CN102910724A - Method for treating organic wastewater by oxidation of bicarbonate activated load-type metal catalysts - Google Patents

Abstract

The invention discloses a method for treating organic waste water by catalytic oxidation of bicarbonate-activated hydrogen peroxide, which comprises mixing loaded transition metal ions and bicarbonate-activated hydrogen peroxide with organic waste water and stirring for reaction until the hydrogen peroxide is completely consumed That is to end; wherein, the supported transition metal ion is used as a catalyst, the concentration is 0.1-10wt%, and the consumption is 0.01-10 g/L, and hydrogen peroxide is used as an oxidant, which is formed by preparing an aqueous solution of hydrogen peroxide and bicarbonate, wherein The concentration of bicarbonate in the mixture is 0.5-1000 mM/L, and the concentration of hydrogen peroxide is 1-500 mM/L. The present invention has the following technical advantages: (1) mild reaction conditions, low equipment requirements, simple reaction system, and low investment; (2) organic wastewater is carried out under neutral to slightly alkaline conditions, which is environmentally friendly and free of secondary pollution; (3) It has wide application range, low processing cost, and can be used on a large scale.

Description

Bicarbonate Activation Supported Metal Catalyst Oxidation Treatment Method for Organic Wastewater

technical field

The invention belongs to wastewater treatment technology, and in particular relates to a method for catalytic oxidation treatment of organic wastewater by using bicarbonate to activate a loaded metal catalyst. The catalyst catalyzes the oxidation degradation of organic wastewater. the

Background technique

With the improvement of the degree of industrialization and people's living standards, the pressure of degradation and treatment of various organic wastewater is increasing. Especially with the continuous expansion of production scale and the rapid development of industrial technology, the pollution sources of organic wastewater containing high concentration, refractory, toxic and harmful are increasing day by day. Current methods for treating various types of wastewater include physical, biological, and chemical methods. Among them, the physical method is to collect and transfer pollutants rather than eliminate them; the biological method is currently the most successful and widely used method, but the treatment cycle is long and it is difficult to treat pollutants with poor biochemical activity and high biological toxicity. There are many kinds of chemical methods, which are suitable for the rapid treatment of high-concentration wastewater, and have good application prospects, especially based on the Fenton technology (Pignatello JJ, Environment Science & Technology 2006) of activated hydrogen peroxide and its improved system, such as Guangzhu Fenton (CN1636893) , Electric Fenton (CN1789150), Fenton/O ₃ (CN101311130), Fenton/Ultrasonic (CN1546395), etc., have become the focus of attention from all sides. It is characterized by the formation of hydroxyl radicals with extremely high oxidizing ability, which can quickly and non-selectively oxidize various pollutants to carbon dioxide and water. However, there are still some technical difficulties in the actual industrial application of these catalytic technologies, which limit their extensive application in actual wastewater treatment. Wherein especially supported metal ion catalyst, still has following shortcoming: 1) owing to using a large amount of metal ion as catalyst, along with the carrying out of reaction, reaction medium is gradually acidified, simultaneously because higher processing temperature, metal ion dissolves in a large amount, forms two Secondary pollution (Mantzavinos D, WaterResearch, 2009), 2) The reaction is severely limited by pH (such as the Fenton system needs to be treated at pH 3-4), 3) The investment in equipment is large (such as wet oxidation), thus limiting their use in actual wastewater treatment a large number of applications. In order to overcome the above shortcomings, the invention patent "A method for oxidatively degrading organic pollutants in wastewater by activating hydrogen peroxide" (ZL 2009 1 0061122.0) developed a hydrogen peroxide system activated by bicarbonate to achieve effective degradation of organic wastewater, adding a small amount of water-soluble transition Metal ions will further enhance its catalytic activity. However, the use of water-soluble transition metal ions as catalysts also causes secondary pollution, and the metal catalysts are difficult to recycle and the cost is high.

