Do drinking water treatment residuals underperform in the presence of compost in stormwater media filters?

Onja D Raoelison; Tonoy K Das; Ananya Visweswaran; Keegan Guyett; Sophia Spallone; Roxana Ramos; Rachel Merrifield; Timothy M Dittrich; Sanjay K Mohanty

doi:10.1016/j.scitotenv.2023.166635

Do drinking water treatment residuals underperform in the presence of compost in stormwater media filters?

Sci Total Environ. 2023 Dec 15:904:166635. doi: 10.1016/j.scitotenv.2023.166635. Epub 2023 Aug 28.

Authors

Onja D Raoelison¹, Tonoy K Das², Ananya Visweswaran², Keegan Guyett², Sophia Spallone², Roxana Ramos², Rachel Merrifield², Timothy M Dittrich³, Sanjay K Mohanty⁴

Affiliations

¹ Civil and Environmental Engineering, University of California, Los Angeles 90095, USA. Electronic address: davidsononja@g.ucla.edu.
² Civil and Environmental Engineering, University of California, Los Angeles 90095, USA.
³ Civil and Environmental Engineering, Wayne State University, Detroit 48202, USA.
⁴ Civil and Environmental Engineering, University of California, Los Angeles 90095, USA. Electronic address: mohanty@ucla.edu.

PMID: 37647961
DOI: 10.1016/j.scitotenv.2023.166635

Abstract

Drinking water treatment residuals (WTR), a waste-derived product, are often recommended to use as an amendment in stormwater biofilters to enhance their capacity to remove phosphate and microbial pollutants. However, their efficacy has been assumed to remain high in the presence of compost, one of the most common amendments used in biofilters. This study tests the validity of that assumption by comparing the removal capacities of WTR-amended biofilters with and without the presence of compost. Our results show that amending sand with WTR increased E. coli removal by at least 1-log, but the addition of compost in the sand-WTR media lowered the removal capacity by 13 %. Similarly, the addition of WTR to sand improved phosphate removal to nearly 1177 %, but the removal decreased slightly by 8 % when adding compost to the media. The results confirmed that dissolved organic carbon (DOC) leached from the compost could compete for adsorption sites for bacteria and phosphate, thereby lowering WTR's adsorption capacity based on the amount of DOC adsorbed on WTR. Collectively, these results indicate that the stormwater treatment industry should avoid mixing compost with WTR to get the maximum benefits of WTR for bacterial removal and improve the performance lifetime of WTR-amended biofilters.

Keywords: Drinking water sludge; Eutrophication; Green infrastructure; Organic amendment; Pathogens; Urban runoff.

MeSH terms

Composting*
Drinking Water*
Escherichia coli
Phosphates
Rain
Sand
Waste Products
Water Purification* / methods
Water Supply

Substances

Drinking Water
Sand
Phosphates
Waste Products