How to Treat Brewery Wastewater
As a low alcoholic beverage, beer is produced mainly from corn and barley, with the addition of hops and fresh yeast for fermentation and brewing.
The beer production process uses a large amount of water, especially in the brewing and canning processes, and as a result, a large amount of fresh water is used, which generates a large amount of waste water.
The amount of wastewater generated varies from one production process to another.
In terms of water consumption per ton of beer, for example, the international advanced level is more than 6 t, and some domestic manufacturers are as high as 12 t. Breweries with new production processes can reach a level of 5-6 t.
Wastewater sources and characteristics
The main sources of wastewater are malt production process water for washing, soaking wheat water, germination cooling spray water, wheat tank water, washing water, coagulation washing water; saccharification process water, washing water; fermentation process water for fermentation pile washing, filtration washing water; packaging process water for bottle washing, sterilization water and cooling water and finished plant washing water.
Brewery wastewater mainly contains organic substances such as sugars and alcohols, and the concentration of organic substances is high, which is non-toxic but easily corruptible and harmful to the water body environment. Domestic brewery wastewater contains 1,000 to 2,500 mg/L of CODCr and 600 to 1,500 mg/L of BOD5, which is highly biodegradable and contains a certain amount of Kjeldahl nitrogen and phosphorus.
Wastewater treatment
In view of the characteristics of beer wastewater itself, beer wastewater cannot be directly discharged into water bodies. According to statistics, if industrial wastewater from breweries is not treated, the BOD value discharged from every 100 tons of beer produced is equivalent to the BOD value of 14,000 people's domestic sewage, and the suspended solids SS value is equivalent to the SS of 8,000 people's domestic sewage, so the degree of pollution is quite serious.
There are several ways to deal with it:
1. Acidification-SBR method for treating beer wastewater
Its main treatment equipment is acidification column and SBR reactor. In this method, when treating beer wastewater, the methane fermentation stage with long reaction time and high control conditions is abandoned in the anaerobic reaction, and the reaction is controlled in the acidification stage.
2. UASB-Aerobic contact oxidation process for treating beer wastewater
The main treatment equipment in this treatment process is upflow anaerobic sludge bed and aerobic contact oxidation tank. The main process of treatment is: the wastewater passes through the rotary drum filter, which removes more than 10% of SS, and the concentration of organic matter in the wastewater is reduced with the removal of wheat hull type organic matter.
3. New contact oxidation method to treat beer wastewater
The treatment process of this method is as follows: the wastewater is firstly removed most of the suspended matter by microfilter, and the effluent enters the conditioning tank, then the medium lift pump is pumped into the VTBR reactor for biochemical treatment, and the forced air supply by fan makes the wastewater contact with the filler to maintain the oxygen demand of biochemical reaction, and the effluent of VTBR reactor enters the precipitator to remove part of the shed biofilm to reduce the treatment load of air floatation equipment, and then flows into the VTBR reactor to remove the remaining biofilm. After that, the remaining biofilm is removed from the air flotation equipment, and the dirty floating sludge is sent to the sludge tank for concentration and dewatering.
4. Biological contact oxidation method for treating beer wastewater
This process adopts hydrolysis acidification as the pretreatment of biological contact oxidation. Hydrolysis acidification bacteria hydrolyze the solids in water into dissolved substances through metabolism, and degrade the large-molecule organic matter into small-molecule organic matter. Hydrolytic acidification not only removes some organic pollutants, but also improves the biochemical properties of the wastewater, which is beneficial to the subsequent aerobic biological contact oxidation treatment.
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