2003 Volume 89 Issue 4 Pages 422-429
Availability of the elements originated from decarburization steelmaking slag, such as iron, phosphorus and silicon, was confirmed in the previous part of this paper. However, the slag does not contain nitrogen. On the other hand, treated urban sewage is rich in ammonic nitrogen, while relatively poor in phosphorus. In this part, combined effect of the slag and the sewage on growth of the marine planktonic diatom Thalassiosira guillardii was tested. Media used in the growth experiments were modified ESAW media, in which the powdered slag and/or the sewage were/was added. Growth response of the diatom was determined by changed in vivo chlorophyll a fluorescence. The results obtained suggest that, although the combined effect is usually significant, the availability of the elements can sometime be reduced under a certain experimental condition.