The project‐based learning (PBL) methodology has proven to be a valuable pedagogical approach in engineering programs for decades. However, a significant gap remains in the application of such methodologies in the field of bioprocess engineering. This study addresses this gap by exploring the implementation and outcomes of innovative PBL methodology in the context of bioprocess engineering education. The educational innovation involved the study of a bioprocess at the industrial scale, which comprises the definition of the culture medium, the operational units of the process, the design of the bioreactor with the assistance of MATLAB software, and the performance of a techno‐economic analysis. The results over eight academic years (441 students) demonstrated consistently high average grades in case studies (8.9 ± 0.3 out of 10), indicating successful student navigation of PBL challenges. The students’ positive feedback highlighted the satisfaction and effectiveness of the methodology in promoting collaboration, enhancing comprehension, and preparing students for real‐world scenarios. Overall, this study provides valuable insights into the successful implementation of PBL in bioprocess engineering education, highlighting its potential for fostering active learning, practical skill development, and student engagement. These findings contribute to the growing body of literature on innovative pedagogical approaches in engineering education and underscore the importance of ongoing evaluation and refinement for enhancing student learning outcomes.

This study explores an eco-friendly method for recovering platinum group metals from a synthetic automotive three-way catalyst (TWC). Bioleaching of palladium (Pd) using the thiosulfate-copper-ammonia leaching processes, with biogenic thiosulfate sourced from a bioreactor used for biogas biodesulfurization, is proposed as a sustainable alternative to conventional methods. Biogenic thiosulfate production was optimized in a gas-lift bioreactor by studying the pH (8–10) and operation modes (batch and continuous) under anoxic and microaerobic conditions for 35 d. The maximum concentration of 4.9 g S2O3²⁻ L⁻¹ of biogenic thiosulfate was reached under optimal conditions (batch mode, pH = 10, and airflow rate 0.033 vvm). To optimize Pd bioleaching from a ground TWC, screening through a Plackett–Burman design determined that oxygen and temperature significantly affected the leaching yield negatively and positively, respectively. Based on these results, an optimization through an experimental design was performed, indicating the optimal conditions to be Na2S2O3 1.2 M, CuSO4 0.03 M, (NH4)2SO4 1.5 M, Na2SO3 0.2 M, pH 8, and 60 °C. A remarkable 96.2 and 93.2% of the total Pd was successfully extracted from the solid at 5% pulp density using both commercially available and biogenic thiosulfate, highlighting the method’s versatility for Pd bioleaching from both thiosulfate sources.

Acid bioleaching of Al by Acidithiobacillus thiooxidans has been explored as an environmentally friendly pretreatment to facilitate the extraction of platinum group metals from spent three-way catalysts (TWC). Biogenic sulfur obtained from desulfurization bioreactors improved the production of acid by A. thiooxidans compared to commercially available elemental sulfur. The lixiviation abilities of bacteria-free biogenic acid and biogenic acid with exponential or stationary phase bacteria were compared against a control batch produced by commercial H2SO4. The maximum Al leaching percentage (54.5%) was achieved using biogenic acids with stationary-phase bacteria at a TWC pulp density of 5% w/v whereas bacteria-free biogenic acid (23.4%), biogenic acid with exponential phase bacteria (21.7%) and commercial H2SO4 (24.7%) showed lower leaching abilities. The effect of different pulp densities of ground TWC (5, 30, and 60% w/v) on Al leaching and bacterial growth was determined. While greater Al leaching yields were obtained at lower TWC pulp density solutions (54.5% at 5% w/v and 2.5% at 60% w/v), higher pulp densities enhanced microbial growth (2.3 × 109 cells/mL at 5% w/v and 9.5 × 1010 cells/mL at 60% w/v). The dissolution of the metal from the solid into the liquid phase triggered the production of biological polymeric substances that were able to absorb traces of both Al (up to 24.80% at 5% w/v) and Pt (up to 0.40% at 60% w/v).