Reactive Filtration Water Treatment: A Retrospective Review of Sustainable Sand Filtration Re-Engineered for Advanced Nutrient Removal and Recovery, Micropollutant Destructive Removal, and Net-Negative CO 2 e Emissions with Biochar

Paulo Yu, Martin C. Baker, Lusine Taslakyan, Daniel G. Strawn and Gregory Möller ()
Additional contact information
Paulo Yu: Department of Mechanical and Industrial Engineering, University of Wisconsin-Platteville, Platteville, WI 53818, USA
Martin C. Baker: Department of Soil and Water Systems, University of Idaho, Moscow, ID 83844, USA
Lusine Taslakyan: Department of Soil and Water Systems, University of Idaho, Moscow, ID 83844, USA
Daniel G. Strawn: Department of Soil and Water Systems, University of Idaho, Moscow, ID 83844, USA
Gregory Möller: Department of Soil and Water Systems, University of Idaho, Moscow, ID 83844, USA

Sustainability, 2025, vol. 17, issue 13, 1-23

Abstract: A core tertiary wastewater reactive filtration technology, where continuously renewed hydrous ferric oxide coated sand is created in an upflow continuous backwash filter, has been adopted in about 100 water resource recovery facilities in several countries. Primarily focused on ultralow phosphorus discharge requirements to address nutrient pollution impacts and harmful algae blooms, the technology has also demonstrated the capacity to address high-efficiency removals of Hg, As, Zn, N, and other pollutants of concern, in addition to water quality needs met by common sand filtration, including total suspended solids. Recent work has demonstrated the capability of an additive iron–ozone catalytic oxidation process to the core reactive filtration technology platform to address micropollutants such as pharmaceuticals. Most recently, direct injection of frangible biochar into the reactive sand filter bed as a consumable reagent demonstrates a novel biochar water treatment technology in a platform that yields dose-dependent carbon negativity. In this work, the reactive filtration technology performance is reviewed from field pilot-scale to full-scale installation scenarios for nutrient removal and recovery applications. We also review the potential of the technology for nutrient recovery with the addition of biochar and micropollutant destructive removal with catalytic oxidation. Research exploration of this reactive filtration technology includes life cycle assessment (LCA) and techno-economic assessment to evaluate the environmental and economic impacts of this advanced water treatment technology. A recent LCA study of a pilot-scale field research and full-scale municipal system with over 2200 inventory elements shows a dose-dependent carbon negativity when biochar is injected into the process stream of reactive filtration. In this study, LCA demonstrates that reactive filtration has the potential as a negative emissions technology with −1.21 kg CO 2 e/m 3 , where the negative contribution from the dosed biochar is −1.53 kg CO 2 e/m 3 . In this biochar water treatment configuration, the system not only effectively removes pollutants from wastewater but also contributes to carbon sequestration and nutrient recovery for agriculture, making it a potentially valuable approach for sustainable water treatment.

Keywords: reactive filtration; nutrient recovery; wastewater treatment; biochar; P removal; denitrification (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/17/13/5799/pdf (application/pdf)
https://www.mdpi.com/2071-1050/17/13/5799/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:17:y:2025:i:13:p:5799-:d:1685928

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().