Integrated iron and manganese removal water treatment process

Abstract

The invention relates to the technical field of water purification, in particular to an integrated iron and manganese removal water treatment process which comprises the following steps: raw water aeration and coagulation treatment, iron removal, ammonia nitrogen removal and manganese removal, and the raw water aeration and coagulation treatment step is as follows: raw water is subjected to aeration treatment after being pre-oxidized by ozone; the raw water subjected to aeration treatment is input into a reaction tank, a coagulant is added into the reaction tank, the dosage of the coagulant is 8-20 mg / L, the contact time of the raw water subjected to aeration treatment and the coagulant is 20-300 s, and primary treatment water is prepared; the coagulant is prepared from the following raw materials in parts by weight: 8 to 12 parts of polyacrylamide, 2 to 4 parts of organic soluble sol and 0.4 to 0.8 part of trimethylolpropane tri [beta-(aziridinyl) propionate]. The device has the advantage of improving the precipitation rate of insoluble impurities in underground water.

Description

Technical Field

[0001] The present application relates to the technical field of water purification, and in particular to an integrated water treatment process for removing iron and manganese. Background Art

[0002] my country's groundwater is generally contaminated by excessively high iron and manganese content. Furthermore, in recent years, groundwater has been contaminated to varying degrees by sewage irrigation, the use of pesticides and fertilizers, and sewage leakage, leading to a significant increase in ammonia and nitrogen concentrations in groundwater. This has severely impacted the value of groundwater as a drinking water source, necessitating the removal of iron, manganese, and ammonia nitrogen from the water. my country's drinking water standards set iron and manganese concentrations at 0.3 mg / L and 0.1 mg / L, respectively. The standard for ammonia and nitrogen concentrations is generally 0.5 mg / L. Existing iron and manganese removal processes typically involve chemical oxidation or biofilm treatment. The biofilm method, however, uses microbial catalytic oxidation, eliminating the need for the addition of chemical agents such as chlorine, ozone, or potassium permanganate, effectively avoiding the risk of secondary contamination. Therefore, the biofilm method is the preferred method for groundwater treatment. However, actual groundwater generally contains a large amount of insoluble impurities. Simple precipitation and filtration take a long time, and the existing precipitation agents have insufficient precipitation effect, so that the water after precipitation still contains residual insoluble impurities. When removing iron and manganese in the later stage, the impurities adhere to the surface of the biofilm, resulting in reduced efficiency of iron and manganese removal, and requiring a large amount of backwash water for flushing, resulting in water waste and damage to the biofilm, which has an adverse effect on iron and manganese removal. Summary of the Invention

[0003] In order to improve the precipitation rate of insoluble impurities in groundwater, the present application provides an integrated water treatment process for iron and manganese removal.

[0004] In the first aspect, the present application provides an integrated water treatment process for iron and manganese removal, which adopts the following technical solution: an integrated water treatment process for iron and manganese removal, comprising the following steps: raw water aeration and coagulation treatment, iron and ammonia nitrogen removal steps, and manganese removal steps, wherein the raw water aeration and coagulation treatment steps are as follows: The raw water is pre-oxidized by ozone and then aerated, and then the aerated raw water is input into a reaction tank, a coagulant is added into the reaction tank, the amount of the coagulant is 8-20 mg / L, and the contact time between the aerated raw water and the coagulant is 20-300 seconds to produce primary treated water; The coagulant comprises the following raw materials in parts by weight: 8-12 parts of polyacrylamide, 2-4 parts of organic sol and 0.4-0.8 parts of trimethylolpropane tris[β-(aziridinyl) propionate].

[0005] By adopting the above technical solution, the composite coagulant can be used to efficiently remove suspended particles and fully remove solid insolubles in the raw water, thereby reducing the precipitation of insolubles in the water when the biofilm is further oxidized to remove iron and manganese, so that the biofilm can play a better role, and the number of backwashing of the biofilm can be reduced, thereby saving water and electricity, and responding to the national call for energy conservation and emission reduction; in the coagulant of the present application, by adding organic sol and polyacrylamide to cooperate with each other, solid insolubles in the water can be adhered, and the organic sol and polyacrylamide can also form a gel under the cross-linking of trimethylolpropane tris [β-(aziridinyl) propionate], which can increase the agglomeration and density of solid particles, thereby accelerating the precipitation of solid particles, and adsorbing more suspended particles during the sedimentation process.

[0006] Preferably, the organic soluble gum is a mixture of xanthan gum and konjac gum.

