintegration of the biosolids.

The effect of multi-feeding on trickling filter performance

Trickling filters have been used to treat wastewater for over 100 years. In this thesis, wastewater was introduced into laboratory trickling filters at 1 to 4 places simultaneously. Where traditional single feeding led to ponding, multi-feeding let to reduced ponding and improved removal of carbon and nitrogen.

Simultaneous removal of ammonia and phosphate from wastewater by precipitation of struvite using magnesia

A thorough investigation of conditions required for the precipitation of magnesium ammonium phosphate hexahydrate using magnesia as the source of magnesium was carried out and two computer models were used to make predictions as to optimum conditions for production of suitable crystal size and structure for a successful process. A process was developed and a bench scale model operated for a number of high ammonia wastes. Removal of ammonia was affected to levels of up to 97% with 94% ammonia removal being achievable consistently.

Ecological renovation of a constructed wetland

MasterFoods wetlands exhibit phytoplankton communities, yet no zooplankton to consume them. Macrophytes were planted to improve the water quality. However a lack of oxygen, methane production and highly soluble salts in the wetland water potentially disrupted osmoregulation mechanisms in both colonising zooplankton and submerged macrophytes, thereby inhibiting their survival.

DOC and UVA attenuation with soil aquifer treatment in the saturated zone of an artificial coastal sandfill

Results from a direct recharge experiment conducted in the field to investigate DOC and UVA(254) attenuation rates during the direct injection of UF treated wastewater into a artificial coastal sandfill are presented in this paper. Approximately 500 m(3) of ultra-filtered wastewater was injected into the saturated zone, over a period of 9 days. The movement of the plume was tracked over 80 days, during which time samples were obtained from multilevel samplers installed in transects across the drift axis of the plume. An analysis of fluorescein in the samples obtained during the drift of the UF plume showed that DOC and UVA were attenuated beyond rates predicted by conservative mixing, by up to a maximum of 45%. A degradation coefficient of 0.0175 day(-1) was found to be applicable for DOC degradation. After a drift period of 80 days, DOC and UVA reduced to approximately 4.5 mg/l and 0.100 cm(-1), respectively, from initial values of 8.06 mg/l and 0.199 cm(-1).