The researchers tested different types of powdered activated carbon to find the best one for cleaning up polluted water from the Huangpu River. They found that adding powdered activated carbon made from bamboo can greatly improve the water quality by removing organic pollutants. The more powdered activated carbon they added, the more pollutants were removed. Using bamboo powdered activated carbon at a dosage of 10-15mg/L can reduce the pollutant levels in the water to very low levels, making the water much cleaner.