China endeavors to turn construction waste into resources

At China Construction Fourth Engineering Division Corp. Ltd.’s construction site in Guangzhou, capital of south China’s Guangdong province, residual waste is ground into fine aggregates and turned into bricks permeable to water.

The construction project is able to process 500 cubic meters of solid waste for eight consecutive hours per day on average, with the waste processing and recycling rate reaching 40 percent to 50 percent, said Niu Yongxu, manager of the project.

Turning construction waste into resources and putting them into use right on the construction site can not only save debris clearing and transportation fees, but effectively reduce dust and other kinds of environmental pollutants during transportation, Niu noted.

Since 2018, the Ministry of Housing and Urban-Rural Development of China has carried out a pilot project to treat construction waste in 35 cities and districts.

Under the pilot project, the 35 cities and districts have basically established a construction waste classification, management, and whole-process supervision system and accelerated the construction of waste disposal facilities and waste utilization projects.

It is estimated that the utilization rate of construction waste in the 35 cities and districts reached about 50 percent, 15 percentage points higher than that before the pilot project was implemented in 2018 and 10 percentage points higher than the national average of Chinese cities.

The annual construction waste disposal capacity of these cities and districts has exceeded the amount of local construction debris produced annually.

Construction waste can be divided into earth, mud, engineering ,demolition, etc.

It has been calculated that the amount of urban construction waste produced in China exceeds two billion tons a year, which is about eight times that of domestic waste and accounts for about 40 percent of the total solid waste generated in urban areas of the country.

Construction waste occupies a large land area and can pollute groundwater, soil, and air if it is mismanaged.

Accurate waste classification plays a crucial role in improving waste utilization rate.

An environmental technology company in east China’s Jiangsu province has an intelligent waste disposal line for waste generated from building decoration. The intelligent waste sorting robot of the line can accurately identify the material, size, and position of waste and then grasp and put it into the right waste container.

Waste from building decoration is complicated, as it includes concrete, plasterboard, paint bucket, and scrap metal, said Chen Lian, manager of the company, adding that through seven identification methods, the company’s automatic waste sorting technology can help classify such waste into more than ten categories and accurately sort it for reutilization.

Jiangsu province has speeded up the construction of waste disposal and reutilization facilities. So far, all cities with subordinate districts have built facilities for construction waste recycling. Over 60 percent of the counties and county-level cities of the province have built and put standardized waste utilization facilities into operation.

One of the goals of China’s construction waste treatment pilot project is advancing the construction of a whole-process waste supervision system.

Shanghai and some other cities in China have included the daily supervision of construction waste into the endeavor to build a smart city featuring network-based unified management, basically forming a waste supervision system that ensures real-time detection of violations and automatic generation of punitive measures through information sharing among government departments, big data analysis, and other information-based methods.