This is the information that the China Chemical Industry News reporter learned from the 2017 National Water Quality Safety and Chlorine Dioxide Application Technology Symposium held in Qingdao, Shandong Province from August 18th to 20th.
The meeting was hosted by the National Chemical Standards Substances Committee, the Chlorine Dioxide Professional Committee, the China Urban Water Supply and Drainage Association Science and Technology Committee, and the China Chlorine Dioxide Society.
Cui Chongwei, director of the new National Standards Committee for Chemical Substances and chlorine dioxide professional committee and professor of environmental science at Harbin Institute of Technology, said that chlorine dioxide is recognized as the latest generation of broad-spectrum, high-efficiency, safe and environmentally friendly disinfectant for more than 70 years. History. The World Health Organization and the World Food Organization listed it as an A1 class high-efficiency bactericidal and disinfectant. Developed countries such as North America and Europe also apply it to sterilization and disinfection in various fields. China's Health Planning Commission has also approved it as a disinfectant for disinfectants such as drinking water, and can be used as a food additive. In addition, it also has the functions of algae removal, mildew resistance, antisepsis, preservation, deodorization and so on.
Professor Cui Chongwei said that the quality and safety of urban drinking water is related to the national economy and people's livelihood. As we all know, China's cities are generally severely deprived of water. With the large-scale construction and commissioning of projects such as “South-to-North Water Transfer, Yellow River Diversion, and Diversion to Tianjin”, the urban raw water source is diversified, the raw water quality is complicated, and the people’s health awareness is increasing. The performance, ancillary services and supervision of chlorine disinfection generators are placing increasing demands. Although the relevant laws and regulations have been relatively perfect, due to the weak foundation of our generator manufacturers and insufficient investment in R&D, the level of domestically produced generators is still low, and there is still a gap from well-known foreign brands.
In addition, by-products from chlorine dioxide disinfection are potentially toxic to human health. At present, countries around the world have established drinking water control standards for inorganic disinfection by-products of chlorine dioxide. The production of disinfection by-products is closely related to the chlorine dioxide dosage and the conversion rate of the generator.
Zhang Wei, a researcher at the China Center for Disease Control and Prevention, told reporters that as early as 2011, during the national water quality survey of municipal waterworks, 1185 municipal water plants in 29 provinces, autonomous regions and municipalities were surveyed, including chlorine dioxide. There are 376 disinfections, accounting for 31.7% (small and medium-sized water plants with a concentration of less than 50,000 tons). In 2007, the survey on the water supply of rural water plants in Beijing, including 109 rural water plants in 11 districts and counties at that time, 68.9% of the water plants equipped with drinking water disinfection devices were disinfected with chlorine dioxide. In recent years, the application of chlorine dioxide in the field of urban drinking water disinfection has been fully affirmed, and breakthrough progress has been made.
Song Lanhe, chief engineer of the Urban Water Supply and Water Quality Monitoring Center of the Ministry of Housing and Urban-Rural Development, said that according to the actual detection of drinking water quality in various places, there are currently more than normal water quality indicators with a large number of over-standards and high frequency. Among the 64 water quality unconventional indicators, only trihalomethane, trichloroacetaldehyde, monochlorodibromomethane, dichloroacetic acid and other indicators in the water plant exceeded the standard phenomenon, caused by chlorine disinfection and complex chlorine dioxide disinfection. Five indicators, such as tribromomethane, parathion, phthalate, styrene, and nickel, have only exceeded the standard in individual water plants.
Professor Yu Zuoliang, director of the Science and Technology Committee Office of China Urban Water Supply and Drainage Association and Minister of Technology of Shenzhen Water Group, said that the most important problem encountered in the process of chlorine dioxide disinfection is that there may be excessive by-products, mainly due to the unqualified raw water quality. Poor equipment performance, raw materials are not pure, and the use of technology is not good.
As the main drafter of GB5749-2006 "Sanitary Standard for Drinking Water", Zhang Wei further mentioned that chlorine dioxide has good disinfection performance and good application prospects, but in the case of increasingly complicated raw water conditions, Combined with the applicability analysis of the disinfection method of raw water quality, the application of chlorine dioxide in the disinfection of water supply is mainly for small and medium-sized water plants, the overall technical level of equipment is low, the risk of excessive by-products, the supporting capacity of water plants and The status quo of insufficient technical means. Not only do manufacturers have to make good equipment, but water plants also have good equipment and equipment to ensure that the water is up to standard.
Researcher Jia Ruibao, director of the Shandong Municipal Water Supply and Drainage Water Quality Monitoring Center, said: After the South-to-North Water Transfer Project, the water source in the Shandong water-receiving area is more complicated, the water source types are more diversified, the water quality fluctuates greatly, and the compound pollution is intensified. The chlorine or chlorine dioxide combined disinfection process has achieved good results and can significantly reduce the content of AOX such as organic disinfection by-products. Shandong Province is a major province for the production and application of chlorine dioxide. The meeting was very suitable in Qingdao. In recent years, local standards such as “Technical Specifications for Chlorine Dioxide Disinfection in Urban Water Supply Plants” (DB 37/T 5040-2015) have been formulated to further regulate the use of chlorine dioxide disinfection in water plants.
