Assessment of Conventional Water Treatment Plant Efficiency in Removing Microplastic Pollutants: A Case Study of Mtoni CWTP, Dar es Salaam
DOI:
https://doi.org/10.47941/je.3874Keywords:
Microplastics, Water Treatment Plant, Removal EfficiencyAbstract
Purpose: Microplastics are defined as plastic particles smaller than 5 mm. This study explores the MP’s presence, and efficiency of a conventional water treatment plant (CWTP) in removing microplastic pollutants, in Dar es Salaam, Tanzania.
Methodology: Field sampling was conducted at three treatment stages, at the raw water abstraction point at Kizinga river, after clarification stage, and after filtration (RSF). Microplastics concentrations in raw water were 22,000± 4714 particles/ m³ during dry season and 13333±943 particles/ m3 during rainy season.
Findings: The Conventional water treatment plant (CWTP) achieved overall microplastic removal efficiency between 70% and 81% with rapid sand filtration contributing significantly to removal, while clarification showed variable performance. Despite significant reduction, microplastics were still present in treated water, indicating incomplete removal with concentrations ranging 6667±3771 particles/m3 in dry season and 2500±236 particles/m3 in rainy season. Microplastics identified included both primary (pellets) and secondary forms (fibres, fragments, films), with polypropylene and polyethylene being the dominant polymers.
Unique Contribution to Theory, Policy and Practice: This study demonstrates that while conventional treatment processes reduce microplastic loads, they are not fully effective, particularly for smaller particles. Findings provide critical baseline data for improving water treatment performance and informing policy on emerging contaminants in Tanzania.
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