Wastewater treatment by soil infiltration: Long-term phosphorus removal
2012 (English)In: Journal of Contaminant Hydrology, ISSN 0169-7722, E-ISSN 1873-6009, Vol. 140, 24-33 p.Article in journal (Refereed) Published
Phosphorus (P) leaching from on-site wastewater treatment systems may contribute to eutrophication. In developed countries the most common on-site treatment technique is septic systems with soil infiltration. However, the current knowledge about long term P removal in soil treatment systems is not well developed and the data used for estimation of P losses from such systems are unreliable. In this study we sampled four filter beds from community-scale soil treatment systems with an age of between 14 and 22 years to determine the long-term P removal and to investigate the chemical mechanisms behind the observed removal. For one site the long-term P removal was calculated using a mass balance approach. After analysis of the accumulated P. it was estimated that on average 12% of the long-term P load had been removed by the bed material. This indicates a low overall capacity of soil treatment systems to remove phosphorus. Batch experiments and chemical speciation modelling indicated that calcium phosphate precipitation was not an important long-term P removal mechanism, with the possible exception of one of the sites. More likely, the P removal was induced by AlPO4 precipitation and/or sorption to poorly ordered aluminium compounds, as evidenced by strong relationships between oxalate-extractable Al and P.
Place, publisher, year, edition, pages
2012. Vol. 140, 24-33 p.
Soil infiltration, On site waste water treatment, Phosphorus removal, Adsorption, Precipitation
Soil Science Other Environmental Engineering Water Engineering
IdentifiersURN: urn:nbn:se:kth:diva-12046DOI: 10.1016/j.jconhyd.2012.08.003ISI: 000310768800004ScopusID: 2-s2.0-84866040536OAI: oai:DiVA.org:kth-12046DiVA: diva2:300247
FunderSwedish Research Council, 2006-632
QC 20121206. Updated from manuscript to article in journal.2010-02-252010-02-252013-04-19Bibliographically approved