Application of Iron Humates to Barren Ground in a Coastal Area for Restoring Seaweed Beds

Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

“…Based on these issues, a steel-slag/compost fertilizer was developed to supply dissolved Fe complexed with DOM to barren coastal areas, which resulted in the restoration of seaweed-beds. 2 In this technique, it is assumed that Fe species are eluted from the steel-slag via complexation with HA and/or FA. 2,3 However, it has been reported that HA and FA are flocculated at higher ionic strengths, like seawater.…”

“…2 In this technique, it is assumed that Fe species are eluted from the steel-slag via complexation with HA and/or FA. 2,3 However, it has been reported that HA and FA are flocculated at higher ionic strengths, like seawater. 4 This suggests that HA and FA in the compost cannot serve as carriers of Fe from the fertilizer.…”

Effects of Organic Matter on Acceleration of the Iron Elution Rate from Steelmaking Slag

“…In addition to removal of herbivorous sea creatures, production of seed and saplings, installation of adhesive substrates, and nutrient fertilization has been conducted for restoration of seaweed beds in such areas. 1) We have previously developed an Fe fertilization method using a mixture of steelmaking slag, and compost containing humic substances 2,3) (hereafter referred to as slag-compost fertilizer). The effectiveness of the method was confirmed by a field test on the coast of the Sea of Japan in Mashike-cho, Hokkaido, Japan.…”

“…The effectiveness of the method was confirmed by a field test on the coast of the Sea of Japan in Mashike-cho, Hokkaido, Japan. 2,3) We installed the slag-compost fertilizer on the shoreline and monitored changes in the seaweed bed distribution and water quality, such as dissolved Fe, total N (T-N), and total P (T-P). In addition to the field test, fundamental studies such as analyses of the characteristics of Fe elution from the slag-compost fertilizer, [4][5][6] effects of compost on Fe elution from steelmaking slag and formation of Fe-humate complexes, [7][8][9][10] and safety of Fe fertilization in coastal areas 11) have also been conducted.…”

Determination of Labile Fe(II) Species Complexed with Seawater Extractable Organic Matter Under Seawater Conditions Based on the Kinetics of Ligand-exchange Reactions with Ferrozine

“…2,[13][14][15] Based on this, a fertilizer comprised of a steel slag and compost was tested for its ability to supply dissolved Fe to barren coastal areas, and this attempt was successful and resulted in the restoration of seaweed beds. 16 In this technique, seawater extractable organic matter (SWEOM) from the compost serves as a chelator of Fe and allows for its elution from the steel slag. 17,18 Fe(III)-oxides are found on the surface of the steel slag, 19 and can be reduced to soluble Fe(II) species in the presence of dissolved organic matter.…”