Reduction of Primary Microplastic in Nitrifying Medium under Closed System

Abstract

Currently, microplastic is considered a major concern worldwide and noteworthy among the researcher and authorities. Microplastic has spread ubiquitously in the environment, particularly in the aquatic system, due to its tiny size. This microplastic is indispensable to treat since it poses hazards to marine life, human, and soil-plant. This research paper aims to investigate the performance of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polystyrene (PS) microplastic in a closed system. This microplastic has been biodegraded in the batch culture system using a colony of bacteria acquired from landfill leachate as a carbon source. The percentage of microplastic removal after the incubation period (7, 14, and 21 days) was determined. Moreover, the analysis of chemical properties, morphology surfaces of microplastic, and ammonia-nitrogen for each batch culture were evaluated. The findings revealed that all microplastic could be degraded after the incubation period. However, PE microplastic showed the highest percentage weight loss (8.8%) compared with other microplastic. Analysis by Fourier transform infrared spectroscopy demonstrates that the chemical structure of each polymer has changed, which involved the formation of C=O in PP and PE. The observation by scanning electron microscope indicated the alteration on the surface in each microplastic, such as fractures and rough surfaces. Besides that, PP microplastic indicated the maximum ammonia-nitrogen removal after 16 days incubation period (97.41%). This method can be applied in the leachate treatment system to achieve a higher quality of effluent. Furthermore, extending the incubation period for microplastic biodegradation can attain better optimal results in further research.