Lamella settlers for storm water treatment - performance and design recommendations.
Three lamella settlers were monitored over a period of 4 years. The main objective was to determine removal efficiencies for total suspended solids and associated pollutants. For this purpose a new sampling method based on large volume solid samplers was developed allowing a detailed analysis of solids. With regard to total suspended solids the average removal efficiency of the plants range from 49 to 68%. Similar values could be achieved for phosphorus and heavy metals mainly because of the high portion of fine particles in treatment plants' influent. A clear dependency between solid removal efficiency and the parameters maximum surface load and influent concentration could be observed on a single event basis. The aggregation of all findings result in a recommended maximum design surface loading rate (SLR) of 4 m/h. A solid removal rate of 50%, which is defined as minimum long-term efficiency, can be achieved safely at this SLR. In addition to the definition of the maximum SLR, a proper dissipation of the inflow energy and an equal collection of the clear water above the lamellas turn out to be essential.
Karlsruhe Institute of Technology (KIT), Institute for Water and River Basin Management, Chair Aquatic Environmental Engineering, Gotthard-Franz-Str. 3, 76131 Karlsruhe, Germany E-mail: stephan.fuchs@kit.edu.
Stephan
S
Fuchs
Karlsruhe Institute of Technology (KIT), Institute for Water and River Basin Management, Chair Aquatic Environmental Engineering, Gotthard-Franz-Str. 3, 76131 Karlsruhe, Germany E-mail: stephan.fuchs@kit.edu.
Ingo
I
Mayer
Regierungspräsidium Karlsruhe, D 76247 Karlsruhe Germany.
Bernd
B
Haller
Regierungspräsidium Karlsruhe, D 76247 Karlsruhe Germany.
Hartmut
H
Roth
D019216:Metals, Heavy / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D019216:Metals, Heavy; D010758:Phosphorus