A method for treating industrial wastewater

Abstract

The invention discloses a method for treating industrial wastewater, and relates to the technical field of wastewater treatment. The treatment method comprises the following steps: S1. adjusting the pH value of the industrial wastewater to obtain the industrial wastewater after adjusting the pH value; S2. adding a flocculant to the industrial wastewater after adjusting the pH value, stirring, and settling to obtain the precipitated water body; S3. filtering the precipitated water body with a nanofiltration membrane to obtain the water body after the nanofiltration membrane filtration; S4. adding a water purifier to the water body after the nanofiltration membrane filtration, stirring, and standing, and performing a second nanofiltration membrane filtration to obtain the water body after the second nanofiltration membrane filtration; S5. adding a scale inhibitor to the water body after the second nanofiltration membrane filtration to obtain the water body after the scale inhibition treatment; S6. performing membrane filtration on the water body after the scale inhibition treatment to obtain the dischargeable water body. The treatment method provided by the invention can effectively remove harmful substances such as ammonia nitrogen, nickel, chromium, and COD in industrial wastewater. Among them, the removal rate of COD is 99.9%, and the removal rate of ammonia nitrogen is 99.9%.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for treating industrial wastewater. Background Art

[0002] Industrial wastewater refers to wastewater and waste liquid discharged during the production process, which contains industrial production materials, intermediate products, by-products and pollutants generated in the production process that are lost with the water.

[0003] Industrial wastewater often contains organic matter, inorganic matter, heavy metals, and even radioactive substances, such as Cr, Ni, phosphate, ammonia nitrogen compounds, organic acids, etc., which need to be treated to meet the standards. Otherwise, these harmful substances will enter the environment and will definitely cause serious harm to the ecological environment and humans, and even accumulate in organisms through the food chain and direct contact, posing a threat to biological and human health.

[0004] Currently, there is no efficient method for treating industrial wastewater. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a method for treating industrial wastewater, which can effectively remove harmful substances such as ammonia nitrogen, nickel, chromium, COD, etc. in industrial wastewater. Among them, the removal rate of COD is 99.9%, and the removal rate of ammonia nitrogen is 99.9%.

[0006] The object of the present invention is to provide a method for treating industrial wastewater, the steps of which are as follows:

[0007] S1. adjusting the pH value of industrial wastewater to obtain industrial wastewater after the pH value is adjusted;

[0008] S2. Adding a flocculant to the industrial wastewater after adjusting the pH value, stirring, and settling to obtain a precipitated water body;

[0009] S3. filtering the precipitated water through a nanofiltration membrane to obtain water filtered by the nanofiltration membrane;

[0010] S4. Add a water purifier to the water after the nanofiltration membrane filtration, stir, let stand, and perform a second nanofiltration membrane filtration to obtain the water after the second nanofiltration membrane filtration;

[0011] S5. adding a scale inhibitor to the water body after the second nanofiltration membrane filtration to obtain a scale-inhibited water body;

[0012] S6. The water body after the scale inhibition treatment is subjected to membrane filtration to obtain dischargeable water body.

[0013] Preferably, in step S1, the pH value is adjusted to ≤7.

[0014] Preferably, in step S2, the flocculant is one or more of polyaluminum ferric chloride sulfate, polyacrylamide, and NOC-1.

[0015] Preferably, in step S2, the solid-to-liquid ratio of the flocculant to the industrial wastewater after adjusting the pH value is 200-300 mg / L.

[0016] Preferably, in steps S3 and S4, the nanofiltration membranes are both NF270-400 / 34I.

[0017] Preferably, in step S4, the water purifier comprises the following raw material components in parts by weight: 30-35 parts of diatomaceous earth, 20-25 parts of activated carbon, 8-12 parts of sulfonated activated clay, and 0.3-0.5 parts of composite bacterial agent.

[0018] Further preferably, the composite bacterial agent comprises Rhodopseudomonas palustris, Thiobacillus thiooxidans, and Bdellovibrio bacteriophage in a weight ratio of 0.7:1:1.5.

[0019] Preferably, in step S4, the stirring time is 20-30 minutes; and the standing time is 5-6 hours.

[0020] Preferably, in step S5, the scale inhibitor is one or more of PESA and PASP.

[0021] Preferably, in step S6, the membrane filtration is performed using a reverse osmosis membrane, and the reverse osmosis membrane is BW30FR-400 / 34.

[0022] The beneficial effects of the present invention are embodied in:

[0023] (1) The treatment method provided by the present invention can effectively remove harmful substances such as ammonia nitrogen, nickel, chromium, COD, etc. in industrial wastewater. Among them, the removal rate of COD is 99.9%, and the removal rate of ammonia nitrogen is 99.9%.

