Influence of diammonium phosphate and ammonium sulfate on cadmium absorptive strength of soils

[Author abstract]The study has been carried out Cd absorption by soil suspension with the solution of 1～10 ppm Cd. And, the effect of ammonium phosphate and sulfate solution on Cd absorption of soil were discussed. The conclusion were summarized as fellow. In this experimental condition, the effect of ammonium phosphate on Cd absorption of soil remarkably could not recognized. The release of Cd from the phosphate added soil by the 0.01M-HCI treatment apparently decreased. This result suggested the formation of sparingly soluble cadmium phosphate. The absorbed amount of Cd by soil with treatment diminished to the every useed soils. The release of Cd from the sulfate added soil by to 0.01M-HC1 treatment apparently increased. Therefore, the absorption of Cd by soil suspension largely were effected by the species and concentration of soluble ions in the system. The released Cd amounts with Cd absorpted soil and water, diammonium phosphate and ammonium sulfate solution arrainged ammonium sulfate>water>diammonium phosphate treatments. There results seemed to form the precipitate of insoluble cadmium phosphate to the soil absorbed Cd.[著者抄録]本研究は､土壌によるCdの吸収を1～10ppmCd溶液によって行ない､Cdの吸収及び吸収Cdの溶出に及ぼすリン酸二アンモニウム及び硫酸アンモニウムの影響を調べたものである｡得られた結果は以下のようである｡本実験条件下においては､土壌のCd吸収に及ぼすリン酸二アンモニウムの影響は､顕著に認められなかった｡しかし､処理土壌の0.01M塩酸によるCdの溶出は､明らかに抑制を受けた｡これは不溶性のリン酸カドミウムの生成を示唆した｡硫酸アンモニウムの共存処理による土壌のCd吸収量は､明らかに減少した｡また､0.01M塩酸による硫酸アンモニウム処理土壌からの吸収Cdの溶出は､いずれの土壌に対しても著しかった｡したがって､土壌によるCdの吸収は懸濁平衡系における溶存イオンの種類､濃度などに強く影響を受けると思われる｡ Cd吸収処理土壌と水､リン酸二アンモニウム及び硫酸7ンモニウム溶液による懸濁操作で溶出したCd量は､リン酸二アンモニウム処理区<水処理区