); [EMAIL_ADDRESS] (F.W. ); [EMAIL_ADDRESS] (S.C.)  
Yungao Li  
College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China; [EMAIL_ADDRESS] (T.L. ); [EMAIL_ADDRESS] (Q.Y. ); [EMAIL_ADDRESS] (X.W. ); [EMAIL_ADDRESS] (D.G. ); [EMAIL_ADDRESS] (F.W. ); [EMAIL_ADDRESS] (S.C.)  
Yungao Li  
College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China; [EMAIL_ADDRESS] (T.L. ); [EMAIL_ADDRESS] (Q.Y. ); [EMAIL_ADDRESS] (X.W. ); [EMAIL_ADDRESS] (D.G. ); [EMAIL_ADDRESS] (F.W. ); [EMAIL_ADDRESS] (S.C.)  
Yungao Li  
College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China; [EMAIL_ADDRESS] (T.L. ); [EMAIL_ADDRESS] (Q.Y. ); [EMAIL_ADDRESS] (X.W. ); [EMAIL_ADDRESS] (D.G. ); [EMAIL_ADDRESS] (F.W. ); [EMAIL_ADDRESS] (S.C.)  
Yungao Li  
College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China; [EMAIL_ADDRESS] (T.L. ); [EMAIL_ADDRESS] (Q.Y. ); [EMAIL_ADDRESS] (X.W. ); [EMAIL_ADDRESS] (D.G. ); [EMAIL_ADDRESS] (F.W. ); [EMAIL_ADDRESS] (S.C.)  
Yungao Li  
College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China; [EMAIL_ADDRESS] (T.L. ); [EMAIL_ADDRESS] (Q.Y. ); [EMAIL_ADDRESS] (X.W. ); gaodi1113@gmail. to repair seafloor water quality is an innovation developed by Japan for improving the marine environment [7; 8]. The utilization rate of steel slag in China is lower than that in other developed countries. According to statistics, China's total crude steel output was 928 million tons in 2019. The new produced steel slag almost reached 200 million tons, compared with the huge discharge of steel slag, meaning its utilization rate is only about 22% [9]. The massive accumulation of steel slag not only occupies land and pollutes the environment, but also the heavy metal elements in steel slag are leached by rainwater to cause serious pollution to the soil and groundwater, which threatens the life and survival of the surrounding residents [10]. With the development of circular economy and the gradual promotion of energy saving and emission reduction all over the world, more and more attention has been paid to the resource utilization of steel slag. Microalgae refers to the kind of microorganism that is tiny in shape with chlorophyll a in cells and can process photosynthesis [11]. Microalgae, with a variety of kinds, is widely scattered in waters such as oceans and lakes, and has a strong adaptability to environment, a short growth cycle, a high absorption rate of N and P and is easy to cultivate [12]. Microalgae can be produced by wasstelands and mudflat lands, leaving much land for agriculture, whose per unit yield is several times more than higher plants [13]. Its various metabolites are rich in such active ingredients as protein, grease and pigment [14]. It has such photosynthetic organs as chloroplast, which can directly convert solar energy into chemical energy. CO\({}_{2}\) sequestration efficiency is high. Algal biomass can be used for the production of energy materials [15]. The mainly factors influencing microalgae's growth include light, pH value, metal ions, temperature, nutrients, carbon sources and so on. At present, microalgae's application fields focus on medical food [16], renewable energy [17], wastewater purification [18] and so on. There are many nutrient elements in slag that are necessary for microalgae's growth, such as Fe, P, Ca, Mg, etc., so slag can provide nutrition for microalgae's growth. Culturing microalgae by slag can lower the cost and solve the problem of lacking Fe during the process of marine microalgae's growth. Meanwhile, it can alleviate the phenomenon of the substantial stacking of slag. Culturing microalgae with slag as nutrition provides a new perspective for the industrialization of microalgae and the resource utilization of steel slag.