Adsorption Characteristics of Several Bioretention-Modified Fillers for Phosphorus

Abstract

To optimize the bioretention mixed fillers with better removal of phosphorus, this paper studies the adsorption characteristics of single filler and modified mixed filler through static adsorption experiments, and adopts the dynamical mini-column experiments to examine the adsorption capacities of the soil and modified mixed fillers. Results show that, in the static adsorption experiments, both water treatment residual (WTR) and fly ash exhibit good adsorption capacity when used as a single filler and modifier. Adsorption capacity increases with increasing WTR and fly ash dosage in the mixed filler. The modified mixed filler with WTR exerts a clear effect in the dynamic adsorption experiment, which is unsaturated when influent phosphorus concentration is 1 mg/L and inflow amount is equivalent to 15 years of precipitation. The adsorption capacity of WTR is 3.5-4.5 times that of other mixed fillers. Fly ash as a modifier shows a poor dynamic adsorption effect and thus must be continuously studied. In this study, WTR is recommended as a bioretention phosphorus removal additive. In engineering applications, the amount of WTR added can be controlled within 5-10% (by mass) according to influent phosphorus concentration.

A comprehensive review on the long-term performance of stormwater biofiltration systems (SBS): Operational challenges and future directions

“…Phosphorus is removed by plants and microbial uptake or absorbed by the filter media (Marvin et al, 2020). Many studies focused on the efficacy and the mechanism involved in nitrogen (Jiang et al, 2017;Tian et al, 2019;Wu et al, 2017) and phosphorus (Chang et al, 2019;Zhang et al, 2018a) removal, but few studies have examined the long-term performance in SBS (Table 2). Previous research suggested that SBS could reduce nutrients after a long-term operation.…”

Reduction and Accumulative Characteristics of Dissolved Heavy Metals in Modified Bioretention Media

“…Then, the modified media were prepared by mixing modifiers including water treatment residue (WTR), green zeolite (Gz), medicinal stone (Ms), vermiculite, turfy soil (Ts), coconut bran, and fly ash and BSM with different proportions [22]. Selection and proportion of modifiers are determined by previous adsorption experiments [23]. In the static adsorption experiments, the modifiers with good adsorption capacity were selected.…”

Field Scale Demonstration of Fly Ash Amended Bioretention Cells for Stormwater Phosphorus Removal: A Review of 12 Years of Work

“…Marvin et al [5] have recently presented a systematic literature review of phosphorous sorption in bioretention media. They note that a number of other researchers have more recently conducted laboratory or mesocosm scale tests of phosphorus retention with fly ash amended filter media [6][7][8][9][10][11][12]. Those tests showed that fly ash is generally superior to other additives for phosphorus reduction.…”