Use of different fractions of construction and demolition waste based porous media to treat synthetic stormwater in deep bed filtration
Younas, Muhammad Zaid (2026)
Diplomityö
2026
School of Engineering Science, Kemiantekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe20260628104915
https://urn.fi/URN:NBN:fi-fe20260628104915
Tiivistelmä
Rapid urbanization and infrastructure development have contributed to an increase in the construction and demolition waste (CDW) and stormwater precipitation. Resultantly, this has raised the demand for research in sustainable ways to treat stormwater. Repurposing CDW as porous media for filtration is a novel solution to the problem.
This study examines two different CDW fractions used to develop a porous media to filter synthetic stormwater for three water quality parameters including turbidity, total suspended solids (TSS), and total dissolved solids (TDS). The CDW fractions were ∞-5 mm and 2.5-1.25 mm in size, used as single layer (CDW fine) as well as multi-layered (CDW mixed) for deep bed filtration experiments carried out inside a column of the diameter of 9.5 cm and 70 cm height. A digital test sieve shaker and cross-beater mill were used to prepare required material samples, and preparation steps included sieving and crushing respectively. Synthetic stormwater solution of 500mg/L concentration was prepared using two types of clay. For turbidity analysis, a turbidity meter was used while gravimetric method was employed to measure TSS and TDS concentrations Flow properties under constant pressure were analysed using three filtration models including the Kozeny-Carman equation, the Ergun equation, and the Darcy-Weisbach equation. The TSS was characterised and its influence on hydraulic behaviour, treatment efficiency, and clogging tendency was studied. As for porosity, it was calculated using the relationship between bed pores and tap water filling that void.
All models under-predicted the pressure drop (Δp), with the Kozeny-Carman equation producing the values closest to that of the experimental Δp. The Ergun equation followed that, and the Darcy-Weisbach equation predicted the lowest value. These values were 3.21-24 cmH₂O, 2.69-20.3 cmH₂O, and 1.28-9.60 cmH₂O respectively.
At least two CDW beds did not experience breakthrough and treated greater volumes of stormwater with over 97% removal of TSS and 87-98% of removal of turbidity. TDS rose by almost 10-200 % across all CDW bed configurations. Removal efficiencies suggested that bed configuration, TSS type, waterhead, and porosity could potentially affect the performance of the bed materials.
This study examines two different CDW fractions used to develop a porous media to filter synthetic stormwater for three water quality parameters including turbidity, total suspended solids (TSS), and total dissolved solids (TDS). The CDW fractions were ∞-5 mm and 2.5-1.25 mm in size, used as single layer (CDW fine) as well as multi-layered (CDW mixed) for deep bed filtration experiments carried out inside a column of the diameter of 9.5 cm and 70 cm height. A digital test sieve shaker and cross-beater mill were used to prepare required material samples, and preparation steps included sieving and crushing respectively. Synthetic stormwater solution of 500mg/L concentration was prepared using two types of clay. For turbidity analysis, a turbidity meter was used while gravimetric method was employed to measure TSS and TDS concentrations Flow properties under constant pressure were analysed using three filtration models including the Kozeny-Carman equation, the Ergun equation, and the Darcy-Weisbach equation. The TSS was characterised and its influence on hydraulic behaviour, treatment efficiency, and clogging tendency was studied. As for porosity, it was calculated using the relationship between bed pores and tap water filling that void.
All models under-predicted the pressure drop (Δp), with the Kozeny-Carman equation producing the values closest to that of the experimental Δp. The Ergun equation followed that, and the Darcy-Weisbach equation predicted the lowest value. These values were 3.21-24 cmH₂O, 2.69-20.3 cmH₂O, and 1.28-9.60 cmH₂O respectively.
At least two CDW beds did not experience breakthrough and treated greater volumes of stormwater with over 97% removal of TSS and 87-98% of removal of turbidity. TDS rose by almost 10-200 % across all CDW bed configurations. Removal efficiencies suggested that bed configuration, TSS type, waterhead, and porosity could potentially affect the performance of the bed materials.