The purification tank was first born in Japan. There are many professional purification tank manufacturers in Japan, and each enterprise has its own technical advantages. Most of the domestic purification tank technologies are based on Japanese products. Although the process principle is similar, in terms of technical precipitation, the internal structure optimization of products, the selection of equipment parts and the refinement of workmanship are still slightly insufficient compared with Japanese products. Strictly speaking, the top three purification tank products with comprehensive performance are Japanese brands. Domestic purification tanks have risen in the last 3-5 years, and the reputation of Shangda and CRRC is a little bit, but the performance of the equipment is just like that. Those that fail to reach the first-class A effluent are only the first-class B level. The CRRC projects in Changshu are all good for public visit, and there are still many problems in the project. The LD-S purification tank product of Liding Environmental Protection Co., Ltd. has a good cost performance. To be honest, there is not much difference between domestic technology and Japan, but the equipment workmanship is not as good as that made in Japan. Domestic sewage treatment indicators are different from those in Japan, which does not pay much attention to the treatment efficiency of total nitrogen and phosphorus. There are too many domestic brands, and I won't list them here. To say that the technology is top-notch, I have to learn from Professor Wang Chang's research. Attached below are some picture parameters of purification tanks made in Japan for your reference only. The specifications of small purification tanks in Japan are basically calculated according to the number of people. Five people are almost 1 tons, seven people are 1.5 tons, and 11 people are 2 tons. Finally, let's talk about the only criterion for testing the quality of equipment when the inlet water quality is similar.