气氛含氧量对DDT热处理特性的影响

Effect of oxygen content on heat treatment characteristics of DDT

滴滴涕属于有机氯农药,其所含成分DDTs在环境中难以降解,并具有生物毒性。利用高温管式炉研究气氛中含氧量对滴滴涕热处理特性的影响,为研发废弃滴滴涕高温热处理技术提供理论依据。实验结果表明,在600℃时,滴滴涕去除率最高为含氧量21%时的70.48%;在900℃条件下,当含氧量为21%时DDT去除率≥99%;在1 200℃条件下,当含氧量≥12%时DDT去除率≥99.9%。在滴滴涕热处理残渣中,o,p’-DDT占DDTs总量的比例在3个温度段中都随含氧量的增加而增长,DDT则都随含氧量增加而减少,且上述变化随温度升高而幅度加大。在尾气中,p,p’-DDE占DDTs总量的比例在3个温度段中都随含氧量增加而递增,在1 200℃条件下尤为明显。

DDT is a kind of organochlorine pesticide,the DDTs in the pesticide are of hard-degradation and biological toxicity.In order to provide theoretical basis for developing high-temperature process on treating obsolete DDT,high temperature tube furnace was used to research the effect of oxygen content on heat treatment disposal characteristics of DDT.The results showed that,the destruction efficiency of DDT could reach 70.48% at 600℃ in the 21% oxygen atmosphere and be over 99% at 900℃ under the condition of 21% oxygen content only,at 1 200℃,it was over 99.9% when the oxygen content reached 12%.In the combustion residue,the percentage of o,p＇-DDT in DDTs increased and the percentage of DDT reduced as the oxygen content rose under three temperature conditions,and the changes became distinct as the temperature increased.In the tail gas,the percentage of p,p＇-DDE in DDTs increased as the oxygen content rose under three temperature conditions,and the phenomenon was more obvious at 1 200℃.