Composition, application thereof and treatment method of waste liquid containing ammonia nitrogen

Abstract

The invention relates to the field of sewage treatment, in particular to a composition, application of the composition and a treatment method of waste liquid containing ammonia nitrogen. The composition comprises an inorganic ammonia nitrogen removal component and / or an organic ammonia nitrogen removal component and a molecular sieve. The molecular sieve is added into the composition, the molecular sieve can be organically combined with the inorganic ammonia nitrogen removal component and / or the organic ammonia nitrogen removal component to synergistically remove the ammonia nitrogen compound, and the composition and the preparation method thereof are suitable for removal of the ammonia nitrogen compound and have the advantage of high removal efficiency.

Description

Technical Field

[0001] The invention relates to the field of sewage treatment, and in particular to a composition and application thereof, and a method for treating waste liquid containing ammonia nitrogen. Background Art

[0002] Garbage leachate comes from the water contained in the garbage in the landfill itself, the rain and snow water that seeps from the surface, and passes through the garbage layer and soil layer. It contains a large amount of suspended matter and high concentrations of organic and inorganic components. The organic pollutants in the garbage leachate mainly include organic heterocyclics (heterocyclics, polycyclic aromatic hydrocarbons), acids, amides, etc., accounting for more than 70% of the total organic components of the garbage leachate; inorganic pollutants include a large amount of inorganic salts, heavy metals, ammonia nitrogen and chlorinated organic matter and other difficult-to-degrade pollutants. Studies have found that the pollutants contained in garbage leachate are one hundred times that of urban sewage. If not handled properly, it may cause secondary pollution to the surrounding environment, easily cause groundwater, surface water and soil pollution, cause great harm to the environment and human body, and affect the ecological environment and people's normal life.

[0003] At present, the mainstream treatment process used in the landfill leachate treatment project in my country is a combination of pretreatment + biological treatment + membrane deep treatment (nanofiltration + reverse osmosis). This process solves the problem of treating large amounts of salt and high ammonia nitrogen in landfill leachate, and the effluent quality is relatively good. The biological method for treating landfill leachate is relatively low in cost, but first of all, the metal ions in the landfill leachate must be removed, otherwise it will not only affect the biochemical process, but also form precipitation, causing the biochemical reactor to clog and affect the biochemical removal efficiency; secondly, the biological method is difficult to adapt to the high load impact of the leachate, and the biological treatment effect is generally improved by adjusting the sludge organic load in the regulating tank; thirdly, the high concentration of ammonia nitrogen in the leachate has a strong inhibitory effect on microbial activity, and denitrification treatment must be carried out before biological treatment. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems of long treatment cycle and low removal rate of toxic and difficult-to-degrade substances in the prior art, and to provide a composition and its application and a method for treating waste liquid containing ammonia nitrogen, which has the characteristics of short treatment cycle and high removal rate of toxic and difficult-to-degrade substances.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a composition comprising an inorganic deamination nitrogen component and / or an organic deamination nitrogen component and a molecular sieve.

[0006] The second aspect of the present invention provides an application of the composition described in the first aspect in removing ammonia nitrogen from waste liquid containing ammonia nitrogen.

[0007] The third aspect of the present invention provides a method for treating waste liquid containing ammonia nitrogen, which comprises contacting the waste liquid with the composition described in the first aspect to obtain an oxide stream after optionally performing oil-water separation, optional water quality adjustment and heterogeneous Fenton catalytic oxidation.

[0008] Through the above technical solution, the present invention has the following advantages:

[0009] The present invention adds molecular sieves to the composition, and the molecular sieves can organically combine with inorganic ammonia nitrogen removal components and / or organic ammonia nitrogen removal components to synergistically remove ammonia nitrogen compounds. The composition of the present invention and its applicability to the removal of ammonia nitrogen compounds have the advantage of high removal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of a wastewater (landfill leachate) treatment process according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0011] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0012] The invention provides a composition, which comprises an inorganic deamination nitrogen component and / or an organic deamination nitrogen component and a molecular sieve.

[0013] The present invention adds molecular sieves to the composition, and the molecular sieves can organically combine with inorganic ammonia nitrogen removal components and / or organic ammonia nitrogen removal components to synergistically remove ammonia nitrogen compounds. The composition of the present invention and its applicability to the removal of ammonia nitrogen compounds have the advantage of high removal efficiency.