[0007] By adopting the above technical solution, xanthan gum has excellent water solubility, can dissolve quickly in water, adsorb and bond solid suspended particles, and then form a gel together with the dissolved konjac gum. When the two are added at the same time, the speed and effect of gel formation are better, and the two have a synergistic effect in forming the gel.

[0008] Preferably, the mass ratio of xanthan gum to konjac gum is (3-5):1.

[0009] By adopting the above technical solution, at this ratio, a better effect of precipitating suspended particles can be achieved.

[0010] Preferably, the coagulant further comprises 0.5-2 parts by weight of a hydroxyl-terminated hyperbranched polyester.

[0011] By adopting the above technical solution, the terminal hydroxyl hyperbranched polyester has a large number of hydroxyl groups, and its molecules are fully stretched in water, with low viscosity, and can be adsorbed on suspended solid particles, thereby increasing the anionicity of the solid particle surface, improving the adhesion activity and polarity of the suspended particles, and then combining with an organic sol and polyacrylamide to accelerate the precipitation of the suspended particles. In addition, the terminal hydroxyl hyperbranched polyester can also utilize its polyhydroxyl effect to form cross-links with the raw materials in the coagulant through the hydroxyl effect to form a three-dimensional network structure, thereby improving its precipitation rate.

[0012] Preferably, the average molecular weight of the hydroxyl-terminated hyperbranched polyester is 1100-5200.

[0013] By adopting the above technical solution, the molecular weight is low, the cross-linking density and the adsorption effect on suspended particles are improved, and the molecular weight is high, the cross-linking effect is reduced, and the precipitation rate is reduced.

[0014] Preferably, the average molecular weight of the polyacrylamide is 8 million.

[0015] By adopting the above technical solution, high molecular weight (8 million) polyacrylamide has a long molecular chain and can adsorb multiple suspended particles to form large flocs, accelerating sedimentation; polyacrylamide of this molecular weight has better compounding performance with the raw materials in the coagulant.

[0016] Preferably, the iron removal and ammonia nitrogen removal steps are carried out in an iron removal tank, wherein a quartz sand composite biofilm is placed in the iron removal tank, and the preparation method of the quartz sand composite biofilm is as follows: Quartz sand was placed in the iron removal tank, and then groundwater with high iron, high manganese and high ammonia nitrogen was used for water treatment. The manganese content of the groundwater was 10-14 mg / L, the iron content was 0.8-1.2 mg / L, and the ammonia nitrogen content was 1.2-1.8 mg / L. The groundwater was flow treated for 25-35 days. The iron oxidizing bacteria concentration was prepared to be (2.5-3.5)×10 9 CFU / mL, the concentration of ammonia oxidizing bacteria is (0.8-1.2)×10 9 CFU / mL, the concentration of nitrite oxidizing bacteria is (0.8-1.2)×10 9 The composite bacterial liquid with a CFU / mL is mixed with groundwater containing high iron, high manganese and high ammonia nitrogen at a volume ratio of 1: (700-900), and then transported to an iron removal tank to soak quartz sand for 40-55 hours and then released, and the process is repeated 3-6 times to obtain a quartz sand composite biofilm.

[0017] By adopting the above technical solution, nitrite-oxidizing bacteria convert ammonia nitrogen into nitrate, realizing the integration of "iron and manganese removal + denitrification". The high concentration of iron ions screens out bacteria with strong tolerance, the thickness of the biofilm increases, and the lifespan is extended. Then, iron-oxidizing bacteria, ammonia-oxidizing bacteria and nitrite-oxidizing bacteria are inoculated to make the biofilm flora more efficient. In addition, the biofilm on the surface of the quartz sand carrier forms a micro-electrolysis environment, which can promote the formation of insoluble iron oxides.

[0018] Preferably, the manganese removal step is performed by a manganese removal tank, in which a manganese sand composite biofilm is placed. The preparation method of the manganese sand composite biofilm is as follows: Place quartz sand in the iron removal tank, and then use groundwater with high iron, high manganese and high ammonia nitrogen for water treatment. The manganese content of the groundwater is 10-14 mg / L, the iron content is 0.8-1.2 mg / L, and the ammonia nitrogen is 1.2-1.8 mg / L. The groundwater is flow treated for 25-35 days. The concentration of (3-5)×10 9A manganese oxidizing bacteria solution with a CFU / mL content is mixed with groundwater containing high iron, high manganese and high ammonia nitrogen at a volume ratio of 1:(700-900), and then transported to an iron removal tank to soak in quartz sand for 40-55 hours and then released, and the process is repeated 3-6 times to obtain a manganese sand composite biofilm.

