Design of an Efficient Model for Microplastic Removal in Wastewater using Advanced Filtration, Nanotechnology, and Bioremediation

Abstract

Introduction: The escalating prevalence of microplastics in wastewater poses a formidable environmental challenge, necessitating innovative solutions beyond conventional treatment methodologies. Existing wastewater treatment frameworks exhibit limitations in microplastic removal, primarily due to insufficient removal efficiency, low adsorption capacity, and inadequate selectivity. Moreover, these systems often fall short in enhancing the biodegradation rate of microplastics, leading to persistent environmental contamination.

Objectives: This study introduces an integrated approach that synergistically combines advanced filtration materials, nanotechnology applications, and bioremediation techniques, aiming to address the deficiencies in conventional treatment methodologies.

Methods: In this novel model, bio-based filter media, specifically chitosan and alginate beads, are employed for their intrinsic high adsorption capacity, biodegradability, and affinity towards microplastic particles. Nanotechnology is harnessed through Carbon Nanotubes (CNTs) and magnetic nanoparticles, such as iron oxide variants like magnetite or maghemite. CNTs are functionalized to augment selectivity towards specific microplastic types. Magnetic nanoparticles facilitate the expedient separation of adsorbed microplastics from water, leveraging their magnetic characteristics. Bioremediation is incorporated via enzyme-based degradation and microbial remediation. Enzymes like laccase and manganese peroxidase are immobilized on filtration materials, catalysing breakdown of microplastics into less harmful substances. Concurrently, the integration of microorganisms capable of plastic degradation bolsters the biodegradation process.

Results: The proposed model markedly elevates the removal efficiency of microplastics to over 95%, a significant advancement over current standards. The advanced filtration materials exhibit an enhanced adsorption capacity of 10-20 mg/g. Furthermore, the rate of biodegradation of microplastics is accelerated by 30-50%, outpacing natural degradation rates. The system also boasts improved selectivity for diverse microplastics, achieving a specificity rate of over 80%. Post-treatment water quality sees substantial improvements in parameters like turbidity, COD, and BOD, with targets such as <5 NTU for turbidity, and reductions in COD and BOD by >70% and >60%, respectively. Operational stability is ensured for 6-12 months, minimizing the need for frequent maintenance. Additionally, the energy consumption for the treatment process is maintained below 0.5 kWh/m³, making it economically viable and environmentally sustainable for different use cases.

Conclusions: This integrative approach stands as a pivotal advancement in wastewater treatment, presenting a scalable, efficient, and eco-friendly solution to the microplastics crisis. Its implications extend beyond mere environmental remediation, potentially fostering healthier ecosystems and safeguarding public health, thereby contributing significantly to global environmental sustainability efforts for real-time scenarios.