Rights accessRestricted access - publisher's policy
Gravel constitutes the filter medium in subsurface flow constructed wetlands (SSF CWs) and its porosity and hydraulic conductivity decrease over time (clogging), limiting the lifespan of the systems. Using gravel of poor quality accelerates clogging in wetlands. In this study, gravel samples from six different wetland systems were compared with regards to their mineral
composition and mechanical resistance properties. Results showed that both mineralogy and texture are related to mechanical resistance. Accordingly, gravel with high content of quartz (480%) showed a lower percentage of broken particles (0.18–1.03%) than those with lower content of quartz (2.42–4.56% media broken). Although granite is formed by high durability
minerals, its non-uniform texture results in a lower resistance to abrasion (ca. 10% less resistance than calcareous gravel). Therefore, it is recommended to use gravels composed mainly of quartz or, when it is not available, limestone gravels (rounded and uniform) are recommended instead. The resistance to abrasion (LAA test) seems to be a good indicator to determine the mechanical properties of gravels used in CWs. It is recommended to use gravels with LAA below 30% in order to avoid a rapid clogging due to gravel crumbling and subsequent mineral solids accumulation.
CitationPedescoll, A. [et al.]. Mechanical resistance properties of gravel used in subsurface flow constructed wetlands: implications for clogging. "Water science and technology", 05 Maig 2011, vol. 63, núm. 9, p. 1801-1807.
Tots els drets reservats. Aquesta obra està protegida pels drets de propietat intel·lectual i industrial corresponents. Sense perjudici de les exempcions legals existents, queda prohibida la seva reproducció, distribució, comunicació pública o transformació sense l'autorització del titular dels drets.
Per a qualsevol ús que se'n vulgui fer no previst a la llei, dirigiu-vos a: email@example.com