This chapter describes effects of an eluate from steelmaking slag on
phytoplankton, particularly Chlorella species as model phytoplankton. Eluates used to
assess toxicity in this study were derived from slag using a leaching test condition
based on JIS K 0058-1. Electric arc furnace slag in particular was used as a slag. In this
study, we also developed methods to estimate not only the number of algal cells by
hemocytometry but also their physiological activities via flow cytometry. After a
leaching test, the concentrations of eluates from slag were almost lower than those of
environmental quality standards. In addition to an elemental analysis, a Chlorellabased
bioassay was performed on the eluates. After the treatment of algae with eluates,
algae were analyzed by microscopy and flow cytometry. As a result, treatment with
eluates induced neither death nor growth inhibition. This treatment was not extremely
toxic but rather induced algal growth and a vigorous physiological state.
Keywords: Chlorella, Chlorophyll, Electric arc furnace slag, Environmental
quality standards, Flow cytometry, Fluorescence, Phytoplankton.
