Method for realizing shortcut nitration of high ammonia nitrogen wastewater

Abstract

The invention discloses a method for realizing shortcut nitration of high ammonia nitrogen wastewater. The method comprises the following steps of: culturing nitrosation dominant flora; and performing ammonia sewage treatment by using the flora as an inoculum, namely adding the cultured nitrosation dominant flora into an aeration reactor to treat the ammonia wastewater, wherein the adding amount of the cultured nitrosation dominant flora accords with a condition that: sludge concentration is 800-2,000mg / L after the cultured nitrosation dominant flora is added; and the treatment conditions arethat: the temperature is 18-40DEG C, the dissolved oxygen is 0.1-3mg / L, and the pH is 7- 9. The unique nitrosation dominant flora culture method is adopted, stable and high-efficiency ammonia nitrogen wastewater treatment effect can be achieved, and the problem of instability of the shortcut nitration in actual application is solved.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering wastewater biological treatment, and in particular relates to a treatment method mainly used for high ammonia nitrogen wastewater, in particular to a method for stably maintaining high ammonia nitrogen wastewater in short-range nitrification. Background technique [0002] The biological denitrification of wastewater mainly relies on the joint action of nitrifying bacteria and denitrifying bacteria in activated sludge, and finally converts various forms of nitrogen in sewage into gaseous nitrogen and escapes from the water. From the perspective of nitrification process, ammonia nitrogen (NH 3 -N) is oxidized to nitrite nitrogen (NO 2 -N) and nitrate nitrogen (NO 3 -N) are two different reactions performed by two separate types of bacteria, which should be separable. From the perspective of denitrification process, NO 2 -N and NO 3 -N can be used as the final electron acceptor...

AI Technical Summary

Problems solved by technology

However, in practical engineering applications, it is difficult to stably control the DO concentration within the required low concentration range. Once the DO concentration is high, the short-cut nitrification will transform into the full-range nitrification

CN1785843A discloses a method for short-range nitrification of wastewater with low C / N ratio and high concentration of ammonia nitrogen. The method uses the nitrification granular sludge cultivated by anaerobic granular sludge as an inoculum, and gradually increases the concentration of ammonia nitrogen in the substrate to realize it. Although oxygen granular sludge has the advantage of fast cultivation speed, in the subsequent aerobic short-cut nitrification process, there are still shortcomings in the transformation from short-cut nitrification to full-range nitrification.

Although the control of external conditions such as temperature, dissolved oxygen, pH and sludge age will lead to HNO in the nitrification process 2 However, most of them are in the stage of laboratory research. How to maintain the long-term stable existence of nitrite after accumulation is the key to the short-range biological denitrification technology. The current research results show that only high temperature control methods can achieve better stability

Some conditions such as high temperature are also difficult to realize in actual engineering, so so far, the NO 2 - The successful application of -N pathway to realize biological denitrification in practical engineering is rare

Only the SHARON process developed by Delft University of Technology in the Netherlands is only used to treat sludge digestion liquid in sewage treatment plants. This process is based on the fact that the specific growth rate of nitrous bacteria is greater than that of nitric acid bacteria at high temperatures (30-35 ° C) to achieve short-range nitrification. The different control strategies for the growth rate of nitrifying bacteria determine that this process can only be applied to high-temperature wastewater, which limits its application

For most sewage treatment projects, the large-scale heating of water and keeping it at 30-35°C has become a bottleneck for the large-scale application of this process.

From the perspective of selective inhibition, many researchers have found that 0.6mg / L of free ammonia (FA) can almost completely inhibit the activity of nitric acid bacteria, but nitric acid bacteria have the ability to vary and adapt, and once they adapt to high concentrations of FA, they will Slow accumulation makes the short-cut nitrification system unstable, and stable FA concentration control is also unrealistic for sewage treatment plants

[0006] CN1911833A discloses a method for realizing short-range nitrification in a biological aerated filter with an inhibitor, the method is to use NaClO 3 As an inhibitor, selectively inhibiting nitric acid bacteria and retaining some nitrous bacteria, although it has the advantage of not using harsh environmental conditions to control the reaction process, but the ammonia nitrogen concentration in the water of this method needs to be strictly controlled at 30-80mg / L, and The biological aerated filter is used as the reaction carrier, so for high-concentration ammonia nitrogen wastewater, it is not suitable to use this method to achieve short-range nitrification when the concentration of ammonia nitrogen in the influent is higher than 100mg / L

Zu Bo et al. (Experiment on the enrichment of aerobic ammonium oxidizing bacteria in ordinary activated sludge, Journal of Chongqing University, 2005, 28 (2)) at pH 7.8-8.3, DO at 0.8-1.2mg / L, and temperature at 30± At 2°C, the enrichment of aerobic ammonia oxidizing bacteria was carried out by gradually increasing the concentration of ammonia nitrogen in the influent. This enrichment method can significantly increase the number of nitrosating bacteria, but the long-term Stability still needs to be further improved