Abstract : This paper takes the environmentally friendly water treatment industry as an example, focusing on the application of frequency converters and analyzing their energy-saving performance. Keywords : Frequency converter, environmental protection, purification 1 Introduction The serious pollution and increasing scarcity of water resources have become a topic of global concern. In fact, in recent years, with the development of China's economy, the amount of urban sewage and industrial wastewater has increased dramatically. By 2000, urban sewage discharge had increased from 6.012 billion cubic meters in 1981 to 22.1 billion cubic meters, and industrial wastewater had increased to 19.4 billion cubic meters. The surge in sewage is flowing into rivers and lakes and even into the water sources of urban residents. To address this, the state decided that 667 cities with a population of over 100,000 must build wastewater treatment plants by 2005, so that wastewater treatment capacity could reach 60% by 2010. Currently, China's annual environmental protection investment in water treatment reaches over 30 billion yuan, and it is estimated that the water treatment market will need over 50 billion yuan annually in the future. Such a large demand provides a huge market space for the environmentally friendly water treatment industry, and also brings greater opportunities to the important execution product in the industry - frequency converter. According to conservative estimates, the annual consumption of frequency converters for environmental water treatment will exceed 100 million yuan. This article discusses the application analysis of frequency converters in the water treatment environmental protection industry. 2 Energy-saving application of frequency converters in water treatment environmental protection engineering The electromechanical equipment for sewage treatment generally includes the following aspects: [1] Biochemical treatment series: microporous aeration system, etc. (2) Sludge treatment series: dosing system thickener, belt filter press thickener, plate and frame filter press, horizontal spiral centrifuge, etc.; (3) Disinfection treatment series: chlorinator ultraviolet sewage processor, rack-type ultraviolet sterilizer, etc.; (4) Sludge discharge equipment series: sludge scraper, sand suction machine, etc. From the perspective of practical application, basically every treatment method needs to use frequency converters or has a significant improvement effect after the application of frequency converters. Here are some examples. [b][align=center]For detailed information, please click: Variable Frequency Energy Saving Analysis of Water Treatment Equipment[/align][/b]