Wastewater with suspended solids should be pretreated in a settling tank. A correctly designed settling tank should provide optimal treatment efficiency and sufficient storage capacity for suspended solids.
A settling tank can be a standalone device (Settling Tanks) or can be integrated with a coalescence separator where the settling tank is placed below the coalescence column – typically marked H (e.g. ESK-H, ESK-BH etc.). The purpose of such integrated system is to reduce the size of treatment installation, while providing high degree of treatment of petroleum derivatives and suspended solids. It is used mainly in highly urbanised areas.
Optionally, this device can be fitted with an alarm system (Monitoring System) or linked up to Bumerang, an intelligent rainwater management system.
ESK-H separators were tested for nominal and maximum flows and the results of the tests were confirmed by the Building Research Institute by issuing the National Technical Assessment ITB-KOT-2017/0212 edition 1. ESK-H separators represent class I (according to EN 858-1), it also obtained CE mark allowing to be applied in all EU countries. The chamber is made in accordance with Norm EN 1917 or National Technical Assessment ITB, concrete of class at least C35/45 waterproof ≥W8, with water absorption lower than 5%, frost resistant F150 in the water and F50 in 2% NaCl, stable for petroleum products in accordance with EN 858-1.
COALESCENCE SEPARATORS IN OVERFLOW SYSTEMS WITH REGULATORS
Using regulators enables efficient protection of rainwater pretreatment facilities against their overload resulting from torrential rain inflows. Overflow systems designed by Ecol-Unicon are chosen individually and consist of:
- distribution chambers with a flow regulator adjusted to pretreatment devices throughput;
- a connecting chamber;
- external overflow of a diameter and gradient adjusted to accept maximum rainwater inflows.
In case of pretreatment systems before which a distribution chamber with a flow regulator and a by-pass pipe are installed it is important that the chamber is able to distribute the wastewater properly. Nominal flow from the watershed (Qnom) should be treated completely while in case of the maximum flow from the watershed (Qmax), the separator should be protected against hydraulic overload. An appropriately chosen flow regulator ensures that Qreg = Qnom at two points A and B.
The height of the bottom of a by-pass pipe (or the location of the top of overflow edge) should be at elevation of H ≥ HA, which ensures that the flow directed into pretreatment system is Qreg. With wastewater inflow, impoundage level rises to H = HB and the flow lower than Qreg, is directed thought the regulator, which protects the device against hydraulic overload. The flow higher than Qreg is directed into the by-pass pipeline.
Coalescent separator with ESK-H settling tank
Oil separators are installed in rainwater drainage systems as one of the devices used in pretreatment of rainwater from watersheds that are likely to be polluted by petroleum derivatives – urban, road and facility.
They are most often used at:
- roads and motorways,
- car parks,
- railroad areas,
- public transport areas,
- transportation equipments depots,
- production plants, etc.