The sewage treatment plant was dimensioned and engineerized for a 45.000 inhabitants equivalent capacity, in the way to satisfy the needs of population in local areas, of tourism, of industry and artisan shipment, guarantying in the meanwhile higher levels in quality, with the maximum efficiency in organic pollutant load knocking down and phosphoric and nitrogen components strong reduction.
The target of sewage treatment is reached with physical, biological, chemical and biochemical processes.
The mechanical sewage, with a 25% organic load reduction efficiency, is assured by a spire screen, by aerated grit chamber, bar-screens and primary clarifier.
After that, the sewage treated mechanically cross a series of 5 falls: in the first one, in totally oxygen absence, takes place the bio-chemical process of partial phosphoric compounds deleting, in the second one, the nitrous compounds reduction is realized (denitrification) while in the last three, the biggest ones, atmospheric oxygen is injected to permit la biodegradation of organic compounds and nitrous compounds oxidation (nitrification).
The recycle of vented sewage, of actives sludges and the regulation of oxygen concentration, permit the creation of an ambient in which microorganisms and various nature batteries may easily do the proper work of degradation of pollutant load.
These microorganisms, in bow structures, are the actives sludges that are separated by sedimentation in the big secondary clarifier. The last reduction of phosphoric compounds is obtained by simultaneous precipitation (adding chemicals agents).
The water’s superior layer, now purified, flows out on toothed threshold, is analyzed by a measurement and metering station ( for quality and flow rate), and flows out into Rienza river.