培养条件下生物炭对土壤锌的吸附作用

Adsorption of Zn by Added Biochars in Soil at Incubated Conditions

将稻壳分别在350℃和550℃热解温度下制备成生物质炭,按土壤质量的1%、3%和5%的添加量施入土壤中,保持一定的土壤含水率,探究施入生物炭的土壤对重金属锌吸附的影响。结果表明,土壤中施入生物炭之后,会提高土壤对重金属的吸附固定能力,生物炭的添加量越高,土壤对锌的最大吸附量越大。在试验开始阶段,随着生物炭的老化,土壤对锌的吸附性能会增强,同时土壤对锌的解吸率降低,随着时间的延长,生物炭与土壤发生的共腐殖化过程,导致土壤对锌的吸附性能逐渐降低,同时土壤对锌的解吸率提高。

Biochars were prepared by pyrolysis of rice husk at 350 ℃ and 550 ℃ respectively. The biochar equal to 1%, 3% and 5% of dried-soil weight was applied into soil and a certain soil moisture content was maintained in the tested soil. The effect of biochar on soil Zn adsorption behavior was explored. The investigation results showed that after adding biochars into soil, the capacity of Zn adsorption in soil was higher than that in the control of no biochar addition. The more amounts of biochar application, the higher maximum adsorption of Zn. At the beginning of tested phase, the capacity of Zn adsorption increased and the rate of Zn desorption decreased with the aging time of biochars. However, the capacity of Zn adsorption decreased and the rate of Zn desorption increased during the humification process of soil together with biochar.