Enhancing Dissolved Oxygen and Biofilm Formation in Municipal Wastewater Treatment Systems Using Magnetic Air Stone

Fe3O4-Fused Magnetic Air Stone Prepared From Wasted Iron Slag Enhances Denitrification in a Biofilm Reactor by Increasing Electron Transfer Flow

“…In the first 15 days after inoculation, the removal efficiencies of COD, TN, and NH 4 + -N in the two reactors showed similar fluctuating patterns, indicating both reactors were unstable at the initial adapting stage. The removal efficiencies by the MAS reactor were slightly lower because the porosity and specific surface area of MAS were reduced after nFe 3 O 4 was loaded (Liu et al, 2015).…”

“…The modified nFe 3 O 4 and air stone (AS) were placed in a beaker containing 200 ml n-hexane. We used a vacuum drying oven to immerse at 40 °C under negative pressure for half an hour, then sintered in a nitrogen muffle furnace at 200 °C and 450 °C for 1 h respectively, and finally made into magnetic air stone (MAS) (Liu et al, 2015).…”

“…After the activated sludge was domesticated, eight pieces of MAS and AS were added to the reactor, respectively. The aeration head and the water inlet were in concurrent contact at the bottom of the reactor, the air-water ratio is 8:1, and the hydraulic residence time was for 5 h, the temperature was controlled at about 25 °C, and the dissolved oxygen was 2~4 mg L −1 ; then the biofilm was loaded (Liu et al, 2015). After the biofilm matured, water was continuously fed in and out, and the removal efficiencies of COD, TN, and NH 4 + -N were monitored every day.…”