Against the backdrop of the rapid development of the waste incineration power generation industry, flue gas purification is the core link to ensure environmentally friendly emissions. At present, most domestic waste incineration power plants adopt the combined process of "semi-dry method + dry method" flue gas purification. However, in some operating conditions, the wet desulfurization process of flue gas will inevitably produce acidic wastewater with significant characteristics such as high salt and high ammonia nitrogen (i.e., flue gas washing wastewater). As a key process wastewater discharged at the end of waste incineration power plants, the flue gas washing wastewater has a high concentration of TDS (Total Dissolved Solids), suspended solids and ammonia nitrogen, and extremely poor biodegradability. Traditional biochemical treatment processes are difficult to achieve the ideal treatment effect, which has become an important pain point restricting the environmental protection compliance discharge of power plants.

Against this backdrop, Shandong Huanke Environmental Protection Technology's internal circulation ammonia nitrogen stripping ammonia removal system, with its targeted technical design and excellent treatment efficiency, provides an efficient solution to the problem of high ammonia nitrogen in flue gas washing wastewater. It can directly reduce the ammonia nitrogen concentration from over 1000ppm to below 20ppm, fully meeting the ammonia nitrogen control requirements of enterprise drainage.

I. Core Characteristics and Treatment Difficulties of Flue Gas Washing Wastewater from Waste Incineration Power Plants

The generation of flue gas washing wastewater is directly related to the wet desulfurization process of flue gas. Pollutants such as ammonia and nitrogen oxides in the flue gas react with the desulfurization agent and dissolve into the water, forming industrial wastewater with multiple complex characteristics. The treatment difficulties mainly lie in three aspects: First, the pollutant concentration is high, with ammonia nitrogen content ranging from several hundred ppm to over a thousand ppm. At the same time, it is accompanied by high salt and high suspended solids, and the water quality composition is complex. Second, it has poor biodegradability. The acidic substances, heavy metals and refractory organic matter contained in the wastewater inhibit the activity of microorganisms. The efficiency of traditional biochemical treatment processes is extremely low, and in some cases, they cannot operate normally. Thirdly, the environmental protection requirements are strict. As the terminal wastewater of power plants, its discharge must strictly comply with relevant regulations such as the "Pollution Control Standard for Municipal Solid Waste Incineration" (GB 18485-2014). The ammonia nitrogen emission limit is strict, and the pressure to meet the treatment standards is high. Traditional physicochemical treatment processes often have problems such as high energy consumption, high risk of secondary pollution, and unstable treatment effects, making it difficult to meet the treatment requirements of tobacco washing wastewater.

Ii. Core Technical Advantages of the Internal Circulation ammonia nitrogen stripping ammonia removal System

Shandong Huanke Environmental Protection's internal circulation ammonia nitrogen stripping ammonia removal system is precisely developed based on the characteristics of flue gas washing wastewater. With the core goals of "efficient nitrogen removal, energy conservation and consumption reduction, environmental protection and controllability, and resource recovery", it has formed five core technical advantages, comprehensively solving the treatment difficulties

Efficient nitrogen removal, no worries about meeting standards: The system integrates multiple core mass transfer enhancement technologies. By optimizing the gas-liquid contact structure, it significantly improves the ammonia nitrogen desorption efficiency, with a stable ammonia nitrogen removal rate of 90% to 95%. For the high ammonia nitrogen concentration of over 1000ppm in the flue gas washing wastewater, it can be directly treated to below 20mg/L, easily meeting the strict ammonia nitrogen requirements of power plants for drainage and completely eliminating concerns about compliance with discharge standards.
Energy conservation and consumption reduction, with controllable costs: Innovatively adopting a full closed-loop gas circulation design of "fan - ammonia removal tower - acid absorption tower - fan", it achieves 100% gas reuse without the need for additional gas sources. Meanwhile, the heat loss during the internal circulation process is extremely low. The system can maintain a constant temperature operation state independently without the need for additional heating equipment. Compared with the traditional stripping process, the energy consumption is reduced by 30% to 50%, significantly lowering the operating cost of wastewater treatment in power plants.
Environmentally friendly and non-disruptive, eliminating secondary pollution: The fully enclosed gas circulation structure, combined with a zero exhaust emission design, restricts the ammonia gas produced by desorption within a closed system throughout the process. After subsequent acid absorption treatment, it will not leak out, completely eliminating the risk of air pollution caused by ammonia gas emissions. This achieves an environmentally friendly and non-disruptive wastewater treatment process, meeting the strict environmental control requirements of waste incineration power plants.
Resource recovery, turning waste into treasure: The system is equipped with a directional acid absorption stage. After desorption, the ammonia gas is purified by water washing and then reacts with the acid to produce high-quality by-product ammonium sulfate. Ammonium sulfate can be used as agricultural fertilizer and other resources for recycling and utilization, transforming the original pollutants into economically valuable products, achieving the dual benefits of "wastewater treatment + resource recovery", and enhancing the resource utilization level of power plants.
Intelligent adaptation and stable operation: Equipped with a complete set of intelligent control system, it can monitor the water quality and quantity fluctuations of the washing wastewater in real time, automatically adjust the fan speed, liquid flow rate, pH value and other operating parameters, ensuring the system can still operate stably under complex working conditions. It does not require dedicated personnel to be on duty around the clock, significantly reducing the pressure of operation and maintenance management, and is suitable for the continuous production rhythm of waste incineration power plants.
Iii. Application Value and Industry Significance of the Process

The application of the internal circulation ammonia nitrogen stripping ammonia removal system in the treatment of flue gas washing wastewater from waste incineration power plants not only effectively solves the problem of high ammonia nitrogen wastewater treatment, but also brings multiple industry values: from an environmental protection perspective, it achieves efficient removal of ammonia nitrogen in flue gas washing wastewater and zero exhaust gas emissions, helping power plants fully implement environmental protection compliance requirements and avoid environmental protection penalty risks; From an economic perspective, energy conservation and consumption reduction can lower operating costs, while recovering by-products of ammonium sulfate can create additional economic benefits and enhance the overall profitability of the power plant. From a technical perspective, it has broken through the adaptation limitations of traditional processes for the poor biodegradability and complex water quality of flue gas washing wastewater, providing a reliable physicochemical treatment technology path for the terminal wastewater treatment of waste incineration power plants.

With the continuous tightening of domestic environmental protection policies, the requirements for wastewater treatment in waste incineration power plants will further increase. The internal circulation ammonia nitrogen stripping ammonia removal process, with its targeted technical design, excellent treatment efficiency and significant economic and environmental benefits, is expected to become the preferred solution for the treatment of flue gas washing wastewater in waste incineration power plants, providing strong support for the green and low-carbon development of the industry.