1.3 biochemical treatment
Biochemical treatment technology is widely used in pharmaceutical wastewater treatment technology, including aerobic biological, anaerobic biological, aerobic - anaerobic combination of methods.
1.3.1 aerobic biological treatment
As the pharmaceutical wastewater is mostly high concentrations of organic wastewater, aerobic biological treatment is generally required to dilute the stock solution, so the power consumption is large, and the wastewater can be biodegradable, it is difficult to direct biochemical treatment after discharge, so the use of aerobic alone Processing is not much, generally need to be pretreated. Commonly used aerobic biological treatment methods include activated sludge method, deep well aeration method, adsorption biodegradation method (AB method), contact oxidation method, batch batch intermittent activated sludge method (SBR method), circulating activated sludge method (CASS method) and so on.
(1) deep well aeration method
Deep well aeration is a kind of high speed activated sludge system. The method has the advantages of high oxygen utilization rate, small footprint, good treatment effect, low investment, low running cost, no sludge expansion and low sludge production. In addition, the insulation effect is good, the treatment is not affected by climatic conditions, can guarantee the effect of winter winter wastewater treatment. The COD removal rate of the high concentration organic wastewater from the Northeast Pharmaceutical Factory was 92.7% after the biochemical treatment of the deep well aeration tank. It was found that the treatment efficiency was very high, and the treatment of the next step was extremely favorable. Play a decisive role.
(2) AB method
AB method of ultra high load activated sludge. AB process on the BOD5, COD, SS, phosphorus and ammonia nitrogen removal rate is generally higher than the conventional activated sludge method. Its outstanding advantages are high load of A, high impact resistance load, pH and toxic substances have a large buffer effect, especially for dealing with higher concentrations, water quality changes in the larger sewage. Yang Junshi, etc. using hydrolytic acidification-AB biological process of treatment of antibiotic wastewater, short process, energy saving, treatment costs are lower than the same kind of wastewater chemical flocculation - biological method.
(3) biological contact oxidation method
The technology combines the advantages of activated sludge and biofilm in one, with the advantages of high volume load, less sludge production, strong impact resistance, stable process operation and convenient management. Many projects use two methods, the purpose is to domesticate different stages of the dominant species, give full play to the synergies between different microbial populations, improve biochemical effects and impact resistance. In the project often anaerobic digestion, acidification as a pretreatment process, the use of contact oxidation treatment of pharmaceutical wastewater. Harbin North Pharmaceutical Factory using hydrolytic acidification - two biological contact oxidation process of pharmaceutical wastewater treatment, the results show that the process is stable, the combination of reasonable process. With the gradual maturity of the technology, application areas are more extensive.
(4) SBR method
SBR method has the advantages of strong impact load, high sludge activity, simple structure, no need to return flow, flexible operation, small footprint, stable investment, stable substrate removal rate, high efficiency of denitrification and phosphorus removal, and is suitable for treating water quality Fluctuating large waste water. The experiment of treating the pharmaceutical wastewater with SBR process shows that the aeration time has a great influence on the treatment effect of the process. The setting of the hypoxia stage, especially the hypoxia and aerobic alternating design, can obviously improve the treatment effect. PAC with SBR enhanced processing technology, can significantly improve the system to remove the effect. In recent years, the process is becoming more and more perfect in the pharmaceutical wastewater treatment applications are more, the use of hydrolytic acidification -SBR treatment of bio-pharmaceutical wastewater, water quality to GB8978-1996 a standard.