Preparation method and application of NiCu/BDD composite electrode used for directional catalytic oxidation of ammonia nitrogen in wastewater

Abstract

The invention discloses a preparation method of a NiCu / BDD composite electrode and application of the NiCu / BDD composite electrode to directional catalytic oxidation of ammonia nitrogen in wastewater, belonging to the field of novel material wastewater treatment. According to the method, after a diamond film is deposited on a tantalum sheet through a hot wire vapor deposition method, an electrode is ultrasonically cleaned through HCl, acetone, ethyl alcohol and ultrapure water in sequence, and the electrode is dried through a drying oven; and then electrochemical deposition of a Ni and Cu bimetallic compound is conducted in an electrolyte solution containing a certain amount of NiSO4, CuSO4 and lauryl sodium sulfate (SDS), and the deposited electrode is fully cleaned with ultrapure water, and then naturally aired. The prepared NiCu / BDD composite electrode can be applied to directional catalytic oxidation of ammonia nitrogen in wastewater. By optimizing the preparation parameters of the BDD electrode and the deposition parameters of the NiCu bimetallic oxide, the synergistic denitrification effect of the BDD substrate and the NiCu bimetallic oxide catalytic material can be effectively exerted, efficient directional catalytic oxidation of ammonia nitrogen can be realized under low voltage, and excellent nitrogen selectivity and stability are shown.

Description

technical field [0001] The invention belongs to the field of waste water treatment of new materials, and in particular relates to the preparation of a NiCu bimetallic-supported boron-doped diamond (BDD) composite electrode and its application in directional catalytic oxidation of ammonia nitrogen in waste water. Background technique [0002] In recent years, due to the excessive discharge of ammonia nitrogen pollutants, water pollution problems such as eutrophication and odor have become more and more serious. Literature shows that ammonia nitrogen in wastewater consumes a large amount of dissolved oxygen in the process of oxidation to nitrite nitrogen or nitrate nitrogen, which further leads to black and odorous water bodies. Common methods for removing ammonia nitrogen in water still have many limiting factors in terms of energy consumption, reaction conditions, and reaction by-products, and part of ammonia nitrogen is only oxidized to NO 3 -N and NO 2 -N, did not achiev...

AI Technical Summary

Problems solved by technology

However, the above studies have not applied the catalyst to the denitrification of ammonia nitrogen wastewater. The catalyst will NH 3 -N oxidation to N 2 selectivity is unknown

[0005] In order to further reduce the dependence of the ammonia oxidation catalyst on Pt, reduce the cost of the catalyst, and avoid the deactivation of the Pt catalyst, a Ni-based Ni-based catalyst prepared by a hydrothermal method was reported. 2 P-loaded nickel foam electrode, which in the starting NH 3 - When the N concentration is 1000mg / L and the current is 10mA, the Faradaic efficiency of ammonia oxidation can reach 52.8%. 2 The selectivity is 55%, which converts to NO 3 -N and NO 2 -N of NH 3 -N is 25% and 20%, respectively, although N 2 The selectivity of nitrate nitrogen has been improved, but the part converted into nitrate nitrogen and nitrite nitrogen will still have a negative impact on the environment

[0006] In summary, NH 3 The direct oxidation of -N still has a low oxidation rate and the product N 2 Low selectivity, poor electrode corrosion resistance, etc.

The lower oxidation rate is mainly due to the NH 3 The oxidation of -N is still limited by the electron transfer rate on the surface of the catalytic electrode, and the adsorptive intermediate products produced during the oxidation process will still greatly reduce the oxidation performance of the electrode.

In addition, ordinary carbon-based catalyst electrodes are usually easily corroded in strong acid and alkali environments, resulting in short service life of the electrodes

Images