No 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.

Landfill leachate contains high concentration of contaminants in the form of nitrogen, suspended solids and heavy metals, which effects the environment adversely. Hence leachate treatment is considered vital in landfill management as the effluent needs to undergo several treatments before being discharged into natural water bodies. Without treatment, the leachate will contaminate the surface and ground water as it can penetrate through soils and subsoils. Several methods have been applied for the treatment of landfill leachate. However, these methods have several constraints due to area required and cost incurred. This paper presents the application of electrocoagulation in removing pollutants from landfill leachate; particularly ammonia-nitrogen and heavy metals. Three metals namely aluminium, iron and zinc were used as electrodes. Aluminium electrode was found to be the most effective where it was capable to extract 89% of zinc and 75% of iron in 30-minute retention time. Subsequently, 93% of zinc and 83% of iron was removed in 120 minutes. In addition, 93% of ammonia-nitrogen was also removed. These results led to a conclusion that the electrocoagulation had the capacity to remove heavy metals and ammonia-nitrogen present in landfill leachate.

Plastic waste has become a sensitive issue in the world since this material needs a longer time to degrade. This material will take a month to a thousand years to decompose. Thus, would contribute to the environment pollution, which will affect human health and aquatic life. This research study focused on the biodegradation process of micro-plastic (PE, PP, PET and PS) in the batch culture system using a colony of bacteria obtained from leachate in Ayer Hitam Landfill, Puchong. After the batch experiment of micro-plastic degradation, percentage removal of ammonia-nitrogen, chemical structure and percentage weight loss were examined and evaluated. Succeeding through the incubation of micro-plastic in batch culture for fourteen (14) days period, biodegradation was verified by the estimation of the dry weight loss. From the result obtained, dry weight loss of polyethylene (PE) is the highest (3.46%) in 14 days and polyethylene (PE) shows the greater removal of ammonia nitrogen (NH3 -N) (44.17%). Besides that, polystyrene (PS) micro-plastic showed a significant change in chemical structural which was obtained by Fourier Transform Infrared (FTIR). Here, the new absorption peak C=O (aldehydes) was present in PS micro-plastic. Furthermore, PS micro-plastic has a high percentage mass loss in the second stage of thermal degradation by Thermogravimetric (TGA) analysis. It can be concluded that incubation time is needed to optimize the micro-plastic in the biodegradation process.