Stormwater quality design manuals lack scientifically creditable bases for many novel LID （Low-Impact Development） designs presently proposed to meet stormwater runoff management requirements. Potential stormwater p...Stormwater quality design manuals lack scientifically creditable bases for many novel LID （Low-Impact Development） designs presently proposed to meet stormwater runoff management requirements. Potential stormwater pollutant adsorption and infiltration enhancement capabilities of forest-derived by-products （e.g. woodchips, bio-char） provide an opportunity to combine these readily availability materials into stormwater quality designs. On-site stormwater runoff treatment through determination of the soil-water transport and lead （Pb） retention capacity of two sandy soils from Oregon is considered. Using synthetic stormwater （-120 mg CI/L and -5 mg Pb/L） displacement tests in pairs ofABS （Acrylonitrile butadiene styrene） soil columns （75 mm dia by 0.46 m tall） with upward flow （to minimize air entrapment） saturated hydraulic conductivity, chloride dispersion and Pb retention by plain and amended soils is evaluated. Generally, soil amendment incorporation （woodchips, compost or biochar） as compared to an amendment layer resulted in improved hydraulic conductivities as compared to that of the soil alone. Chloride breakthrough curves verified that resident soil-water displacement occurred with 0.9 to 1.6 pore volumes and residence times for most columns were 15-30 minutes. No synthetic stormwater Pb ＂breakthrough＂ within the displaced or replaced soil-water was found, rather most Pb was adsorbed within the first 150 mm of soil.展开更多
文摘Stormwater quality design manuals lack scientifically creditable bases for many novel LID （Low-Impact Development） designs presently proposed to meet stormwater runoff management requirements. Potential stormwater pollutant adsorption and infiltration enhancement capabilities of forest-derived by-products （e.g. woodchips, bio-char） provide an opportunity to combine these readily availability materials into stormwater quality designs. On-site stormwater runoff treatment through determination of the soil-water transport and lead （Pb） retention capacity of two sandy soils from Oregon is considered. Using synthetic stormwater （-120 mg CI/L and -5 mg Pb/L） displacement tests in pairs ofABS （Acrylonitrile butadiene styrene） soil columns （75 mm dia by 0.46 m tall） with upward flow （to minimize air entrapment） saturated hydraulic conductivity, chloride dispersion and Pb retention by plain and amended soils is evaluated. Generally, soil amendment incorporation （woodchips, compost or biochar） as compared to an amendment layer resulted in improved hydraulic conductivities as compared to that of the soil alone. Chloride breakthrough curves verified that resident soil-water displacement occurred with 0.9 to 1.6 pore volumes and residence times for most columns were 15-30 minutes. No synthetic stormwater Pb ＂breakthrough＂ within the displaced or replaced soil-water was found, rather most Pb was adsorbed within the first 150 mm of soil.
