A composite free radical type sludge deodorant and a method for preparing the same

Abstract

This invention discloses a composite free radical sludge deodorizer and its preparation method, belonging to the field of sludge treatment technology. The deodorizer consists of an active free radical source, an active activator, a balancing stabilizer, a penetrating dispersant, and a sustained-effect promoter. This invention uses a compound of various persulfates and ferrates as free radical sources to synergistically generate highly active free radicals such as sulfate radicals (·SO4−) and hydroxyl radicals (·OH). Chlorides and quaternary ammonium salts are used as activators, organic acids as stabilizers, and surfactants are innovatively introduced to enhance permeability. This deodorizer can rapidly and thoroughly decompose malodorous substances such as hydrogen sulfide, thiols, ammonia, and humic amines in sludge, mineralizing them into CO2, H2O, and inorganic salts without secondary pollution. Simultaneously, this invention can effectively break down the cell walls of microorganisms in sludge, releasing internal organic matter and significantly improving the methane yield and volatile solids removal rate of subsequent anaerobic digestion. This invention has the advantages of high deodorization efficiency, rapid action, low cost, environmental friendliness, and enhanced sludge resource value.

Description

Technical Field

[0001] This invention relates to the field of sludge treatment technology, specifically to a composite free radical sludge deodorizer based on advanced oxidation principles and its preparation method. Background Technology

[0002] Sludge refers to the sediment, particulate matter, and floating matter produced during wastewater treatment using physical, chemical, physicochemical, and biological methods. It is a byproduct of wastewater treatment. Sludge has a high water content, easily produces foul odors, and breeds mosquitoes and flies, causing serious environmental problems. GC-MS analysis results show that the volatile substances released during sludge bio-fermentation are complex, mainly including ketones, aromatic hydrocarbons, alcohols, sulfides (such as methanethiol, dimethyl sulfide, dimethyl disulfide, and hydrogen sulfide), terpenes, ammonia, and trimethylamine. These odorous substances directly affect human olfaction, potentially leading to lethargy, low work efficiency, and lung and neurological diseases.

[0003] Currently, the main methods for controlling odor from sludge include chemical deodorization, physical deodorization, and biological deodorization. While chemical and physical methods are direct and effective, they often involve high investment and operating costs and may generate secondary pollution. Biological deodorization, although energy-efficient and requiring less maintenance, suffers from low deodorization efficiency, long processing times, and large land area requirements. Therefore, developing a highly efficient, rapid, low-cost, and environmentally friendly sludge deodorization technology has broad application prospects and market value. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a composite free radical type sludge deodorizer and its preparation method. This deodorizer aims to achieve rapid and thorough decomposition of sludge odor through the synergistic oxidation of multiple free radicals, while simultaneously improving the biochemical properties of the sludge, reducing treatment costs, and avoiding secondary pollution.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention discloses a composite free radical type sludge deodorizer, characterized in that it is made from the following raw materials in parts by weight, including 45-60 parts of active free radical source, 5-15 parts of active activator, 15-25 parts of balancing stabilizer, 5-15 parts of residual effect promoter and 5-15 parts of carrier.

[0007] Furthermore, the active free radical source includes one or more mixtures of sodium persulfate, potassium peroxymonosulfate, potassium persulfate, and sodium perborate;

[0008] Furthermore, the active activator includes one or more mixtures of calcium chloride and tetraethylammonium bromide. The balancing stabilizer includes one or more mixtures of citric acid monohydrate and malic acid.

[0009] Furthermore, the retention promoter includes one or a mixture of two or more of permanganate and ferrate.

[0010] Furthermore, the carrier is sodium sulfate.

[0011] The present invention also provides a method for preparing the above-mentioned composite free radical type sludge deodorizer, characterized by comprising the following steps:

[0012] Add the active free radical source, active activator, balancing stabilizer, carrier and retention promoter into a stirring container according to the stated weight parts, and stir and mix thoroughly at room temperature and pressure to obtain the finished powder.

[0013] Compared with the prior art, the present invention has the following significant advantages:

[0014] This invention generates sulfate radicals (·SO4) by combining multiple free radical sources and activating them in aqueous solution. - It contains a variety of highly reactive free radicals, such as hydroxyl radicals (·OH) and hypochlorous acid radicals. These free radicals have extremely high oxidation potentials and can synergistically attack almost all thiocyanates, sulfur-containing organic matter, humic amines, and other odorous and toxic organic matter in sludge that are difficult to biodegrade, completely converting them into harmless inorganic sulfates, carbon dioxide, and water.

[0015] The deodorizer of this invention, while decomposing malodors, also possesses strong oxidizing properties that can destroy the cell walls / cell membranes of microorganisms in sludge, accelerating the outflow of internal organic matter. This provides a higher-quality substrate for subsequent anaerobic digestion and other biochemical treatments, significantly improving the removal rate of volatile solids and achieving sludge reduction, harmlessness, and resource recovery.

[0016] This invention completely mineralizes odorous substances, preventing the generation of pollutants during the deodorization process and avoiding secondary pollution and media contamination transfer. The raw materials are all common chemical products with wide availability, and the preparation method is simple and the operation process is streamlined, reducing production costs. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below with reference to the embodiments. Example 1

[0018] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 18 parts sodium persulfate, 10.0 parts potassium persulfate, 10.0 parts sodium ferrate, 7 parts potassium persulfate, 7 parts sodium perborate, 10.0 parts calcium chloride, 2 parts tetraethylammonium bromide, 15 parts citric acid monohydrate, 6 parts malic acid, and 15.0 parts sodium sulfate.