Contents of the invention

The present invention aims at the defect that the use of water-soluble transition metal ions as catalysts is likely to cause secondary pollution, and provides a bicarbonate-activated supported metal ion catalyst, a method for catalytic oxidation treatment of organic wastewater using hydrogen peroxide as an oxidant, realizing organic Effective degradation of wastewater. the

The invention provides a method for treating organic wastewater by catalytic oxidation of bicarbonate-activated hydrogen peroxide, which comprises mixing loaded transition metal ions and bicarbonate-activated hydrogen peroxide with organic wastewater and stirring the reaction until the hydrogen peroxide is completely consumed ends; where,

The supported transition metal ion is used as a catalyst, the mass percent concentration of the transition metal ion in the catalyst is 0.1-10%, and its consumption is 0.01-10g/L, the hydrogen peroxide is used as an oxidant, and the bicarbonate-activated The hydrogen peroxide oxidizing agent is formed by preparing an aqueous solution of hydrogen peroxide and bicarbonate, wherein the concentration of bicarbonate in the mixture is 0.5-1000mM/L, and the concentration of hydrogen peroxide in the mixture is 1-500mM/L. the

As an improvement of the above technical solution, the supported transition metal ion is one or more of cobalt, chromium, manganese, copper, iron, nickel, vanadium, molybdenum and tungsten. the

As a further improvement of the above-mentioned technical scheme, an additive is added to the supported transition metal catalyst, the additive of the catalyst is an alkaline earth metal ion or/and a transition metal ion without redox activity, and the mass percentage concentration of the additive in the catalyst is It is 0.1-20wt%. the

As a further improvement of the above technical solution, the catalyst additive is one or more of magnesium, calcium, barium, strontium, scandium, yttrium, zirconium and zinc ions. the

As a further improvement of the above-mentioned technical scheme, the cation of the bicarbonate is an alkali metal ion or/and an alkaline earth metal ion; the cation of the bicarbonate is lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium and one or more of ammonium ions; the carrier of the catalyst is aluminum oxide, titanium dioxide, silicon dioxide, diatomaceous earth or montmorillonite. the

The present invention uses supported metal ions as catalysts and hydrogen peroxide activated by bicarbonate as an oxidant to achieve high-efficiency degradation of organic wastewater at near room temperature, eliminates secondary pollution caused by water-soluble metal ions, and effectively overcomes the Defects of the above-mentioned "Fenton-like advanced oxidation technology". The technology included in the invention has the advantages of mild reaction conditions, recyclable catalyst, no secondary pollution and low equipment investment. the

The bicarbonate-hydrogen peroxide-loaded metal ion catalytic technology of the invention is suitable for treating dye-containing wastewater, pesticide-containing wastewater, phenol-containing wastewater, urban domestic wastewater and various garbage permeates. The evaluation standard of organic wastewater degradation is to measure the conversion rate of organic pollutants and the removal rate of chemical oxygen demand after catalytic oxidation. By adopting the technology of the invention, the treated organic wastewater can be completely decolorized and deodorized, and the COD removal rate can reach 20-70%. the

In a word, the present invention has the following technical advantages: (1) mild reaction conditions, low equipment requirements, simple reaction system, and small investment; (2) organic wastewater is carried out under neutral and slightly alkaline conditions, which is environmentally friendly and has no secondary pollution; (3) wide application range, low treatment cost, and large-scale use. the

The present invention uses supported metal ions as catalysts, which effectively overcomes the secondary pollution caused by the existing hydrogen peroxide activated by bicarbonate and the use of water-soluble metal ions as catalysts, and the shortcomings of difficult recovery of catalysts (ZL 200910061122.0); and compared with traditional Compared with supporting metal ions as catalysts, the catalytic technology included in the present invention uses less catalyst and has lower loss rate of metal ions. the

Detailed ways

The present invention prepares hydrogen peroxide and bicarbonate into an aqueous solution to form a bicarbonate-activated hydrogen peroxide oxidant, wherein the concentration of bicarbonate is 0.5-1000mM/L, and the concentration of hydrogen peroxide is 1-500mM/L; The transition metal ion catalyst, the organic wastewater and the pre-prepared oxidant are mixed and stirred in the reaction tank. The dosage of the catalyst is 0.01-10g/L, and the loading amount of the transition metal ion is 0.1-10wt%, as the addition of the supported transition metal catalyst The loading amount is 0.1-20wt%, and the reaction temperature is 10-100°C; the reaction ends when the hydrogen peroxide is completely consumed (usually 1 minute to 24 hours). the

