China has become a big country in the production and consumption of plastic products. In 2006, the output of plastic products has exceeded 40 million tons, ranking second in the world, and has maintained a double-digit annual growth rate for more than 20 years. It is foreseeable that with the increase in domestic consumer demand and the increase in the number of exports to the international market as a world-wide manufacturing base, the annual output of China's plastic products will continue to grow rapidly for a long period of time.

Characteristics of nano-active calcium carbonate: Compared with pure calcium carbonate, it has narrow particle size distribution range, reduced water absorption, reduced oil absorption value and good affinity with resin, which is beneficial to improve the tensile, compressive and wear-resisting properties of the product. After mixing, the melting time is shortened, the balance torque is reduced, the dispersion is high, the coloring is easy, and the surface gloss of the product is increased.

Since the quartz sand of the three-layer filter bed is smaller than the quartz grit of the double-layer filter, and there is a layer of finer heavy anthracite filter under the quartz sand layer, the other conditions are the same, even the filter speed is high. In some cases, the water quality of the filtered water of the three-layer filter media is better than that of the double-layer filter. When using quartz sand, try to use it together. Most of the sewage treatment plants in China implement the Class I B standard in the Pollutant Discharge Standards for Urban Sewage Treatment Plants, and the implementation of the Class A standard can greatly reduce the “phosphorus and nitrogen removal” of sewage. Subsequent to the pollution of the receiving water body, the effluent can be used as water reuse to solve the problem of water shortage in some areas of China. Quartz sand filter