CN-117125819-B - Anaerobic ammonia oxidation gel particles and method for preparing and enhancing denitrification performance of anaerobic ammonia oxidation process under high total nitrogen load condition

CN117125819BCN 117125819 BCN117125819 BCN 117125819BCN-117125819-B

Abstract

The invention belongs to the field of biological denitrification treatment of wastewater, and discloses anaerobic ammonia oxidation gel particles and a method for preparing and strengthening denitrification performance of an anaerobic ammonia oxidation process under a high total nitrogen load condition. The preparation method of the anaerobic ammonia oxidation gel particles comprises the steps of preparing chitosan modified diatomite, preparing a gel agent and preparing the anaerobic ammonia oxidation gel particles. According to the invention, the ANAMMOX gel particles and the ANAMMOX particle sludge with low total nitrogen load are mixed and added into the anaerobic ammonia oxidation process reactor with high total nitrogen load, so that the problems of remarkably reduced denitrification efficiency and unstable operation of the ANAMMOX process under the condition of higher total nitrogen load in the prior art are solved.

Inventors

ZHANG SHUJUN
ZHANG JING
JIANG YONG
GU PENGCHAO
HAN XIAOYU
LV XINTAO
HUANG JING
TIAN XIADI

Assignees

北京城市排水集团有限责任公司

Dates

Publication Date: 20260512
Application Date: 20230901

Claims (8)

1. A method for enhancing denitrification performance of an anaerobic ammonia oxidation process under high total nitrogen load condition, which is characterized by comprising inoculating anaerobic ammonia oxidation granular sludge and anaerobic ammonia oxidation gel particles in an anaerobic ammonia oxidation process reactor; The preparation method of the anaerobic ammonia oxidation gel particles comprises the following steps: s1, preparation of chitosan modified diatomite Mixing the chitosan aqueous solution with diatomite, and sequentially stirring, vacuum filtering, roasting and grinding to obtain the chitosan modified diatomite; The roasting equipment comprises a muffle furnace, wherein the roasting temperature is 450-550 ℃ and the roasting time is 3-4 hours; s2, preparation of gel Mixing polyvinyl alcohol, sodium alginate and high-temperature distilled water, stirring to obtain a gelatinous mixture, uniformly mixing and stirring the gelatinous mixture and the chitosan modified diatomite, and cooling to obtain the gel; s3, preparation of anammox gel particles Uniformly mixing anaerobic ammonia oxidation sludge, the gel agent and nano zero-valent iron to obtain a mixed solution, mixing the mixed solution with a calcium chloride aqueous solution and performing first crosslinking to obtain anaerobic ammonia oxidation primary gel pellets, mixing the anaerobic ammonia oxidation primary gel pellets with a potassium dihydrogen phosphate aqueous solution and performing second crosslinking to obtain the anaerobic ammonia oxidation gel particles; The high total nitrogen load condition comprises that the total nitrogen load is 26.3-35.5 kg-TN/(m 3 .d), the pH value of the reactor inlet water is 7.0-8.0, the dissolved oxygen concentration of the reactor inlet water is below 0.4 mg/L, and the running temperature of the reactor is 33-38 ℃.
2. The method for enhancing denitrification performance of an anaerobic ammoxidation process under high total nitrogen loading conditions of claim 1 wherein in step S1: The stirring equipment comprises a temperature-controlled magnetic stirrer, wherein the stirring temperature is 30-35 ℃, the stirring time is 3-5h, and the stirring speed is 120-130r/min; the particle size range of the chitosan modified diatomite is 100-125 mu m, the specific surface area is 90-100m 2 /g, and the pore diameter is 19-136nm.
3. The method for enhancing denitrification performance of an anaerobic ammoxidation process under high total nitrogen loading conditions of claim 1 wherein in step S2: the high-temperature distilled water is distilled water with the temperature of more than or equal to 90 ℃; The content of polyvinyl alcohol is 11-15wt% and the content of sodium alginate is 1-2wt% based on the total weight of the gelatinous mixture; the concentration of the chitosan modified diatomite in the gel is 2-6 g/L; the cooling is to cool the gel to 45-55 ℃.
4. The method for enhancing denitrification performance of an anaerobic ammoxidation process under high total nitrogen loading conditions of claim 1 wherein in step S3: The mass fraction of the calcium chloride aqueous solution is 7-9wt%; The time of the first crosslinking is 12-24h, and the temperature is 30-35 ℃; the molar concentration of the potassium dihydrogen phosphate aqueous solution is 0.7-1.0mol/L; The second crosslinking time is 1-5h, and the temperature is 30-35 ℃; The anaerobic ammonia oxidation sludge is anaerobic ammonia oxidation sludge with total nitrogen load lower than 0.4 kg-TN/(m 3 . D); the volume ratio of the gel to the anaerobic ammonia oxidation sludge is (10-5) (3-4); The concentration of the nano zero-valent iron in the mixed solution is 1.1-2.3 g/L, and the particle size of the nano zero-valent iron is 100-150 nm.
5. The method for strengthening the denitrification performance of the anaerobic ammonia oxidation process under the condition of high total nitrogen load according to claim 1 or 4, wherein the preparation method of the nano zero-valent iron comprises the steps of mixing high-valent molten iron solution with citric acid and strong reducing agent aqueous solution, uniformly mixing and stirring under nitrogen atmosphere, and obtaining the nano zero-valent iron through vacuum filtration, flushing and vacuum drying.
6. The method for enhancing denitrification performance of an anaerobic ammonia oxidation process under high total nitrogen loading conditions according to claim 5, wherein, The molar concentration of the high-valence molten iron solution is 1.1-1.3mol/L, and the high-valence molten iron solution is Fe 3+ aqueous solution and/or Fe 2+ aqueous solution; the molar concentration of the strong reducing agent aqueous solution is 0.8-1.2mol/L, and the strong reducing agent is sodium borohydride and/or potassium borohydride; The temperature of the vacuum drying is 55-65 ℃ and the time is 15-25h.
7. The method for enhancing denitrification performance of an anaerobic ammonium oxidation process under high total nitrogen loading conditions according to claim 1, wherein the particle size of the anaerobic ammonium oxidation gel particles is 3-8 mm.
8. The method for enhancing denitrification performance of an anaerobic ammoxidation process under high total nitrogen loading conditions as claimed in claim 1 wherein, The reactor is an upward flow sludge bed reactor; The anaerobic ammonia oxidation granular sludge is taken from a reactor which operates for more than 2 years and has a total nitrogen load lower than 0.4 kg-TN/(m 3 .d), and the particle size of the anaerobic ammonia oxidation granular sludge is 0.8-2.5 mm; the volume ratio of the anaerobic ammonia oxidation gel particles to the anaerobic ammonia oxidation granular sludge is (1-2) (2-1); The ratio of the total volume of the anaerobic ammonia oxidation gel particles and anaerobic ammonia oxidation granular sludge to the effective volume of the reactor is 1 (5-20).

