Integrating natural and engineered remediation strategies for water quality management within a low-impact development (LID) approach

Abstract

The objective of this paper is to demonstrate an interdisciplinary strategy combining both engineering- and biology-based approaches for stormwater and wastewater treatment. The work involves a novel and environmentally friendly surface material that can withstand urban load over its design service life, allows preliminary treatment through filtration, and diverts water to the subsurface to conduct secondary treatment below the surface through phytoremediation via the extensive rooting systems of trees. The present study highlights an interdisciplinary low-impact development (LID) approach developed for a polluted industrial wastewater site, for a cleaner and greener environment. The LID system involves (i) rhizofiltration and phytoremediation methods for removing heavy metals and organic pollutants using a hybrid poplar and aspen species; (ii) porous infrastructure produced using industrial waste, referred to as geopolymer pavers; and (iii) use of Silva cells as a tree-friendly and load support system. The design of the pavers over the Silva cells is innovative as it can deal with rainwater runoff and urban transportation loads simultaneously. The proposed system has the ability to extract heavy metals that are common in urban runoff or domestic and industrial effluents thus preserving the ecosystem naturally. The test site is only 15 m, but designed for a water-retention capacity of 2 m (roughly 1:100 year design volume draining a 10 × 10 m parking lot), and remediation levels for Cu and Zn are expected to reach 180 mg/kg dry weight and 1200 mg/kg dry weight, respectively.

Exploring the Potential in LID Technologies for Remediating Heavy Metals in Carwash Wastewater

“…In a joint co-operative with researchers in India, researchers in Canada are conducting a study for treating carwash wastewater by using a stable filtration technology and phytoremediation. In this treatment method, the carwash wastewater flows through a highly permeable surface where some contaminants are removed by primary filtration, and the rest of the impurities are absorbed by the trees planted in this research site [81]. The primary distinctions in the Canadian site include the fact that it is facility dedicated to research only, and the permeable pavement system and the vegetated component (trees only) are integrated into one unit.…”

Novel Integration of Geopolymer Pavers, Silva Cells and Poplar Trees for In-Situ Treatment of Car-Wash Wastewater

“…Figure 1 illustrates a schematic design of the LID approach with all the essential components to treat a contaminated wastewater site. The steps for site preparation are discussed in detail in [18], but briefly mentioned below: i. excavation of existing soil up to 500 mm in depth; ii.…”

“…In 2018, researchers had conducted a preliminary study in Canada and proposed a novel interdisciplinary strategy for treating urban wastewater [18]. This work focused on treating wastewater through double filtration technology, i.e., (i) The primary filtration was provided by a stable-permeable surface prepared by an environmentally safe material; (ii) the secondary filtration was achieved by the process of phytoremediation, via extensive rooting system of trees.…”

A review on the porous geopolymer preparation for structural and functional materials applications

“…204 It can be prepared by DFM, AFM, and PSM. Interlocked needle-like mullite crystals not only enhance the porosity but also enable F I G U R E 7 Preparation of pervious geopolymer pavers 161 the pores to constitute a good network structure and improve the sound-adsorption performance of the porous materials. 205 After the addition of silica fume, the bubbles were formed and attempted to escape from the paste to the air, resulting in expansion, producing a porous structure, improving the open void porosity, and increasing the sound adsorption.…”

“…201 Compared to cement pervious concrete, the 28d compressive strength of the geopolymer-based ones was only lower by 5%, while the removal of heavy metal ions increased by 33%-120% by good adsorption. 118 As a novel and environment-friendly surface material, the rainwater is preliminarily treated through filtration which is transferred to the underground, and conduct secondary treatment below the surface phytoremediation via the extensive rooting systems of trees, 161 as shown in Figure 7.…”