Type C-N-D-SM | EVIB – EKOVODOINZENJERING BELGRADE

LEGEND:

01 – Reactor chambers
02 - Compressor with control unit
A - Biological chamber
B - Sedimentary chamber
C - Measuring shaft

Purification process
Unit is designed for treatment of active mud in order to eliminate carbon compounds and simultaneous stabilization of sludge. Alternatively, product could be extended with device with capacities of SBR technology or the de-nitrification. Device can be added at the request with the unit for tertiary treatment and chemical removal of phosphorus.

Mechanism of Treatment
Wastewater gravity comes in carrying shaft with submersible pumps and grid. If there are conditions water can come directly to anoxic chamber and then the device is performed without the reception shaft. After separation of the massive material in the reception manhole water is transferred to anoxic chamber. In this chamber is simultaneously inserted (recalculate) water from the biological chamber and active sludge. In anoxic chamber performed process is de nitrification and partially removing phosphorus. In the biological aeration chamber is done to the oxidation of carbon compounds, nitrification and sludge stabilization. After sedimentary chamber water goes into the recipient or tertiary treatment. Activated sludge from the chamber of sedimentary recalculate in anoxic chamber, and excess sludge is evacuated in thickener.

The efficiency of the process depends on:

Proper maintenance of the concentration of dissolved oxygen in the aeration basin. This is achieved by building reliable dissolved oxygen meter and compressor coupled work-oxygen meter.
Re-circulated amounts of mud and water from aeration pool. In order to influence the opportunities of this size it is desirable to install pumps with variable capacity, i.e. frequency regulators.
Elimination of phosphorus from the water is mainly chemical treatment in order that the device is added to the unit for preparation and dosage of chemicals (ferry sulfate or similar).

Materials for manufacturing
Reactor chambers are made of polyethylene or ordinary anti-corrosion-protected steel or stainless steel. Chamber D performed in the concrete variant or polyethylene (buried). Compressor and control cabinet are placed in basement or other suitable premises. If there is no such space equipment require additional premise to build.

Effluent parameters

	Average (mg/lit)	Maximum (mg/lit)
BPK5	15	25
Suspended solids	20	30
N-NH₄	5	≤7

TERTIARY TREATMENT UNIT

Water after mechanical and biological treatment occurs in the gravitational reservoir, where the pump throws to the sand filter under pressure. Filtered water leaves the reservoir of clean water and overflow to the recipient. Washing of filters is done with clean water under pressure and as needed additional air, already available. Water drains from the washing of filters at the beginning of the process.
Filtration process bringing following effects:

BPK5 reduction of up to 60%
Reduction of suspended matter up to 65%

Chemical treatment can be added after filtration, but only in case required by recipient.

DISINFECTION
Often, in order to protect the environment, it is important to make disinfection.
It is common disinfection by sodium hypochlorite, chlorine or by UV disinfection. Method of disinfection shall be elected on the basis of the size of the device, requirement of a recipient and it is an influential factor in pricing of disinfection.