Investigation of Composition of Particle Size in Sediments of Stormwater Sedimentation Tank Nuos d , susidaran i pavir ini nuotek nusodinimo talpose, granuliometrin s sud ties tyrimas

The main object for the storm water runoff treatment is to remove suspended solids before the storm water runoff is discharged into surface waters. Therefore the sedimentation tank is the most often used treatment facility. In order to optimise the sedimentation, the tendency of particle size distribution in bottom sediments must be known. Two similar size storm water runoff sedimentation tanks in Vilnius city were selected for the analysis of the particle size distribution in sediments. The composite samples of drained storm water runoff sediments were collected at the sedimentation tanks located in the districts of Verkiai and Karoliniskes on the 2nd of June, 2008. The analyses of grain size distribution were performed according the standard ISO/TS 17892-4:2004. The results showed that the particles with the particle size of 1–2 mm were obtained up to 10 m from the inlet and the particles with the size of 0,01–0,05 mm mainly were obtained close to the outlet of sedimentation tank. It is recommended to divide the sedimentation tank in two parts in order to get proper management of sediments: the particles that size is 1–10 mm could be managed as waste from grit chambers and particles of smaller size could be managed as primary sludge. Article in Lithuanian Vienas i svarbiausi pavir ini nuotek valymo tiksl – pa alinti skendin ias med iagas i pavir ini nuotek . iuo tikslu da niausiai naudojamos vairios nusodinimo talpos. Nusodinimo veiksmingumas jose apibūdinamas pagal susidariusi nuos d granuliometrin sud t . iuo tikslu buvo pasirinkti du Vilniaus mieste esantys pavir ini nuotek valymo renginiai: Karolini ki ir Verki . Nustatyta nuos d granuliometrin sud tis parod , kad stambesn s dalel s (1–10 mm) nus do ar iau t kio, t. y. 10 metr atkarpoje nuo t kio, o smulkesn s (0,001–1 mm) – ar iau i t kio. Straipsnis lietuvi kalba