Dual-function growth medium and structural soil for use as porous pavement

Area of Science:

• Environmental Science
• Soil Science
• Horticulture

Background:

• Permeable surfaces mitigate stormwater runoff and chemical pollution.
• Structural soils are crucial for urban green infrastructure and turf health.
• Heavy metal contamination from pavement runoff poses environmental risks.

Purpose of the Study:

• To engineer permeable structural soils for optimal turf growth.
• To assess the efficacy of these soils in filtering heavy metals from runoff.
• To evaluate the impact of expanded shale particle size, peat moss, and zeolites on soil performance.

Main Methods:

• Formulated basic soil blends of expanded shale (ExSh) and quartz sand (QS) with varying ExSh particle sizes.
• Incorporated sphagnum peat moss and natural zeolites at different percentages (0-20%).
• Cultivated Bermudagrass in pots with these mediums, applying heavy metals and analyzing leachate.

Main Results:

• Sphagnum peat moss significantly enhanced Bermudagrass growth and fertilizer utilization.
• Mediums with 10-20% peat moss and 10-20% zeolites yielded greater biomass than unamended soils.
• Over 99% of added cadmium, copper, lead, and zinc were retained in the soil mediums.
• Zeolites effectively reduced cadmium and lead in leachate, but not copper or zinc.

Conclusions:

• Permeable structural soils amended with sphagnum peat moss and zeolites support robust turf growth.
• These engineered soils demonstrate high efficiency in retaining heavy metals, exceeding 99% retention.
• The findings support the use of these structural soils in managing stormwater runoff and mitigating heavy metal pollution.