Evaluation of microplastic pollution in industrial wastewater and their biodegradation using a novel indigenous...

Microplastics (MPs) are an emerging environment pollutant that widely distributed across various environmental matrices and pose significant risks to marine biota, invertebrates and humans. Industrial wastewater sample was collected from the Urkura industrial area, Raipur, Chhattisgarh, India to evaluate the presence as well as biodegradation of microplastics. Microplastics were extracted and characterized for size, shape and colour using stereo and fluorescence microscopy, while polymer composition was identified using Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy (RS). The analysis revealed (PE) as the predominant polymer, mainly occurring in fibre and fragment forms. Other polymers including polypropylene (PP), polystyrene (PS), low density polyethylene (LDPE) and polyethylene terephthalate (PET) were also identified. Quantitative analysis revealed a mean concentration of 64±1 particles/L (64000 particles/m³). The microplastics exhibited different colors including blue, black, red, violet, brown, grey, green, orange, and transparent, with particle sizes from 50 µm to 5000 µm. A novel bacterial strain, Bacillus paralicheniformis strain PWDS (NR_137421.1), was isolated from soil sample obtained from a plastic dumping area located in Raipur. Biodegradation was carried out for 30 days and process parameters such as pH, temperature, inoculum volume and shaking speed were optimized. The bacterial strain showed a maximum degradation efficiency of about 8.4±0.4%. The study highlights presence of microplastics in wastewater and the efficiency of microbial approaches for effective microplastic bioremediation and environmental sustainability.