The study aimed to investigate the degradation of formaldehyde in an anaerobic-aerobic combined system, upflow and with immobilized biomass, consisting of an Anaerobic Filter (AF) followed by Aerated Submerged Biofilter (ASB). The concentrations of formaldehyde applied to the system ranged from 26 to 1,055 mg HCHO.L-1, resulted in a removal efficiency of formaldehyde of 97±3% and chemical oxygen demand (COD) of 90±6%. From the results, it is concluded that the combined system was suitable for treating wastewater containing formaldehyde, since besides representative removal efficiencies; operation was stable during the course of the study.
formaldehyde degradation; anaerobic filter; aerated submerged biofilter; combined system; immobilized biomass; municipal wastewater
