Composition Of Residue From Anaerobic Pyrolysis Of Hazardous Waste And Its Characteristic Pollutant Release Law

The annual production and types of hazardous waste in China are constantly increasing,and the issue of treatment and disposal of hazardous waste is gradually being taken seriously.At present,technologies such as incineration,landfill,and comprehensive utilization are mainly adopted for hazardous waste.With changes in environmental policies,anaerobic cracking technology has begun to be promoted.However,further research is needed on the application of anaerobic cracking technology in the treatment of hazardous waste and the treatment and disposal of the generated anaerobic cracking residue.This article selected oil sludge and resin powder to undergo anaerobic cracking at600℃,700℃,and 800℃ for 1.5 hours to obtain simulated anaerobic cracking residues in the laboratory.At the same time,comparative studies were conducted on 11 types of anaerobic cracking residues produced in practical engineering.This article studies the characteristic pollutants and their release rules in anaerobic cracking residue,as well as the desorption kinetics of anaerobic cracking residue solidification blocks and the release rules of characteristic pollutants under leaching conditions in the preparation of roadbed materials from anaerobic cracking residue.The main conclusions obtained are as follows:(1)The characteristic pollutants in anaerobic cracking residue produced in laboratory simulation and actual engineering were heavy metals,and volatile and semi volatile organic pollutants in anaerobic cracking residue were below the detection limit.(2)The leaching concentration of heavy metals in anaerobic cracking residue did not exceed the standard in the "Identification Standard for Hazardous Waste-Identification of Leaching Toxicity"(GB 5085.3-2007),but some heavy metals exceeded the Class III water quality index in the "Groundwater Quality Standard"(GB/T 14848-2017).The surface distribution characteristics of heavy metals in the anaerobic cracking residue simulated in the laboratory conform to linear equations,and the solid-liquid distribution process was related to the anaerobic cracking temperature of the anaerobic cracking residue and the type of heavy metals themselves.(3)The solidification rate of heavy metals in anaerobic cracking residue,except for Cr,could reach over 50%.The experimental results of the desorption kinetics of heavy metals in the solidified block were highly fitted with the Elovich equation and parabolic equation.The activation energy of the desorption and release process of heavy metals in the solidified block varied greatly,and the release was controlled by a series of reaction mechanisms,as well as multiple diffusion mechanisms.During the leaching and release process of heavy metals in the preparation of roadbed materials from anaerobic cracking residue,Cr and Ba released more in acidic environments with higher p H,while Zn released more in acidic environments with lower p H.The results of heavy metal leaching release had a high fitting degree with the parabolic model and dual constant model.The process of heavy metal leaching and release was mainly controlled by various diffusion mechanisms and adsorption desorption.