Pollution Characteristics And Environmental Risk Assessment Of Organic Chemical Distillation Residue In Chongqing

In organic Chemistry industrial processes useful products or intermediates were separated by distillation, at the same time a large amount of impurities and toxic and harmful substances will be produced at the bottom, we call it distillation residue (HW11). The quantity of distillation residue is also increasing with the industrial development, but the domestic study and control management measures about distillation residue system is still very lack. Survey chemical companies, analysis distillation residue, and conduct the health risk assessment of residues, this work will be very meaningful.The paper is on the base of summarizing survey results of typical organic chemical enterprise, and then analyze the collected residue samples. Distillation residue is mostly viscous and tarry liquid or solid, their composition is always complex, contaminants in residue can be divided into benzene homologues, polycyclic aromatic hydrocarbons, halogenated compound, heavy metals and other classes. Using the risk evaluation index system, using linear and exponential score respectively to assess the main pollutants risk level, studies have shown that polycyclic aromatic hydrocarbons and benzene homologues have a very high risk level. Using potential ecological risk index to quantitative evaluate the risk of environmental pollution of heavy metals in the solid state distillation residue, studies have shown that the potential ecological risk level of PTA distillation residue is strong, Ni is the main pollution factor, its potential ecological risk index is 474.85, and Ni, Cr, Zn, Cu are the common contamination risks exist in distillation residue.The pollutants in residue are divided into two non-volatile contaminants and volatile contaminants according to the different routes of exposure, then conduct the crowd health risk assessment. Take an example of heavy metal to study health risk of distillation residue nonvolatile pollutants. Studies have shown that heavy metal oral ingestion pathway carcinogenic risk values of the distillation residue generated by three companies are 8.55E-04、4.91E-04、 4.48E-03、4.19E-04 respectively, the carcinogenic risk is strong. Carcinogenic pollution factor is Cd and As, and the danger of As is stronger than Cr. We calculate the number of carcinogens caused by residues annually is 38.5、 12.3、22.4、25.1.Take an example of strong volatility and toxicity hydrochloric ether to study health risk of distillation residue volatile pollutants.Studies have shown that hydrochloric ether comprehensive carcinogenic risk values of the distillation residue generated by three companies are 3.62E-05、3.68E-06、 9.81E-06 respectively. The main carcinogenic risk is from breathing pathways, CCl4 and C2HCl3 are the main pollution factors, risk contribution rates are 66% and 33% respectively. We calculate the number of carcinogens caused by residues annually is 116、0.552、11.3, if methane chloride production process to optimize the number of carcinogenic people can be decreased from 116 to 3.