enhanced biodegradation of formaldehyde using aerobic sequencing batch rotating bed bioreactor with and without stimulation by hydrogen peroxide

The removal of formaldehyde as a toxic substance from aqueous solutions is of particular importance.in this research, a sequencing batch rotating-bed bioreactor (sbrb) was used on a laboratory scale forbiodegradation of formaldehyde from synthetic wastewater. the reactor was made of plexiglas with acylindrical shape. kaldnes media were placed in a rotating cylindrical basket in the reactor. the effectsof formaldehyde concentration (500–1500 mg/l), hydraulic retention time (hrt) (8, 15, 24 hours), andinjection of hydrogen peroxide (0.1-0.5 mm) on the performance of the reactor were investigated. theresults showed that in the sbrb, at an hrt of 24 hours and an inlet formaldehyde concentration of 1000mg/l, the removal efficiencies of formaldehyde and chemical oxygen demand (cod) were 99.2% and92%, respectively, while without rotating the bed, the removal efficiency of formaldehyde and cod wasfound to be 95% and 83%, respectively. by adding hydrogen peroxide at a concentration of 0.3 mmand operation of the sbrb with an hrt of 8 hours and an inlet formaldehyde concentration of 1000mg/l, an improvement in the removal efficiency of formaldehyde and cod (4% and 22%, respectively)was observed. accordingly, sbrb stimulation with hydrogen peroxide could be considered as a highperformanceprocess for the removal of formaldehyde and corresponding cod at a short hrt.