Thread Content
This post was last edited by sunjl1981 on 2013-1-6 at 20:05. The chlor-alkali industry belongs to the category of basic chemical raw material industries, and its products are used in many areas of the national economy and people’s daily lives. It is estimated that each 10,000 tons of chlor-alkali products can generate an industrial output value of 500–700 million yuan. Developing the chlor-alkali industry is an urgent desire of the related industrial sectors, and its level of development reflects, to a certain extent, the degree of development of the national economy. At the same time, it can be seen that the chlor-alkali industry is a major consumer of water and a significant source of pollution. One of the environmental issues that need to be addressed urgently in China’s chlor-alkali industry is the control of persistent organic pollutants in chlorine-containing products. In the calcium carbide production process, a mercury chloride–activated carbon catalyst is used, which is a significant source of pollution. Calcium carbide slurry wastewater not only contains acetylene gas and sulfur ions that are difficult to treat, but also has a high pH value. Its water quality and volume are random and variable, making it a type of wastewater that is difficult to treat and requires high treatment costs. Water treatment projects based primarily on membrane technology facilitate the reuse of wastewater, serving as a key technique for water conservation. This technology has been widely applied in China, and it is already in use in industries such as steel and petrochemicals. Our center was the first to conduct research on membrane-based treatment methods for the chlor-alkali wastewater generated by Tianjin Chemical Plant. The Tianjin Chemical Plant is located in Hangu District, Tianjin. It is a large-scale chlor-alkali chemical enterprise of ** level, producing products such as caustic soda, polyvinyl chloride, paste-like PVC, benzene monochloride, epichlorohydrin, hydrochloric acid, and liquid chlorine. In recent years, the economy of Hangu District has grown rapidly, but the increasingly scarce water resources have gradually become one of the key factors restricting business development. Excessive extraction of groundwater has caused land subsidence in the Tianjin area, resulting in annual direct and indirect economic losses of up to 10 billion yuan. After the Fifth Plenary Session of the 16th Party Committee included accelerating the development and opening up of the Tianjin Binhai New Area within the **overall strategic development plan, the economic development pace in Hangu District will further accelerate. How to resolve the conflict between rapid economic growth and limited water resources has become a major challenge ahead. Resource recovery technologies that involve advanced treatment of wastewater for reuse are undoubtedly effective solutions to this problem, and they represent the necessary path for the sustainable development of enterprises. The Tianjin Chemical Plant is not only the economic pillar of Hangu District but also a major water consumer in the same district. At present, the total amount of wastewater generated by Tianjin Chemical Plant is approximately 1,300–1,400 m3/h, of which acidic and alkaline wastewater accounts for about 300 m3/h; this wastewater is discharged directly to the district’s wastewater treatment plant for centralized treatment ； The volume of wastewater with poor water quality is approximately 500 m3/h, and it is discharged through the drainage system ； An additional 500–600 m3/h of wastewater with slightly better quality (heavy wastewater) is planned to be subjected to advanced treatment before being reused. At present, chemical plants only subject the wastewater with relatively good quality collected from their systems to simple sedimentation treatment before using it in applications that require lower water quality standards, such as washing waste materials in power plants. This basic approach to reusing wastewater can no longer meet the needs of the companies’ own development, nor is it in line with the spirit of building a resource-conserving society. Therefore, it is not only highly necessary but also urgent to employ effective and reliable treatment processes for the in-depth treatment and reuse of wastewater, as this can bring about significant economic, social, and environmental benefits. . Note ← ) # ← , .