1.3.2 Anaerobic biological treatment
At present, the treatment of high concentration organic wastewater at home and abroad is mainly based on anaerobic method, but the effluent COD is still high after treatment by separate anaerobic method, and it is generally necessary to carry out post-treatment (such as aerobic biological treatment). At present, it is necessary to strengthen the development and design of high efficiency anaerobic reactor and carry out in-depth study of operating conditions. (UASB), anaerobic composite bed (UBF), anaerobic baffled reactor (ABR), hydrolysis method and so on in the treatment of pharmaceutical wastewater.
(1) UASB method
UASB reactor has the advantages of high anaerobic digestion efficiency, simple structure, short hydraulic retention time, no need for another sludge reflow device. UASB treatment of kanamycin, chlorine enzymes, VC, SD and glucose and other pharmaceutical production of waste water, usually requires SS content can not be too high to ensure that COD removal rate of 85% to 90% or more. The COD removal rate of the second-order UASB can reach more than 90%.
(2) UBF method
UASB and UBF were compared and tested. The results showed that UBF had the characteristics of good mass transfer and separation effect, good biomass and biological species, high processing efficiency and strong running stability. Oxygen bioreactor.
(3) Hydrolysis and acidification
The hydrolysis cell is called a hydrolyzed upflow sludge bed (HUSB), which is an improved UASB. Hydrolysis of the pool than the whole process of anaerobic tanks have the following advantages: no closed, stirring, no three-phase separator, reducing the cost and conducive to maintenance; can be large pollutants in sewage, biodegradable organic degradation of small molecules , Biodegradable organic matter, to improve the biodegradability of raw water; rapid response, small pond size, less investment in infrastructure, and can reduce the amount of sludge. In recent years, the hydrolysis-aerobic process has been widely used in the treatment of pharmaceutical wastewater. For example, a biological pharmaceutical factory uses hydrolytic acidification - two-stage biological contact oxidation process to treat pharmaceutical wastewater, stable operation, organic matter removal effect is obvious, COD, BOD5 And SS removal rates were 90.7%, 92.4% and 87.6%, respectively.