Experiment study on carriers in moving bed biofilm reactor

Two methods of mixture modified and corona discharge were used to modify hydrophilic performance of the surface of the carriers. By mixture modified, the contact angle reduced from 108° to 88°, which showed carriers were hydrophilic; corona discharge could strengthen the effect and contact angle could reduce to 72° further, although the effect lasted short time. To compare two carriers modified by corona discharge or not, evaluation system for biological quality of carries were established from two aspects: monitor indexes and monitor methods. Experiment lasted for 20 days. The results showed that the reactor filled with the former started up more quickly. On the 2nd day, removal rate of COD and NH₄⁺-N was 80% and 97%, respectively; while removal rate of the reactor filled with the latter only reached 61% and 63%, respectively. But soon, the removal rate of the both pollutants was nearly the same. It confirmed that the modified effect by corona discharge lasted short time, and indicated this evaluation system was fast, feasible and reliable.