Pharmaceutical wastewater treatment equipment
Sewage produced by pharmaceuticals is a kind of organic substance with complex structure, toxic, harmful and biologically difficult to degrade because of its pollutants, which causes serious pollution to water bodies. At the same time, industrial wastewater is still acidic and alkaline, and some wastewater contains excessively high salinity pharmaceutical plants. Wastewater mainly includes four major categories: antibiotic production wastewater, synthetic drug production wastewater, Chinese patent medicine production wastewater, and washing water and washing wastewater in the production process of various preparations. Its wastewater is characterized by complex components, high organic content, high toxicity, deep chroma and high salt content, especially poor biochemical properties, and intermittent discharge, which is difficult to treat industrial wastewater. The pharmaceutical wastewater treatment technology can be summarized into the following types: physical and chemical treatment, chemical treatment, biochemical treatment, and combined treatment of various methods. Each treatment method has its own advantages and disadvantages. The wastewater treatment process used by each method is also not exactly.
Physical and chemical treatment
According to the water quality characteristics of pharmaceutical wastewater, physical and chemical treatment is required as a pre-treatment or post-treatment process for biochemical treatment in the treatment process. The physical and chemical treatment methods currently applied mainly include coagulation, air flotation, adsorption, ammonia stripping, electrolysis, ion exchange, and membrane separation methods.
This technology is a water quality treatment method currently widely used at home and abroad. It is widely used in pharmaceutical wastewater pretreatment and post-treatment processes, such as aluminum sulfate and polyferric sulfate for traditional Chinese medicine wastewater. The key to efficient coagulation treatment is to properly select and add coagulants with excellent performance. In recent years, the development direction of coagulants is from low-molecules to polymerized polymers, from single-component functions to composite types. Liu Minghua et al. Used its highly efficient composite flocculant F-1 to treat acute branch syrup production wastewater. When the pH was 6.5 and the amount of flocculant was 300 mg / L, the COD, SS and color removal rate of the waste liquid were removed. Reaching 69.7%, 96.4%, and 87.5%, respectively, its performance is significantly better than PAC (powder activated carbon), polyacrylamide (PAM) and other single flocculants.
Coagulation wastewater treatment process
2. Air floatation
Air floatation generally includes aerated air floatation, dissolved air floatation, chemical air floatation and electrolytic air floatation. Xinchang Pharmaceutical Factory uses a CAF vortex concave air flotation device to pretreat pharmaceutical wastewater. With the proper formulation, the average COD removal rate is about 25%.
Air floatation wastewater treatment process
3. Adsorption method
Commonly used adsorbents are activated carbon, activated coal, humic acids, adsorption resins, etc. Wuhan Jianmin Pharmaceutical Factory uses coal ash adsorption-two-stage aerobic biological treatment process to treat its wastewater. The results showed that the COD removal rate of the wastewater by adsorption pretreatment reached 41.1%, and the BOD5 / COD value was increased.
Adsorption sewage treatment process
4. Membrane separation method
Membrane technologies include reverse osmosis, nanofiltration membranes, and fiber membranes to recover useful substances and reduce total organic emissions. The main features of this technology are simple equipment, convenient operation, no phase change and chemical change, high processing efficiency and energy saving. Zhuanna et al. Used nanofiltration membranes to perform separation experiments on jiemycin wastewater, and found that both the inhibitory effect of jiemycin on microorganisms in the wastewater was reduced and jiemycin was recovered.
Membrane separation wastewater treatment process
5. Electrolytic method
The treatment of wastewater by this method has the advantages of high efficiency and easy operation, etc. At the same time, the electrolytic method has a good decoloring effect. Using electrolysis to pretreat the riboflavin supernatant, the removal rates of COD, SS and chromaticity reached 71%, 83% and 67%, respectively.
When chemical methods are applied, the excessive use of certain reagents can easily lead to secondary pollution of water bodies, so relevant experimental research work should be done before design. Chemical methods include iron-carbon method, chemical redox method (fenton reagent, H2O2, O3), and deep oxidation technology.
Chemical treatment sewage process
Industrial operation shows that the biodegradability of effluent can be greatly improved by using Fe-C as a pretreatment step for pharmaceutical wastewater. Lou Maoxing and others used the iron-carbon-micro-electrolysis-anaerobic-aerobic-air flotation process to treat metharubicin, ciprofloxacin hydrochloride and other pharmaceutical intermediate production wastewater. The COD removal rate after iron-carbon treatment reached 20 %, The final effluent reaches the first level standard of the National Comprehensive Wastewater Discharge Standard (GB8978-1996).
2.Fenton reagent treatment method
The combination of ferrous salt and H2O2 is called Fenton reagent, which can effectively remove difficult-to-degrade organic matter that cannot be removed by traditional wastewater treatment technology. With the deepening of research, ultraviolet light (UV) and oxalate (C2O42-) were introduced into the Fenton reagent, which greatly enhanced its oxidation ability. Cheng Cangcang et al.  used TiO2 as catalyst, 9 W low-pressure mercury lamp as light source, and used Fenton reagent to treat pharmaceutical wastewater, and achieved the decolorization rate of 100% and the COD removal rate of 92.3%. The nitrobenzene compounds ranged from 8.05. mg / L decreased to 0.41 mg / L.
Reagent method wastewater treatment process
3. The method can improve the biodegradability of wastewater
Using this method can improve the biodegradability of wastewater, and at the same time has a good removal rate of COD. For example, Balcioglu and others carried out ozone oxidation treatment on three kinds of antibiotic wastewater, and the results showed that not only the ratio of BOD5 / COD increased, but also the removal rate of COD was more than 75%.
