Production method of self-fitting nano catalytic wastewater treatment agent

Abstract

The method in the disclosure is achieved by chemically reacting diluted sulfuric acid generated when industrial sulfate titanium white powder production with a titanium raw material, and controlling an acid/titanium ratio and an iron/titanium ratio so as to produce the nano catalytic wastewater treatment agent. When being used for treatment of dyeing wastewater and other alkaline wastewater, by virtue of alkaline and dilution environment in wastewater, the nano catalytic wastewater treatment agent is subjected to self-fitting hydrolysist to produce a new ecological nano titanium dioxide ultrafine particle as a catalyst for decomposing organic matters in wastewater so as to decompose the organic matters into carbon dioxide and water; a decomposed and oxidized hydrated iron compound is used as a flocculation and adsorption nano particle, achieving the purpose of removing organic matters in wastewater.

Claims

1. A wastewater treatment method comprising: preparation of a nano catalytic wastewater treatment agent adding a diluted sulfuric acid and a titanium raw material into a reactive tank for a decomposition reaction; wherein the diluted sulfuric acid is a byproduct from production of sulfate titanium white powder; feeding decomposed reaction materials into a cyclone for a cyclonic separation to obtain a heavy phase material and a light phase material; charging the heavy phase material back to the reactive tank for another decomposition reaction, and feeding the light phase material into a storage tank; wherein the light phase material is used as the nano catalytic wastewater treatment agent; feeding the nano catalytic wastewater treatment agent into a wastewater, regulating a pH value of the wastewater and producing a nano TiO.sub.2; carrying out an oxidative decomposition on the waste water which is pH-regulated and has produced the nano TiO.sub.2; regulating, by alkaline liquor, a pH value of a solution obtained after the oxidative decomposition, and adding a flocculant into the regulated solution for sedimentation and obtain a clear liquid qualified for discharging.

2. The wastewater treatment method of claim 1, wherein, the diluted sulfuric acid is a waste sulfuric acid.

3. The wastewater treatment method of claim 1, wherein, the diluted sulfuric acid contains ferrous sulfate and a concentration range of the diluted sulfuric acid is 15-30%.

4. The wastewater treatment method of claim 1, wherein, the titanium raw material is selected from a group consisting of ilmenite, acid-soluble titanium slag, and an intermediate product in a sulfate titanium white production.

5. The wastewater treatment method of claim 1, wherein, the reactive tank is a single reactor having a stirrer or multiple reactors having stirrers.

6. The wastewater treatment method of claim 1, wherein, a mass ratio of the diluted sulfuric acid to the titanium raw material is 100:(0.5-2.0).

7. The wastewater treatment method of claim 1, wherein, a content of titanium sulfate in the nano catalytic wastewater treatment agent is 0.5-2.5% and the mass ratio of the diluted sulfuric acid to a titanium sulfate is 8.0-50.

8. The wastewater treatment method of claim 1, wherein, a content of ferrous sulfate in the nano catalytic wastewater treatment agent is 5-15%; and the mass ratio of the diluted sulfuric acid to a ferrous sulfate is 1.5-3.5.

9. The wastewater treatment method of claim 1, wherein, a temperature of the decomposition reaction is 0-50 C.

10. The wastewater treatment method of claim 1, wherein, the pH value of the wastewater is regulated to 3.0-6.0 when feeding the nano catalytic wastewater treatment agent into the wastewater.

11. The wastewater treatment method of claim 10, wherein, the wastewater is hydrolyzed to produce the nano TiO.sub.2 with high-dispersion.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a production flowchart of a self-fitting nano catalytic wastewater treatment agent of the disclosure;

(2) In the drawing, R1first decomposition reactive tank; R2second decomposition reactive tank; R3third decomposition reactive tank;

(3) P1reaction material liquid deliver pump; P2product wastewater treatment agent loading pump;

(4) Ccyclone;

(5) Scyclonic liquid underflow returning material;

(6) T1product storage tank; T2production transport truck;

(7) FIG. 2 is a production flow diagram of sulfate titanium white powder.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Example 1

(8) As shown in FIG. 1, 13.4 t/h diluted sulfuric acid (see FIG. 2) (containing 23.3% of sulfuric acid, 10.70% of ferrous sulfate and 0.45% of titanium sulfate, see Table 1) from sulfate titanium white powder production, 134.0 kg/h ilmenite (compositions are seen in Table 2) and 268.0 kg slurry S returned back from underflow of a cyclone C are continuously added into the decomposition reactive tank R1, adversely flows to the reactive tank R2, and then adversely flows to the reactive tank R3; the standing time of the reactants is 2.5 h, and the temperature is 30 C. The material from the reactive tank R3 after complete reaction is fed to the cyclone C with the pump P1 for cyclonic separation, 268 kg of slurry S from underflow is returned back to the reactive tank R1 to further react together with newly added material, 13.534 tons of top flow is stored in the storage tank T1 as the self-fitting nano wastewater treatment wastewater agent, wherein, in the compositions of the product, the content of titanium sulfate is increased from 0.45% to 1.8% (see Table 3); the stored product is fed to the tank car T2 with the pump to be transported to the wastewater treatment station.

