How to treat wastewater from pharmaceutical companies?

2021-02-26

Wastewater discharge from pharmaceutical companies is the focus of pollution prevention. The environmental impact assessment will determine a reasonable wastewater treatment process based on the company's production process, types of wastewater, wastewater quality and water volume. 

1. Wastewater source and water quality

  1.1, production process

The factory first prepares pure water and water for injection. Safflower extraction uses a combined extraction process of water extraction and alcohol extraction. Then, safflower extract is used as raw material, and different configurations and packaging are carried out to produce small-volume injections and oral liquids. , Freeze-dried powder injection and other products.

  1.2. Wastewater source and water quality

  1.2.1Types of wastewater

There are many types of production wastewater generated in this project, mainly including equipment flushing water, decoction bag flushing water, electrodialysis flushing water, electrodialysis drainage, process cleaning wastewater, water bath sterilization drainage, a small amount of alcohol residue, pure water and injection Concentrated water produced by water preparation and boiler sewage, equipment cooling sewage, air conditioning system circulating sewage and other clean wastewater. In addition, domestic sewage is produced.

   In the above-mentioned wastewater, except for the direct discharge of pure wastewater, all other types of wastewater need to be treated in the sewage treatment station in the plant.

  1.2.2 Characteristics of wastewater

  A) The pollutants are all conventional pollutants, namely COD, BOD5, SS, ammonia nitrogen, etc., without heavy metals and other toxic substances;

  B) There is a big difference in the quality and quantity of various types of wastewater. Among them, the amount of alcohol residue produced is very small (intermittent discharge, about 60 L/d on average), but the pollutant concentration is high, with CODCr as high as about 18 000 mg/L; comparison of the pollutant concentration of equipment washing water and decoction bag washing water High, CODCr can reach 2 000 mg/L ~ 4 000 mg/L; the concentration of pollutants in electrodialysis drainage, process cleaning wastewater, and water bath sterilization drainage is relatively low; pure water and concentrated water discharged from water for injection are relatively clean, only High salt content, but large displacement;

  C) According to the production characteristics, all kinds of wastewater are discharged intermittently, and the discharge is uneven, resulting in large fluctuations in the quality and volume of wastewater and extremely unstable;

  D) The wastewater is biodegradable.

  1.2.3, wastewater quality

Based on the multiple monitoring results of wastewater quality in each drainage link of the existing project and the amount of various wastewater produced, and considering the fluctuation of water quality, it is determined that the water quality of the sewage treatment station is: 200 times to 300 times chromaticity, COD Cr 800 mg/ L1 200 mg/L, BOD5 300 mg/L500 mg/L, SS 200 mg/L350 mg/L, ammonia nitrogen <40 mg/L.

2. Wastewater treatment process selection

  2.1. Existing traditional Chinese medicine wastewater treatment process

  Traditional Chinese medicine wastewater treatment processes include: physicochemical methods, biological methods and physicochemical-biological methods, of which physicochemical methods can be used as a separate treatment process, or as a pretreatment or post-treatment process for biological methods.

       a) Physical and chemical methods: including coagulation, precipitation, filtration, air flotation, adsorption, ion exchange, membrane separation, neutralization, redox, extraction, stripping and steam stripping, etc. Commonly used processes are coagulation sedimentation and air flotation . For example, the polyacrylamide (PAM) produced by Gongyi Xinqi Polymer Co., Ltd. has a good flocculation effect on the treatment of traditional Chinese medicine wastewater;

  B) Biological method: There are mainly anaerobic and aerobic methods. Anaerobic treatment includes UASB reactor, UBF anaerobic reactor, ABR anaerobic baffle reactor, hydrolysis acidification, etc. Aerobic treatment includes ordinary activated sludge method, biological contact oxidation method, SBR method, oxidation ditch method, biological turntable Method, CASS method, MBR method, etc.;

  C) Physicochemical-biological method: refers to a combined process with biological method as the main process, and physical-chemical method as pretreatment or post-treatment. The general combination method is pretreatment-anaerobic-aerobic-post-treatment. The physicochemical-biological method is the most commonly used treatment process in the treatment of traditional Chinese medicine wastewater, and different combined processes can be used according to the characteristics of the wastewater.

At present, most extraction Chinese medicine companies adopt anaerobic-aerobic main treatment processes. Anaerobic treatment mainly adopts UASB reactor, UBF reactor, hydrolysis acidification and other processes, while aerobic treatment mainly adopts biological contact oxidation method and SBR. Law, etc., has a better effect on wastewater treatment.

  2.2, processing requirements

   The wastewater discharge of the pharmaceutical factory shall meet the requirements of Table 2 in the GB21905-2008 Extraction Pharmaceutical Industry Water Pollutant Discharge Standard.

  2.3. Wastewater treatment process selection

Comparing the commonly used aerobic treatment processes, the common activated sludge method and the biological turntable have problems such as high engineering investment, complicated processes and inconvenient operation and management; although the oxidation ditch has good treatment effects, the amount of residual sludge produced is small, but it covers an area Large; although the SBR method only needs to set up a single reaction tank to complete the functions of adjustment, aeration, precipitation, etc., the process flow is simple, and the area is small, but the operation and management of the method are strict, and most of the automatic control equipment depends on imports. The cost is high; the biological contact oxidation method has high volume load, stable treatment effect, low sludge output, no sludge expansion phenomenon, impact load resistance, mature operation and management experience.

Compared with the previous biological treatment methods, the biological contact oxidation method has the characteristics of low operating cost, compact structure, less land occupation, low investment, convenient operation and management, etc., which is more suitable for the actual requirements of this project.

Therefore, the main process of the wastewater treatment process of this project adopts the biological contact oxidation method. At the same time, the acidification hydrolysis tank is added in the treatment process, so that the macromolecular organic matter in the influent water becomes small molecular organic matter, which improves the biodegradability of the wastewater and is beneficial to aerobic Microbial decomposition and utilization, and remove part of the suspended solids.

In addition, in order to ensure the quality of the effluent water, a subsequent treatment process of flocculation, sedimentation and filtration is added. The final determination of the wastewater treatment process is: hydrolysis acidification + two-stage contact oxidation + flocculation sedimentation + filtration process.

  2.4, processing efficiency

   The wastewater treatment process has a good removal effect on COD, BOD5, SS, and the removal rates are respectively 91.7%, 96% and 85.7%. Thanks to the high-efficiency microbial technology, it can also effectively remove the ammonia nitrogen in the wastewater.

After treatment, the effluent quality of the sewage treatment station is: CODCr<100 mg/L, BOD5<20 mg/L, chromaticity<50 times, SS<50 mg/L, ammonia nitrogen<15 mg/L.

3. Conclusion

  A) The contact oxidation process is adopted, the process is mature and the operation is stable; the acidification hydrolysis tank is added in the process to effectively improve the water quality, improve the biodegradability of wastewater, and remove some suspended solids;

  B) Adopt a new type of combined packing + three-dimensional elastic packing, microbes are fixed well, and the film is easy to hang;

  C) Adopt high-efficiency microbial sewage treatment technology, with strong microbial activity and high pollutant removal rate;

d) The whole project adopts fully automatic control, the sewage treatment system runs automatically, the operation is reliable and stable, and the impact load resistance is strong. The effluent pollutant concentration is lower than the standard limit in Table 2 of the GB21905-2008 Extraction Pharmaceutical Industry Water Pollutant Discharge Standard Value, meet emission standards.


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