Engineering education down under : distance teaching at Deakin University, Australia

Deakin University in Australia is one of the leading providers of distance education in the South Pacific region. The School of Engineering offers four-year professional engineering-degree programs and three-year technologist programs. The over 600 total students studying engineering at Deakin fall into four categories:&bull; 18-19 year-old students fresh from high school, who largely study on-campus,&bull; older students in the technical workforce, seeking a university degree to upgrade their qualifications,&bull; industry-based students studying in university-industry partnership programs,&bull; overseas students studying either on-campus, or off-campus through education partners in Malaysia and Singapore.Geographically these students form a very wide student base. The study programs are designed to produce multi-skilled, broadly focused engineers and technologists with multi-disciplinary technical competence, and the ability to take a systems approach to design and operational performance. A team of around 25 academic staff deliver courses in seven different majors in the general fields of manufacturing, environmental engineering, mechatronics, and computer systems. We discuss here the history of the School, its teaching philosophy, and its unique methods in delivering engineering education to a widely scattered student body.<br /

Reduction of sodium strengths in wastewater streams from food and beverage industries

Book section was presented as a paper at the 4th International Conference on "Challenges in Environmental Science & Engineering", held at Taiwan City during 25-30 September 2011.\u

Comparison of fouling mechanisms in low-pressure membrane (MF/UF) filtration of secondary effluent

Membrane filtration in municipal wastewater treatment is being increasingly used to improve the quality of water and increase the productivity of existing plants. However, membrane fouling encountered in reclamation of municipal wastewater represents serious design and operational concern. There are several fouling models which are being developed and used as a powerful tool to increase the understanding of the fouling mechanisms and its key characteristics that influence the design of optimal process and operating conditions. This study investigates and compares the fouling mechanisms of three different types of polymeric and ceramic ultrafiltration (UF) and microfiltration (MF) membranes in the recovery of water from secondary effluent. The result demonstrated that ceramic UF membrane produced very high quality of water compared to polymeric UF and ceramic MF membranes. Out of four fouling models used to fit the experimental flux data, cake filtration and pore narrowing and complete pore blocking models predicted the initial fluxes of polymeric UF membrane more accurately. On the other hand, the cake filtration and pore narrowing models predicted the performance of ceramic UF membrane. Whereas, pore narrowing model predicted the performance of ceramic MF membrane more precisely compared to other three models. Further, the application of unified membrane fouling index (UMFI) was used to assess the fouling potential of the membranes. Good agreement between UMFI and other models was found. &copy; 2013 Copyright Balaban Desalination Publications.<br /

Sodium adsorption using activated alumina for application in the dairy industry

Basic activated alumina with negatively charged surface is considered as a potential adsorbent for a targeted molecule with positive polarity. Adsorption of sodium by basic activated alumina was investigated as a method for desalting dairy waste streams, in which sodium ion concentration averaged 600 mg/L. Sodium equilibrium and kinetic adsorption were investigated using basic activated alumina with synthetic brines. The results of equilibrium adsorption show that uptake of sodium by activated alumina is significantly higher when the pH is greater than 8 and increases as the pH of the brines increases until pH reaches around 10. The results of kinetic adsorption show that 90 hours were needed to reach equilibrium for sodium adsorption. Binding and diffusion processes are suggested to have taken place within the activated alumina.<br /

Tuning nanofiltration membrane performance: OH–MoS2 nanosheet engineering and divalent cation influence on fouling and organic removal

Natural organic matter (NOM) present in surface water causes severe organic fouling of nanofiltration (NF) membranes employed for the production of potable water. Calcium (Ca2+) and magnesium (Mg2+) are alkaline earth metals present in natural surface water and severely exacerbate organic fouling owing to their ability to cause charge neutralization, complexation, and bridging of NOM and the membrane surface. Hence, it is of practical significance to engineer membranes with properties suitable for addressing organic fouling in the presence of these cations. This study employed OH-functionalized molybdenum disulphide (OH–MoS2) nanosheets as nanofillers via the interfacial polymerization reaction to engineer NF membranes for enhanced removal of NOM and fouling mitigation performance. At an optimized concentration of 0.010 wt.% of OH–MoS2 nanosheet, the membrane was endowed with higher hydrophilicity, negative charge and rougher membrane morphology which enhanced the pure water permeance by 46.33% from 11.2 to 16.39 L m−2 h−1 bar−1 while bridging the trade-off between permeance and salt selectivity. The fouling performance was evaluated using humic acid (HA) and sodium alginate (SA), which represent the hydrophobic and hydrophilic components of NOM in the presence of 0, 0.5, and 1 mM Ca2+ and Mg2+, respectively, and the performance was benchmarked with control and commercial membranes. The modified membrane exhibited normalized fluxes of 95.09% and 93.26% for HA and SA, respectively, at the end of the 6 h filtration experiments, compared to the control membrane at 89.71% and 74.25%, respectively. This study also revealed that Ca2+ has a more detrimental effect than Mg2+ on organic fouling and NOM removal. The engineered membrane outperformed the commercial and the pristine membranes during fouling tests in the presence of 1 mM Ca2+ and Mg2+ in the feed solution. In summary, this study has shown that incorporating OH–MoS2 nanosheets into membranes is a promising strategy for producing potable water from alternative water sources with high salt and NOM contents