(9) TABLE-US-00002 TABLE 2 Compositions Of Ilmenite Components Total TiO.sub.2 FeO FeO Fe.sub.2O.sub.3 MgO CaO Al.sub.2O.sub.3 Compo- 45.07 34.62 31.85 5.61 6.18 0.76 1.35 sitions (%)

(10) TABLE-US-00003 TABLE 3 Reaction Products Components Contents (%) Components Contents (%) H.sub.2SO.sub.4 23.08 MgSO.sub.4 1.39 FeSO.sub.4 11.43 Al.sub.2(SO.sub.4).sub.3 0.71 Ti(SO.sub.4).sub.2 1.80 H.sub.2SO.sub.4/FeSO.sub.4 2.02 H.sub.2SO.sub.4/Ti(SO.sub.4).sub.2 12.82 Note: the density of the dilute sulfuric acid is 1.342 g/cm.sup.3.

Example 2

(11) 186 L/h nano catalytic wastewater treatment agent prepared in Example 1 is fed to a pH regulating pool of a 62 m.sup.3/h dyeing wastewater pretreatment tank to down-regulate the pH value of wastewater to 3.60 from 10.26; in wastewater, the Fe.sup.++ concentration of ferric sulfate is 3 mmol/L, and the concentration of nano TiO.sub.2 is 0.3 mmol/L; water discharged from the regulation pool is fed to an oxidation reactive tank equipped with a UV-irradiation device, air is introduced for nano catalytic oxidation and decomposition, the discharged water is fed to an alkaline regulation pool to regulate the pH value of the treatment water to 8.0, and the flocculant is added for settling and separation. Wastewater treatment results are seen in Table 4.

(12) TABLE-US-00004 TABLE 4 Pretreatment and Posttreatment Results of Wastewater in Example 1 Items Chroma- COD/ BOD/ SS/ TP/ TN/ ticity/ pH (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) fold Pre- 10.26 1100 270 300 5 40 500 treat- ment post- 8.00 50 15 20 1 20 25 treat- ment

Example 3

(13) 186 L/h nano wastewater treatment agent prepared in Example 1 is fed to a pH regulating pool of a 62 m.sup.3/h dyeing wastewater pretreatment tank to down-regulate the pH value of wastewater to 3.60 from 10.26; in wastewater, the Fe.sup.++ concentration of ferric sulfate is 3 mmol/L, the concentration of nano TiO.sub.2 is 0.3 mmol/L, and meanwhile 5 mmol/L hydrogen peroxide is added; water discharged from the regulation pool is fed to an oxidation reactive tank equipped with a UV-irradiation device, air is introduced for nano catalytic oxidation and decomposition, the discharged water is fed to an alkaline regulation pool to regulate the pH value of the treatment water to 8.0, and the flocculant is added for settling and separation. Wastewater treatment results are seen in Table 5.

(14) TABLE-US-00005 TABLE 5 Pretreatment and Posttreatment Resultsof Wastewater in Example 2 Items Chroma- COD/ BOD/ SS/ TP/ TN/ ticity/ pH (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) fold Pre- 10.26 1100 270 300 5 40 500 treat- ment post- 8.00 40 10 20 1 15 20 treat- ment

Example 4

Comparative Example (Fenton's Reagent Method)

(15) 62 m.sup.3/h dyeing wastewater is fed to a pretreatment regulation pool and diluted sulfuric acid which is diluted by commercial sulfuric acid from 98% to 30% is added so that the pH value of wastewater is down-regulated to 3.60 from 10.26, water discharged from the regulation pool is fed to an oxidative reaction pool, ferric sulfate solution which is diluted to 30% via solid ferrous sulfate heptahydrate and 25% hydrogen peroxide solution are added to the oxidative decomposition pool, the Fe.sup.++ concentration of ferric sulfate in wastewater is controlled to 6 mmol/L, and the concentration of H.sub.2O.sub.2 is controlled to 45 mmol/L, so as to carry out oxidative decomposition; discharged water obtained after oxidative decomposition is fed to alkaline regulation pool to regulate the pH value of treatment water to 8.0, and flocculant is added for settling and separation. Wastewater treatment results are seen in Table 6.

(16) TABLE-US-00006 TABLE 6 Pretreatment and Posttreatment Results of Wastewater in Comparative Example Items Chroma- COD/ BOD/ SS/ TP/ TN/ ticity/ pH (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) (mgL.sup.1) fold Pre- 10.26 1100 270 300 5 40 500 treat- ment post- 8.00 80 30 25 2 25 30 treat- ment