On April 19, 2017, the comprehensive treatment project for oily and saline wastewater in machining, designed and constructed by Jiangsu Wodetop Thermal Technology Co., Ltd. for a certain mechanical company in Suzhou, was successfully started at once. All operating indicators were better than the design indicators, and it received high praise from the owner.

This project is a self-developed system by the R&D personnel of Wardtop Company, combining years of engineering practice experience and adopting the company's core patented technology of salt containing wastewater pretreatment and multi effect evaporation crystallization, which can fully achieve "zero discharge" of oily wastewater in machining. The project enterprise is a Japanese funded enterprise with a global leading position in steel ball manufacturing. It was invested and established in Taicang, Suzhou in 2002, and its precision steel balls have always enjoyed the reputation of an international high-end machining manufacturer; However, the oily wastewater generated during its machining process has always been in a passive position in terms of "zero discharge" treatment. The incoming wastewater of this project has a high COD content and complex composition, mainly containing a considerable amount of oil, making it a typical difficult to treat wastewater. The advanced pre-treatment process optimized in this project adopts pre-treatment processes such as front-end oil separation sedimentation, Fenton oxidation, coagulation, flocculation, and air flotation. The post-treatment adopts a multi effect evaporation crystallization process. The condensate generated by evaporation crystallization is further treated and reused in the cooling tower or workshop cleaning water. The concentrated liquid produced after desalination flows back to the initial settling tank, achieving the goal of "zero discharge" of oily and saline wastewater.

In the pre-processing stage of this project, an advanced automatic dosing system is adopted, which can change the dosage in real time based on detection data; In the evaporation crystallization section, based on dynamic data and continuous sampling, the stable, continuous, and efficient operation of the system is ensured, and the resource treatment and utilization of oily and saline wastewater in industrial production processes are well achieved. The reuse rate of its wastewater is as high as 98.5%, ranking among the forefront of such technologies in China. This project is a successful case of the company's close integration of theory and practice in the field of environmental protection, which has played a positive role in promoting the construction of an ecological friendly society.