芦竹修复收获物的热解过程会造成重金属的二次污染,本文作者研究外加物料Al2O3、CaCO3、FeCl3和NaOH的添加对热解过程中重金属稳定性的影响。结果表明,当芦竹粉在外加5%Al2O3、250°C下热解2h,37%As和97%Cd固定在芦竹生物炭中;在外加5%CaCO3、400°C下热解1h,59%Pb固定在芦竹生物炭中。在芦竹热解最优条件下通过BCR法分析可知,Cd主要以残渣态存在,Pb和As主要以可氧化态存在。由XRD分析可知,As主要存在于Ca2As2O7中,Cd主要存在于Cd(AlCl4)2、CdPbO3或CdSO3中,Pb主要存在于Pb3O2SO4中。
The pyrolysis of phytoremediated giant reed(Arundo donax)biomass could cause secondary pollution of heavy metals.The stabilization of heavy metals in the pyrolysis process with external materials such as Al2O3,CaCO3,FeCl3and NaOH,wasstudied.The results showed that37%As and97%Cd in biochar were stabilized when giant reed powder was pyrolyzed at250°Cwith5%Al2O3for2h.Furthermore,59%Pb in biochar was stabilized at400°C with5%CaCO3for1h.Under biochar produced inoptimized pyrolysis conditions,Cd mainly existed in a residual fraction,while Pb and As mainly existed in oxidizable fraction inBCR analysis.In XRD analysis,As was only found in Ca2As2O7;Cd in biochar mainly existed in Cd(AlCl4)2,CdPbO3or CdSO3;and Pb mainly existed as Pb3O2SO4.