[0019] By adopting the above technical solution, manganese oxidizing bacteria can 2+ The affinity of manganese sand carrier is higher than that of iron oxidizing bacteria, which can further oxidize manganese. 4+ Oxides provide catalytic active sites and enhance biological oxidation.

[0020] In summary, this application includes at least one of the following beneficial technical effects: 1. The composite coagulant can efficiently remove suspended particles and fully remove solid insolubles in the raw water, thereby reducing the precipitation of insolubles in the water when the biofilm is further oxidized to remove iron and manganese, so that the biofilm can play a better role, and the number of backwashing of the biofilm can be reduced, thereby saving water and electricity, and responding to the national call for energy conservation and emission reduction; in the coagulant of the present application, by adding organic sol and polyacrylamide to cooperate with each other, solid insolubles in the water can be adhered, and the organic sol and polyacrylamide can also form a gel under the cross-linking of trimethylolpropane tris [β-(aziridinyl) propionate], which can increase the agglomeration and density of solid particles, thereby accelerating the precipitation of solid particles, and adsorbing more suspended particles during the sedimentation process.

[0021] 2. The coagulant prepared in the present application is applied to the integrated water treatment process for iron and manganese removal, which can fully settle the solid insoluble matter in the raw water after aeration treatment. After 25 seconds of contact reaction with the coagulant, the TSS of the raw water after aeration treatment can be reduced to 0.6-1.5 mg / L, which can greatly reduce the precipitation deposition on the biofilm of subsequent iron and manganese removal, and can reduce the backwash cycle and backwash water consumption. According to a rough estimate, according to the integrated water treatment process for iron and manganese removal of the present application, for every 100 tons of groundwater treated, 1.5 tons of backwash water can be saved, and about 20 kW·h of electricity can be saved, which is conducive to energy conservation and emission reduction. DETAILED DESCRIPTION

[0022] The following is a further detailed description of this application in conjunction with the specific content.

[0023] raw material Polyacrylamide was purchased from Henan Sairuike Biotechnology Co., Ltd.; xanthan gum FH-80, model, was purchased from Shandong Fufeng Biotechnology Co., Ltd., with a viscosity of 1200cp; konjac gum model was OM-30, purchased from Hubei Yizhi Konjac Biotechnology Co., Ltd.; the polymerized aluminum-iron coagulant model was BPAC-12, and the manufacturer was Shandong Baomo Biochemical Co., Ltd. Example

[0024] The raw water treated in the embodiment of the present application is groundwater. The manganese content in the source water is measured to be 1.6 mg / L, the iron content is 4.0 mg / L, the oxygen consumption OC is 5.2 mg / L, the dissolved oxygen DO is 3.2 mg / L, the pH is 7.1, the ammonia nitrogen is 1.1 mg / L, the algae are slightly contaminated, and the turbidity is low.

[0025] In the embodiment of the present application, a quartz sand composite biofilm is placed in the iron removal tank, and a manganese sand composite biofilm is placed in the manganese removal tank; the preparation methods of the quartz sand composite biofilm and the manganese sand composite biofilm are as follows: Quartz sand was placed in the iron removal tank, and manganese sand was placed in the manganese removal tank. Then, water treatment was performed. The treatment water used was groundwater with high iron, high manganese, and high ammonia nitrogen, wherein the manganese content was 12 mg / L, the iron content was 1 mg / L, and the ammonia nitrogen was 1.5 mg / L. After 30 days of treatment according to the water treatment process in Example 1, the water inlet of the manganese removal tank was closed, that is, the groundwater was directly discharged through the iron removal tank and collected; Then, a composite bacterial solution of iron removal, ammonia oxidizing bacteria and nitrite oxidizing bacteria was prepared: the composite bacterial solution of iron oxidizing bacteria and ammonia oxidizing bacteria (the concentration of iron oxidizing bacteria was 3×10 9 CFU / mL, the concentration of ammonia oxidizing bacteria was 1×10 9 CFU / mL, the concentration of nitrite-oxidizing bacteria was 1×10 9 CFU / mL) was mixed with groundwater containing high iron, high manganese, and high ammonia nitrogen at a volume ratio of 1:800, and then transported to an iron removal tank to soak quartz sand for 50 hours before being released. This process was repeated five times, and iron-oxidizing bacteria, ammonia-oxidizing bacteria, and nitrite-oxidizing bacteria were inoculated to produce a quartz sand composite biofilm. Preparation of manganese oxidizing bacteria: prepare the manganese oxidizing bacteria solution (the concentration of manganese oxidizing bacteria is 4×10 9 CFU / mL) was mixed with groundwater containing high iron, high manganese and high ammonia nitrogen at a volume ratio of 1:800, and then transported to a manganese removal tank to soak manganese sand for 50 hours and then released. This process was repeated 5 times and inoculated with manganese oxidizing bacteria to prepare a manganese sand composite biofilm.

