Ammonia nitrogen wastewater for the first time to achieve resource treatment

(Reporter Li Daqing) On December 2nd, the results of the National 863 Program project developed by the Institute of Process Engineering of the Chinese Academy of Sciences and Tianjin University, “High Concentration Ammonia Nitrogen Wastewater Treatment Technology and Engineering Demonstration” passed the Chinese Society of Environmental Sciences in Beijing. Identification of the results of the organization. The project broke through the high-concentration ammonia nitrogen wastewater treatment problem and formed a complete set of high-concentration ammonia nitrogen wastewater treatment process with independent intellectual property rights. The ammonia nitrogen pollutant reduction rate and resource utilization rate were all greater than 99%, and the ammonia nitrogen wastewater treatment was realized.

According to the 2009 China Environmental Statistics Annual Report, the total amount of ammonia nitrogen discharged from wastewater in China has reached 1.226 million tons, far exceeding the environmental capacity; and among these, ammonia nitrogen emissions from eight industries including high-concentration ammonia-nitrogen wastewater in chemical industry and non-ferrous metals are included. It accounts for 85.9% of the total industrial ammonia emissions in the country. In the past, the removal rate of ammonia in industrial wastewater was less than 68%, and the ammonia nitrogen removed could not be used as a resource.

With the support of the 863 Program, the Chinese Academy of Sciences' Process Engineering Institute and Tianjin University have jointly developed a full-process process and industrialized application device for the “recycling of highly concentrated ammonia nitrogen wastewater”. This technology is based on the difference in the relative volatility of ammonia and water molecules, quantified design by distillation and deamination process, design and manufacture of new tower internals with high throughput, low resistance, high separation efficiency, anti-fouling, and full automation control. The existing process has high energy consumption and equipment is easy to plug and other issues, to achieve the industrialization of high-concentration ammonia nitrogen wastewater treatment. Ammonia nitrogen raw wastewater with an ammonia concentration of 3-30 g/l is treated by this technology, and the ammonia nitrogen concentration can be reduced to less than 10 mg/l, reaching the national first-class discharge standard, and the treated ammonia nitrogen is all in the form of high purity **. Recycling has realized the utilization of resources, and the reduction rate and utilization rate of ammonia nitrogen have been greater than 99%. No secondary pollution such as waste water, waste gas, and waste slag has occurred in the entire process.

It is understood that the current project team has used the technology has been completed in Tianjin, Fujian, Liaoning, Jilin, Guangdong, Hunan and other seven construction projects with a scale of 100-400 tons / day of demonstration projects, all stable operation. Some companies that adopt this technology will be able to make a profit of 2-6 yuan per 1 ton of waste water after offsetting their balance in the processing. Due to its good environmental and economic benefits, this technology has been listed by the Ministry of Environmental Protection in 2010 as "National Advanced Pollution Prevention and Control Demonstration Technology Directory."