[0014] According to a preferred embodiment of the present invention, the molecular sieve comprises a phosphorus aluminum molecular sieve and / or a silicon aluminum molecular sieve, preferably at least one selected from β molecular sieve, Y-type molecular sieve, mordenite, MCM-22, MCM-41, SAPO-34 and SAPO-5. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0015] According to a preferred embodiment of the present invention, based on the total mass of the ammonia nitrogen removal agent, the content of the molecular sieve is 5-20wt%. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0016] According to a preferred embodiment of the present invention, the inorganic deamination nitrogen component includes at least one of alkaline earth metal oxides, carbonates, perchlorates or hypochlorites, preferably alkaline earth metal oxides, carbonates, perchlorates or hypochlorites, and more preferably, the mass ratio of perchlorates or hypochlorites, alkaline earth metal oxides and carbonates in the mixture is 20-50:5-20:5-20.

[0017] According to a preferred embodiment of the present invention, the perchlorate or hypochlorite is calcium chlorate and / or calcium hypochlorite.

[0018] According to a preferred embodiment of the present invention, the oxide of the alkaline earth metal is magnesium oxide.

[0019] According to a preferred embodiment of the present invention, the carbonate is calcium percarbonate.

[0020] According to a preferred embodiment of the present invention, the organic nitrogen removal component is selected from at least one of trichloroisocyanuric acid, sodium dichloroisocyanurate, peracetic acid, and dibromodimethylhydantoin.

[0021] According to a preferred embodiment of the present invention, the components include an inorganic ammonia nitrogen removal component, an organic ammonia nitrogen removal component and a molecular sieve. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0022] According to a preferred embodiment of the present invention, the weight ratio of the inorganic ammonia nitrogen removal component to the organic ammonia nitrogen removal component in the composition is 1: 1-20: 1. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0023] The invention provides an application of the composition in removing ammonia nitrogen from waste liquid containing ammonia nitrogen.

[0024] The use of the composition of the present invention for removing ammonia nitrogen from waste liquid containing ammonia nitrogen has the advantage of high removal efficiency.

[0025] The present invention provides a method for treating waste liquid containing ammonia nitrogen, which comprises contacting the waste liquid with the composition to obtain an oxide stream after sequentially performing optional oil-water separation, optional water quality adjustment and heterogeneous Fenton catalytic oxidation.

[0026] According to a preferred embodiment of the present invention, the oxide stream is further subjected to reverse osmosis treatment.

[0027] According to a preferred embodiment of the present invention, the oxide stream is mixed with a phosphorus precipitant and then solid-liquid separation is performed.

[0028] According to a preferred embodiment of the present invention, the dephosphorization agent is selected from at least one of Ca salts, Mg salts and Fe salts. Preferably, the molar ratio of the metal in the dephosphorization agent to the phosphorus in the filtrate is 1.15:1-3:1.

[0029] According to a preferred embodiment of the present invention, the contact treatment conditions include: the composition accounts for 0.2-5wt% of the total mass of the reaction system. As long as the reaction can proceed, there are no special restrictions on the temperature and pressure conditions of the treatment. For example, in the embodiments of the present application, it can be carried out at room temperature and pressure.

[0030] According to a preferred embodiment of the present invention, the oil-water separation uses an oleophilic medium to separate oil, and the oil-water separation step includes allowing the wastewater to stand, roughly separating the oil and water, extracting the upper oil phase, and using an oleophilic medium to perform a fine oil-water separation on the lower crude water phase to obtain a water phase. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0031] According to a preferred embodiment of the present invention, the oleophilic medium includes at least one of perlite, clay, zeolite, macroporous silica gel, wood fiber, straw, sawdust, polypropylene fiber felt, polyurethane foam, and polystyrene fiber.

[0032] According to a preferred embodiment of the present invention, the particle size of the oleophilic medium is greater than 300 meshes.

[0033] According to a preferred embodiment of the present invention, the step of adjusting the water quality comprises: performing at least one operation of aerating the water phase obtained by oil-water separation, adjusting the pH reaction, optionally filtering and adding a flocculant to perform a precipitation reaction and then performing solid-liquid separation, to obtain an adjusted water phase with a TOC of ≤500ppm. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0034] According to a preferred embodiment of the present invention, the conditions of the aeration treatment include: pH 8-12, aeration time 6-48h, and pH adjustment is generally performed by adding alkaline substances, and the alkaline substances are selected from sodium hydroxide and potassium hydroxide.