[0024] (2) The qualified water obtained by the treatment method provided by the present invention will no longer cause pollution to the environment and can be reused to achieve the recycling of wastewater. DETAILED DESCRIPTION

[0025] The following embodiments of the technical solution of the present invention are described in detail. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0026] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0027] Example 1

[0028] This embodiment provides a method for treating industrial wastewater, the steps are as follows:

[0029] S1. adjusting the pH value of industrial wastewater to obtain industrial wastewater after the pH value is adjusted;

[0030] S2. Adding a flocculant to the industrial wastewater after adjusting the pH value, stirring, and settling to obtain a precipitated water body;

[0031] S3. filtering the precipitated water through a nanofiltration membrane to obtain water filtered by the nanofiltration membrane;

[0032] S4. Add a water purifier to the water after the nanofiltration membrane filtration, stir, let stand, and perform a second nanofiltration membrane filtration to obtain the water after the second nanofiltration membrane filtration;

[0033] S5. adding a scale inhibitor to the water body after the second nanofiltration membrane filtration to obtain a scale-inhibited water body;

[0034] S6. The water body after the scale inhibition treatment is subjected to membrane filtration to obtain dischargeable water body.

[0035] In step S1, the pH value is adjusted to 7.

[0036] In step S2, the flocculant is polyaluminum ferric sulfate chloride, polyacrylamide, and NOC-1 in a weight ratio of 1:1:2.

[0037] In step S2, the solid-liquid ratio of the flocculant and the industrial wastewater after adjusting the pH value is 250 mg / L.

[0038] In steps S3 and S4, the nanofiltration membranes are both NF270-400 / 34I.

[0039] In step S4, the water purifier includes the following raw material components in parts by weight: 32.5 parts of diatomaceous earth, 22.5 parts of activated carbon, 10 parts of sulfonated activated clay, and 0.4 parts of composite bacterial agent.

[0040] The composite bacterial agent comprises Rhodopseudomonas palustris, Thiobacillus thiooxidans and Bdellovibrio bacteriovorus in a weight ratio of 0.7:1:1.5.

[0041] In step S4, the stirring time is 30 minutes and the standing time is 6 hours.

[0042] In step S5, the scale inhibitor is PESA.

[0043] In step S6, the membrane filtration is performed by using a reverse osmosis membrane, and the reverse osmosis membrane is BW30FR-400 / 34.

[0044] Example 2

[0045] This embodiment provides a method for treating industrial wastewater, the steps are as follows:

[0046] S1. adjusting the pH value of industrial wastewater to obtain industrial wastewater after the pH value is adjusted;

[0047] S2. Adding a flocculant to the industrial wastewater after adjusting the pH value, stirring, and settling to obtain a precipitated water body;

[0048] S3. filtering the precipitated water through a nanofiltration membrane to obtain water filtered by the nanofiltration membrane;

[0049] S4. Add a water purifier to the water after the nanofiltration membrane filtration, stir, let stand, and perform a second nanofiltration membrane filtration to obtain the water after the second nanofiltration membrane filtration;

[0050] S5. adding a scale inhibitor to the water body after the second nanofiltration membrane filtration to obtain a scale-inhibited water body;

[0051] S6. The water body after the scale inhibition treatment is subjected to membrane filtration to obtain dischargeable water body.

[0052] In step S1, the pH value is adjusted to 7.

[0053] In step S2, the flocculant is polyaluminum ferric sulfate chloride, polyacrylamide, and NOC-1 in a weight ratio of 1:1:2.

[0054] In step S2, the solid-liquid ratio of the flocculant and the industrial wastewater after adjusting the pH value is 250 mg / L.

[0055] In steps S3 and S4, the nanofiltration membranes are both NF270-400 / 34I.

[0056] In step S4, the water purifier includes the following raw material components in parts by weight: 30 parts of diatomaceous earth, 20 parts of activated carbon, 8 parts of sulfonated activated clay, and 0.3 parts of composite bacterial agent.

[0057] The composite bacterial agent comprises Rhodopseudomonas palustris, Thiobacillus thiooxidans and Bdellovibrio bacteriovorus in a weight ratio of 0.7:1:1.5.

[0058] In step S4, the stirring time is 30 minutes; and the standing time is 6 hours.

[0059] In step S5, the antiscalant is PASP.

[0060] In step S6, the membrane filtration is performed by using a reverse osmosis membrane, and the reverse osmosis membrane is BW30FR-400 / 34.

