Case study 10-Bahco treatment wetland for effluent final polishing (Argentina).

MAINE, M.A.; HADAD, H.R.; SANCHEZ, G.C; MUFARREGE, M.M.; DI LUCA, G.A.

Wetland Technology. Practical information on designing treatment wetlands. IWA Scientific and Technical Report No.27

International Water Association

Año: 2019; p. 122 - 123

A FWS wetland was constructed. This type of TW was selecteddue to the efficiency in metal removal and the low costs foroperation and maintenance. Although FWSs requires a largearea, this is not a problem in this case. Industrial wastewatercontaining metals and sewage from the factory are treatedtogether, both after a primary treatment (25 m3 d-1 of sewage +75 m3 d-1 of industrial wastewater). Sewage improves the abilityof macrophytes to take up heavy metals from wastewater.The FWS wetland showed high removal efficiencies of Cr, Ni,Zn, Fe, COD and BOD. Treated effluent meets the Argentinianlaw limits for discharge. FWS performance improved withwetland maturity. Sediment and macrophyte roots wereresponsible for the metal removal. Metals were bound tosediment fractions that would not release them into water whilethe chemical and environmental conditions of the system weremaintained. Although this FWS wetland was faced withaccidental events, it was capable of recovering its performance,demonstrating its robustness. FWS and the discharge pondprovide an additional ecosystem service with a high diversity ofmacrophytes and have become the habitat for diverse wildlife,such as ducks, geese, coots, coypus, lizards, capybaras, turtles,etc.