以電化學分析法探討堆肥對土壤三價砷活性的影響

Effects of Compost Treatment on Available Arsenic(III)in Soils Studied by Electroanalysis

台灣西南沿?貐^土壤中砷含量有偏高情形,砷含量過高會經由各種途徑對人體造成毒害。以X-射線繞射儀與傅立葉轉換紅外線吸收光譜儀證明普魯士藍對三價砷的孯恍晕綑C制,再以普魯士藍修飾電極搭配流動注入系統來偵測土壤三價砷,並探討堆肥對三價砷在不同土壤中吸附與脫附的影響。試驗結果得知電化學分析技術可快速、簡便且準確地偵測土壤三價砷,且結果中也指出堆肥處理會增加秀水與後里土壤對三價砷的吸附。此外,三種土壤不論有無施用堆肥,脫附百分率的大小順序爲興大>秀水>後里,其中秀水土壤雖在施用堆肥後吸附力大小明顯增加,但脫附百分率下降的情形較不明顯,顯示黏土礦物種類與含量控制三價砷的脫附行爲。

Southwestern coast area of Taiwan contains a high content of arsenic.Arsenic is toxic and harmful to human body through various pathways,so the determination of arsenic is very important.In this study,we studied the mechanism of the adsorption of arsenic（III）on Prussian blue can be understood by X-ray diffraction and FT-IR spectrometers.We report here the suitability of detecting soil As（III）with Prussian blue modified electrode coupled with flow injection system and the effect of compost on adsorption and desorption of arsenic（III）in different soils.The results indicated that electrochemical technique could provide a fast,convenient and accurate method for basic study of soil chemistry,and that also showed compost treatment could increase adsorption of As（III）on Shiushui and Holi soil.The order of desorptive proportion were Hsingta 〉 Shiushui 〉 Holi in blank and compost treatments.Shiushui soils was observable among three soils and its adsorptive ability of As（III）increased apparently after compost treatment,but desorptive proportion did not show a noticeable increase.This indicated the desorption process was controlled mainly by type and content of clay minerals.