A kind of adsorbent preparation method of rare earth doped hydrated manganese oxide

Abstract

The invention discloses a preparation method of a rare earth-doped hydrated manganese oxide adsorbent. The preparation method comprises the following steps: firstly preparing a mixed liquid I from a MnSO4.H2O solution with the molar concentration of 2%-5% and a NaCl solution with the molar concentration of 2%-10%, and adding a 0.1%-0.5% KMnO4 solution into the mixed liquid I so as to prepare a hydrated manganese dioxide seed crystal mixed liquid; carrying out rare earth-doped crystal particle amplification on the hydrated manganese dioxide seed crystal mixed liquid; carrying out precipitate size grading on a rare earth-doped hydrated manganese oxide mixed liquid, and carrying out filter pressing on precipitates with particle sizes larger than 10 microns so as to obtain adsorbent filter cake; drying the adsorbent filter cake at 50-75 DEG C for 1.5-3 hours until no obvious moisture is left on the surface of the adsorbent filter cake, thereby obtaining the finished adsorbent. The adsorbent is high in adsorption reaction speed and adsorption capacity, so that the dosage of the adsorbent in a waste water treatment process is reduced, and the operating cost of waste water treatment is lowered.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a method for preparing an adsorbent of rare earth-doped hydrated manganese oxide. Background technique [0002] At present, traditional nano-metal oxides (such as hydrated manganese oxide, hydrated iron oxide, etc.) have high adsorption capacity for cationic heavy metals such as thallium and cadmium in wastewater. There are many studies on the isothermal adsorption capacity, multi-ion competitive adsorption relationship, and desorption regeneration performance of nano-metal oxides in solution systems. However, nano-metal oxides are rarely used in wastewater treatment projects. This is mainly due to the following points Technical difficulties: First, the particle size of nano-sized metal oxides is small, and it is difficult for nano-scale oxide particles to precipitate and separate from wastewater after adsorbing heavy metals, resulting in no significant reduction in ...

AI Technical Summary

Problems solved by technology

There are many studies on the isothermal adsorption capacity, multi-ion competitive adsorption relationship, and desorption regeneration performance of nano-metal oxides in solution systems. However, nano-metal oxides are rarely used in wastewater treatment projects. This is mainly due to the following points Technical difficulties: First, the particle size of nano-metal oxides is small, and it is difficult for nano-scale oxide particles to precipitate and separate from wastewater after adsorbing heavy metals, resulting in no significant reduction in the concentration of total heavy metals in treated wastewater

Secondly, the adsorption selectivity of nano-metal oxides is not strong, and it is difficult to remove trace heavy metals in wastewater.

When Ca in wastewater 2+ , Pb 2+ When the concentration of cations is much higher than the concentration of target heavy metal pollutants (such as Tl, Hg, etc.) that need to be removed, the surface hydroxyl sites of the adsorbent are replaced by Ca 2+ , Pb 2+ Occupy, making it difficult to meet the effluent requirements of advanced treatment for trace heavy metals remaining in the treated effluent

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