水热法和热解法处理Zn、Pb污染石榴的研究

Comparative study on treatment of Zn and Pb contaminated pomegranate stem by hydrothermal and pyrolysis methods

以重金属Zn、Pb污染植物石榴茎为对象,研究了水热和热解2种技术处理石榴茎时重金属在固相中的迁移转化规律及形态分布。结果表明,在减量化方面,水热法优于热解法,水热法减重率最高达90.06%(300℃);在固体产物重金属富集方面,水热法300℃下处理石榴茎后所得固体产物中Zn、Pb的质量分数高达232.40 mg/kg和283.10 mg/kg,远远高于热解产物中对应的重金属质量分数;X射线衍射(XRD)分析表明,2种热处理方式下,固体中Zn主要以氢氧化物形式存在,而Pb主要以稳定的碳酸盐形式存在于水热固体和低温热解固体中。

Taking Zn and Pb contaminated pomegranate stem as the object,the migration,transformation and morphological distribution of heavy metals in solid products are studied when hydrothermal and pyrolysis methods are used to treat with heavy metals contaminated pomegranate stem.Results show that the maximum weight loss of 90.06%can reach by hydrothermal method at 300℃,which is superior to pyrolysis method in terms of waste minimization.Meantime,the concentrations of Zn and Pb in the solid products obtained from the treatment of pomegranate stem by hydrothermal method at 300℃are as high as 232.40 mg·kg-1 and 283.10 mg·kg-1,respectively,which are far higher than that in the solid products obtained by pyrolysis method.Furthermore,X-ray diffraction analysis shows that Zn presents mainly in the form of hydroxides in the solid,regardless of the methods used,while Pb exists mainly in the form of stable carbonate in the solid obtained by hydrothermal method or low temperature pyrolysis method.