[0035] According to a preferred embodiment of the present invention, the pH is adjusted to 1-5 for reaction, and the reaction time is 2-24 hours. When the acidity provided by the flocculation precipitant is insufficient, acid supplementation is required, and sulfuric acid can be used.

[0036] According to a preferred embodiment of the present invention, the conditions of the precipitation reaction include: pH 2-6, reaction time 0.5-12h; the amount of flocculation precipitant used is 0.1-5% of the total mass of the aqueous phase.

[0037] According to a preferred embodiment of the present invention, the flocculation precipitant is selected from at least one of polyferric sulfate, polyferric chloride, polyaluminum sulfate and polyaluminum chloride.

[0038] According to a preferred embodiment of the present invention, the step of heterogeneous Fenton catalytic oxidation comprises: contacting the regulated water phase obtained by water quality regulation with hydrogen peroxide under catalyst conditions for catalytic oxidation, filtering to obtain an oxide stream, and optionally adding a filter aid during filtration. By adopting the above preferred scheme, the ammonia nitrogen removal efficiency can be further improved.

[0039] According to a preferred embodiment of the present invention, the conditions for catalytic oxidation are: the volume ratio of the aerated and regulated aqueous phase to the hydrogen peroxide is (5-100):1, preferably (20-50):1; the pH is 2-5; the air velocity is 0.2-2.0h -1 .

[0040] According to a preferred embodiment of the present invention, the amount of filter aid added during filtration is 0.5-5wt% of the reacted material, and the filter aid is preferably selected from at least one of diatomaceous earth, perlite, cellulose, asbestos, graphite powder, sawdust, magnesium oxide, gypsum, activated carbon or kaolin.

[0041] The present invention will be described in detail below by way of examples. In the following examples, TOC parameters were measured by a total organic carbon analyzer (TOC-L CPH / CPN , Shimadzu), total phosphorus parameters were measured by vanadium molybdenum phosphate colorimetry, and COD was determined by potassium dichromate method; unless otherwise specified, the raw materials were all commercially available. The effluent compliance standard is in accordance with DB 11 / 307-2013 Beijing Local Standard B emission limit, and the effluent ammonia nitrogen requirement is less than 1.5ppm. According to the preferred embodiment of the present invention, this requirement can be met; the COD value compliance standard is not more than 30ppm, and according to the preferred embodiment of the present invention, this requirement can be met.

[0042] Example 1

[0043] (1) Oil-water separation: Pump out 1 ton of landfill leachate into regulating tank 1 and let it stand for 24 hours for oil-water separation. The upper oil phase is extracted for treatment, and the lower water phase and a small amount of floating oil are pumped into a 100L oil-water separation column from the upper inlet at a flow rate of 50L / h. The upper layer of the oil-water separation column is filled with 40L of coarse-pore silica gel, and the lower layer is filled with 40L of polyurethane foam. The mesh number of the coarse-pore silica gel is 100, and the effluent is fed into regulating tank 2. There is no floating oil in the regulating tank, and the total phosphorus is 264ppm, TOC is 1034ppm, ammonia nitrogen is 1108ppm, total salt is 5960ppm, and pH is 8.09.

[0044] (2) Water quality adjustment: First, aeration was performed in the regulating tank 2 for 24 hours, and the ammonia nitrogen in the effluent was reduced to 120 ppm; then sulfuric acid was added to pH = 5 and reacted for 3 hours, during which a large amount of bubbles escaped and no precipitation occurred; finally, 0.5% polyferric sulfate was added and reacted for 2 hours under the condition of pH = 2.5, and filtered. The effluent TOC was 455 ppm (≤ 500 ppm), and it could enter the heterogeneous Fenton oxidation unit;

[0045] (3) Heterogeneous Fenton: The effluent from the regulating tank 2 and hydrogen peroxide were adjusted to pH 3 and flowed into the reaction column filled with (30 L) heterogeneous Fenton catalyst at flow rates of 50 L / h and 2 L / h, respectively. Activated carbon was added to the effluent at a mass ratio of 100:1. After stirring for 30 min, the effluent was filtered. The ammonia nitrogen content was 100 ppm, the total salt was 5000 ppm, the total phosphorus was 250 ppm, and the TOC was 50 ppm.

