A suitable deterministic modeling approach of urban stormwater nutrient, metal and organic pollutant removal in plant biofiltration

ABSTRACT

Urban water managers regard stormwater runoff and its treatment as one of the greatest challenges, due to its diffused nature and pollutant range. In response, plant biofiltration, a water-sensitive urban design technology, is increasingly preferred. However, due to varying removal performances influenced by design and operational conditions, as well as pollutant removal process complexity, it is under-utilised. This note reviews relevant pollutant removal processes and pathways; and subsequently proffers a first step summary of fundamental processes and pathways applicable to generic plant biofiltration for removal of typical stormwater pollutants. The treatment model combines relevant existing models applicable to the removal pathways of organics, NH₃, NO₃-, PO₄³- and metal pollutant change, as well as recommends further refinements. Advancing the understanding of plant biofilter complexity represents a significant in the urban drainage management strategy, from simple flood reduction to the recognition of the stochastic nature of interactions influencing water quality.

Highlights

• A summary of the complex nutrient and metal removal processes and pathways in a plant biofilter is given.

• A deterministic model based on a biofilm reactor for application to a standard plant biofilter is presented.

• Model refinements for numerical solving are suggested.

Graphical Abstract

KEYWORDS:

• Stormwater quality modeling
• water sensitive urban design
• biofilters
• biofilms
• pollutant removal

Nomenclature

Table

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Research Foundation (NRF) Thuthuka Fund under Grant: TTK180418322426