Waste water treatment method in starch and glucose production

Abstract

The invention discloses a waste water treatment method in starch and glucose production, wherein the waste water comprises corn steep liquor evaporative condensate water and processing waste water. The method comprises the following steps: a. firstly performing an anaerobic degradation reaction on the processing waste water after mixing and buffering; b. mixing the processing waste water treated by anaerobic degradation with the corn steep liquor evaporative condensate water, and performing an anaerobic denitrification reaction; c. performing an aerobic reaction on the waste water treated by the anaerobic denitrification reaction, and carrying out ammonia nitrogen removal and further degradation; and d. adding flocculants to the waste water treated by the aerobic reaction to perform a coagulation reaction, and removing suspended matters from the waste water before discharging. By comprehensively utilizing industrial waste water produced in the starch and glucose production in the waste water treatment to achieve the purpose of treating waste with waste, the method ensures the waste water treatment effect and simultaneously reduces the waste water treatment cost.

Description

technical field [0001] The invention relates to waste water treatment technology, in particular to a waste water treatment method in the production of starch and glucose. Background technique [0002] The starch and glucose production process using corn as raw material can produce a large amount of wastewater, including corn steep liquor evaporation condensate and process treatment wastewater, of which process treatment wastewater includes fiber washing, flotation concentration, protein press filtration and other processes in the starch production process The produced process wastewater, and the regenerated water and circulating cooling water of the ion exchange system in the subsequent glucose production process. [0003] Pollutants in cornstarch and glucose wastewater are mainly soluble organic matter such as starch, soluble protein, sugar, and organic acid. In addition, they also contain insoluble organic matter such as protein powder, corn bran, and inorganic substances ...

AI Technical Summary

Problems solved by technology

However, the A / O biological treatment method has the following problems in the treatment of starch and glucose production wastewater: due to the high COD emission per ton of pollutants discharged from starch production, there are more organic matter in the effluent after anaerobic treatment, and the organic matter load in the subsequent aerobic system is higher. , which is not conducive to the further degradation of organic matter; in addition, after anaerobic treatment of wastewater, high-concentration organic matter is degraded, COD and BOD are reduced, and at the same time, organic nitrogen compounds such as protein contained in wastewater will eventually degrade after entering the anaerobic reactor A high concentration of ammonia nitrogen, such a high concentration of ammonia nitrogen entering the subsequent aerobic treatment system can cause many adverse effects:

[0005] 1. The high concentration of ammonia nitrogen in the anaerobic effluent enters the subsequent aerobic treatment system. Excessively high ammonia nitrogen load will inhibit the activity of nitrifying bacteria and accumulate in one step of nitrifying ammonia nitrogen to nitrite nitrogen. On the one hand, it is not conducive to the nitrification and removal of ammonia nitrogen , on the other hand, since 1mg / L nitrous nitrogen will show as 1.14mg / LCOD in the process of COD determination, the apparent value of COD will increase

[0006] 2. The C / N ratio in the anoxic section is low, which is not conducive to denitrification and denitrification. High concentrations of nitrate nitrogen and nitrite nitrogen remain in the effluent of the anoxic section, so that after entering the subsequent aerobic section, the ammonia nitrogen nitrification reaction is inhibited.

In addition, due to the lack of carbon sources required for denitrification and denitrification, microorganisms will degrade themselves to provide carbon sources. The direct consequence of this is that the effluent is turbid, there are more suspended solids, and the COD rises

[0007] 3. If the nitrification reaction is relatively normal, high-concentration ammonia nitrogen can be nitrified into high-concentration nitrate nitrogen, which will make the pH in the reaction tank lower. If the nitrification reaction continues, the required alkalinity is insufficient, which is not conducive to the further full nitrification of ammonia nitrogen.

[0008] Combining the above unfavorable factors will eventually lead to problems such as high COD and ammonia nitrogen concentrations in the effluent, high SS content, deep color, low pH, etc., and it is difficult to reach the first level in the "Comprehensive Wastewater Discharge Standard of the People's Republic of China" (GB8978-1996) Emission Standards

Therefore, within the load operating range of the aerobic system, if the C / N ratio is increased to enhance the denitrification and denitrification capacity, substances such as sodium acetate and glucose are usually added to provide carbon sources, which will eventually lead to an increase in the cost of sewage treatment

Images