Economic achievements come with a price. Pollution is one. There have been numerous cases of the world’s rivers being polluted by heavy metal waste over the past 10 years. In China, lead, chromium, arsenic, cadmium and mercury are the five key heavy metal pollutants. Heavy metal ions in the water will enter the food chain and can accumulate in the human body. Scientists are trying to save these waterways, and CGTN reporter Yang Zhao met Shanghai Jiao Tong University’s Professor Li Liang, who has an unusual water treatment solution.