Coking wastewater treatment method

Abstract

The invention provides a coking wastewater treatment method, which is characterized by comprising the following steps: introducing coking wastewater to an anaerobic tank and an anoxic tank, and carrying out denitrification to remove nitrogen by using refractory organic matters in the wastewater as a carbon source; then carrying out two-stage aerobic biological treatment to convert ammonia nitrogen into nitrite nitrogen and nitrate nitrogen by virtue of nitration reaction, wherein biochemical effluent does not reach emission standard; and carrying out coagulation-sedimentation treatment, namely carrying out A / A / O1 / O2 (anaerobic / anoxic / first-stage aerobic / second-stage aerobic) coagulation combined process. The method provided by the invention does not need the introduction of additional carbon sources such as methanol, removes nitrogen through denitrification by using the refractory organic matters in the wastewater as the carbon source, reduces the load of sequent aerobic segment and reduces power consumption. Phenol-containing sodium carbonate wastewater and the basicity generated by the denitrification can supply the basicity required by the nitration reaction, thus reducing the consumption of sodium hydroxide and lowering the running cost.

Description

technical field [0001] The invention belongs to the field of sewage treatment, in particular, the invention relates to a coking wastewater treatment method. Background technique [0002] The coking wastewater treatment process is mainly divided into physical and chemical treatment and biological treatment. Physicochemical treatment methods include ammonia distillation, incineration, coagulation precipitation, membrane separation, extraction, and biological treatment includes ordinary activated sludge, A / O (anoxic / aerobic) method, A / A / O (anaerobic / anoxic / aerobic) method, SBR method, etc. [0003] Ordinary activated sludge method can effectively remove phenol and cyanide in coking wastewater, and both indicators can meet the national discharge standards. However, because this technology cannot remove refractory organic pollutants in coking wastewater, COD, Ammonia nitrogen and other indicators are not up to standard, especially for ammonia nitrogen pollutants have almost no ...

AI Technical Summary

Problems solved by technology

[0007] However, in the actual operation of the above-mentioned methods such as A / O, A / A / O, and A / O / O, it is difficult for COD and ammonia nitrogen to reach the standard at the same time, and they are discharged after being diluted with industrial water. The concentration of ammonia nitrogen is high, while the concentration of biodegradable COD in the influent is low, resulting in a serious shortage of organic matter in the denitrification carbon source in the anoxic section. In addition, the influent COD concentration in the aerobic section is high and contains bioinhibitory organic matter, which inhibits the growth of nitrifying bacteria. activity, making it difficult for ammonia nitrogen to reach the standard

[0008] Therefore, the purpose of the present invention is to provide a coking wastewater treatment technology, which can effectively remove impurities such as COD and ammonia nitrogen, so that the effluent water quality can reach the national first-level discharge standard, so as to solve the technical problem that the COD and ammonia nitrogen indicators of coking wastewater cannot reach the standard at the same time

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