New Packing Moving Bed Biofilm Reactor, The Organic Carbon Oxidation, Ammonia Nitrification

Wastewater biological treatment needs no chemical, which is helpful to avoid second pollution, and involved reaction is mild, and the microbe can be gotten everywhere. All of these make it become one of the most important methods used to decontaminate wastewater. Heretofore, there are few reports on the technology of moving bed biofilm reactor (MBBR for short) at home, and the research is still on the phase of lab scale. MBBR is a very promising technology in the field of wastewater treatment.The basic principle of wastewater biological and biofilm treatment were introduced in this paper. The concept of MBBR and the factors that affect the function of MBBR were summarized too. The capacity of MBBR to remove organic compound and ammonium nitrogen using new polyethylene carrier was studied.Firstly, the influence of carrier on oxygen transfer test and the benefit of pre-inoculation biofilm were researched. The experimental data showed that the capability of oxygen transfer could be raised by 29% when the ratio of carrier filled into the reactor was 60%. And pre-inoculation biofilm conduced to quick start-up of the system.Secondly, the treatment of sewage water (containing some industrial wastewater) using MBBR was investigated. The results showed that when the hydraulic retention time (HRT for short) of single MBBR were more than 8 hours, the removal rate of organic compound reached to 90% in MBBR1 only. A high correlation between removed loading rate and applied volumetric loading rate appeared when organic volumetric loadings in MBBR1 were less than 5kg COD/(m3 d), at the same time, the maximum removal loading was about 4kg COD/(m3 d). The removal efficiency of CODcr could be over 90% when two-phrase MBBR was used, and outlet COD were below 100 mg/L. Furthermore, the obtained data in experiments confidently adjust to the model of Stover-Kincannon: Lr=M L0/(K+L0), R2=0.9979. The maximal specific substrate degradation rate and proportionality constant were 57.77 g/(m2 d) and 59.89 g/(m2 d)respectively.Finally, the function of MBBR to decontaminate synthetic wastewater containing high ammonium loading but low concentration organic compound was studied. In this study, the value of NaHCO3/NH4+-N representing the alkalinity added into system was 8~10 and pH value being favor of nitrification was 8.0~9.0. In addition, nitrification efficiency declined rapidly with increase of organic loading and nitrite would build-up when the concentrations of free ammonia were more than 2.5-3.0 mg/L. In the experiment, the maximum ammonium volumetric loadings and maximum removal loadings were 1.16 Kg/(m3 d) and 0.85 Kg/(m3 d) respectively. When the system operated stably, the ammonium removal rate reached to 665.5gNH4+-N/(m3 d) in MBBR1. The removal efficiency of ammonium exceeded 99% and the outlet concentration was about 1mg/L when the synthetic wastewater with inlet concentrations below 300 mgNH4+-N/L was purified by two-phrase MBBR. Even though the inlet ammonium concentrations were as high as near 400 mg/L, the total removal efficiency still remained 95% and outlet ammonium were less than 25 mg/L.