High Performance of Asymmetric Alumina Hollow Fiber Membranes for the Clarification of Genipap (Genipa americana L.) Fruit Extract

The intelligent prediction of membrane fouling during membrane filtration by mathematical models and artificial intelligence models

Recently, membrane separation technology has been widely utilized in filtration process intensification due to its efficient performance and unique advantages, but membrane fouling limits its development and application. Therefore, the research on membrane fouling prediction and control technology is crucial to effectively reduce membrane fouling and improve separation performance. This review first introduces the main factors (operating condition, material characteristics, and membrane structure properties) and the corresponding principles that affect membrane fouling. In addition, mathematical models (Hermia model and Tandem resistance model), artificial intelligence (AI) models (Artificial neural networks model and fuzzy control model), and AI optimization methods (genetic algorithm and particle swarm algorithm), which are widely used for the prediction of membrane fouling, are summarized and analyzed for comparison. The AI models are usually significantly better than the mathematical models in terms of prediction accuracy and applicability of membrane fouling and can monitor membrane fouling in real-time by working in concert with image processing technology, which is crucial for membrane fouling prediction and mechanism studies. Meanwhile, AI models for membrane fouling prediction in the separation process have shown good potential and are expected to be further applied in large-scale industrial applications for separation and filtration process intensification. This review will help researchers understand the challenges and future research directions in membrane fouling prediction, which is expected to provide an effective method to reduce or even solve the bottleneck problem of membrane fouling, and to promote the further application of AI modeling in environmental and food fields.

Strategies to Enhance the Membrane-Based Processing Performance for Fruit Juice Production: A Review

Fruit juice is an essential food product that has received significant acceptance among consumers. Harmonized concentration, preservation of nutritional constituents, and heat-responsive sensorial of fruit juices are demanding topics in food processing. Membrane separation is a promising technology to concentrate juice at minimal pressure and temperatures with excellent potential application in food industries from an economical, stable, and standard operation view. Microfiltration (MF) and ultrafiltration (UF) have also interested fruit industries owing to the increasing demand for reduced pressure-driven membranes. UF and MF membranes are widely applied in concentrating, clarifying, and purifying various edible products. However, the rising challenge in membrane technology is the fouling propensity which undermines the membrane's performance and lifespan. This review succinctly provides a clear and innovative view of the various controlling factors that could undermine the membrane performance during fruit juice clarification and concentration regarding its selectivity and permeance. In this article, various strategies for mitigating fouling anomalies during fruit juice processing using membranes, along with research opportunities, have been discussed. This concise review is anticipated to inspire a new research platform for developing an integrated approach for the next-generation membrane processes for efficient fruit juice clarification.

Photoreduction of chromium(VI) in microstructured ceramic hollow fibers impregnated with titanium dioxide and coated with green algae Chlorella vulgaris

Here we propose an innovative photocatalytic hybrid system for the reduction of hexavalent chromium (Cr(VI)) from aqueous solutions. The hybrid system was composed of titanium dioxide (TiO₂) immobilized in the micro-voids of asymmetric alumina hollow fibers and of the green algae Chlorella vulgaris coated on the outer sponge-like layer of the fiber. The photoreduction of Cr(VI) was systematically studied in different systems: single systems with TiO₂ or algae; the synergistic system of algae combined with TiO₂; and the proposed hybrid system composed of TiO₂ and algae supported in ceramic hollow fibers. Morphological and energy dispersive spectroscopy analyses showed that TiO₂ and the algae were properly supported in the substrate (alumina hollow fibers). For an initial Cr(VI) concentration of 10 mg L^-1 and dosages of 1 g L^-1 of TiO₂ and algae, the hybrid system resulted in total Cr(VI) reduction after 16 h of process. Additionally, the efficiency of the hybrid system for Cr(VI) reduction was reduced in only 9% after 5 cycles of reuse and in 42% after 10 cycles of reuse. Thus, micro-structured ceramic hollow fibers impregnated with TiO₂ and decorated with the green algae C. vulgaris was efficient for Cr(VI) reductions.