Study On Degradation Mechanism Of Typical Illegal Drugs In Incineration Process

Drug abuse is a severe problem in China.According to‘China Drug Report'over the past several years,the seized illicit drugs?IDs?gradually increased year by year,and its amount reached up to 102 tons in 2015,which is a very considerable amount.Illegal drug abuse will not only cause incalculable harm to living organisms,but also adversely affect the ecological environment and social security.Therefore,how to properly handle the disposal of illegal drugs is one of the urgent problems to be solved.The IDs are mainly disposed by incineration,while the concentrations of the reaction products and the formation mechanisms during the incineration process are not clearly understood.Methamphetamine and ketamine,the two typical IDs widely abused in China,are selected as the target reactants in this study to investigate their degradation mechanisms during the incineration.By altering the experimental parameters including oxygen concentration,reaction residence time and temperature,the degradation processes will be simulated and investigated in both incineration and outdoor conditions.The toxic reaction products formed during the IDs incineration will be identified and quantified as well.The gas chromatography-mass spectrometry will be used in this study to identify and quantitate the toxic and harmful pollutants produced during the incineration of two IDs.According to the experimental results,the incineration degradation pathways of two typical illegal drugs under different conditions are further revealed as well.The main findings in this study are as follows:?1?The main pyrolysis products of ketamine under anaerobic conditions are1,2-diethylbenzene,2-chlorobenzaldehyde,2-chlorobenzonitrile,naphthaleneand dibenzofuran.The maximum concentration of the main products is 2.6?g/mL,66.7?g/mL,142.0?g/mL,45.6?g/mL,and 9.8?g/mL,respectively.The ketamine pyrolysis under the condition of 10%oxygen concentration mainly produces 2-chlorobenzaldehyde,2-chlorobenzonitrile and dibenzofuran.The maximum concentration of main products is58.7?g/mL,76.9?g/mL and 15.7?g/mL,respectively.?2?The pyrolysis products of methamphetamine under anaerobic conditions are2-ethylhexanol,1,2-diethylbenzene,1-vinyl-ethylbenzene and naphthalene,and the main pyrolysis products is naphthalene.Methamphetamine pyrolyzed mainly to form benzonitrile,2-ethylhexanol and naphthalene at an oxygen concentration of 10%.The maximum formation concentrations of the main products were 13.77?g/mL,41.37?g/mL,and 14.33?g/mL,respectively.The pyrolysis of methamphetamine at an oxygen concentration of 10%produces phenol,which is highly prone to dioxin formation by incineration at high temperatures.?3?Ketamine pyrolysis products and mechanisms have similarities but not identical under the conditions of anaerobic conditions and oxygen concentration of 10%.The similarity is that they all rupture and link their internal benzene.The C-C bond of the ring and the six-membered ring generates a chlorobenzene radical,and the chlorobenzene radical further generates a small molecule compound.Under anaerobic conditions,two molecules of chlorobenzene radicals are reacted to form 2,6'-dichlorobiphenyl,and 2,6'-dichlorobiphenyl is added to the-NHCH3 group,and one is removed.The molecular chlorine gas produces9-methylcarbazole;under the condition of aerobic participation,the chlorobenzene radical further generates benzene,and the biphenyl is easily reacted with oxygen to generate the target dibenzofuran.?4?Under the condition of no oxygen and high temperature,the C-C bond linking the benzene ring and-C₄H₁₀N in the methamphetamine molecule is first broken and broken,and further forms some small molecule compounds with benzene ring,such as 1,2-diethylbenzene,1-Vinyl-3-ethylbenzene,etc.;undertheconditionofaerobicparticipation,The methamphetamine heat releases some small molecular compounds and also reacts with oxygen to form some oxygenated organic pollutants such as phenol and 1,2-diethylhexanol.