Application of Gypsum Granule as a Capping Material to Reduce Phosphorus Release from Sediment of Lake Paldang
In this study, the capping effects of granular gypsum (Ca2SO4·2H2O) and sand on sediment and water column were evaluated in in-situ experiments in Lake Paldang. The results indicate that capping treatment is very effective for the restoration of eutrophied lake. It was demonstrated that phosphorus, T-N and T-P concentration in the water column of treated basin was relatively lower than control basin. As a consequence of reduction of nutrient concentration by capping treatment, chlorophyll-a concentration in treated basin was considerably lower than control basin. The chlorophyll-a concentration in water column could be reduced to 52% and 25% as compared to control basin, respectively, by the capping treatment with gypsum and sand. From the experimental results, it was concluded that gypsum was more effective capping material than sand for controlling of nutrients and chlorophyll-a. In addition, capping with gypsum bring calcium cation into sediment, which offer more site for phosphorus to bind. In case of the capping with gypsum, apatite P composition, mainly consist of Ca boun P, in the sediment increased from 24% to 43% for the two month of operation.
Hyungsun Kim, Junichi Hojo and Soo Wohn Lee
Y. J. Park et al., "Application of Gypsum Granule as a Capping Material to Reduce Phosphorus Release from Sediment of Lake Paldang", Materials Science Forum, Vols. 544-545, pp. 521-524, 2007