[0046] (4) Post-treatment: The heterogeneous Fenton effluent enters the RO system, and the total salt of the fresh water is reduced to 728 ppm; 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of β molecular sieve, 50 wt% of calcium hypochlorite, 12 wt% of magnesium oxide, 18 wt% of calcium percarbonate, and 5 wt% of trichloroisocyanuric acid) is added and reacted for 30 minutes, and the ammonia nitrogen is reduced to 0.5 ppm; polyferric sulfate is added according to the molar ratio of iron element to phosphorus element in wastewater of 1.2:1, and the total phosphorus is reduced to 0.8 ppm, and the COD value is less than 30 ppm.

[0047] Example 2

[0048] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of SAPO molecular sieve, 30 wt% of calcium hypochlorite, 6 wt% of magnesium oxide, 20 wt% of calcium percarbonate, and 29 wt% of sodium dichloroisocyanurate) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 0.6 ppm and the COD value is less than 30 ppm.

[0049] Example 3

[0050] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of mordenite, 20 wt% of calcium hypochlorite, 20 wt% of magnesium oxide, 20 wt% of calcium percarbonate, and 25 wt% of peracetic acid) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 0.8 ppm and the COD value is less than 30 ppm.

[0051] Example 4

[0052] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of SAPO molecular sieve, 45 wt% of calcium hypochlorite, 20 wt% of magnesium oxide, and 20 wt% of calcium percarbonate) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 3.5 ppm and the COD value is less than 30 ppm.

[0053] Example 5

[0054] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of ZIF-8 molecular sieve, 30 wt% of calcium hypochlorite, 6 wt% of magnesium oxide, 20 wt% of calcium percarbonate, and 29 wt% of sodium dichloroisocyanurate) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 10 ppm and the COD value is less than 30 ppm.

[0055] Example 6

[0056] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (35 wt% of SAPO molecular sieve, 30 wt% of calcium hypochlorite, 6 wt% of magnesium oxide, 20 wt% of calcium percarbonate, and 9 wt% of sodium dichloroisocyanurate) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 3 ppm, and the COD value is less than 30 ppm.

[0057] Example 7

[0058] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of SAPO molecular sieve and 85 wt% of sodium dichloroisocyanurate) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 1.9 ppm, and the effluent COD is higher than that in Example 1, which is 230 ppm.

[0059] Example 8

[0060] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% SAPO molecular sieve, 30 wt% calcium chloride, 6 wt% sodium oxide, 20 wt% calcium carbonate, 29 wt% sodium urate) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is 98 ppm and the COD value is less than 30 ppm.

[0061] Comparative Example 1

[0062] The same method as in Example 2 was used for oil-water separation and water quality adjustment. After the heterogeneous Fenton treatment, bacteria were added to remove ammonia nitrogen and organic matter by biological methods. The effluent total phosphorus was 260 ppm, TOC was 219 ppm, ammonia nitrogen was 1000 ppm, total salt was 5220 ppm, COD value was 800 ppm, and the total salt was too high, which restricted the growth and reproduction of microorganisms.

[0063] Comparative Example 2

[0064] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (15 wt% of diatomaceous earth, 50 wt% of calcium hypochlorite, 12 wt% of magnesium oxide, 18 wt% of calcium percarbonate, and 5 wt% of trichloroisocyanuric acid) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 150 ppm and the COD value is 90 ppm.

[0065] Comparative Example 3

[0066] The method described in Example 1 is different in that in step (4), 1 wt% of a self-prepared ammonia nitrogen remover (50 wt% calcium hypochlorite, 12 wt% magnesium oxide, 18 wt% calcium percarbonate, 20 wt% trichloroisocyanuric acid) is added in the post-treatment and reacted for 30 minutes, and the ammonia nitrogen is reduced to 150 ppm and the COD value is 90 ppm.

[0067] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition, It is characterized in that The composition comprises an inorganic deamination nitrogen component and / or an organic deamination nitrogen component and a molecular sieve.

