Choice of the sand for sand filters used for secondary treatment of wastewater

• Published in: Water science and technology Vol. 44; no. 2-3; pp. 189 - 196
• Main Authors: Liénard, A., Guellaf, H., Boutin, C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: London IWA 01.01.2001; IWA Publishing
• Subjects: Applied sciences; Biological and medical sciences; Biological treatment of waters; Biomass; Biotechnology; Case studies; Environment and pollution; Exact sciences and technology; Facility Design and Construction; Filtered wastewater; Filters; Filtration; Foundry sands; France; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Infiltration; Other wastewaters; Permeability; Pollution; Quarries; Rural areas; Rural communities; Sand; Sand filters; Secondary wastewater; Silicon Dioxide; Waste Disposal, Fluid - methods; Wastewater; Wastewater treatment; Wastewaters; Water Purification - methods; Water treatment and pollution; Domestic waste water; Sand filter; Biofilter; Waste water purification; Biological purification
• ISBN: 190022299X; 9781900222990
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2001.0769

In a range from 100 to about 1,000 People Equivalent (PE), Secondary Wastewater Sand Filters (SWSF) are used by a lot of rural communities in France. A series of case studies however point out that several criteria concerning global and detailed design and implementation of these systems have to be approached scientifically, in order to obtain the expected results on a long-term basis. The choice of the sand constituting the infiltration bed, core of the biological reactor, is of course one of the key elements and is the main subject of this article. It must have a sufficient initial permeability in order to ensure an adapted infiltration speed, after colonisation by the purifying biomass. The d10 fines content and degree of uniformity mainly control this permeability. The quarry or the aggregate extractor, who masters his production this way, usually gives these elements, based on granulometric analysis. However the adjustment of an infiltration test with clear water is essential to check on site the conformity of the deliveries.