CN1280105A - Electric ally caltalytic contact oxidizing technology - Google Patents

Abstract

An electrically catalytic contact oxidizing process uses titania or vanadium pentoxide as catalyst, and molecular sieve, active carbon, zeolite or sand as stuffing. After stuffing and catalyst are loaded into a reactor, waste water is led in, voltage is applied duping reaction and oxygen is led in, and through treatment in 20 min to 10 hr, and then treated water is led out. The process of the present invention has the advantages of short technological path, low treatment cost, complete decoloring of texitile printing sewage, and degradtion of organic matter.

Description

Electrocatalytic Contact Oxidation Process

The electrocatalytic contact oxidation process is used to treat printing and dyeing wastewater and wastewater containing refractory organic matter.

The dyes used in the printing and dyeing industry are basically artificially synthesized chemical dyes. Due to the characteristics of many types of chemical dyes, complex structures, difficult decolorization, and poor biodegradability, they have not been well resolved at home and abroad. Printing and dyeing wastewater The chromaticity has brought great difficulties to wastewater treatment and reuse, and has become an obstacle to the realization of wastewater resource utilization. It is an urgent problem to be solved in the field of environmental science research.

Due to its poor biodegradability, wastewater containing refractory organic matter has brought great pollution to the environment. It is also a technical problem that has been concerned and solved in the research field for many years.

The above two organic pollutants are difficult to control and the treatment cost is high. Traditional treatment methods include chemical coagulation, chemical oxidation, adsorption, iron filings filtration, and biochemical methods. In actual engineering, it is difficult to achieve satisfactory results with a single treatment method. Therefore, multiple methods are used in actual engineering. The result is that the treatment process route is long and complicated, the treatment cost is high, and the pollutant indicators after treatment still cannot meet the emission standards required by the national control. This standard mainly refers to chromaticity and COD value.

The purpose of the electrocatalytic contact oxidation process is to solve the problem of standard discharge or reuse of printing and dyeing wastewater and refractory organic wastewater, that is, to shorten the process flow, and fundamentally solve the difficulties of decolorization and organic degradation that cannot be solved by the original traditional technology.

The mechanism of the present invention is that the organic matter in the wastewater is difficult to be oxidized at normal temperature, even when there is a catalyst, it is also difficult to oxidize, but when an external voltage is applied, the oxygen adsorbed on the surface of the catalyst used in the present invention can form oxygen-containing free radicals, and the catalyst has Oxygen-containing free radicals are stabilized, and the life span is increased. Oxygen-containing free radicals are non-selective to the oxidation of organic matter. The fillers used in the present invention play the role of electric polarization, adsorption and dispersion. Therefore, when enough oxygen is provided, the waste water Organic matter can be continuously oxidized and decomposed. The catalytic oxidation reaction process is completed in one reactor, and only one unit operation is used to completely solve the technical difficulties in the decolorization of printing and dyeing wastewater and the degradation of organic matter. The reaction formula is expressed as:

The composition of the electrocatalytic contact oxidation process includes catalyst, filler and oxygen. The catalyst is titanium dioxide or vanadium pentoxide. The shape of the catalyst can be powder or granular. The filler is molecular sieve, activated carbon, zeolite or sand. The filler is Electropolarization, adsorption, and dispersion increase the probability of collision between the reactant and the catalyst. The reaction conditions are: the temperature of the wastewater is 0-40°C, the optimum temperature is 15-25°C, the atmospheric pressure is 0.8-1.2 atmospheres, and the pH of the wastewater The value is 1 to 14, the best is 6 to 8, the organic matter concentration COD of the wastewater is below 2000mg/L, the catalyst and the filler are evenly mixed in a ratio of 1:9 to 9:1, and the catalyst can also be fixed in the same ratio On the packing, then put them together in the reactor, introduce the wastewater into the reactor, the ratio of the catalyst to the wastewater to be treated is, the amount of catalyst is 10% to 90% of the amount of wastewater to be treated, at both ends of the electrodes of the reactor Apply a voltage of 5-50V to speed up the speed of catalysis-oxidation, and continuously feed air through the aeration tube to ensure sufficient oxygen during the reaction process. The residence time of wastewater in the reactor is 20 minutes to 10 hours. The treated water is led out of the reactor.

From the effect of the present invention, in the presence of catalyst, voltage and sufficient oxygen, refractory organic substances such as synthetic dyes in printing and dyeing wastewater can be completely oxidized, and the water quality index after treatment can fully meet the national discharge standard. Technology is an excellent method to treat printing and dyeing wastewater and wastewater containing refractory organic matter. The invention has the advantages of short process route, simple equipment and small floor space, which not only reduces the cost per ton of water treatment, but also completely solves the problems of decolorization of printing and dyeing wastewater and sufficient degradation of organic matter.

The concrete implementation of the present invention is as follows:

Process the printing and dyeing wastewater of a certain factory under normal temperature and normal pressure with the inventive method, and its steps are:

The first step: water quality investigation:

Organic concentration COD: 1190mg/L

Wastewater chromaticity: 450 times

Wastewater pH: 3

Wastewater temperature: 20°C

The second step: fix 20 grams of titanium dioxide on 180 grams of molecular sieve, put it in the reactor, add 1 liter of waste water, apply a voltage of 20V across the electrodes of the reactor to speed up the speed of catalysis-oxidation, and pass through the aeration tube Air is fed continuously to ensure sufficient oxygen in the reaction. The whole reactor is like a fluidized bed. The wastewater stays in the reactor for 30 minutes to fully react, and finally the treated water is led out of the reactor.

Step 3: The water quality test results after treatment are:

Organic concentration COD: 70mg/L

Chroma: 30 times

PH value: 6

Water temperature after treatment: 20°C

The water quality after treatment reaches the national secondary discharge standard.

Claims (3)

1. the composition of electric ally caltalytic contact oxidizing technology mainly comprises catalyzer, filler, it is characterized in that, forms and also comprises oxygen, wherein, catalyzer is titanium dioxide or Vanadium Pentoxide in FLAKES, and filler is molecular sieve, gac, zeolite or sand grains, and the ratio of catalyzer and filler is 1: 9 to 9: 1.

2. electric ally caltalytic contact oxidizing technology is characterised in that, catalyzer and amount of filler are 10%～90% of the desire processing water yields, catalyzer and filler are placed in the reactor, waste water is introduced reactor, add voltage in the reaction process, aerating oxygen, waste water stopped in reactor 20 minutes～10 hours, and the water after handling is drawn reactor.

3. electric ally caltalytic contact oxidizing technology according to claim 2 is characterised in that, is reflected under the following condition and carries out:

A. the waste water water temperature is 0～40 ℃, 15～25 ℃ of optimum tempss,

B. normal atmosphere is 0.8～1.2 normal atmosphere,

C. the pH value of waste water is 1～14, and the best is 6～8,

D. the organic concentration COD of waste water is below 2000mg/L,

E. voltage is 5～50V,

F. aerating oxygen is continuous aerating oxygen.