Functionalized MoS2 nanosheets enabled nanofiltration membrane with enhanced permeance and fouling resistance

In this study, a novel thin film nanocomposite (TFN) membrane incorporated with -OH functionalized molybdenum disulfide (OH-MoS2) nanosheets was fabricated through interfacial polymerization between piperazine (PIP) and trimesoyl chloride (TMC) by addition of nanosheets in the aqueous phase. The physicochemical characterizations of the resultant TFN membrane confirmed the embedding of OH-MoS2 nanosheets and showed excellent compatibility with polypiperazine amide (PPA) matrix, as well as the nanosheets incorporation significantly increased the hydrophilicity, negative charge, surface roughness. In addition, the hydroxyl groups attached to the MoS2 nanosheets can be covalently bonded into the skin layer through its reaction with TMC, promoting excellent compatibility with the polymer matrix. At an optimum concentration of 0.010 wt% OH-MoS2, the TFN membrane exhibited 45.17% increase in pure water flux (84.14 L m−2 h−1) when compared to control membrane (57.96 L m−2 h−1) and maintained stable salt rejection for Na2SO4 (96.67%). This optimized TFN membrane exhibited high normalized flux of 96.92% when compared to 91.22% for control membrane and high flux recovery ratio of 98.88% was maintained as well as enhanced organic removal at 89.14% in terms of dissolved organic carbon (DOC) and 99.2% as ultraviolet absorbance at 254 nm (UV254) was recorded during 6 h filtration studies with humic acid containing feed water. 0.010 wt% OH-MoS2 incorporated membranes exhibited enhanced permeance, salt rejection and stability along with excellent fouling resistance and organic removal demonstrating the potential of OH-MoS2 nanosheets for engineering high performance and fouling resistant TFN NF membranes for water treatment

Removal of natural organic matter from surface water sources by nanofiltration and surface engineering membranes for fouling mitigation – a review

Given that surface water is the primary supply of drinking water worldwide, the presence of natural organic matter (NOM) in surface water presents difficulties for water treatment facilities. During the disinfection phase of the drinking water treatment process, NOM aids in the creation of toxic disinfection by-products (DBPs). This problem can be effectively solved using the nanofiltration (NF) membrane method, however NOM can significantly foul NF membranes, degrading separation performance and membrane integrity, necessitating the development of fouling-resistant membranes. This review offers a thorough analysis of the removal of NOM by NF along with insights into the operation, mechanisms, fouling, and its controlling variables. In light of engineering materials with distinctive features, the potential of surface-engineered NF membranes is here critically assessed for the impact on the membrane surface, separation, and antifouling qualities. Case studies on surface-engineered NF membranes are critically evaluated, and properties-to-performance connections are established, as well as challenges, trends, and predictions for the field's future. The effect of alteration on surface properties, interactions with solutes and foulants, and applications in water treatment are all examined in detail. Engineered NF membranes containing zwitterionic polymers have the greatest potential to improve membrane permeance, selectivity, stability, and antifouling performance. To support commercial applications, however, difficulties related to material production, modification techniques, and long-term stability must be solved promptly. Fouling resistant NF membrane development would be critical not only for the water treatment industry, but also for a wide range of developing applications in gas and liquid separations

Performance of reverse osmosis (RO) for water recovery from permeates of membrane bio-reactor (MBR)

In this study, permeate from a hollow fiber polyethylene (PE) membrane bio-reactor (MBR) system treating synthetic agricultural wastewater was fed into a cellulose acetate brackish water reverse osmosis (BWRO30 2540) membrane system; three different trans-membranes pressures (TMPs) of 1000, 2500, and 4000 kPa were selected to evaluate the system performance in terms of general operating parameters as well as the removal of chosen important potential fouling water quality parameters. The results showed that highest corrected permeate flux rate was at a TMP of 2500 kPa, whereas lowest recorded at a TMP of 4000 kPa. Similar situation prevailed in water recovery rate. But temperature corrected specific fluxes decreased as the applied TMPs increased. In all selected TMPs, more than 96% of salinity was removed. Permeate from MBR as feed to reverse osmosis required frequent chemical cleaning than the microfiltration/ultrafiltration (MF/UF) permeates and granular media filter (GMF) filtered in order to maintain the required rate of product water. One of the reasons for this frequent chemical cleaning is due to higher total organic carbon as well as total nitrogen (TN) in the MBR permeate. This result needs to be further evaluated through field trials. <br /