停留时间对滴滴涕农药热处理特性的影响研究

利用高温管式炉研究停留时间对滴滴涕农药热处理特性的影响。结果表明,600℃时ηDDT在15 min内迅速增长,在15 min后稳定在85%上下;900℃时,当停留时间≥15 min,ηDDT≥99%;1 200℃时,各时段的ηDDT≥99.9%。在滴滴涕农药残渣中,DDTs在600℃和900℃时的配比随停留时间的增加变化甚微,在1 200℃时,p,p’-DDD、DDT和o,p’-DDT分别占DDTs总量的比例随时间增加明显降低,p,p’-DDE则大幅增加。在尾气中,DDTs在600℃时的配比随停留时间的增加无明显变化,DDT为主要尾气残留物质,900℃时DDTs在尾气中配比变化混乱,1 200℃时,p,p’-DDE的比例随停留时间的增长迅速增加,并成为尾气中的主要DDTs残留物质。

Effect of Residence Time on Heat Treatment Characteristics of DDT Pesticide

High temperature tube furnace was used to study the influence of air flux to heat treatment characteristics of DDT pesticide.Results showed that the destruction efficiency of DDT jumped to 85% within 15 min at 600 ℃ and it still raised at 900 ℃ and 1 200 ℃ as the residence time increase,the destruction efficiency of DDT was over 99% when the residence time above 15 min at 900 ℃ and reached 99.9% at 1 200 ℃ under different residence time conditions.In the combustion residue,the residence time had little influence to the constitution ratio of DDTs at 600 ℃ and 900℃,but at 1 200 ℃ the percentage of p,p’-DDE raise obviously and the rest just fell down.In the tail gas,the residence time had little influence to the constitution ratio of DDTs at 600 ℃ and DDT was the main remain.At 900 ℃,the station was confused,when the temperature was 1 200 ℃,the station was that the percentage of p,p’-DDE raised quickly as the residence time increase and p,p’-DDE became the main remain gradually.