4. Oxidation technology
Also called advanced oxidation technology, it brings together the latest research results of modern optical, electrical, acoustic, magnetic, materials and other related disciplines, mainly including electrochemical oxidation, wet oxidation, supercritical water oxidation, photocatalytic oxidation and Ultrasonic degradation.
Among them, ultraviolet photocatalytic oxidation technology has the advantages of novelness, high efficiency, and non-selectivity to wastewater, and is particularly suitable for the degradation of unsaturated hydrocarbons. The reaction conditions are relatively mild and there is no secondary pollution, which has a good application prospect. Compared with ultraviolet, heat, pressure and other processing methods, ultrasonic waves are more direct in the treatment of organic matter and require less equipment. As a new type of processing method, it is receiving more and more attention. Xiao Guangquan et al.  used ultrasonic-aerobic biological contact to treat pharmaceutical wastewater. Under the condition of ultrasonic treatment for 60 s and power of 200 w, the total COD removal rate of wastewater reached 96%.
Oxidation technology wastewater treatment process
Biochemical treatment technology is a widely used treatment technology for pharmaceutical wastewater, including aerobic biological method, anaerobic biological method, aerobic-anaerobic combined method.
Aerobic biological treatment
Because pharmaceutical wastewater is mostly high-concentration organic wastewater, the original solution is usually diluted during aerobic biological treatment, so the power consumption is large, and the biodegradability of the wastewater is poor. It is difficult to directly discharge after biochemical treatment, so aerobic alone is used. Not much processing, generally need to be pre-processed. Commonly used aerobic biological treatment methods include activated sludge method, deep well aeration method, adsorption biodegradation method (AB method), contact oxidation method, sequential batch intermittent activated sludge method (SBR method), and circulating activated sludge method. (CASS method) and so on.
(1) .Deep well aeration method
Deep well aeration is a high-speed activated sludge system. This method has the advantages of high oxygen utilization rate, small footprint, good treatment effect, low investment, low operating cost, no sludge expansion, and low sludge production. In addition, its thermal insulation effect is good, the treatment is not affected by climatic conditions, and the effect of winter wastewater treatment in the northern region can be guaranteed. After the Northeast Pharmaceutical General Plant ’s high-concentration organic wastewater was biochemically treated in the deep well aeration tank, the COD removal rate reached 92.7%. It can be seen that the treatment efficiency is very high, and it is extremely beneficial to the next step of treatment, and the effluent of the process treatment reaches the standard. Plays a decisive role.
Deep well aeration wastewater treatment process
(2) .AB method
AB method belongs to ultra-high load activated sludge method. The removal rate of BOD5, COD, SS, phosphorus and ammonia nitrogen by AB process is generally higher than that of conventional activated sludge process. Its outstanding advantages are high load in section A, strong anti-shock load capacity, large buffering effect on pH and toxic substances, especially suitable for treating wastewater with higher concentration and large changes in water quality and quantity. Yang Junshi and others used a hydrolytic acidification-AB biological process to treat antibiotic wastewater. The process is short, energy saving, and the treatment cost is lower than the chemical flocculation-biological process of the same kind of wastewater.
AB method wastewater treatment process
(3). Biological contact oxidation method
This technology combines the advantages of activated sludge and biofilm method, and has the advantages of high volume load, low sludge production, strong impact resistance, stable process operation, and convenient management. Many projects use a two-stage method, which aims to domesticate the dominant species at different stages, give full play to the synergy between different microbial populations, and improve biochemical effects and impact resistance. In the engineering, anaerobic digestion and acidification are often used as pretreatment procedures, and the contact oxidation method is used to treat pharmaceutical wastewater. Harbin North Pharmaceutical Factory uses a hydrolytic acidification-two-stage biological contact oxidation process to treat pharmaceutical wastewater. The operation results show that the process has a stable treatment effect and a reasonable process combination. With the gradual maturity of this process technology, the application fields are also more extensive.
(4) .SBR method
The SBR method has the advantages of strong impact load resistance, high sludge activity, simple structure, no need for backflow, flexible operation, small footprint, low investment, stable operation, high substrate removal rate, and good nitrogen and phosphorus removal effect, etc., and is suitable for treating water quantity and water quality. Fluctuating wastewater.
The test of Wang Zhong using the SBR process to treat pharmaceutical wastewater shows that: the aeration time has a great influence on the treatment effect of the process; the setting of an anoxic section, especially the alternate design of anoxic and aerobic, can significantly improve the treatment effect; the reaction tank The SBR intensive treatment process of Zhongtou plus PAC can obviously improve the removal effect of the system. In recent years, the process has become more and more perfect, and it has been used more in the treatment of pharmaceutical wastewater. Qiu Lijun and others used hydrolytic acidification-SBR method to treat biological pharmaceutical wastewater, and the effluent water quality reached the GB8978-1996 first-class standard.
SBR wastewater treatment process
2. Anaerobic biological treatment
At present, anaerobic methods are mainly used to treat high-concentration organic wastewater at home and abroad, but the effluent COD is still high after separate anaerobic methods, and generally require post-treatment (such as aerobic biological treatment). At present, it is still necessary to strengthen the development and design of high-efficiency anaerobic reactors and conduct in-depth research on operating conditions. The most successful applications in the treatment of pharmaceutical wastewater include up-flow anaerobic sludge bed (UASB), anaerobic composite bed (UBF), anaerobic baffled reactor (ABR), hydrolysis method and so on.
UASB reactor has the advantages of high anaerobic digestion efficiency, simple structure, short hydraulic retention time, and no need to set up a sludge reflux device. When the UASB method is used to treat pharmaceutical production wastewater such as kanamycin, chloroenzyme, VC, SD, and glucose, the SS content is generally not required to be too high to ensure that the COD removal rate is above 85% to 90%. The COD removal rate of the two-stage series UASB can reach more than 90%.
UASB method wastewater treatment process