Study On Disposal Characteristics Of DDT Pesticide And Applicability Of Co-process Of DDT In Cement Kiln

DDT pesticide is a kind of organochlorine pesticide, and its main active ingredient is p,p’-DDT (DDT). DDT is also a kind of organic persistent pollution (POPs), it possess toxicity and can accumulate in organic creation without biodegrading. In environment, it can transfer through air, water and other media and accumulate the ecosystem in a long time. DDT could cause caner, damage the nervous system, trigger immune system disorders and interfere with the normal development of infants and young children. By the meaning time, the derivatives of DDT, o,p’-DDT, p,p’-DDD and p,p’-DDE also have the bio-toxicity. In the time between 1950s and 1980s, the consumption of the DDT pesticide was 430,000t totally in China, accounting for 20% of the international usage. In 2009,China government abandoned DDT pesticide and now there is 2,600-4,500t waste DDT pesticide waiting for management and disposal.The high temperature tube furnace was used to research the heat treatment characteristics of DDT pesticide under 4 factors, the temperature, residence time, air flux and oxygen ratio.The results showed that the destruction efficiency of the DDT could represents that of all DDTs for the proportion of DDT in DDTs was 73.39%; the destruction efficiency of the DDT increased when temperature raise; the residence time just worked on the destruction efficiency of the DDT in 600-900℃atmosphere and the destruction efficiency of the DDT got stable after 15min; the air flux worked on the destruction efficiency of the DDT in 600℃atmosphere; the oxygen ratio influenced the destruction efficiency of the DDT in all temperature atmosphere, but the affect reduced as the temperature got down. DDT was the main pesticide remain in residue and the p,p’-DDE got domestic in high temperature tail gas. There was another organic compounds in the tail gas besides DDTs, in the tail gas below the 600℃, the hydrocarbon was the predominant organic remain, the derivatives of the polycyclic aromatic hydrocarbon which molecular structures were similar with the DDTs was the predominant organic remain in the 700-900℃tail gas,and the derivatives of the polynuclear aromatic hydrocarbon were the main remain in the 1000-1200℃tail gas.The result of co-process DDT pesticide in cement kiln showed that the destruction efficiency of the DDT could reached 99.9999% at the normal condition of cement production. All the indicator in the tail gas were under the emission limite, especially, the co-process did not influenced the emission of PCDD/Fs. Meanwhile the quality cement did not get down for geting more Cl in the kiln from the DDT pestide. So the conclusion was that the co-process waste in cement kiln was greatly efficient, safe and environment friendly technology for dealing DDT pesticide and POPs waste.