Issue 4, 2017

Improved contaminant removal in vegetated stormwater biofilters amended with biochar

Abstract

The potential for carbonaceous sorbents to improve contaminant removal (particularly for trace organic contaminants, TOrCs) in stormwater biofilters was evaluated in intermittently dosed, vegetated columns simulating scaled-down treatment systems. Columns amended with biochar or granular activated carbon (GAC) were evaluated relative to performance benchmarks set by columns representing unamended treatment systems (i.e., sand filters and vegetated biofilters). Biochar amendment (6.7 wt%, 33 vol%) strongly improved TOrC removal, despite potential fouling due to the presence of an upper compost-amended layer. Biochar-amended biofilter columns maintained greater than 99% TOrC removal throughout five months of dosing with TOrC-spiked creek water (equivalent to approximately 1.3 years of runoff volume), relative to less than 50% removal of most TOrCs by unamended biofilter columns. GAC amendment (6.7 wt%, 12.5 vol%) also improved TOrC removal, though less effectively than biochar (>70% removal), because the biochar's lower density (i.e., higher volume composition) and smaller particles improved performance. These results indicate that full-scale biochar-amended biofilters could potentially remove TOrCs effectively for several years, as treatment depths up to five times greater than the 10 cm experimental depth may be feasible for full-scale systems. Further, contaminant removal survey experiments conducted after 6 months of operation revealed that biochar amendment improved removal of total organic carbon, total nitrogen, nitrate, and total dissolved phosphorus in biofilters by greater than 60%. The findings of this study demonstrate the potential of biochar amendment to broadly improve contaminant removal in biofilters, motivating and informing the application of full-scale biochar-amended biofilters for improved water quality.

Graphical abstract: Improved contaminant removal in vegetated stormwater biofilters amended with biochar

Supplementary files

Article information

Article type
Paper
Submitted
03 Marts 2017
Accepted
08 Maijs 2017
First published
09 Maijs 2017

Environ. Sci.: Water Res. Technol., 2017,3, 726-734

Improved contaminant removal in vegetated stormwater biofilters amended with biochar

B. A. Ulrich, M. Loehnert and C. P. Higgins, Environ. Sci.: Water Res. Technol., 2017, 3, 726 DOI: 10.1039/C7EW00070G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements