Dairy wastewater treatment employing microencapsulated Pseudomonas aeruginosa on low acyl gellan gum

Abstract

This study assessed the ability of Pseudomonas aeruginosa, microencapsulated in gellan gum, to decontaminate dairy wastewater and explored the potential reuse of microcapsules. P. aeruginosa was microencapsulated using the internal ionic gelation technique, employing low-acyl gellan gum as the wall material. The free and microencapsulated P. aeruginosa were inoculated into 150 mL of sterile wastewater and incubated in a shaking flask (150 rpm) at 30°C. Subsequently, the Baranyi Model was employed to calculate the growth parameters of P. aeruginosa. Concurrently, Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were determined. The obtained results indicated that the microencapsulation process reduced the growth rate of the encapsulated microorganism. However, the microencapsulated bacteria achieved COD and BOD reduction percentages of 61.54% and 64.05%, respectively. Similarly, when reusing the microcapsules, removal percentages exceeding 57.00% were achieved. These findings could have significant implications for the industry in terms of reducing effluent contamination caused by substantial amounts of pollutants. Keywords: dairy wastewater, gellan gum, microencapsulation, Pseudomonas aeruginosa.