Harnessing biodegradation potential of rapid sand filtration for organic micropollutant removal from drinking water: A review

Abstract

A cost-effective approach for efficient organic micropollutants (OMPs) removal is to optimize existing infrastructure at drinking water treatment plants. A promising option is rapid sand filtration (RSF), as OMPs removal has been observed in this treatment technology. However, the mechanisms and pathways involved are not fully understood and strategies to optimize removal have yet to be thoroughly explored. Therefore, this article firstly described basic RSF functions that can support OMPs removal. OMPs can be removed by chemical and biological Mn/Fe oxides or degraded co-metabolically by ammonia oxidizing bacteria and methane oxidizing bacteria. In addition, heterotrophic bacteria can metabolically transform OMPs and their transformation products. Then, we reviewed current literatures described OMPs removal in RSF, showing biodegradation can contribute significantly to OMPs removal. Thereafter, we presented strategies to improve OMPs biodegradation, including bioaugmentation, optimizing hydraulic conditions by adjusting contact time and backwashing intensity, and adding biocarriers to retain biomass during rapid flow rates. Finally, we provided recommendations for further research towards optimizing and maintaining OMPs removal in RSF for safe drinking water production. This review therefore gives a critical evaluation of RSF-based technologies for OMPs removal from drinking water and provides recommendations for further improving OMPs removal in RSF.

Performance of Modified Slow Sand Filter to Reduce Turbidity, Total Suspended Solids, and Iron in River Water as Water Treatment in Disaster Areas

“…The adsorption process occurs because there is a diffusion process so that the adsorbate is adsorbed. In addition, there is an attachment mechanism caused by the van der Walls force (Wang et al, 2020). Silica sand and shells of Anadara granosa have a negative (-) charge, so they can attract positively (+) charged particles such as cations from iron molecules (Fitriani et al, 2022).…”

Removal of organic micropollutants in a drinking water treatment plant by powdered activated carbon followed by rapid sand filtration

“…The involved removal mechanisms by RSF encompass a complex mixture of physical-chemical processes, e.g. adsorption onto sand material, and biological processes [28]. However, since sand is not a good adsorbent material, the adsorption of OMPs onto the sand particles mainly correlated with the retention time [47].…”

“…Although rapid sand filters are not specifically designed for the removal of OMPs, many studies indicated that they have the potential to degrade several different OMPs [26,27]. These studies reported that for most OMPs adsorption onto sand material [28] and biodegradation by bacteria (autotrophic and heterotrophic) ( [26,29] are the most important removal mechanisms by RSF. Although it is challenging to separate the OMPs removal by adsorption from biodegradation in RSF [28], the studies showed that biodegradation is the dominating removal process in RSF [27,30].…”

Microbial ecology of biofiltration used for producing safe drinking water

“…In RSF, large amounts of nutrients are introduced into the filter bed, supporting rapid accumulation of the microbial community. This community includes nitrifying bacteria, methane-oxidising bacteria, iron-oxidising bacteria, and heterotrophic bacteria that were found to play important roles in degrading and removing ammonium, methane, and bentazone and in co-metabolising various organic micropollutants (such as CECs and naturally produced organic compounds) (de Vet et al 2011 ; Wang et al 2020 ). However, biomass accumulation (and also metal precipitates) in the filter leads to clogging and thus decreases the filtration rate over time (Maurya et al 2020 ).…”