成型压强对秸秆灰颗粒中水溶钾释放特性的影响

摘要

秸秆灰的压缩成型可以减少施用过程中的扬尘污染及营养快速释放对农作物的冲击.为了研究成型压强对秸秆灰颗粒中营养元素释放特性的影响,在成型压强为381,460,539,618 MPa的条件下压制了尺寸约为φ9 mm×2 mm的麦秸灰颗粒和玉米秸灰颗粒,采用钾离子选择性电极配合参比电极连续检测溶液中钾离子的浓度变化,并通过数值模拟的方法计算水溶钾的溶出特性.实验结果表明:灰颗粒的水溶钾释放速率明显小于灰粉体,灰颗粒释放75%的水溶钾所需的时间超过灰粉体所需时间的80倍;随着成型压强的增大,颗粒中水溶钾的释放速率略有下降,但并不显著;玉米秸灰颗粒的水溶钾释放速率高于麦秸灰颗粒,两者释放75%的水溶钾所用时间分别为22 min和35 min.%The utilization of biomass ash as fertilizer is of great significance for the sustainable development of agro-ecosystem in our country. Punching the ash into tablets provides better handling with less dust and slower release rate of nutrients with fewer shocks to crops. In order to investigate the effects of punching pressure on nutrient release characteristics of straw ash, tablets with the size of φ9 mm×2 mm of wheat straw and corn stover ash were made under the punching pressure of 381,460,539,618 MPa. About 0.2 g of each type of tablets were put into a beaker with about 200 g of deionized water. The concentration of potassium ion in solution was measured online using a potassium ion electrode with the corresponding reference electrode. The simulation method was also used in this paper. Experiments and simulations showed that:Release rate of water soluble potassium of ash tablets is obviously lower than that of powder. For 75% release of potassium, the ash tablets need 80 times than ash powder as much time. With the increase of molding pressure, the release rate of water soluble potassium decreased slightly, but not significantly. The release rate of potassium in corn straw ash tablets is higher than that of wheat straw ash tablets. For 75% release of potassium, they used 22 minutes and 35 minutes respectively.