AUTHOR=Simha Prithvi , Ahopalo Nea , Pay Oliver , Jermakka Johannes , Vasiljev Anastasija TITLE=On-site reactor for treating source-separated human urine with sparingly soluble fumaric acid in building-scale sanitation systems JOURNAL=Frontiers in Environmental Science VOLUME=13 YEAR=2025 URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2025.1546396 DOI=10.3389/fenvs.2025.1546396 ISSN=2296-665X