CN102774933A

CN102774933A - Method for processing high-concentration ammonia nitrogen in rare earth wastewater

Info

Publication number: CN102774933A
Application number: CN2012102532634A
Authority: CN
Inventors: 雷春生; 张凤娥; 麦源珍
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2012-07-18
Filing date: 2012-07-18
Publication date: 2012-11-14
Anticipated expiration: 2032-07-18
Also published as: CN102774933B

Abstract

The invention discloses a method for processing high-concentration ammonia nitrogen in rare earth wastewater. The method comprises the specific steps as follows: firstly, taking 100-mesh to 150-mesh granular active carbon for preparing an electrode with catalytic activity; secondly, filling the rare earth wastewater with the high-concentration ammonia nitrogen into an electrolytic tank; thirdly, adding a NaCl solid and electrolyzing for 3-4h at the voltage of 36-110V; and finally, reducing the concentration of the ammonia nitrogen in the discharged rare earth wastewater to be less than 0.2mg/L. According to the method, the concentration polarization of ion concentration in a surrounding solution is eliminated by the granular active carbon and the electrode with catalytic activity, so that the redox reaction is conducted to convert the high-concentration ammonia nitrogen in the rare earth wastewater into nitrogen, and the nitrogen is discharged into the air; the ammonia nitrogen removal rate is more than 99.8%; the voltage is low; the energy consumption is low; and the secondary pollution risk is avoided.

Description

A kind of processing RE waste water middle and high concentration ammonia nitrogen method

Technical field

The present invention relates to a kind of processing RE waste water middle and high concentration ammonia nitrogen method, belong to sewage treatment area.

Background technology

Three kinds of waste water of pharmacy discharging in the Rare Earth Production smelting process mainly are acid waste water, the ammonium salt waste water of carbonated rare earth production process generation and the ammonium salt waste water that Rare Earth Separation produces that rare earth ore concentrate roasting tail gas spray cleaning produces.Wherein, the annual wastewater flow rate that produces of rare-earth trade reaches more than 2,000 ten thousand tons, and ammonia-nitrogen content 300～5000mg/L exceeds tens times of discharging standards to hundreds of times.One of three big waste water that ammonia nitrogen pollutant produces in the rare-earth smelting just in the waste water; Ammonia nitrogen is a kind of important pollutent that causes body eutrophication and environmental pollution in the water-quality guideline; It can make water lose the self-purification ability; It gets into human body and synthetic nitroso compound, brings out canceration, can cause the generation of gastrointestinal disorders and endemic illness when ammonia-nitrogen content is too high in the tap water.

In the electrolytic process of handling RE waste water middle and high concentration ammonia nitrogen, it is advantageous that the decrement of secondary pollutant, easy handling; Long-distance Control adapts to widely etc., and this method can effectively be removed other pollutents in ammonia nitrogen and the waste water; But it also exists power consumption big simultaneously, shortcomings such as cost height.In order to address this problem, to electrolysis, He Xuwen, Liu Tong etc. propose the research that a kind of electrolysis is removed high-concentration ammonia nitrogenous wastewater technology in document, and this research as stock, is chosen 7～9A current strength, NH with plumbous and ruthenium ₄ ⁺With Cl ^-Mol ratio be 1: 4 Cl ^-Concentration; Improve ammonia nitrogen removal speed along with increasing quantity of polar plate in the electrolytic process, the ammonia nitrogen removal effect is high, has reduced certain electrisity consumption and cost; But this research only is directed to agricultural chemicals waste water etc.; For the ammonia nitrogen in high density removal effect in the RE waste water still is not desirable, and 7～9A current strength still causes electrisity consumption big, must bring disposal cost expensive.Remove method to the electrolysis of RE waste water middle and high concentration ammonia nitrogen, can accomplish simultaneously that power consumption is low, cost is low, avoid the document of secondary pollution risk not appear in the newspapers as yet, in patent, also fail to be protected.

Summary of the invention

In order to seek a kind ofly to accomplish simultaneously that power consumption is low, cost is low, avoid the RE waste water middle and high concentration ammonia nitrogen electrolysis of secondary pollution risk to remove method; The invention reside in a kind of processing RE waste water middle and high concentration ammonia nitrogen method that provides; Through having prepared a kind of electrode with catalytic activity; The concentration polarization of effects of ion concentration around eliminating converts rare waste water middle and high concentration ammonia nitrogen of going up in the nitrogen exhausted air into thereby produce redox reaction, and ammonia nitrogen removal frank is up to more than 99.8%; Solve the problem that voltage is high in the prior art, energy consumption is high, avoided the generation of secondary pollution risk.

For achieving the above object, the concrete technical scheme that the present invention takes is:

(1) gets 100～150 order granulated active carbons; In 0.5MHCl solution, soaked 2～3 hours; Wash 3 times with during deionized water is under action of ultrasonic waves, put into 2MNaOH solution and soaked 3～4 hours, wash 3 times under action of ultrasonic waves with deionized water again; Naturally dry, be 105 ℃ in temperature and dried 2～3 hours down;

(2) the Cu (NO of the immersion of the granulated active carbon after oven dry 2.5M ₃) ₂, 1.0M Ni ((NO ₃) ₂In the mixing solutions 5～6 hours, dry naturally, be 105 ℃ of oven dry 2～3 hours down in temperature;

(3) the hollow cylinder micropore iron-clad of packing into of the grain active carbon after the above-mentioned processing, as electrolysis electrode;

(4) feed electrolyzer to the ammonia nitrogen in high density RE waste water, adding mass ratio is 0.1～0.5%NaCl solid, and electrolysis is 3～4 hours under 36～110V voltage, gets final product.