2. The composition according to claim 1, in, The molecular sieve comprises a phosphate aluminum molecular sieve and / or a silicon aluminum molecular sieve, preferably at least one selected from β molecular sieve, Y-type molecular sieve, mordenite, MCM-22, MCM-41, SAPO-34 and SAPO-5; and / or Based on the total mass of the ammonia nitrogen removal agent, the content of the molecular sieve is 5-20wt%.

3. The composition according to claim 1 or 2, in, The inorganic deamination nitrogen component includes at least one of alkaline earth metal oxides, carbonates, perchlorates or hypochlorites, preferably alkaline earth metal oxides, carbonates, perchlorates or hypochlorites, and more preferably, the mass ratio of perchlorates or hypochlorites, alkaline earth metal oxides and carbonates in the mixture is 20-50:5-20:5-20.

4. A composition according to any one of claims 1 to 3, in, The organic nitrogen removal component is selected from at least one of trichloroisocyanuric acid, sodium dichloroisocyanurate, peracetic acid, and dibromodimethylhydantoin.

5. A composition according to any one of claims 1 to 4, in, The composition comprises an inorganic deamination nitrogen component, an organic deamination nitrogen component and a molecular sieve. Preferably, The weight ratio of the inorganic deamination nitrogen component to the organic deamination nitrogen component in the composition is 1:1-20:

1.

6. Use of the composition described in any one of claims 1 to 5 in removing ammonia nitrogen from waste liquid containing ammonia nitrogen.

7. A method for treating waste liquid containing ammonia nitrogen, It is characterized in that The method comprises contacting the waste liquid with the composition according to any one of claims 1 to 3 to obtain an oxide stream after selective oil-water separation, selective water quality adjustment and heterogeneous Fenton catalytic oxidation, preferably, The oxide stream is then subjected to reverse osmosis treatment; and / or The oxide stream is then mixed with a phosphorus precipitant and then solid-liquid separated. Preferably, the phosphorus removal agent is selected from at least one of Ca salts, Mg salts, and Fe salts. More preferably, the molar ratio of the metal in the phosphorus removal agent to the phosphorus in the filtrate is 1.15:1-3:

1. and / or The contact treatment conditions include: the composition accounts for 0.2-5wt% of the total mass of the reaction system.

8. The processing method according to claim 7, in, The oil-water separation adopts an oleophilic medium to separate oil, and the oil-water separation step includes allowing the wastewater to stand, roughly separating the oil and water, extracting the upper oil phase, and further separating the lower crude water phase from the oil with an oleophilic medium to obtain a water phase; Preferably, the oleophilic medium comprises at least one of perlite, clay, zeolite, macroporous silica gel, wood fiber, straw, sawdust, polypropylene fiber felt, polyurethane foam, and polystyrene fiber; More preferably, the particle size of the oleophilic medium is greater than 300 mesh.

9. The processing method according to claim 7 or 8, in, The step of water quality adjustment comprises: performing at least one operation of aerating the water phase obtained by oil-water separation, adjusting pH reaction, optionally filtering and adding a flocculant to perform precipitation reaction and then solid-liquid separation, to obtain an adjusted water phase with TOC ≤ 500 ppm; preferably, The aeration treatment conditions include: pH 8-12, aeration time 6-48h; and / or Adjust the pH to 1-5 and the reaction time to 2-24h; and / or The conditions of the precipitation reaction include: pH 2-6, reaction time 0.5-12h; the amount of flocculation precipitant is 0.1-5% of the total mass of the aqueous phase; and / or The flocculating precipitant is selected from at least one of polyferric sulfate, polyferric chloride, polyaluminium sulfate and polyaluminium chloride.

10. The processing method according to any one of claims 7 to 9, in, The step of heterogeneous Fenton catalytic oxidation comprises: contacting the regulated water phase obtained by water quality regulation with hydrogen peroxide under catalyst conditions for catalytic oxidation, filtering to obtain an oxide stream, and optionally adding a filter aid during filtration; preferably, The conditions for the catalytic oxidation are: the volume ratio of the aerated and regulated aqueous phase to the hydrogen peroxide is (5-100):1, preferably (20-50):1; the pH is 2-5; the air velocity is 0.2-2.0h -1 ; and / or The amount of filter aid added during filtration is 0.5-5wt% of the reacted material, and the filter aid is preferably selected from at least one of diatomaceous earth, perlite, cellulose, asbestos, graphite powder, sawdust, magnesium oxide, gypsum, activated carbon or clay.

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