Water Supply (Aug 2021)

Performance of rapid sand filter – single media to remove microplastics

  • Emenda Sembiring,
  • Mutiara Fajar,
  • Marisa Handajani

DOI
https://doi.org/10.2166/ws.2021.060
Journal volume & issue
Vol. 21, no. 5
pp. 2273 – 2284

Abstract

Read online

Microplastics (MPs) have been detected in drinking water and raw water sources. Therefore, it is important to know the performance of drinking water treatment process. The rapid sand filter (RSF) is one of the water treatments that can be an alternative treatment in removing MPs after several configuration processes (pre-sedimentation, coagulation-flocculation, and sedimentation). This study aims to determine the effectiveness of RSF to remove MPs. The artificial samples were made from plastics bags and tyre flakes, with sizes from 10 μm to more than 500 μm. Bentonite was added to represent turbidity in the water. The average removal efficiency of plastics flakes before entering the filter was 50.48% (using bentonite) and 47.78% (without bentonite). Overall, the removal efficiency for the tyre flakes was 90.72% (using bentonite) and 93.03% (without bentonite). The filtration used in this study was varied between 4 and 10 m/h. Removal efficiency using RSF for plastic flakes on which the Effective Size (ES) filter media 0.39 mm was 97.7% and on which ES 0.68 mm was 94.3%. Meanwhile, the removal efficiency of the tyre flakes for ES 0.39 mm were 90.6% and ES 0.68 mm was 85.2%. However, in this study, RSF mostly removed MPs particles greater than 200 μm in size. HIGHLIGHTS Mostly MPs >= 200 μm can be removed by using a conventional rapid sand filter.; Increased turbidity will not increase the efficiency of MPs removal.; Part of the MPs can also be removed in coagulation and flocculation.; Size of MPs is important for the surface screening mechanism.;

Keywords