Effects of phosphate and hydrogen peroxide on the performance of a biological activated carbon filter for enhanced biofiltration

Abstract

Biofilm formation on biofilters can influence their hydraulic performance, thereby leading to head loss and an increase in energy use and costs for water utilities. The effects of a range of factors, including hydrogen peroxide and phosphate, on the performance of biological activated carbon (BAC) and biofilm formation were investigated using laboratory-scale columns. Head loss, total carbohydrates, and proteins were reduced in the nutrient-enhanced, oxidant-enhanced, and nutrient + oxidant-enhanced BAC filters. However, there were no changes in the removal of dissolved organic matter, trihalomethane formation potential, or selected trace organic contaminants. The biofilm formation on polyvinyl chloride and stainless steel coupons using the laboratory biofilm reactor system was lower when the effluent from a nutrient-enhanced column was used, which indicated that there was less biofilm formation in the distribution systems. This may have been because the effluent from the nutrient-enhanced column was more biologically stable. Therefore, enhanced biofiltration could be used not only to reduce head loss in biofilters, but also to delay biofilm formation in distribution systems.

Phosphate Dosing in Drinking Water Distribution Systems Promotes Changes in Biofilm Structure and Functional Genetic Diversity

“…In this study, biofilms obtained from phosphate treatment samples showed less total cells (Figure 2) and restricted/limited development on coupon surfaces when they were observed by SEM (Figure 3). Contrary to these results, other studies in drinking water related systems, reported an increase of cells in biofilms developed under different phosphate treatments (Fang et al, 2009;Noh et al, 2019). An explanation for these contradictory results might be that these studies were performed using annular bioreactors (Fang et al, 2009) and biological FIGURE 7 | Heatmap with the relative abundance of annotated genes in the whole metagenome of each of the sequenced samples.…”

“…activated carbon columns (Noh et al, 2019) where biofilms were less exposed to hydraulic forces than under representative hydraulic conditions in DWDS. Besides, previous studies have shown that the addition of phosphate in drinking water can reduce the synthesis of EPS by biofilms (Fang et al, 2009;Kirisits et al, 2013;Liu et al, 2016;Noh et al, 2019).…”

“…activated carbon columns (Noh et al, 2019) where biofilms were less exposed to hydraulic forces than under representative hydraulic conditions in DWDS. Besides, previous studies have shown that the addition of phosphate in drinking water can reduce the synthesis of EPS by biofilms (Fang et al, 2009;Kirisits et al, 2013;Liu et al, 2016;Noh et al, 2019). The EPS matrix, among other functions, contribute to cell adhesion and anchoring, stability of aggregates and films, as well as physical and chemical protection (Neu and Lawrence, 2010) against antibiotics (Mah and O'Toole, 2001), and chlorine (Chen and Stewart, 1996).…”

Influence of phosphate dosing on biofilms development on lead in chlorinated drinking water bioreactors

“…Several studies have reported that increasing PO 4 3− levels in drinking water reduces the production of EPS in biofilms 22,46,47 . Among other functions, EPS is involved in protecting biofilm cells from external damage as well as maintaining its integrity and aiding the attachment of cells to substrates 48 .…”

Recent progress in the design of photocatalytic H2O2 synthesis system

“…H 2 O 2 is an indispensable chemical in daily life. It has many applications in fields such as biology ( Chang et al, 2021 ; Noh et al, 2020 ; Guarino et al, 2019 ), medicine ( Andersen et al, 2006 ; Kozlova et al, 2015 ; Wang Y. et al, 2020 ), chemical industry ( Chung et al, 2020 ; Zhang et al, 2021 ), environmental protection ( Dinakar et al, 2020 ; Moreno, 2011 ). As a clean oxidant, the decomposition of H 2 O 2 only yields H 2 O, which does not pose an environmental risk.…”