Overview

Feed mills will produce a lot of unpleasant odors during the production and fermentation process. The gas produced is mainly the heating of the production workshop. If the waste gas is not treated, it will cause certain pollution to the atmospheric environment. Therefore, most feeds The factory uses spray water to absorb waste gas, and the spray water is recycled. The circulating spray water repeatedly absorbs waste gas and particulate dust, which produces a certain concentration of wet scrubber wastewater. The waste water contains various production raw materials and ingredients. Complicated, after repeated spraying, spraying wastewater with higher concentration is produced.

Treatment of wastewater from wet scrubbers in feed mills

The spray washing water in the production workshop of the feed factory wet scrubber wastewater contains a lot of organic components, some also contain fluoride components, and the concentration of pollutants is relatively high. Most of the organic components are contained in the organic feed components of the pollutants. Brings good biodegradability, but if the wastewater is not treated in time, it will also produce unpleasant odors, which will affect people's health, and discharge without treatment will cause irreparable damage to the water environment.

Sources and characteristics of wastewater

• The spray wastewater comes from the full contact of the exhaust gas with the liquid medicine flowing on the surface of the filling, as well as the spray water during the drying and cooling process during the processing, and part of it comes from the spraying of the exhaust gas generated during the heating process. Contains inorganic substances such as fluoride, chloride, ammonia nitrogen, silica and other substances;

• The amount of spray wastewater is not large, but the concentration of pollutants is high;

• Wastewater contains small particles, which cannot be easily removed after coagulation and sedimentation in the early stage;

• The wastewater contains organic substances with good biodegradability, which is conducive to the subsequent biochemical treatment.

• Deal with difficulties

• The wet scrubber wastewater has a small inflow at a time and contains relatively high concentrations of organic pollutants;

• Wastewater contains a large number of suspended particles, some of which have small particle size, poor sedimentation, and are difficult to remove;

• The wastewater contains ammonia nitrogen and other substances, which leads to a high concentration of ammonia nitrogen in the wastewater and increases the difficulty of treatment;

• The biodegradability of feed wastewater is good, which is a favorable condition for biochemical treatment.

Treatment process selection

Since the feed wastewater contains biochemical microorganisms, it is a good condition for biochemical treatment. Therefore, in the biochemical stage, the method of "anaerobic + contact oxidation" can remove most of the soluble organic pollutants, while combining with physicochemical Treatment method: air flotation, coagulation sedimentation, etc., to further treat wastewater, effectively removing suspended particulates and organic matter in wastewater.

Anaerobic treatment: Using the high-efficiency degradation of feed pellet sludge, most of the organic matter in the sewage is decomposed into carbon dioxide and methane, and most of the organic pollutants are removed under the action of methanogens.

Aerobic treatment: Biological contact oxidation process is currently a widely used treatment method in sewage treatment. It uses the full contact of microorganisms and pollutants to further remove pollutants and reduce the ammonia nitrogen content in wastewater.

After physical and chemical coagulation, air flotation and other preliminary treatments, combined with anaerobic and aerobic comprehensive treatment, the purpose of removing pollutants from sewage is achieved, and the sewage can be discharged after reaching the standard.