TY - JOUR
T1 - Effects of bioretention media compost volume fraction on toxic metals removal, hydraulic conductivity, and phosphorous release
AU - Paus, Kim H.
AU - Morgan, Joel
AU - Gulliver, John S.
AU - Hozalski, Raymond M.
N1 - Publisher Copyright:
© 2014 American Society of Civil Engineers.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Batch and column experiments were conducted to investigate the effects of compost volume fraction (CVF; 0-50%) on bioretention media hydraulic conductivity, toxic metal (i.e., Cd, Zn, and Cu) capture, and phosphorus (P) release. Three sources of compost were tested and all exhibited high Cd and Zn sorption capacities. Thus, metal breakthrough times in the columns increased with increasing CVF. Typical breakthrough behavior was not observed for Cu, because little to no Cu was observed in the column effluents after more than 1,000 pore volumes. The unique behavior of Cu was attributable to its precipitation in the synthetic storm water with removal primarily attributed to filtration rather than sorption. Although beneficial for metal removal from storm water, increasing the CVF of the media resulted in reduced hydraulic conductivity and significant release of P. The release of nutrients from compost is a significant concern, and addition of a second layer of media beneath the compost-amended sand to promote P retention, such as iron-amended sand, should be considered.
AB - Batch and column experiments were conducted to investigate the effects of compost volume fraction (CVF; 0-50%) on bioretention media hydraulic conductivity, toxic metal (i.e., Cd, Zn, and Cu) capture, and phosphorus (P) release. Three sources of compost were tested and all exhibited high Cd and Zn sorption capacities. Thus, metal breakthrough times in the columns increased with increasing CVF. Typical breakthrough behavior was not observed for Cu, because little to no Cu was observed in the column effluents after more than 1,000 pore volumes. The unique behavior of Cu was attributable to its precipitation in the synthetic storm water with removal primarily attributed to filtration rather than sorption. Although beneficial for metal removal from storm water, increasing the CVF of the media resulted in reduced hydraulic conductivity and significant release of P. The release of nutrients from compost is a significant concern, and addition of a second layer of media beneath the compost-amended sand to promote P retention, such as iron-amended sand, should be considered.
KW - Bioretention
KW - Compost
KW - Hydraulic conductivity
KW - Phosphorus
KW - Storm water
KW - Toxic metals
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U2 - 10.1061/(ASCE)EE.1943-7870.0000846
DO - 10.1061/(ASCE)EE.1943-7870.0000846
M3 - Article
AN - SCOPUS:84920823393
SN - 0733-9372
VL - 140
JO - Journal of Environmental Engineering, ASCE
JF - Journal of Environmental Engineering, ASCE
IS - 10
M1 - 04014033
ER -