Method for efficiently immobilizing heavy metals in sludge incineration residues by preparing geopolymer

Abstract

The invention belongs to the field of resources and environments, and in particular relates to a method for efficiently immobilizing heavy metals in sludge incineration residues by preparing a geopolymer. By adjusting the ratio of different sludge incineration residues to a gel material, namely metakaolin, an optimal sludge incineration residue addition amount (less than or equal to 10%) capable of efficiently immobilizing heavy metals is achieved, and by using the immobilizing method provided by the invention, the optimal immobilization rate of Cu and Zn are up to 95%, and the immobilization rates of Cr, Ni and Pb are all greater than 90%. By adopting the method, a technical support is provided for efficient immobilization on heavy metals in sludge incineration residues, and a base is made for resource utilization of the sludge incineration residues.

Description

technical field [0001] The invention belongs to the field of resources and environment, and in particular relates to a method for efficiently fixing heavy metals in sludge incineration residues by preparing geopolymers. Background technique [0002] Sludge incineration residues are rich in heavy metals such as Zn, Cu, Cr, Cd, Ni, Pb, etc., and the heavy metals contained in them must be solidified before recycling, so that the concentration of heavy metals in and out is lower than the national standard, and the sludge incineration residue can reach Standards for recycling. The solidification methods of heavy metal-containing wastes that have been studied or applied mainly include: cement-based solidification technology, lime solidification technology, encapsulation technology, glass solidification technology, geopolymer solidification technology, etc. [0003] (1) Cement-based solidification technology [0004] Cement-based solidification of heavy metal waste technology is ...

AI Technical Summary

Problems solved by technology

[0017] (1) The secondary treatment of cement / lime solidification requires a large amount of land, which often exceeds the volume of heavy metal waste itself

[0018] (2) After curing, there will be many capillary pores inside the cured body, and the impermeability of the cured body will not be very high, which may cause the escape of water-soluble heavy metals; The output is large and the sustainability is poor. At the same time, the prepared cement containing sludge incineration residue has poor mechanical properties, acid and alkali resistance, high temperature resistance and carbonization resistance.

[0019] (3) Encapsulation / vitrification technology has high energy consumption and high cost, and the types of wastes containing heavy metals are relatively limited

[0021] (5) Whether the doping amount of sludge incineration residue in the solidified geopolymer has a significant impact on the solidification effect of heavy metals is still unknown

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