Study For The Degradation Of Chlorinated Organic Matter Especially DDT

DDT has been widely used as a kind of pesticides,and its chemical property was very stable.DDT is hardly chemical and biological degraded,and it can be transferred and transported into the aquatic environment in many ways.Due to its toxicity and stable structure,it can do great harm to the human beings and is listed as Priority Pollutants in many countries.In this thesis,the geometric configurations and electronic structures of organochlorine pesticide DDT and its possible dechlorinated products such as o,p'-DDT,p,p'-DDT,o,p'-DDD,p,p'-DDD,o,p'-DDE and p,p'-DDE have been studied using the ab initio molecule orbit rule (HF/6-31G)within the Gaussian-98 software package.The calculated structural parameters such as bond length,bond angle,energy value and dipole moments have explained their structural character.The results we gained from calculation are very important to study the degradation behavior of DDT.On this basis,degradation of low concentration DDT in aqueous solution was studied by using zero-valent iron as reducing agent.The results show that DDT can be reductive degradation by zero-valent iron, so the toxicity of DDT is reduced.Furthermore,this thesis has also investigated the degradation effect of chlorinated organic matter especially DDT jointly using the zero-valent iron and ultrasound.The results show that the cooperative effect of zero-valent iron and ultrasound is very effective for the degradation of DDT.And according to the calculated results and the experimental discuss,the degradation mechanism of DDT has also been studied.