Designing turbulence promoters with optimal geometry and using them for ultrafiltration systems has been a key challenge in mitigating membrane fouling. In this study, six different turbulence promoters were created using three-dimensional printing technology and applied in dead-end ultrafiltration. Three-dimensional-printed (3DP) turbulence promoter configurations were integrated into a classical batch ultrafiltration cell. The effects of these configurations and the stirring speeds on the permeate filtration flux, organic rejections, and membrane resistances were investigated. The fouling control efficiency of the 3DP promoters was evaluated using two polyethersulfone membranes in a stirred ultrafiltration cell with model dairy wastewater. The Hermia and resistance-in-series models were studied to further investigate the membrane fouling mechanism. Of the Hermia models, the cake layer model best described the fouling in this membrane filtration system. It can be concluded that the 3DP turbulence promoters, combined with intense mechanical stirring, show great promise in terms of permeate flux enhancement and membrane fouling mitigation. Using a well-designed 3DP turbulence promoter improves the hydrodynamic flow conditions on the surface of the stirred membrane separation cells based on computational fluid dynamics modeling. Therefore, the factors effecting the fabrication of 3DP turbulence promoters are important, and further research should be devoted to revealing them.

Supercritical carbon dioxide (scCO2) is a non-toxic, inert, and widely used solvent in green chemistry, offering tunable properties such as density, diffusivity, viscosity, and polarity, adjustable through temperature, pressure, or co-solvent addition. This study employs the Design of Experiment (DoE) methodology to optimize scCO2-assisted synthesis of Li-S battery cathodes, presenting the first systematic investigation of how scCO2 conditions affect the structural and surface properties of reduced graphene oxide (rGO) during sulfur decoration. Results show that temperature and pressure significantly influence sulfur integration and cathode performance. By combining DoE with detailed electrochemical impedance analysis using complex nonlinear least squares fitting, the study provides deeper insight into composite electrochemical behavior under varying conditions. An optimal rGO structure with low charge transfer resistance, enabling efficient ion and electron transport, was obtained at 150 bar and 60 °C, balancing sulfur loading and pore accessibility. Conversely, harsher conditions (180 bar, 80 °C) caused sulfur agglomeration and higher resistance, reducing performance. These findings highlight the necessity of precisely controlling scCO2 synthesis parameters to enhance cathode structure and improve electrochemical performance and long-term stability of Li-S batteries.