High-concentration nitrogen-containing organic wastewater denitrification device based on biochemical-supercritical water oxidation coupling technology

Abstract

The invention discloses a high-concentration nitrogen-containing organic wastewater denitrification device based on a biochemical-supercritical water oxidation coupling technology. The device comprises a material conveying system, an anaerobic system, a first anoxic system, a first aerobic system, a second anoxic system, a second aerobic system, a sedimentation tank, a nitrification liquid reflux system, a liquid oxygen supply system, an organic wastewater pretreatment system, a supercritical water oxidation reaction system, a cooling depressurization system, a heat exchange system, a softened water conveying system and a separation system, and an energy recovery system. According to the present invention, with the treatment innovation idea of first-generation and then supercritical water oxidation, the structure design is reasonable, the nitrogen-containing organic wastewater with characteristics of high toxicity and difficult degradation can be effectively degraded, and the separation of the gaseous nitrogen, the nitrogen-containing liquid compound and the salt, the pollution-free emission of the gaseous nitrogen and the recycling of the nitrogen-containing liquid compound can be achieved.

Description

technical field [0001] The invention belongs to the technical field of environmental protection and organic wastewater harmless treatment devices, and is a denitrification device that organically combines biochemical methods and supercritical water oxidation methods, and specifically relates to a high-concentration nitrogen removal device based on biochemical-supercritical water oxidation coupling technology. Nitrogen-containing organic wastewater denitrification device. Background technique [0002] Supercritical water oxidation (SCWO) technology has been applied to remove stable and toxic nitrogen-containing organic compounds due to its advantages of fast reaction rate, complete reaction (>99.99%), self-heating of reaction, and no secondary pollution. , ammonia nitrogen, as an important nitrogen-containing intermediate product of nitrogen-containing organic matter, has good stability at high temperature. Even if the temperature rises to 550°C, the removal rate of ammoni...

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Problems solved by technology

[0003] However, in many existing supercritical water oxidation patents, the denitrification device for supercritical water oxidation of nitrogen-containing organic matter is rarely mentioned, and neither the denitrification of organic matter nor the poor biochemical property of organic matter is considered.

[0004] Based on supercritical water oxidation has problems such as reactor corrosion, salt deposition, heat transfer, etc., although salt deposition is considered The problem is that the reactor is equipped with a stirrer, a double-layer partition for placing the catalyst, and a salt storage tank for discharging nitrates, but it does not fully consider the blockage of the reactor pipes by nitrates, although the problem of heat transfer is also considered , but the thermal energy released by supercritical water oxidation has not been fully utilized. Although it is considered that the removal rate of ammonia nitrogen and the removal rate of total nitrogen can be improved through staged oxidation, the staged injection of oxidant is not considered.

In addition, although the use of supercritical water oxidation technology to effectively remove nitrogen has been considered, the harsh conditions (high temperature and pressure) of supercritical water oxidation technology have been ignored to indirectly increase the cost of organic matter denitrification

Although it is considered that the ammonia nitrogen removal rate can be improved by increasing the temperature and injecting auxiliary fuels (such as methanol, ethylene glycol, isopropanol, etc.) To a certain extent, the removal rate of ammonia nitrogen is not obvious when the temperature is raised, and the temperature rise indirectly reflects the high temperature resistance of the reactor and increases the cost of making the reactor

Since the possible low BOD of nitrogenous wastewater was not considered 5 / COD value, that is, the problem of poor biodegradability that may exist in sewage is not considered

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