Biological treatment method, biological treatment system and bioreactor of coal chemical wastewater

Abstract

The invention relates to a biological treatment method of coal chemical wastewater, which adopts a biological reaction-muddy water separation integrated bioreactor. The method comprises the following steps of: sequentially feeding materialized and pre-treated coal chemical wastewater into an anaerobic bioreactor, an anoxic bioreactor, a first-stage aerobiotic bioreactor, a second-stage aerobiotic bioreactor and a third-stage aerobiotic bioreactor, selecting each aerobiotic bioreactor to discharge water and inflow into the anoxic bioreactor; and carrying out anaerobic acidification treatment by the anaerobic reactor, reinforcing a biological denitrification reaction in the anoxic reactor to remove non-gradable organic matters, completely decarbonizing by the first-stage aerobiotic bioreactor, and realizing the short-course nitratlon reaction and the whole-course nitratlon reaction by the second-stage aerobiotic bioreactor and the third-stage aerobiotic bioreactor, wherein the sludge concentration in the reactor can be guaranteed to be greater than 8mg / L due to the biological reaction-muddy water separation integrated bioreactor, the sludge age is greater than 60 days, the specific strains can be preferably cultured, and the function realization of a novel method can be guaranteed. The coal chemical wastewater is treated by the method, so that the discharged water can reach the requirement of the national wastewater comprehensive discharge standard.

Description

technical field [0001] The invention relates to the field of wastewater treatment, in particular to the field of coal chemical industry wastewater treatment containing high-concentration organic pollutants and ammonia nitrogen. Background technique [0002] Coal chemical industry wastewater is the wastewater generated during the coal chemical production process during high-temperature coal coking, gas purification, coking product recovery and refining. There are many kinds of pollutants in coal chemical industry wastewater with complex components, such as organic pollutants such as phenols, benzene series, nitrogen-containing heterocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, toxic inorganic pollutants such as sulfides, rhodanides, cyanides, and high concentration of ammonia nitrogen. Biological method is a treatment technology widely used at present, among which the traditional biological denitrification process (A / O process) and its improved process (su...

AI Technical Summary

Problems solved by technology

During the biological aerobic degradation process of the traditional activated sludge method, the degradation rate of such substances is very slow or cannot be degraded; on the other hand, the aerobic degradation process may produce long-chain acids and ketones with the ring opening of the PAH , lipids and other substances that are more difficult to be biodegraded, resulting in generally higher COD of treated wastewater, at 300-500mg / L

[0006] (2) On the other hand, the traditional biological process often uses a single aerobic reaction tank to remove organic matter and ammonia nitrogen, that is, aerobic heterotrophic bacteria and nitrifying bacteria grow simultaneously, and the biological process uses a high sludge return ratio (>150%) , so that the activated sludge periodically changes the growth conditions and exerts different biological functions, which is not conducive to the formation of functional flora and inhibits the activity of nitrifying bacteria, resulting in low removal efficiency of organic matter in the treatment process, poor operation stability, and high treatment costs

High concentrations of organic matter will inhibit the activity of nitrifying bacteria. Nitrifying reactions only occur at the end of the aerobic reaction tank, and nitrifying bacteria grow slowly, have a long generation cycle, and have poor toxicity resistance, which affects the stability of the biological process and increases the treatment cost.

[0007] (3) Coal chemical industry wastewater contains a high concentration of ammonia nitrogen. The traditional biological denitrification process takes a long time and consumes a lot of power and chemicals, resulting in high wastewater treatment costs.

However, it adopts one-step nitrification, short-range nitrification reaction and full-process nitrification reaction at the same time, and in order to reduce the nitrite content in the effluent water and reduce the toxicity of the effluent, it is necessary to focus on the full-process nitrification. Therefore, the oxygen demand and alkali consumption are relatively high. High processing cost and low processing rate

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