http://hdl.handle.net/10453/35200 2026-06-10T16:08:15Z http://hdl.handle.net/10453/195264 Title: Effects of Hydraulic Retention and Inorganic Carbon During Municipal Wastewater Treatment Using a Microalgal Bacterial Consortium Authors: Thiruchchelvam, T; Johir, M; Krishna, KCB; Sathasivan, A Abstract: Municipal wastewater (MWW) was treated using a microalgal–bacterial consortium without mechanical aeration. An inoculum for the reactor was prepared by acclimatizing Chlorella vulgaris to MWW and supplementing with a small amount of activated sludge. The hydraulic retention time (HRT) and solids retention time (SRT) were progressively reduced from 6.67 to 1.17 d and from 10 to 6.67 d, respectively, to test the process robustness under realistic MWW operation. The COD removal efficiency was 88% at 0.23 kg-COD/m3/d. Mass balance suggested the major nitrogen and phosphorus removal mechanism as assimilation. A high percentage (80%) of oxidized nitrogen indicated an efficient nitrification at all HRTs. Inorganic carbon (IC) balance calculation explained the observed IC dynamics. The chlorophyll a-to-mixed liquor volatile suspended solids (MLVSS) ratio and percentage of nitrite responded to IC limitation and supplementation. The mixed liquor exhibited excellent settleability (sludge volume index: 42 mL/g) with dense algal–bacterial flocs. An increased organic loading rate, however, reduced daytime dissolved oxygen, suggesting limitation under non-aerated conditions. These findings demonstrate the potential of microalgal–bacterial systems to achieve efficient COD removal and nitrification at realistic HRTs without aeration while emphasizing the importance of IC management. 2026-12-24T00:00:00Z http://hdl.handle.net/10453/195263 Title: Advanced geotechnical solutions for sustainable transportation infrastructure using waste materials Authors: Indraratna, B; Qi, Y; Ngo, T; Arachchige, CK Abstract: In view of worldwide national policies embracing the socio-economic and environmental perspectives of a circular economy, the Transport Research Centre at the University of Technology Sydney (UTS-TRC) has launched innovative measures of trialling recycled rubber derivatives in sustainable and innovative design of load-bearing substructure for railways in collaboration with industry. In this regard, this paper critically reviews two novel applications of recycled materials: (i) rubber intermixed ballast stratum (RIBS) to replace conventional rockfill, (ii) a hybrid track using recycled rubber tyre cells infilled with waste granular mixtures as an energy absorbing layer (REAL) which also provides additional confinement to the track substructure. Comprehensive laboratory tests using prototype cyclic triaxial testing rigs, the National Facility for High-speed Rail (NFHSR), and field tests have been conducted to examine the performance of these rubber inclusions. The tangible outcomes of laboratory and field tests reveal that the recycled rubber inclusions can act as energy reservoirs, thereby alleviating ballast breakage, deformation, and track acceleration, thus increasing the track stability. 2026-03-12T00:00:00Z http://hdl.handle.net/10453/195262 Title: Closure to "enhancing Rail Track Performance Using Recycled Rubber Energy-Absorbing Grids: Laboratory and Field Evidence" Authors: Hettiyahandi, S; Indraratna, B; Ngo, T; Qi, Y; Arachchige, C 2026-03-01T00:00:00Z http://hdl.handle.net/10453/195261 Title: Advances in capacitive deionization for selective lithium recovery from brines: Mechanisms, strategies, and future perspectives Authors: Yu, H; Phuntsho, S; Naidu, G; Askari, M; Shon, HK Abstract: The growing global demand for lithium, fueled by the expansion of electric vehicles and energy storage systems, calls for efficient and sustainable extraction technologies. Capacitive deionization (CDI) is emerging as a promising electrochemical method for lithium recovery from diverse aqueous sources, including low-grade brines, geothermal waters, and industrial effluents. By applying a low-voltage electric field, CDI captures lithium ions either through electrosorption onto porous electrodes or via intercalation into redox-active materials. Compared to conventional separation technologies, CDI offers distinct advantages such as low energy consumption, mild operating conditions, rapid adsorption kinetics, and scalable modular design. This review systematically summarizes recent advancements in CDI-based lithium extraction with a focus on research methodology. Key research strategies are categorized into four domains: structural engineering of electrodes, surface and interface modification, advanced material integration, and machine learning and simulation. Applications across various source solutions are discussed, and standard performance metrics such as adsorption capacity, selectivity, energy consumption, and cycling stability are outlined. The review concludes by identifying critical challenges and proposing future research directions that emphasize multifunctional electrode design, scalable fabrication, and data-driven material discovery. This work offers comprehensive guidance for advancing CDI technologies toward practical and sustainable lithium recovery. 2026-07-01T00:00:00Z