生物质气化灰渣和粉煤灰的农业化学行为比较

Comparison of Agrochemistry Behavior of Biological Material Steal Melt Residuce and Fly Ash

为了开拓生物质气化灰渣农用资源化利用,对稻壳灰和粉煤灰的农业化学行为进行了比较研究.结果表明,稻壳灰组成以物理性砂粒为主,容重为0.3 g.cm-3,pH>10.0,可以用作粘质酸性土壤的改良剂.稻壳灰中全磷和有效磷的质量分数分别为0.12%和204.73 mg.kg-1,都大于粉煤灰,能向土壤提供更多量的磷.稻壳灰中水溶性硅的质量分数为3.71 g.kg-1,远远大于粉煤灰中水溶性硅的质量分数0.05 g.kg-1.在168 h内,稻壳灰有效硅的释放大于粉煤灰,灰渣中硅的释放量随时间的变化关系可以用Freund lich方程较好地进行描述.稻壳灰对磷的吸附随溶液中磷含量的增加而增大;稻壳灰对加入磷的固定随着含水率的增加而增加,颗粒越小对磷的固定率越高;稻壳灰对磷的吸附固定作用小于粉煤灰.

To exploit biological material steal melt residuce resource in agriculture, physical and chemical properties of ashes and their agrochemistry behavior were studied. The results showed that the rice husk ash could be used as soil modifier and its bulk density was lower than that of fly ash and its pH exceeded 10. 0. The mass fraction of total P and available P in rice husk ash were 0. 12% and 204. 73 mg · kg^-1 respectively, which were higher than those of fly ash, so rice husk ash could supply soil with more P. The mass fraction of water-soluble Si in rice husk ash was 3.71 g· kg^-1 ,which was higher than that in fly ash. The amount of silicon released from the rice husk ash in 168 h was 1.01 times as high as that in fly ash. The releasing process of silicon in the ashes could be well described with Freundlich equation. The adsorption of P in rice husk ash increased with addition of P content, and fixation amount increased abviously by the addition of fineness and water content of ashes. The capacity of P-fixation in rice husk ash was lower than that of fly ash.