Description

Anaerobic ammonia oxidation gel particles and method for preparing and enhancing denitrification performance of anaerobic ammonia oxidation process under high total nitrogen load condition Technical Field The invention belongs to the field of biological denitrification treatment of wastewater, and in particular relates to anaerobic ammonia oxidation gel particles and a method for preparing and strengthening denitrification performance of an anaerobic ammonia oxidation process under the condition of high total nitrogen load. Background The anaerobic ammonia oxidation (ANAMMOX) process belongs to a novel biological denitrification technology, and has the obvious advantages of no need of aeration, no need of additional carbon source, high reaction rate and the like compared with the traditional biological denitrification technology. It is reported that the application of the ANAMMOX process to treat nitrogen-containing wastewater can eliminate the need of adding a carbon source and an aeration system and related electric equipment compared with the traditional nitrification and denitrification process, so that the operation and maintenance cost is greatly reduced, the output of surplus sludge is remarkably reduced, a sludge treatment unit is omitted, the occupied area of a process structure is remarkably reduced, in addition, the emission of greenhouse gases is remarkably reduced due to the fact that the gas generated by the ANAMMOX reaction is mainly nitrogen, and the ANAMMOX process is regarded as a novel biological denitrification technology which is economical, energy-saving, efficient and low in carbon and has popularization and application values. However, the existing large-scale popularization and application of the ANAMMOX process also face some non-negligible problems. For example, ANAMMOX bacteria grow slowly and have higher temperature, and in addition, when the total nitrogen load of inflow is higher, the ANAMMOX denitrification process often faces the problems of floating and loss of sludge, difficult retention of biomass, great reduction of denitrification capacity of a reaction device and obvious deterioration of treatment effect. How to improve the operational stability and denitrification efficiency of the ANAMMOX denitrification process at high total nitrogen loading has been a challenging problem. And realizing good operation stability and higher denitrification efficiency of the ANAMMOX process under high total nitrogen load greatly promotes the practical application of the ANAMMOX process technology. At present, related researchers have also continuously tried and explored to improve the treatment performance of the ANAMMOX process under high total nitrogen load, mainly comprising the steps of improving the structure of a reaction device, controlling proper hydraulic conditions, crushing floating sludge aggregates after being collected and then re-adding the sludge aggregates into a reactor, regulating and controlling the sedimentation performance of the sludge by utilizing an exogenous addition group induction signal, and the like. However, the above-mentioned method still suffers from various limitations in practical application, such as the improvement of the structure of the reaction device, complicated implementation and high cost, and the control of suitable hydraulic conditions is only suitable for specific conditions with slow inflow velocity, and the exogenous addition of quorum sensing signals also faces the problems of signal cost and the like. Therefore, it is currently needed to propose an anaerobic ammonia oxidation gel particle and a preparation method thereof, and apply the same to enhance the denitrification performance of the anaerobic ammonia oxidation process under the condition of high total nitrogen load. Disclosure of Invention The invention aims at overcoming the defects of the prior art, and provides anaerobic ammonia oxidation gel particles and a method for preparing and strengthening denitrification performance of an anaerobic ammonia oxidation process under the condition of high total nitrogen load. According to the invention, the ANAMMOX gel particles and the ANAMMOX particle sludge with low total nitrogen load are mixed and added into the anaerobic ammonia oxidation process reactor with high total nitrogen load, so that the problems of remarkably reduced denitrification efficiency and unstable operation of the ANAMMOX process under the condition of higher total nitrogen load in the prior art are solved. In order to achieve the above object, a first aspect of the present invention provides a method for preparing anaerobic ammonium oxidation gel particles, the method comprising the steps of: s1, preparation of chitosan modified diatomite Mixing the chitosan aqueous solution with diatomite, and sequentially stirring, vacuum filtering, roasting and grinding to obtain the chitosan modified diatomite; s2, preparation of gel Mixing polyvinyl alcohol, sodium alginate