[0061] Example 3

[0062] This embodiment provides a method for treating industrial wastewater, the steps are as follows:

[0063] S1. adjusting the pH value of industrial wastewater to obtain industrial wastewater after the pH value is adjusted;

[0064] S2. Adding a flocculant to the industrial wastewater after adjusting the pH value, stirring, and settling to obtain a precipitated water body;

[0065] S3. filtering the precipitated water through a nanofiltration membrane to obtain water filtered by the nanofiltration membrane;

[0066] S4. Add a water purifier to the water after the nanofiltration membrane filtration, stir, let stand, and perform a second nanofiltration membrane filtration to obtain the water after the second nanofiltration membrane filtration;

[0067] S5. adding a scale inhibitor to the water body after the second nanofiltration membrane filtration to obtain a scale-inhibited water body;

[0068] S6. The water body after the scale inhibition treatment is subjected to membrane filtration to obtain dischargeable water body.

[0069] In step S1, the pH value is adjusted to 7.

[0070] In step S2, the flocculant is polyaluminum ferric sulfate chloride, polyacrylamide, and NOC-1 in a weight ratio of 1:1:2.

[0071] In step S2, the solid-liquid ratio of the flocculant and the industrial wastewater after adjusting the pH value is 250 mg / L.

[0072] In steps S3 and S4, the nanofiltration membranes are both NF270-400 / 34I.

[0073] In step S4, the water purifier includes the following raw material components in parts by weight: 35 parts of diatomaceous earth, 25 parts of activated carbon, 12 parts of sulfonated activated clay, and 0.5 parts of composite bacterial agent.

[0074] The composite bacterial agent comprises Rhodopseudomonas palustris, Thiobacillus thiooxidans and Bdellovibrio bacteriovorus in a weight ratio of 0.7:1:1.5.

[0075] In step S4, the stirring time is 30 minutes; and the standing time is 6 hours.

[0076] In step S5, the scale inhibitor is PESA.

[0077] In step S6, the membrane filtration is performed by using a reverse osmosis membrane, and the reverse osmosis membrane is BW30FR-400 / 34.

[0078] Test example

[0079] Effects of the treatment methods of test examples 1-3

[0080] Test method: Industrial wastewater from a local chemical plant was randomly selected and divided into three equal parts. The wastewater was treated using the treatment methods of Examples 1-3 respectively to test the removal rates of COD, heavy metals, ammonia nitrogen and phosphorus in the wastewater.

[0081] Test results: See Table 1.

[0082] Table 1

[0083]

[0084]

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for treating industrial wastewater, characterized in that: The processing method comprises the following steps: S1. adjusting the pH value of industrial wastewater to obtain industrial wastewater after the pH value is adjusted; S2. Adding a flocculant to the industrial wastewater after adjusting the pH value, stirring, and settling to obtain a precipitated water body; S3. filtering the precipitated water through a nanofiltration membrane to obtain water filtered by the nanofiltration membrane; S4. Add a water purifier to the water after the nanofiltration membrane filtration, stir, let stand, and perform a second nanofiltration membrane filtration to obtain the water after the second nanofiltration membrane filtration; S5. adding a scale inhibitor to the water body after the second nanofiltration membrane filtration to obtain a scale-inhibited water body; S6. filtering the water after the scale inhibition treatment through a membrane to obtain a dischargeable water body; In step S1, the pH value is adjusted to ≤7; In step S2, the flocculant is one or more of polyaluminum ferric chloride sulfate, polyacrylamide, and NOC-1; In step S2, the solid-liquid ratio of the flocculant and the industrial wastewater after adjusting the pH value is 200-300 mg / L; In steps S3 and S4, the nanofiltration membrane is NF270-400 / 34I; In step S4, the water purifier comprises the following raw material components in parts by weight: 30-35 parts of diatomaceous earth, 20-25 parts of activated carbon, 8-12 parts of sulfonated activated clay, and 0.3-0.5 parts of composite bacterial agent; The composite bacterial agent comprises Rhodopseudomonas palustris, Thiobacillus thiooxidans and Bdellovibrio bacteriovorus in a weight ratio of 0.7:1:1.

5.

2. The method for treating industrial wastewater according to claim 1, characterized in that: In step S4, the stirring time is 20-30 minutes; the standing time is 5-6 hours.

3. The method for treating industrial wastewater according to claim 1, characterized in that: In step S5, the scale inhibitor is one or more of PESA and PASP.

4. The method for treating industrial wastewater according to claim 1, characterized in that: In step S6, the membrane filtration is performed using a reverse osmosis membrane, and the reverse osmosis membrane is BW30FR-400 / 34.

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