E. coli removal in laboratory scale stormwater biofilters: Influence of vegetation and submerged zone

Chandrasena, Gayani; Pham, Tony; Payne, Emily; Deletić, Ana; McCarthy, David Thomas

doi:10.1016/j.jhydrol.2014.08.015

Cited by 77 publications

(79 citation statements)

References 29 publications

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“…Contrary to other studies [13,14], there was no notable differences in indicator concentration reductions between vegetated and un-vegetated controls (p > 0.05; independent samples t-test; Figure 2). Plants have previously been highlighted as a key covariant controlling faecal indicator removal due to advanced adsorption to roots and interactions with exudates and the rhizosphere; as such, our results might instead be reflecting the relatively higher importance of other design (e.g., presense of an SZ) and operational conditions (large vs. small inflow volumes).…”

Section: Overall Removal Performance Of Indicators and Reference Pathcontrasting

confidence: 86%

“…Three biofilter columns were planted with Leptospermum continentale (small shrub) (hereinafter LC) while the remaining three columns were left unplanted as an un-vegetated control (hereinafter WS). L. continentale was selected for the current study as it showed good faecal microorganism removal in the authors' previous work [13].…”

Section: Experimental Configurationsmentioning

confidence: 99%

“…Generally, SZ water is lost during extended dry weather periods due to evapotranspiration (Figure 3c shows a 50% reduction in outflow volume after the dry period even though the inflow volume in the preceding event was the same). This loss of SZ water diminishes the contribution of the 'old' SZ water to the effluent, which generally has lower E. coli concentrations because of its longer contact time and hence more microbial die-off [13]. As a result, the outflow after four weeks of drying is mainly comprised of freshly treated stormwater, which has relatively higher E. coli concentrations because of its shorter contact time.…”

Section: Effect Of Dry Weather Periodsmentioning

confidence: 99%

“…For instance, vegetation with extensive root structures was shown to improve E. coli retention in stormwater biofilters [13]. Filter media modified with either antimicrobial compounds [14,15] or adsorption enhancements [16,17] were found to improve faecal indicator microorganism attenuation rates.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stormwater Biofilters as Barriers against Campylobacter jejuni, Cryptosporidium Oocysts and Adenoviruses; Results from a Laboratory Trial

Chandrasena

Deletić

Lintern

et al. 2017

Water

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Biofilters are a widely used stormwater treatment technology. However; other than some evidence regarding non-pathogenic indicator microorganisms; there are significant knowledge gaps in the capacity of stormwater biofilters to remove actual pathogens and how this removal is impacted by biofilter design elements and operational conditions. In this study; we explored the capacity of stormwater biofilters to remove three reference pathogens (Campylobacter spp.; adenovirus and Cryptosporidium oocysts) and compared these to commonly used indicator microorganisms (E. coli; FRNA coliphages and Clostridium perfringens). Two different biofilter designs; each having a submerged zone (SZ); were tested under extended dry weather periods (up to 4 weeks) and different event volumes (the equivalent of 1-2 pore volumes) in a laboratory trial. These systems were able to consistently reduce the concentrations of all tested reference pathogens (average log reduction in Campylobacter spp. = 0.7; adenovirus = 1.0 and Cryptosporidium oocysts = 1.7) and two of the indicators (average log reduction in E. coli = 1.2 and C. perfringens = 2.1). However; none of the tested indicators consistently mimicked the removal performance of their corresponding reference pathogens after extended dry weather periods and during larger simulated storm events. This indicates that the behaviour of these pathogens in stormwater biofilters are not adequately represented by their corresponding indicator microorganisms and that to optimise biofilter designs for pathogen removal it is critical to further study pathogen removal processes in these systems.