[0019] Preparation method

[0020] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained. Example 2

[0021] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 20 parts sodium persulfate, 10 parts potassium persulfate, 10 parts sodium ferrate, 10 parts potassium persulfate, 10 parts sodium perborate, 5 parts calcium chloride, 5 parts tetraethylammonium bromide, 10 parts citric acid monohydrate, 10 parts malic acid, and 10 parts sodium sulfate.

[0022] Preparation method

[0023] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained. Example 3

[0024] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 20 parts sodium persulfate, 8 parts potassium peroxymonosulfate, 10 parts sodium ferrate, 8 parts potassium persulfate, 9 parts sodium perborate, 10 parts calcium chloride, 5 parts tetraethylammonium bromide, 10 parts citric acid monohydrate, 10 parts malic acid, and 10 parts sodium sulfate.

[0025] Preparation method

[0026] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained. Example 4

[0027] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 20 parts sodium persulfate, 8 parts potassium persulfate monosulfate, 5 parts sodium ferrate, 8 parts potassium persulfate, 9 parts sodium perborate, 10 parts calcium chloride, 5 parts tetraethylammonium bromide, 10 parts citric acid monohydrate, 10 parts malic acid, and 15 parts sodium sulfate.

[0028] Preparation method

[0029] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained. Example 5

[0030] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 20 parts sodium persulfate, 8 parts potassium persulfate monosulfate, 5 parts sodium ferrate, 8 parts potassium persulfate, 9 parts sodium perborate, 5 parts calcium chloride, 5 parts tetraethylammonium bromide, 15 parts citric acid monohydrate, 10 parts malic acid, and 15 parts sodium sulfate.

[0031] Preparation method

[0032] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained. Example 6

[0033] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 10 parts sodium persulfate, 20 parts potassium persulfate monosulfate, 5 parts sodium ferrate, 5 parts potassium persulfate, 10 parts sodium perborate, 5 parts calcium chloride, 5 parts tetraethylammonium bromide, 15 parts citric acid monohydrate, 10 parts malic acid, and 15 parts sodium sulfate.

[0034] Preparation method

[0035] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained.

[0036] Example 7

[0037] A composite free radical type sludge deodorizer is made from the following raw materials in parts by weight: 10 parts sodium persulfate, 10 parts potassium persulfate, 10 parts sodium ferrate, 10 parts potassium persulfate, 10 parts sodium perborate, 5 parts calcium chloride, 5 parts tetraethylammonium bromide, 15 parts citric acid monohydrate, 10 parts malic acid, and 15 parts sodium sulfate.

[0038] Preparation method

[0039] Add all the above raw materials into a rolling mixer according to the weight proportions, and stir at 60 rpm for 30 minutes at room temperature and pressure to ensure uniform mixing, and the finished powder is obtained. How to use

[0040] The deodorizing agent powder of this embodiment is dissolved in water at a mass ratio of 3g / 1L and activated for 5 minutes to form an activated solution. For sludge that is being stockpiled or transported, the activated solution can be sprayed evenly onto the sludge surface; for sludge before it enters the anaerobic digester, the activated solution can be pumped into the premixing tank at a mass of 0.1%-0.3% of the sludge mass and stirred thoroughly for 0.5-1 hour. After treatment, the odor of the sludge can be significantly controlled within 2-3 days.

[0041] The sludge deodorizer of the present invention has high and uniform deodorization efficiency in sludge systems, long deodorization duration, and excellent storage stability.

[0042] The sludge deodorizer of the present invention is safe and environmentally friendly, easy to use and low in cost.

[0043] The sludge deodorizer of this invention not only focuses on the single objective of "deodorization," but also improves the intrinsic properties of sludge, creating favorable conditions for subsequent resource utilization (such as anaerobic digestion to produce biogas), thus achieving a balance between environmental and economic benefits. This patent draft is a standardized and theoretical expression of this excellent design.

[0044] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Those skilled in the art can make various modifications without departing from the spirit of the present invention and existing knowledge.

Claims

1. A composite free radical type sludge deodorizer, characterized in that, It is made from the following raw materials in parts by weight: 45-60 parts active free radical source, 5-15 parts active activator, 15-25 parts balancing stabilizer, 5-15 parts duration promoter and 5-15 parts carrier.

2. The composite free radical type sludge deodorizer according to claim 1, characterized in that, The active free radical source is one or more of sodium persulfate, potassium peroxymonosulfate, potassium persulfate, and sodium perborate.

3. The composite free radical type sludge deodorizer according to claim 1, characterized in that, The active activator is one or a mixture of calcium chloride and tetraethylammonium bromide.

4. The composite free radical type sludge deodorizer according to claim 1, characterized in that, The balancing stabilizer is one or a mixture of citric acid monohydrate and malic acid.

5. The composite free radical type sludge deodorizer according to claim 1, characterized in that, The retention promoter is one or a mixture of two or more of permanganate and ferrate.

6. The composite free radical type sludge deodorizer according to claim 1, characterized in that, The carrier is sodium sulfate.

7. The preparation method of the composite free radical type sludge deodorizer according to any one of claims 1-6, characterized in that, The process includes the following steps: adding the active free radical source, active activator, balancing stabilizer, carrier and retention promoter into a mixing container according to the corresponding weight parts, and mixing thoroughly and evenly at room temperature and pressure to obtain the finished powder.

8. The preparation method according to claim 7, characterized in that, A rolling mixer is used during the mixing process, with a mixing speed of 60 rpm and a mixing time of 30 minutes.