Since the birth of MBBR reactor, due to the advantages of the process of concentrating biological filter, fixed bed and fluidized bed, it has attracted extensive interest from experts and scholars from all over the world, especially its simple construction, convenient operation, high organic matter removal efficiency, strong phosphorus and nitrogen removal ability, especially suitable for the advanced treatment of small and medium-sized enterprises sewage and the treatment of organic wastewater.
In 1991, Rumen et al. used MBBR to treat neutral sulfite pulping wastewater, under the conditions of CODcr up to 20~30kg/(m3·d) and carrier filling rate of 70%, the total removal rate of CODcr was 70%, and the removal rate of BOD5 was 96%, and when the CODcr gradually increased to 50kg/(m3·d), the removal rate remained basically constant, and the total removal rate was 60%--70%.
Broch et al. used a pilot-scale MBBR to treat newsprint factory wastewater, and when the hydraulic retention time was 4~5h, the removal rates of CODcr and BOD5 were 65%~75% and 85%~95%, respectively, and the removal rates of CODcr and BOD5 could be increased to 80% and 96%, respectively, when the hydraulic retention time was 4~5h.
Chandler et al. used plastic fillers and applied two-stage MBBR to conduct a pilot test on paper mill wastewater, and the results showed that the hydraulic retention time was 3h, and the effluent BOD5r could be reduced by 93%, and the average concentration reached 7.83mg/L.
Li Wenjun et al. of Sichuan Institute of Technology used the coagulation-MBBR method to conduct experiments on the middle section of sewage (including washing and screening sewage, bleaching sewage and remaining white water, etc.) of a plant. The plant uses Cizhu as raw material, adopts KP method for cooking, and CEH three-stage bleaching. Its main water quality indicators are: CODcr 1640mg/L, SS 1330mg/L, color 187 times, pH 6.9, and yellow-brown color. After coagulation treatment, the effluent CODcr was about 780mg/L under the optimal conditions, and then the effluent color was 23 times after MBBR biochemical treatment, CODcr was 130mg/L, SS< 90 mg/L, the total removal rates of CODcr and BOD5 were 92.1% and 93.3%, respectively.
According to the literature, relevant experts are developing fillers with good adsorption performance, appropriate density, durability, corrosion resistance and low price to improve their treatment effect and promote their improvement and development. Although the current research and application in China is still in its infancy, the results of foreign tests have proved that MBBR can not only treat papermaking wastewater efficiently and stably, but also that the MBBR process can be easily modified by using the existing treatment process. It is suitable for the application of small and medium-sized enterprises, especially for the current situation of small scale of papermaking enterprises in China, which is worthy of our attention and reference