Study on the Mechanism and Pattern of Synergistic Removal of Phosphorus in Wastewater by Steel Slag

In recent years, phosphorus has become a major pollutant in rivers and lakes, causing eutrophication of water bodies. When the phosphorus concentration in water exceeds a certain limit, it triggers massive algal proliferation, forming algal blooms, which seriously affects the balance of the aquatic ecosystem. Currently, China has accumulated over 1 billion tons of waste steel slag, and the crushed steel slag has characteristics such as high specific surface area and high porosity, which are favorable for phosphorus removal. This project explores and verifies the synergistic phosphorus removal mechanism of physical adsorption and chemical adsorption (forming HAP precipitate) of steel slag for phosphorus in sewage through experiments and tests such as SEM and XRD. The research was carried out in terms of adsorption time, initial phosphorus concentration of the effluent and safety of phosphorus removal from steel slag. And it is concluded that the optimal adsorption time for steel slag phosphorus removal is 20 minutes, the initial phosphorus concentration has a small impact on the phosphorus removal rate of steel slag, and steel slag can effectively treat high-concentration phosphorus-containing sewage; the heavy metal content in the leaching solution of steel slag is lower than the first-level emission concentration limit in the comprehensive sewage discharge standard, and steel slag can achieve reliable and safe phosphorus removal. This study provides new ideas for combining the utilization of solid waste steel slag with water pollution control.