Ammonia removal by TMCS technology will usher in a booming development

After completing several membrane deammoniation projects and operating them successfully for several years, we decided to promote this membrane contactor process worldwide. It has some advantages that users cannot resist.

For a long time, the primary method for treating high-concentration ammonia nitrogen wastewater has been using a stripping tower or steam stripping. A stripping tower can remove about 90% of ammonia nitrogen. However, in winter, particularly in colder areas, the operation of the stripping tower deteriorates. If the wastewater contains volatile organic matter or other harmful gases like hydrogen sulfide, discharging it into the air will cause environmental pollution. Additionally, the stripping tower occupies a large space and consumes a lot of energy.

As for steam stripping deammoniation, it has a very good ammonia removal effect with a high removal rate. In most cases, ammonia nitrogen can be reduced to the emission standard, and ammonia water can be obtained as a by-product. However, it has its drawbacks. Firstly, the initial investment is large, and secondly, it consumes a lot of energy, requiring a large amount of steam, which is challenging to operate in a factory without steam supply. Moreover, with the global focus on carbon reduction and carbon neutrality, using steam using fossil energy is increasingly restricted. 

The use of membrane contactors for treating high-concentration ammonia nitrogen wastewater has a history of about 20 years. However, this technology has not been widely adopted for several reasons. The first deammoniation membrane used in the industry is made of PP. This hollow fiber membrane has a diameter of about 0.3 mm, allowing for a large number of membrane fibers to be filled in a membrane assembly. It has a high specific surface area and high degassing efficiency. However, the pollution resistance of PP is not very good. It can maintain a good operating state for several years in pure water, but in sewage, especially when it contains organic matter, oxidants, and some fine suspended particles, the service life becomes very short. Organic matter will react with the PP membrane, causing swelling and destroying its surface hydrophobicity. Oxidants such as hydrogen peroxide and ozone will corrode the PP membrane. Additionally, particles in the water will adhere to the membrane surface, causing pollution and blockage. Therefore, despite the advantages of high deammoniation efficiency, low operating costs, and no secondary pollution, the use of membrane deamination technology has been limited.

In recent years, PTFE has gained popularity as a material for degassing membranes due to its numerous advantages. Firstly, it is highly resistant to various corrosive substances such as acids, alkalis, oxidants, and organic matter. Additionally, its low surface energy results in a very smooth surface, making it difficult for pollutants to adhere to. PTFE is also the most hydrophobic plastic and an excellent raw material for gas membrane production. However, the processability of PTFE is relatively poor, limiting the number of manufacturers capable of producing hollow fiber membranes with a minimum diameter of 0.8 mm. While PTFE membranes have a lower degassing efficiency per unit volume compared to those made of PP material, their exceptional corrosion resistance and anti-pollution performance make them a viable solution for industrial wastewater ammonia abatement. This makes the use of membrane ammonia removal process for industrial high-ammonia nitrogen wastewater a realistic and feasible solution.

Recently, in China, we have been pleased with the performance of the PTFE deammoniation membrane in real-world working conditions. We are committed to promoting its use worldwide. Below are the application scenarios in three different fields for your reference.

The pharmaceutical industry was the first to use PTFE deammoniation membranes. Wastewater in this industry often contains high concentrations of organic matter and solvent components, making it challenging to treat using traditional methods like air stripping due to the presence of VOCs. Chinese regulations prohibit air stripping due to the risk of secondary pollution, leaving steam stripping or MVR evaporation as the only options. However, both methods are energy-intensive and require a significant initial investment. Some manufacturers attempted to use PP deammoniation membranes in these cases but found that they had a short service life, typically failing after about six months. After replacing them with PTFE deammoniation membranes, the service life was significantly extended. The first pharmaceutical factory to make this replacement has been operating normally for over two years.

In the lithium battery and hydrometallurgical industries, there is a significant amount of high-concentration ammonia nitrogen wastewater with minimal organic matter but containing heavy metals. The ammonia removal process in these fields often results in the precipitation of tiny particles due to the decomplexation process of heavy metals. Traditionally, air stripping and steam stripping are used for ammonia abatement, but due to high energy consumption and the need for carbon emission reduction, more companies are exploring membrane deammoniation technology. However, they face the challenge of the short service life of PP membranes. Despite this, the number of users of deammoniation membranes in these industries is increasing. PTFE deammoniation membrane has better pollution resistance than PP membrane. Some manufacturers have started using PTFE membrane after verifying its excellent pollution resistance through small-scale tests, despite its higher price, to treat their high ammonia nitrogen wastewater.

The semiconductor industry generates a significant amount of high-ammonia nitrogen wastewater containing hydrogen peroxide. Manufacturers have been facing issues with the short lifespan of PP deammoniation membranes when treating these high-concentration ammonia nitrogen wastewater. However, pilot tests have shown that PTFE deammoniation membranes can replace PP deamination membranes and significantly prolong their service life.

We are experiencing continuous development and change, particularly in water treatment technology, which has now entered the era of membranes. PTFE deammoniation membranes address the shortcomings of PP deammoniation membranes' short service life and fully leverage the advantages of membrane deammoniation over traditional methods such as air stripping and gas stripping ammonia evaporation. Regarding ammonia abatement efficiency, energy consumption, operational costs, and investment benefits, PTFE deammoniation membranes outperform traditional methods. While it has higher influent water quality requirements in some aspects, its numerous advantages make it highly appealing and difficult to resist.