Pharmaceutical wastewater treatment project

1. Project overview

There are many kinds of wastewater in this wastewater treatment project, and the drainage time of production wastewater is uncertain, resulting in unbalanced water and quality, and large fluctuation of sewage concentration, which brings difficulty to the stability of biochemical treatment of sewage. 2. High concentration of organic matter, especially the wastewater produced by water extraction, alcohol extraction and concentration of Chinese patent medicine, belongs to high concentration organic sewage, with a wide variety of wastewater, complex composition and acidic pH value. There are no conditions for direct biochemical treatment. Wastewater contains lignin, fiber, organic acid, tannin and other macromolecular organic matter, low BOD/COD ratio, poor biodegradability, containing a large number of organic matter difficult to biodegrade and even toxic side effects to microorganisms, the biodegradation rate is slow. After the completion of the traditional Chinese medicine wastewater treatment project, the sewage treatment capacity is 420m3/d, of which the high-concentration wastewater is 100m3/d and the low-concentration wastewater is 320m3/d. The high concentration wastewater and low concentration wastewater are pretreated respectively and then mixed for treatment, which effectively reduces the treatment cost and makes the whole system economical.

2. Design inlet and outlet water quality

According to the data provided by the company and the wastewater site operation data, the design of inlet water quality is as follows:

pH: 4~9

COD: 12500mg/L

SS: 1100mg/L

The effluent of the project meets the Level A standard of Pollutant Discharge Standard of Urban Sewage Treatment Plant, Table 2 standard of Water Pollutant Discharge Standard of Mixed Pharmaceutical Industry and Water pollutant Discharge Standard of Extraction pharmaceutical Industry Enterprise. The project wastewater reuse meets the washing water standard of "Urban Sewage Recycling Industrial Water Quality". The main indicators are as follows:

pH: 6-9

Chemical oxygen demand: 50mg/L

5 days BOD: 10mg/L

Suspended matter: 10mg/L

Animal and vegetable oil: 1mg/L

Oil: 1mg/L

Anionic surfactant: 0.5mg/L

Ammonia nitrogen (N) : 5mg/L

Total nitrogen (N) : 15mg/L

Total phosphorus (in P) : 0.5mg/L

Chroma: 30

Number of fecal coliforms (individual /L) : 103

Acute toxicity: 0.07mg/L

Total organic carbon: 20mg/L

Reuse water standard

pH: 6.5-9

5 days BOD: 30mg/L

Suspended matter: 30mg/L

Chroma: 30

Number of fecal coliforms (pieces /L) : 2000

3. Sewage treatment process analysis

Based on the analysis of the status quo of the sewage station of the enterprise, the following measures are adopted to expand and renovate the sewage treatment station:

A. The current low-concentration wastewater of the sewage station contains some high-concentration wastewater, but the discharge is irregular and the water quality changes greatly, so the low-concentration wastewater must be pretreated together with the high-concentration wastewater, which is the main reason for the excessive sludge output of the sewage station. Therefore, Party a shall completely separate the two wastewater streams in this expansion.

b, low concentration wastewater water quantity is large, the original rotary filter is difficult to meet the requirements, because the replacement of a higher filtration capacity, fiber separation capacity of stronger rotary filter for pretreatment; The amount of high-concentration wastewater is small, so it can continue to be pretreatment by the original process of "regulating tank → rotating filter → coagulation air floating → coagulation precipitation".

c. Highly concentrated wastewater contains saponins, stearic acid, oleic acid and other components, so a certain amount of calcium chloride is added to the original reagent in the coagulation gas floating section to enhance the coagulation effect on the wastewater.