An ecological sediment treatment technology based on zero emission and 4R concept

In order to reduce the amount of the contaminated sediment treatment and utilization, an ecological technology of sediment treatment was developed based on zero emission & 4R (Reduce, Recycle, Reuse, and Revolution) concept, centrifugal solid-liquid separation technology and high speed suspended solid settlement technology by gravity and polymeric flocculants and the biological contact oxidation technology. The polluted sediment can be accurately divided into gravel, sand, silt and clay by four-stage treatment process. The dewatered clay is made into the mixture soil of the sponge city facilities or other building materials, gravel and sand are directly used as concrete aggregate, permeable bricks and the silts are used for backfill and planting soil. The treatment efficiency of the ecological sediment treatment technology is higher than the traditional sediment treatment process used in China, and there is no secondary pollution and cost savings. It can be widely applied to quick treatment of the sediment in the polluted rivers, reservoirs and lakes, and construction wastes of subway and tunnels. The investment of the new treatment system is about CNY25 million Yuan for deposits of 2.48 million cubic meters. The innovative ecological treatment technology has been successfully used in the sediment treatment of the Qingxi River in Qingxi Town, Dongguan City, Guangdong Province in 2019.