Significant advantage of the present invention is:

(1) contain the electrode of catalytic activity, not only have betatopic effect, can also eliminate the concentration polarization of effects of ion concentration on every side;

(2) convert RE waste water middle and high concentration ammonia nitrogen in the nitrogen exhausted air into through redox reaction, it is low to have voltage, and advantage of low energy consumption has realized energy conservation object, has avoided the generation of secondary pollution risk.

Specific embodiments:

Get 100～150 order granulated active carbons earlier; In 0.5MHCl solution, soaked 2～3 hours; Wash 3 times under action of ultrasonic waves with deionized water, put into 2MNaOH solution and soaked 3～4 hours, wash 3 times under action of ultrasonic waves with deionized water again; Naturally dry, be 105 ℃ in temperature and dried 2～3 hours down; Immerse the granulated active carbon after the oven dry Cu (NO of 2.5M then ₃) ₂, 1.0M Ni ((NO ₃) ₂In the mixing solutions 5～6 hours, dry naturally, be 105 ℃ of oven dry 2～3 hours down in temperature; Then the hollow cylinder micropore iron-clad of packing into of the grain active carbon after the above-mentioned processing, as electrolysis electrode; Feed electrolyzer to the ammonia nitrogen in high density RE waste water at last, adding mass ratio is 0.1～0.5%NaCl solid, in electrolysis under 36～110V voltage after 3～4 hours, surveys ammonia nitrogen concentration in the RE waste water after the electrolysis.

Embodiment 1:

Get 105 order granulated active carbons earlier, in 0.5MHCl solution, soaked 2 hours, under action of ultrasonic waves, wash 3 times with deionized water; Putting into 2MNaOH solution soaked 4 hours; Wash 3 times with during deionized water is under action of ultrasonic waves again, dry naturally, be 105 ℃ in temperature and dried 2 hours down; Immerse the granulated active carbon after the oven dry Cu (NO of 2.5M then ₃) ₂, 1.0M Ni ((NO ₃) ₂In the mixing solutions 5 hours, dry naturally, be 105 ℃ of oven dry 2 hours down in temperature; Then the hollow cylinder micropore iron-clad of packing into of the grain active carbon after the above-mentioned processing, as electrolysis electrode; Be ammonia nitrogen concentration the RE waste water feeding electrolyzer of 2500mg/L at last; Adding mass ratio is the 0.1%NaCl solid; In electrolysis under the 40V voltage after 3 hours, record in the RE waste water ammonia nitrogen concentration and drop to 0.1mg/L.COD concentration and drop to 30mg/L by 2000mg/L, clearance is up to 99.9%.

Embodiment 2:

Get 150 order granulated active carbons earlier, in 0.5MHCl solution, soaked 3 hours, under action of ultrasonic waves, wash 3 times with deionized water; Putting into 2MNaOH solution soaked 3 hours; Wash 3 times under action of ultrasonic waves with deionized water again, dry naturally, be 105 ℃ in temperature and dried 3 hours down; Immerse the granulated active carbon after the oven dry Cu (NO of 2.5M then ₃) ₂, 1.0M Ni ((NO ₃) ₂In the mixing solutions 6 hours, dry naturally, be 105 ℃ of oven dry 3 hours down in temperature; Then the hollow cylinder micropore iron-clad of packing into of the grain active carbon after the above-mentioned processing, as electrolysis electrode; Be ammonia nitrogen concentration the RE waste water feeding electrolyzer of 5000mg/L at last; Adding mass ratio is the 0.5%NaCl solid, in electrolysis under the 110V voltage after 4 hours, records that ammonia nitrogen concentration drops to 0.2mg/L in the RE waste water; COD concentration drops to 60mg/L by 3000mg/L, and clearance is up to 99.8%.

Embodiment 3:

Get 125 order granulated active carbons earlier, in 0.5MHCl solution, soaked 2 hours, under action of ultrasonic waves, wash 3 times with deionized water; Putting into 2MNaOH solution soaked 4 hours; Wash 3 times under action of ultrasonic waves with deionized water again, dry naturally, be 105 ℃ in temperature and dried 3 hours down; Immerse the granulated active carbon after the oven dry Cu (NO of 2.5M then ₃) ₂, 1.0M Ni ((NO ₃) ₂In the mixing solutions 5 hours, dry naturally, be 105 ℃ of oven dry 2 hours down in temperature; Then the hollow cylinder micropore iron-clad of packing into of the grain active carbon after the above-mentioned processing, as electrolysis electrode; Be ammonia nitrogen concentration the RE waste water feeding electrolyzer of 3500mg/L at last; Adding mass ratio is the 0.3%NaCl solid, in electrolysis under the 80V voltage after 3 hours, records that ammonia nitrogen concentration drops to 0.1mg/L in the RE waste water; COD concentration drops to 50mg/L by 2500mg/L, and clearance is up to 99.8%.

Claims

1. handle RE waste water middle and high concentration ammonia nitrogen method for one kind, it is characterized in that:

(1) gets 100～150 order granulated active carbons; In 0.5MHCl solution, soaked 2～3 hours; Wash 3 times under action of ultrasonic waves with deionized water, put into 2MNaOH solution and soaked 3～4 hours, wash 3 times under action of ultrasonic waves with deionized water again; Naturally dry, be 105 ℃ in temperature and dried 2～3 hours down;