[0026] Example 1 An integrated water treatment process for removing iron and manganese, comprising the following specific steps: S1. Raw water aeration and coagulation treatment The raw water is transported to the pre-oxidation tank, and then 1.1 mg / L of ozone is introduced. The effective contact time of ozone is 3 minutes. The pre-oxidized raw water is then fed into the reaction sedimentation tank and aerated using a blower to make the DO concentration in the raw water 9 mg / L and the ozone amount below 0.2 mg / L. The aerated raw water is then fed into the reaction tank. A honeycomb three-dimensional filter is provided in the reaction tank. After the raw water after aeration treatment enters the reaction tank, the water inlet speed is 12 m / h. A coagulant is added for coagulation treatment. The dosage of the coagulant is 10 mg / L (the dosage can be changed according to the coagulation effect. The coagulation effect of this dosage in the present application is good, but the maximum should not exceed 20 mg / L). The contact time between the raw water and the coagulant is 25 seconds. The precipitate formed in the raw water sinks to the bottom of the reaction tank through the honeycomb three-dimensional filter and is extracted through the water pipe at the bottom of the reaction tank. The water after coagulation treatment is extracted from the upper end of the reaction tank to obtain the raw water after coagulation treatment, that is, the primary treated water. The coagulant is prepared by mixing 10 kg of polyacrylamide, 2 kg of xanthan gum, 0.5 kg of konjac gum, and 0.6 kg of trimethylolpropane tris[β-(aziridinyl) propionate] uniformly. The polyacrylamide is an anionic type with an average molecular weight of 8 million. S2, iron and ammonia nitrogen removal steps The primary treated water is transported to the deironing tank for filtration and iron removal. The primary treated water is input from the upper end of the deironing tank at a water inlet speed of 12 m / h. The primary treated water is in contact with the quartz sand for 15 minutes and then output from the lower end of the deironing tank to complete the iron and ammonia nitrogen removal to obtain secondary treated water. The contact time of the primary treated water is determined by the water temperature. When the water temperature is 20°C, it is 30 minutes. When the water temperature rises by 10°C, the reaction rate doubles. At 30°C, only 15 minutes is required. The water temperature measured in this embodiment is 30°C. During this period, the backwash cycle of the deironing tank is 120 hours, the backwash intensity is 12 L / (s·㎡), and the backwash time is 5 minutes. S3, manganese removal step The secondary treated water is transported to the manganese removal tank, input from the upper end of the manganese removal tank, so that the contact time between the secondary treated water and the manganese sand is 40 minutes, and output from the lower end of the manganese removal tank, completing the iron and manganese removal treatment of the groundwater to obtain purified water; the contact time between the secondary treated water and the manganese sand is adjusted by the water temperature. When the water temperature is <15°C, the contact time is virtually extended to 60-120 minutes. The water temperature measured here is 30°C; during this period, the backwash cycle of the manganese removal tank is 168 hours, the backwash intensity is 12L / (s·㎡), and the backwash time is 5 minutes; after one week of continuous operation, the iron, manganese and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1mg / L, 0.05mg / L and 0.1mg / L, respectively.

