Operation, preservation, and maintenance of the Abrera group sanitation system

Abera WWTP System
The system will serve the municipalities of Abrera (Abrera, Les Carpes, Santa Maria de Villalba, Ca La Cília); Olesa de Montserrat; Esparreguera; Collbató and El Bruc with 30 km of collection lines and 6 pumping stations designed to treat 34,000 m³/day using an active sludge biological process that removes nitrogen and phosphorus.  The process consists of 2 pretreatment lines, sand removal and screening, 2 primary decanters, 4 biological reactors with a capacity of 4,100m³, and 2 secondary decanters. The sludge line includes a 16m flotation thickener, 1 anaerobic digester and dehydration with 2 45m³/h centrifugal decanters. The biogas generated in the digestion process is used to generate electrical power to be used by the system itself.

Castellbell i El Vilar WWTP
Designed to treat 5,500 m³/day with a 12 km collector network and 7 pumping stations, an active sludge biological process and a low-load carrousel-type system for nutrient removal, with a 4,600m³ line and a 25m secondary decanter. The sludge line includes a 210m³ dynamic thickener, and dehydration is accomplished with 2 centrifugal decanters.

Vacarisses WWTP
Designed to treat 2,320 m³/day. The process consists of pretreatment with fines screening, desander, degreaser, a conventional prolonged-aeration active sludge process with final separation of effluent and biomass using 2 MBR-type ultrafiltration membrane racks of 32.6m².

Monistrol de Montserrat WWTP
Treats 3,300m³/day. The system consists of 6 km of collection lines and 2 pumping stations. It has a 1,500m³ homogenization tank, with agitation, aeration, and a prolonged-aeration biological reactor, as well as a secondary decanter measuring 19m in diameter. The sludge line consists of a gravity thickener.