A modified carbon nanotube and its preparation method and application

Abstract

The invention provides a modified carbon nanotube and its preparation method and application, belonging to the field of advanced wastewater treatment. The material is made by grafting rare earth lanthanum ions to both ends of acidified carbon nanotubes through ultrasonic-assisted precipitation method. The carbon nanotubes loaded with lanthanum ions increase the positive charge and strengthen the adsorption effect on nitrate nitrogen in water. Then the cationic surfactant is coated on the surface of carbon nanotubes through electrostatic interaction, and the hemispherical hemimicelle formed by the cationic surfactant can enhance the hydrophobic characteristics of carbon nanotubes, so as to weaken the interference of water molecules on the adsorption of nitrate nitrogen the goal of. The modified carbon nanotubes have excellent adsorption effect on nitrate nitrogen in sewage, and are especially suitable for the advanced treatment and reuse technology of biochemical tail water with low nitrate nitrogen concentration, and the present invention has high denitrification efficiency and simple preparation process It has the advantages of easy operation, mild reaction conditions and easy control, and has good economic and environmental benefits.

Description

technical field [0001] The invention relates to the technical field of advanced wastewater treatment, in particular to a modified carbon nanotube and its preparation method and application. Background technique [0002] With the further improvement of my country's total nitrogen discharge standards, it is difficult to discharge total nitrogen in sewage, causing a large number of sewage treatment plants to face the problem of standard upgrading. Nitrate nitrogen is the main component of total nitrogen in the biochemical tail water of sewage treatment plants, and it accounts for more than 75% of the total nitrogen in urban biochemical tail water. How to remove nitrate nitrogen in the tail water is of great significance for the discharge of sewage up to the standard. [0003] Traditional technologies for removing nitrate nitrogen from water include catalytic reduction, ion exchange, reverse osmosis, electrodialysis, and denitrification. At present, most sewage treatment plant...

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Problems solved by technology

[0004] In the prior art, for example, Chinese patent CN102941063A discloses a method for adsorbing and removing phosphate in water by carbon nanotubes modified by zirconium oxychloride. It has a good removal effect, but the removal effect on nitrate nitrogen is not good; Chinese patent CN104258812A discloses a preparation method of a metal element-improved biochar-based nitrate adsorbent, which has a good effect on the high concentration of nitrate nitrogen in wastewater. removal effect, but it is difficult to effectively treat low-concentration nitrate wastewater

To sum up, the existing water body nitrate nitrogen adsorbents have the disadvantages of small adsorption capacity, low adsorption efficiency, and poor adsorption effect on low concentration nitrate nitrogen.