Decontamination performance of a bioretention system using a simple sand-based filler proportioning method

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Soil Science

Background:

• Bioretention systems are crucial for managing stormwater runoff and improving water quality.
• Optimizing filler composition is key to maximizing pollutant removal efficiency.

Purpose of the Study:

• To evaluate the decontamination performance of a novel sand-based filler for bioretention systems.
• To assess the impact of various inorganic constituents on pollutant removal rates.

Main Methods:

• A sand-based filler composed of sand and peat soil was developed using a simple proportioning method.
• Inorganic materials (zeolite, volcanic rock, coal slag, vermiculite, perlite) were added to the filler.
• Influent and effluent concentrations of total suspended solids (TSS), total phosphorus (TP), ammonium nitrogen ($$-N), total nitrogen (TN), and chemical oxygen demand (COD) were measured.

Main Results:

• The sand-based filler demonstrated satisfactory overall decontamination performance.
• Removal rates for TSS and TP exceeded 95%, with inorganic constituents enhancing TSS removal.
• Ammonium nitrogen removal surpassed 80% with the addition of adsorptive inorganic materials.
• Vermiculite and coal slag addition increased COD removal by 15-25%.

Conclusions:

• The developed sand-based filler is a feasible and practical option for bioretention systems.
• Inorganic constituents significantly improve the removal of specific pollutants, particularly TSS, $$-N, and COD.
• This research provides valuable guidance for selecting and proportioning fillers in bioretention system design.