Yulan Tang

Simultaneous Biological Removal of Iron, Manganese and Ammonium Nitrogen in Simulated Groundwater Using Biological Aerated Filter

The simultaneous biological removal of iron, manganese and ammonia from simulated contaminated groundwater was studied by biological aerated filter using dual layer ceramsite as support material in the lab. The system was simultaneously inoculated with iron and manganese oxidizing bacteria, nitrifying bacteria and nitrification bacteria and a series of experiments was performed to investigate simultaneous removal performance of the filter. The influence of variation flow rate on simultaneous removal of manganese, iron and ammonia nitrogen was studied. At the mean time effluent concentration and removal ratio of manganese, iron and ammonia nitrogen along the filter depth were analysized. The results showed that the simultaneous removal of the aforementioned pollutants can be achieved by single-step filtration for high pollutants load (influent concentration 2.52~4.22mg/l, 1.22~3.97mg/l, 1.24~3.92 mg/l, respectively). Biofiltration ability to remove Mn for mixed bacteria on the filter can be improved by a sudden increase of flow rate(flow rate was 20l/h, 40l/h, 60l/h and 80l/h,respectively). But iron and ammonia removal were unaffected by a sudden increase of flow rate. Manganese was the rate-limiting pollutant.

Removal of Heavy Metals from Urban Sewage Sludge by Bioleaching

Heavy metals Zn、Cu、Cd、Ni、Pb and Mn in the compressed sludge from Shenyang Northern Sewage Treatment Plant were removed by bioleaching. The results showed that: the treatment cycle of bioleaching was about 4d, water should be timely separated from sludge; After the treatment of bioleaching, the content of heavy metals in compressed sludge were below that of control standards for pollutants in sludge from agricultural use（GB4284-1984）, which indicated the sludge from the waste water treatment plant treated by bioleaching could be used as agricultural fertilizer; After the treatment of bioleaching, the existence forms of the six heavy metals were mainly restorable and oxidized state. These research results are very helpful to the dispose and reclamation of sludge from waste water treatment plant.

Impact of DO Concentration on Shortcut Nitrification

The effect of the DO concentration on the stability of the shortcut nitrification was studied. The static test is done with SBR reactor. Reaction time reduced with the DO concentration raised appropriately, but DO in excess, the shortcut nitrification system will be damaged by the analysis of the impact of DO concentration on ammonia removal, nitrite nitrogen accumulation in shortcut nitrification process. When DO concentration was 0.45～0.9mg/L, the system was stable, and the reaction time was reduced quickly. When DO concentration was beyond 1.6mg/L, shortcut nitrification system would be transformed into complete nitrification.

Influence of Different Sizes of the PAC on TMP and Effluence in IMBR

In this study, the different sizes of the PAC are used to reduce transmembrane pressure (TMP) and prolong cycle of operation in IMBR (Integrate Membrane Biological Reactor). The ranges of size of the powdered activated carbon(PAC) are from 40-60 mesh, 80-100 mesh to 100-200 mesh. As a result, The PAC of 80-100 mesh can effectively reduce membrane fouling. And also, the carbon-slug ratio of 1:4 is best way to maintain the high membrane flux. In sum, the PAC is excellent anti-membrane fouling agent when the sanitary sewage is treated with IMBR.