The cation of the bicarbonate for activating hydrogen peroxide is one or more of alkali metal ions: lithium, sodium, potassium, cesium or alkaline earth metal ions: magnesium, calcium, barium, strontium and ammonium ions. the

The supported catalyst is a transition metal ion: one or more of cobalt, chromium, manganese, copper, iron, nickel, vanadium, molybdenum and tungsten;

The additives of the supported catalyst are alkaline earth metal ions: magnesium, calcium, barium, strontium ions and transition metal ions without redox activity: one or more of scandium, yttrium, zirconium and zinc; the carrier of the catalyst is: trioxide Aluminum, titanium dioxide, silica, diatomaceous earth and montmorillonite. the

The specific embodiments of the present invention will be further described below in conjunction with the attached table. It should be noted here that the descriptions of these embodiments are used to help understand the present invention, but are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other. the

Example 1

Take 24 mL of the prepared reaction solution (I), add 0.2 mL of 30% hydrogen peroxide, let the mixture stir at 25° C., and react for 5 hours. After the reaction, samples were taken for analysis. The results are shown in Table 1. Wherein reaction solution (I) is dyestuff (methylene blue or methyl orange) concentration 50mg/L, cobalt nitrate concentration 20 μ M, the aqueous solution of sodium bicarbonate concentration 25 mM;

Example 2

Take 24 mL of the prepared reaction solution (I) or (II), add 0.2 mL of 30% hydrogen peroxide, let the mixture stir at 45° C., and react for 5 hours. After the reaction, samples were taken for analysis. The results are shown in Table 1. The reaction solution has two types: (I) 50 mg/L phenol concentration, 20 μM cobalt nitrate concentration, and 25 mM sodium bicarbonate concentration; (II) 50 mg/L phenol concentration, 20 μM cobalt nitrate concentration, adjusted pH to 8.7 with sodium hydroxide of aqueous solution. the

Example 3

Take 24 mL of the prepared reaction solution (I) or (II), and add 0.01 g of metal-supported catalyst (the loading amount of the catalyst is 1.7%). Afterwards, the mixture was stirred at a constant temperature of 25° C. and reacted for 5 hours. After the reaction, samples were taken for analysis. The results are shown in Table 2. There are two types of reaction solutions: (I) an aqueous solution with a dye concentration of 50 mg/L, a hydrogen peroxide concentration of 80 mM, and a sodium bicarbonate concentration of 25 mM; (II) an aqueous solution with a dye concentration of 50 mg/L and a hydrogen peroxide concentration of 80 mM. The results are shown in Table 2. After the reaction, the loss of cobalt element in the cobalt-loaded catalyst was 0.2ppm. the

Example 4

Take the prepared reaction solution (I) or (II) 20mL, then add 0.0117g Co (or Cu) supported catalyst (the mass fraction of the metal element in the catalyst is 5%). Afterwards, the mixture was allowed to react at a constant temperature of 45° C. for 5 hours. After the reaction, samples were taken for analysis. The results are shown in Table 3. Wherein the reaction solution is divided into two categories: I and II. For I, the phenol concentration was 0.5 mM, the hydrogen peroxide concentration was 35 mM, and the sodium bicarbonate concentration was 44 mM; while for II, the phenol concentration was 0.5 mM, the hydrogen peroxide concentration was 35 mM, and the pH of the solution was adjusted to 8.70 with sodium hydroxide. the

