Method for absorbing and recycling heavy metals by using persimmon tannins

Abstract

The invention discloses a method for absorbing and recycling heavy metals by using persimmon tannins. The absorbing material used in the method is prepared by the steps of: firstly dissolving cowhide collagen fibers and persimmon powder in water, reacting, adding glutaraldehyde or formaldehyde, reacting at the temperature of 50 DEG C and filtering, drying in vacuum and grinding. According to the method for absorbing and recycling the heavy metal, a chromatographic analytical column adsorption method is adopted to absorb and recycle precious metal, such as copper, iron, chrome and silver, wherein the average adsorption rate is above 95%. The method is applied to the absorbing and recycling treatments of a plurality of heavy metal ions in industrial wastewater with low concentration (less than 1000mg / L); and the method is low in the operating cost, can be reused and has no secondary pollution to the environment.

Description

technical field [0001] The invention relates to the adsorption recovery of heavy metals, in particular to a method for adsorption and recovery of heavy metals by persimmon tannin adsorption materials. Background technique [0002] At present, there are three main methods for treating precious metal-containing wastewater and waste residue at home and abroad: one is chemical precipitation, the other is biological treatment, and the third is adsorption. [0003] In the chemical precipitation method, because of the precipitation of heavy metal ions produced by the precipitation reaction, the final disposal is usually landfill, so the environmental pollution of toxic heavy metals still exists for a long time, which is actually a kind of pollution transfer. At present, most biological treatment methods are in the stage of experimental research, and most of them stay in the discussion of influencing factors, and there is still a considerable distance from industrial application. A...

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Problems solved by technology

Commonly used adsorption materials include activated carbon, synthetic resin, minerals, microorganisms and natural biomass, etc.; the research results of Zhang Huiping, Zhu Liguo, et al. 2+ 、Ni 2+ The saturated adsorption capacity of the modified activated carbon fiber is 5.1mg / g, 6.6mg / g respectively, and the modified activated carbon fiber has a 2+ 、Ni 2+ The saturated adsorption capacity reaches 20.6mg / g, 8.0mg / g, and the adsorption capacity is still relatively small; this method still has some shortcomings in industrial application: first, the adsorption capacity is low, such as activated carbon only adsorbs a few metal ions Effect and small adsorption capacity, usually between 5-20mg / g

The second is that the adsorption and desorption speed is slow. The currently used adsorption materials mainly rely on the porous nature of the adsorption material itself. Heavy metal ions are mainly absorbed by entering the surface of the inner pores of the adsorption material, so the adsorption speed is relatively slow.

Third, many adsorbent materials cannot be regenerated and reused after adsorption and saturation, and can only be treated as solid waste for landfill or incineration, which often causes secondary pollution