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Section: Overall Removal Performance Of Indicators and Reference Pathcontrasting

confidence: 86%

Section: Experimental Configurationsmentioning

confidence: 99%

Section: Effect Of Dry Weather Periodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Stormwater Biofilters as Barriers against Campylobacter jejuni, Cryptosporidium Oocysts and Adenoviruses; Results from a Laboratory Trial

Chandrasena

Deletić

Lintern

et al. 2017

Water

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“…Adsorption will prioritize pollutant removal during the rainfall process, and the different rain garden filter media have different pollutant adsorption potentials [29,30]. Dissolved pollutants are generally difficult to remove in great quantities in short periods of time.…”

Section: Fate Analysis Of Pollutant Purificationmentioning

confidence: 99%

Seven-Year Running Effect Evaluation and Fate Analysis of Rain Gardens in Xi’an, Northwest China

Guo

et al. 2018

Water

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Rain gardens have recently been studied as important low-impact development (LID) facilities that play a critical role in runoff volume reduction and pollutant purification. Approximately 16-40 rainfall events were monitored from March 2011 to October 2017 in order to determine the running effect of three rain gardens with respect to runoff volume reduction and pollutant purification. In particular, running fate analysis of rain gardens is the key focus in this study. Combined analyses revealed three key points. Firstly, performance assessment demonstrated that rain gardens effectively cut inflow volumes through the filter media; when the confluence area ratio was 6:1-20:1 (confluence ratio = roof area or road/garden area) and the rainfall was approximately 2.8-39.9 mm, the runoff volume reduction rate ranged from 9.8% to 100.0%. However, the average annual runoff reduction rate presented an initially increasing and then gradually decreasing trend with monitoring time. Secondly, according to water quality data in 54 rainfall events, the annual average concentration removal rate of NH 4 + -N was relatively good, but generally decreased with monitoring time. The concentration removal rate of NO 3 − -N and total phosphorus (TP) is unstable; however, the removal rate of total suspended solids (TSS) is better than that of total nitrogen (TN). Combined with runoff reduction, the pollutant load reduction by rain gardens is greater than 50%, although this decreases with increasing monitoring time. Thirdly, through the study of 7-year running effect on runoff reduction and pollutant purification, the "three-stage purification (TSP) concept" (periods of purification growth, stability, and attenuation) with respect to pollutant load reduction processes was finally proposed, and a curve chart was drawn for pollutant load reduction and rain garden operating fate (the "P-F" curve chart).

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Meeting the criteria: linking biofilter design to fecal indicator bacteria removal

Rippy

2015

WIREs Water

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The capture, treatment, and reuse of storm‐water runoff are win–win propositions that can lead to improvements in both human water security and ecosystem health. Although not all treatment technologies facilitate the capture, treatment, and reuse of water, biofilters do. Biofilters are engineered analogues of natural systems that use low energy, natural processes to treat stormwater. Biofilter design is closely linked to treatment efficiency. As such, specific design components, such as submerged zones (SZs: saturated, organic‐rich layers near the base of biofilters), can significantly affect contaminant removal. Of particular interest, is the utility of SZ biofilter designs for removing indicators of pathogens, the so‐called fecal indicator bacteria (FIB). FIB exist at high concentrations in stormwater, sometimes several orders of magnitude above recreational, nonpotable reuse, or drinking water standards, and have been identified as one of the primary barriers to stormwater reuse. A comparison of FIB removal values from literature indicates that SZ systems significantly enhance FIB removal (∼10‐fold) relative to other design configurations (p < 0.05). Processes that may contribute to this effect include physicochemical filtration, biofilm formation, and protistan grazing, amongst others. A high degree of synergy exists between processes, and many unknowns remain. Model frameworks developed for evaluation of similarly synergistic systems, including biofilter analogues like the vadose zone, may be useful for addressing these unknowns and informing future biofilter design. WIREs Water 2015, 2:577–592. doi: 10.1002/wat2.1096 This article is categorized under: Engineering Water > Sustainable Engineering of Water Engineering Water > Water, Health, and Sanitation

show abstract

E. coli removal in laboratory scale stormwater biofilters: Influence of vegetation and submerged zone

Cited by 77 publications

References 29 publications

Stormwater Biofilters as Barriers against Campylobacter jejuni, Cryptosporidium Oocysts and Adenoviruses; Results from a Laboratory Trial

Stormwater Biofilters as Barriers against Campylobacter jejuni, Cryptosporidium Oocysts and Adenoviruses; Results from a Laboratory Trial

Seven-Year Running Effect Evaluation and Fate Analysis of Rain Gardens in Xi’an, Northwest China

Meeting the criteria: linking biofilter design to fecal indicator bacteria removal

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