Example 5

Take 20 mL of the prepared reaction solution (I) or (II), and then add 0.0117 g of Co-supported catalysts added with other metal ions. Afterwards, the mixture was allowed to react at a constant temperature of 45° C. for 5 hours. After the reaction, samples were taken for analysis. The results are shown in Table 4. Wherein the reaction solution is divided into two categories: I and II. For I, the phenol concentration was 0.5 mM, the hydrogen peroxide concentration was 35 mM, and the sodium bicarbonate concentration was 44 mM; while for II, the phenol concentration was 0.5 mM, the hydrogen peroxide concentration was 35 mM, and the pH of the solution was adjusted to 8.70 with sodium hydroxide. the

Table 1

Table 2

It can be seen from Table-2 that regardless of the decolorization rate of the dye and the COD removal rate, the effect of the supported transition metal catalyst in the bicarbonate activated hydrogen peroxide system is significantly better than that of the direct use of hydrogen peroxide oxidant. Compared with the direct use of water-soluble transition metal ions in Table-1, the loss rate of the loaded transition metal catalyst in the wastewater treatment is also very low (0.2 ppm), which avoids the technical problem of secondary pollution. the

table 3

In Table-3, the degradation of phenol also shows similar results: using various supports and catalysts supported by transition metal ions, the degradation rate of phenol reflected in the hydrogen peroxide system activated by bicarbonate is higher than that of similar The hydrogen peroxide system under the pH condition, meanwhile, the loss rate of its transition metal ion is also much lower than the system without sodium bicarbonate. the

Table 4

It can be seen from Table-4 that in the presence of various additives, the activity of supported transition metal ions in the bicarbonate-activated hydrogen peroxide system is further improved. the

The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in this embodiment. Therefore, all equivalents or modifications that do not deviate from the spirit disclosed in the present invention fall within the protection scope of the present invention. the

Claims (7)

1. A method for treating organic wastewater by catalytic oxidation of bicarbonate-activated hydrogen peroxide, mixing and stirring the loaded transition metal ions, hydrogen peroxide activated by bicarbonate and organic wastewater, and the reaction ends when the hydrogen peroxide is consumed ;in, The supported transition metal ion is used as a catalyst, the mass percent concentration of the transition metal ion in the catalyst is 0.1-10%, and its consumption is 0.01-10g/L, the hydrogen peroxide is used as an oxidant, and the bicarbonate-activated The hydrogen peroxide oxidizing agent is formed by preparing an aqueous solution of hydrogen peroxide and bicarbonate, wherein the concentration of bicarbonate in the mixture is 0.5-1000mM/L, and the concentration of hydrogen peroxide in the mixture is 1-500mM/L. 2. the method for bicarbonate activated hydrogen peroxide catalytic oxidation treatment organic waste water according to claim 1, is characterized in that, described loaded transition metal ion is cobalt, chromium, manganese, copper, iron, nickel, vanadium, One or more of molybdenum and tungsten. 3. the method for bicarbonate activation hydrogen peroxide catalytic oxidation treatment organic waste water according to claim 1, it is characterized in that, add additive in load-type transition metal catalyst, the additive of described catalyst is alkaline earth metal ion or / and transition metal ions without redox activity, the mass percent concentration of the additive in the catalyst is 0.1-20wt%. 4. the method for bicarbonate activated hydrogen peroxide catalytic oxidation treatment organic waste water according to claim 3, is characterized in that, the additive of described catalyst is magnesium, calcium, barium, strontium, scandium, yttrium, zirconium and zinc one or more of the ions. 5. according to the method for the bicarbonate activated hydrogen peroxide catalytic oxidation treatment organic waste water described in any one in claim 1 to 4, it is characterized in that, the cation of described bicarbonate is alkali metal ion or/and alkaline earth metal ion . 6. according to the method for the bicarbonate activated hydrogen peroxide catalytic oxidation treatment organic waste water described in any one in claim 1 to 4, it is characterized in that, the cation of described bicarbonate is lithium, sodium, potassium, cesium, magnesium , calcium, barium, strontium and ammonium ions or one or more. 7. according to the method for the bicarbonate activated hydrogen peroxide catalytic oxidation treatment organic waste water described in any one in claim 1 to 4, it is characterized in that, the carrier of described catalyst is aluminum oxide, titanium dioxide, silicon dioxide, diatomaceous earth or montmorillonite.