Influence of Biological Manganese Oxides on the Removal of Organic Matter and Ammonia in Micro-Polluted Source Water

In order to improve the removal efficiency of refractory organic matters in micro-polluted source water, biological manganese oxides (BMOs) were generated in situ in the biological aerated filter (BAF) (BAF 2(#)), which could oxidize the refractory organic matters into biodegradable organic matters. CODMn and NH4+-N in the effluent of BAF 2(#) both stabilized on the 39th day, while CODMn and NH4+-N in the effluent of the control BAF (BAF 1(#)) stabilized on the 38th and 42nd days, respectively. In the steady phase, the removal rates of CODMn and NH4+-N in BAF 1(#) were 41.51% and 94.79%, respectively, while in BAF 2(#), they were 54.52% and 95.55%, respectively. BMOs generated in BAF 2(#) evidently improved the efficiency of CODMn removal. With the increase in the influent Mn2+ in BAF 2(#), the rate of CODMn removal was gradually improved to 63.60%, while the efficiency of NH4+-N removal was slightly improved, CODMn was evidently removed in each section of the filter layer, and ammonia was mainly removed in the 0 similar to 0.8 m layer of the filter. CODMn was evidently removed in each section of the filter layer, and NH4+-N was mainly removed in the 0 similar to 0.8 m layers of the filter. Biological CODMn, Mn2+, and NH4+-N removal all followed the first-order kinetic reaction. As the influent Mn2+ gradually increased from 0 to about 0.5, 1, and 2 mg/L, the efficiency of CODMn removal along the filter layer was significantly improved, but the efficiency of NH4+-N removal was slightly improved. The kinetic constant k of biological CODMn removal significantly increased, while the kinetic constant k of biological Mn2+ and NH4+-N removal gradually increased.