Water resources are an important factor for economic development and sustainable social development, and urban sewage treatment rate has become an important symbol of whether a region is civilized or not. The serious pollution and increasing scarcity of water resources has now become a topic of concern all over the world. With the development of economy in China, the amount of urban sewage and industrial wastewater has increased sharply, providing a huge market space for the water treatment industry. D32 inverter has a wide range of applications in sewage treatment, and has achieved good economic and social benefits.