GB26366-2010 "Hybrid Standards for Chlorine Dioxide Disinfectants" is mainly involved in the formulation. Professor He Qihuan of the School of Chemical Engineering of Nanjing University of Science and Technology told the reporter that the "Disinfection Technical Specification" (2002 version) has been in use for 15 years and cannot adapt to the current diversity of disinfection products. The state of complexity, the necessity and urgency of its revision is very realistic, and the revision of the specification as soon as possible is the primary task of the health sector.
He Qihuan said that chlorine dioxide as a new type of disinfectant introduced is very different from the original chlorine-based disinfectant, and must be created independently in its definition and concept, such as the definition of chlorine dioxide disinfectant and activator. The definitions are not properly defined in existing standards at home and abroad. The definition of the commodity state and application state of the product in the standard should be innovative.
On August 20th, more than 200 delegates attended the Qingdao Shiqiao Public Utilities Group Water Company Hongshiya Water Plant to visit the production site of the JCT-type high-purity chlorine dioxide generator that has just been applied by Qingdao Juchuan Environmental Protection Technology Co., Ltd. .
Ge Xuezhen, general manager of Qingdao Juchuan Environmental Protection Technology Co., Ltd. told the reporter that the equipment is based on sodium chlorate, sucrose and dilute sulfuric acid, and can produce high-purity chlorine dioxide gas at a lower raw material price. It has a small volume, a conversion rate of more than 90%, and does not require heating during operation, further reducing operating costs. Suitable for medium and large water plants.
Liu Jinghua, Chairman of Shenzhen Sreman Fine Chemical Co., Ltd. told the reporter that since 1999, the company has been insisting on the research and development of high-purity chlorine dioxide gas generators for 18 years and has become a leading brand in China. Shenzhen Sreman worked closely with Qingdao Judayang Group Co., Ltd. to successfully apply pure chlorine dioxide gas to seaweed production process. Compared with other fungicides, the bactericidal effect of chlorine dioxide on microorganisms is significantly improved, and the yield of sodium alginate is also increased by more than 0.5%. At the same time, it also solves the safety hazard problem of using chlorine in the industry. Effectively remove pigment impurities mixed into alginate, improve the quality of alginate, and add a safe, green and environmentally friendly product to the seaweed industry. The technology has been granted a national invention patent. In addition to the advantages of high purity and low cost, it also supports remote monitoring and intelligent system and chlorite by-product over-standard control system, which makes users more assured during use.
Dr. Wu Mingsong, Secretary-General of the National Committee for Standards and Substances in Chlorine Dioxide, told the reporter that the disinfection effectiveness of traditional liquid chlorine disinfection, the safety of chlorine dioxide disinfection by-products, and the safety of transportation have become increasingly prominent. Alternative disinfectants for liquid chlorine have become a hot spot in the field of drinking water safety in recent years. Sodium hypochlorite and chlorine dioxide are the two most widely used alternatives to chlorine disinfection in urban drinking water plants. According to the latest statistics of the China Center for Disease Control, at present, hundreds of domestic drinking water plants and small and medium-sized water plants with a daily water supply of less than 200,000 tons have been disinfected with chlorine dioxide, accounting for nearly 40% of the national urban drinking water plants. %.
With the introduction of new products, new processes, new technologies and standards, chlorine dioxide as a green disinfectant, its application market has been further developed.
Wu Mingsong introduced that at present, the number of patents related to chlorine dioxide related products in China is relatively small and the technical content is low. In a situation where market competition is becoming more and more fierce and national supervision is becoming more and more strict, enterprises should increase their research and development capabilities to improve quality and efficiency.
Wu Mingsong believes that there is a demand for chlorine dioxide: water disinfection, reinjection water sterilization, epidemic prevention, surface disinfection, wastewater treatment, soil disinfection, animal husbandry, air treatment, fruit and vegetable preservation...
——Organized: At present, from the national level, to industry associations, academic institutions and enterprises, they have established a platform for mutual support. Have intellectual support, resource support, and information support.
- There are rules: At present, the competent authorities of the national government have formulated relatively complete regulations and standards. Nearly 20 standards related to chlorine dioxide analysis methods, water disinfection, surface disinfection, food additives, food disinfection, etc. were revised and updated.
- Promising: Chlorine dioxide has been continuously recognized by drinking water, air purification, soil remediation, etc. It is a disinfectant and treatment agent with suitable oxidizing power.
—— Opportunity: At present, with the strengthening of industry standards and supervision, the chlorine dioxide industry is facing a reshuffle and has not yet become the Red Sea.
Dr. Wu Mingsong said that the future development trend of the chlorine dioxide industry is the high purification of products. To this end, enterprises must continuously increase R&D investment and build well-known brands; adhere to professional ethics and improve product quality; continue to expand new application areas and clarify industry positioning.
The meeting was hosted by Qingdao Juchuan Environmental Protection Technology Co., Ltd. and Qingdao Judayang Group Co., Ltd. The meeting also received strong support from Qingdao Urban Water Supply and Drainage Water Conservation Association, Qingdao West Coast Public Utilities Group Water Co., Ltd. and Shenzhen Sreman Fine Chemical Co., Ltd. Nearly 200 representatives from urban water supply companies, chlorine dioxide equipment and preparation production and sales enterprises, university research institutes and government agencies from all provinces and cities across the country attended the meeting.
