Field-scale evaluation of MN-sourced biochar for comprehensive contaminant removal from parking lot runoff

Abstract

The performance of catchment-scale filters containing sand and red-pine biochar, produced at 550oC, were monitored for 2 years. Six events from the 2022 field season showed relative flow equalization between the sand and biochar filters and were used for detailed performance analysis. Both filters provided removal of E. coli, total phosphorus, metals, total organic carbon, and total suspended solids. The sand and biochar filters provided inconsistent removal of orthophosphate. Both filters exported nitrate, though the biochar filter to a lesser degree. The addition of biochar provided greater concentration decreases for zinc and total suspended solids though no statistically significant difference between the sand and biochar was found for any filter performance. Results from this study highlight the importance of adjusting biochar production conditions for development of characteristics needed for contaminant removal and the importance of validating laboratory results in the field.