The Research Of Biofilm Airlift Suspension Reactor

Presently, conventional biological treatment process is the most effective technology, which is widely applied in the wastewater treatment plants. However, the conventional biological treatment process has some fatal disadvantages, including more space needed, high investment, high operating fee, and high energy consumption. Therefore many new biological treatment processes have recently been developed, and suspended carrier biofilm reactor(SCBR)is the most important technology among them. Based on the comprehensive analysis of SCBR abroad and at home, this dissertation focused on the Biofilm Airlift Suspension Reactor(BASR) and presented systemic investigation and developed a new type of biocarrier.Firstly, this study discusses the operating parameters of start-up, for this designed reactor the bare carrier input volume percentage of reaching the better start-up effect is 3%; the shorter hydraulic retention time(HRT)is, the better biofilm attachment effect is, HRT=1h is the better choice in this reactor; high volumetric load is good at biofilm attachment and start-up,the better volumetric load is 14.4kgCOD/(m3·d); In the way of inputting the carrier, the paper put forward an innovative way of start-up. Inputting the mature biocarrier together with bare carrier is beneficial to the start-up which can induce the time of start-up; besides, the treatment effect of wastewater can not be taken as a symbol of successful start-up, and the stability of the biofilm thickness can be as a sign of successful start-up.Secondly, another innovation of this paper is to develop a modified touchwood carrier to attach the biofilm. The experiments show that the effect of biofilm attachment and treating wastewater is better than activated carbon.In the end, the BASR dynamics model of organic degradation was established to describe and deduce the equations of the COD degradation rate (R) and the equation between feed COD concentration(Si)and effluent COD concentration(Se). The model is matched to the practical effluent satisfactorily.