| With the development of global economy,the environmental pollution is becoming more serious and the research on typical pollutants in the environment has attracted more and more attention from scholars and experts.This study focuses on fly ash from MSW incineration power plant and azo dyes,which provides an important train of thought for the comprehensive treatment of these two kinds of complex environmental pollutants.Fly ash samples from a CFB incinerator power plant were characterized in this study.In this power plant,the stabilization and comprehensive utilization of fly ash were affected by the basicity and total content of the fly ash.The concentration of Zn of fly ash exceeded the limited value,which was due to spent alkaline batteries.SiO2,CaSO4,and Fe2O3 were the major crystal materials of fly ash,which was different from other investigation The leaching test showed that concentrations of heavy metals were almost lower than that of previous studies and the main soluble components were Na+,K+,SO42-,and Cl-.In addition,a certain amount of residual carbon was present in the fly ash.The analysis of PAHs and PCDD/Fs indicated that low-ring PAHs,polychlorinated PCDDs,and low-chlorinated PCDFs were the main organic pollutants.The TEQ of BbF and BaP accounted for over 60.0%,which could be considered as designated pollutants to simplify the regulatory process.PCDFs dominated more than PCDDs.The distribution of PCDD/Fs had a close relationship between fly ash and flue gas,which was associated with the chlorinated degree of PCDD/Fs.The PCDFs tended to be gaseous emissions with increasing chlorine substitution,while the PCDDs had increasing concentrations as chlorine substitution increased in both the fly ash and flue gas.The results obtained in this investigation showed that the content of pH,total salt and Cl-should be the main consideration in application of fly ash.For concentrations of heavy metals,PAHs and PCDD/Fs met the limiting values of related national regulations.It is well kown that azo dyes contain many organic pollutants and threaten the health of people in many direct or indirect ways.In this study,Al95Cu5 was prepared by the method of mechanical alloying.The characterization of the material was analyzed and the reaction between azo dye 3R and metal powder was also investigated,including the influence factors of reaction,the mechanism of degradation and the analysis of final products.The conclusion is that the in the process of ball milling,aluminum and copper atoms have doped mutually in the lattice and the reaction is similar to a cell reaction.The electrons derived from aluminum can attack the electron acceptors and thus reducing them.In this system,azo dyes and water accepted electron to be reduced.This enhanced reducing capacity was confirmed by the excellent decoloration effect of Al95Cu5 alloys.In addition,the flocculation of Al(OH)3 strengthened the effect of reduction.Through a variety of characterization methods,we inferred that,during the decolorization reaction,azo group and C-N bond were broken down,resulting in the formation of the aniline and naphthalene rings,which were further decomposed to multi-substituted benzene.In conclusion,this study provides an important theoretical basis and research idea for the disposal of azo dyes in the reaction environment of high salinity,high concentration and high alkalinity. |
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