Abstract
Steel making slags are produced as a byproduct from the pyrometallurgical processing of iron requirement. Steelmaking slags consist mainly of calcium, silica, iron, aluminium and magnesium, and these are utilized for regeneration of sea desertification in coastal area with humic substances because iron is necessary for algal growth. However, these may contain some hazardous trace metals, and a risk assessment by culture experiments with leaching and bioconcentration testing is necessary prior to the practical use of steelmaking slags to coastal areas. In this study, we examined the effect of leachate elements from the slags with humic substances on the growth of algae. We also evaluated behavior of leachate elements from the slags and bioaccumulation in the algal cells. Addition of steelmaking slags(containing 17% of T-Fe) with humic substances as a fertilizer enhanced the growth of microalgae. The concentrations of Al, Mn, and Pb in the algal cells were higher than those in the culture media, although they are almost the same levels as those in the control. The hazardous metals such as Cr, Pb and Cd, regulated under the environmental legislation, were below the standards and/or under detection limits.
