沉积物和土壤中磷的生物有效性评估新方法

利用自制的氧化铁/醋酸纤维素复合膜(FeO/CAM)发展了一种沉积物和土壤磷的生物有效性评估的新方法. 结果表明:从沉积物和土壤中解吸的生物有效磷(FeO-P)含量随时间增加而增加,至16～20h左右,解吸过程接近平衡;随着土/水比增大而减小,至20～30g/L左右逐渐趋于平缓,且相对标准偏差较小;膜面积为20～30cm²时FeO-P含量差别较小,且相对标准偏差也较小;适当提高振荡频率(一般200r/min左右),有利于促进FeO-P的提取动力学过程.在用于评估水体沉积物和土壤解吸磷的生物有效性方面,FeO/CAM膜克服了氧化铁浸渍滤纸的缺点,易于商品化,具有更好的应用前景.

New Method to Assess Phosphorus Bioavailability in the Sediments and Soils

A new method to assess phosphorus bioavailability in the sediments and soils was developed by using a homemade iron oxide/cellulose acetate membrane(FeO/CAM). The results show that the amount of bioavailable phosphorus(FeO-P) desorbed from the sediment and soil increased with the shaking time,and FeO-P desorption would come to equilibrium after 16 ot 20h. With the increase of the ratio between soil mass and water volume,the quantity of the desorbed FeO-P would decrease and then went planar after 20 to 30g/L. The quantity of the desorbed FeO-P had no significant difference between the FeO/CAMs of 20 to 30cm². The dynamics of FeO-P desorption from the sediments and soils would be accelerated by appropriately increasing the shaking frequency. In short,FeO/CAMs overcome many disadvantages of iron oxide impregnated filter paper and are easy to be commercialized; therefore it may have a better future in the application to assessing phosphorus hioavailability in the sediments and soils.