[0027] Example 2 An integrated water treatment process for iron and manganese removal is provided, which differs from Example 1 in that the raw material of the coagulant further includes 1 kg of a hydroxyl-terminated hyperbranched polyester, the molecular weight of the hydroxyl-terminated hyperbranched polyester is 2400, and the corresponding model is HyPerH103; the remaining steps are the same as those in Example 1; after continuous operation for one week, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0028] Example 3 A water treatment process for integrated iron and manganese removal is provided, which differs from Example 1 in that the molecular weight of the hydroxyl-terminated hyperbranched polyester is 1100, and the corresponding model is HyPer H102; the remaining steps are the same as those in Example 1; after one week of continuous operation, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0029] Example 4 A water treatment process for integrated iron and manganese removal is provided, which differs from Example 1 in that the molecular weight of the hydroxyl-terminated hyperbranched polyester is 5200, and the corresponding model is HyPer H104; the remaining steps are the same as those in Example 1; after one week of continuous operation, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0030] Example 5 An integrated water treatment process for iron and manganese removal is provided, which differs from Example 2 in that the molecular weight of the polyacrylamide is 6 million, and the remaining steps are the same as those in Example 2. After one week of continuous operation, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0031] Example 6 An integrated water treatment process for iron and manganese removal is provided, which differs from Example 2 in that the molecular weight of the polyacrylamide is 10 million, and the remaining steps are the same as those in Example 2. After one week of continuous operation, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0032] Example 7 A water treatment process for integrated iron and manganese removal is disclosed, which differs from Example 1 in that konjac gum is replaced with xanthan gum of equal mass as a coagulant raw material, and the remaining steps are the same as those in Example 1. After continuous operation for one week, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0033] Example 8 A water treatment process for integrated iron and manganese removal is disclosed, which differs from Example 2 in that xanthan gum is replaced by konjac gum of equal mass in the raw material of the coagulant, and the remaining steps are the same as those in Example 2. After continuous operation for one week, the iron, manganese, and ammonia nitrogen concentrations in the obtained purified water are reduced to below 0.1 mg / L, 0.05 mg / L, and 0.1 mg / L, respectively.

[0034] Comparative Example Comparative Example 1 A water treatment process for integrated iron and manganese removal is different from Example 1 in that, in the raw materials of the coagulant, xanthan gum, konjac gum and trimethylolpropane tris[β-(aziridinyl)propionate] are replaced with an equal mass of polymerized aluminum-iron coagulant, and the remaining steps are the same as those in Example 1.

[0035] Performance testing Detection method / test method According to the integrated water treatment process for iron and manganese removal of Examples 1-8 and Comparative Example 1, 1 t of water was treated respectively, and then the total suspended solids in the treated water were tested by gravimetric method. The test results are shown in Table 1. It is known that the total suspended solids (TSS) in the raw water after aeration treatment is 7 mg / L.

[0036] Table 2 Test results of Examples 1-8 and Comparative Example 1 It can be seen from Examples 1-8, Comparative Example 1, and the test data in Table 1 that the coagulant prepared in the present application is applied to an integrated water treatment process for iron and manganese removal, and can fully settle the solid insolubles in the raw water after aeration treatment. After the raw water after aeration treatment is in contact with the coagulant for 25 seconds, its TSS can be reduced to 0.6-1.5 mg / L, which can greatly reduce the precipitation deposition on the subsequent biofilm for iron and manganese removal, and can reduce the backwash cycle and backwash water consumption. According to a rough estimate, according to the integrated water treatment process for iron and manganese removal in the present application, for every 100 tons of groundwater treated, 1.5 tons of backwash water can be saved, and about 20 kW·h of electricity can be saved, which is conducive to energy conservation and emission reduction.

[0037] As can be seen from the detection data of embodiment 1 and comparative example 1, the application can efficiently remove suspended particles by composite coagulant, the solid incompatible substance in raw water is fully removed, by adding organosol and polyacrylamide to collaborate with each other, while the solid incompatible substance in water can be adhered to, organosol and polyacrylamide can also form gel under the crosslinking of trimethylolpropane tris[β-(aziridine radicals) propionate], reunion and the density of solid particles can be increased, thus accelerate the precipitation of solid particles, and in the sedimentation process, adsorb more suspended particles. In conjunction with embodiment 7-8, the water-soluble excellent of xanthan gum can be quickly dissolved in water, adsorption bonding solid suspended particles, then jointly form gel with the konjac glucomannan of dissolving, when both add simultaneously, speed and effect of forming gel are better, and both have synergistic effect on the effect of forming gel. In combination with Examples 2-4, the terminal hydroxyl hyperbranched polyester has a large number of hydroxyl groups, and its molecules are fully stretched in water, with a low viscosity, and can be adsorbed on suspended solid particles, thereby increasing the anionicity of the solid particle surface, increasing the adhesion activity and polarity of the suspended particles, and then combining with an organic sol and polyacrylamide to accelerate the precipitation of the suspended particles. In addition, the terminal hydroxyl hyperbranched polyester can also utilize its polyhydroxyl effect to form cross-links with the raw materials in the coagulant through the hydroxyl effect to form a three-dimensional network structure, thereby increasing its precipitation rate.

[0038] It can be seen from Examples 5-6 that high molecular weight (8 million) polyacrylamide has a long molecular chain and can adsorb multiple suspended particles to form large flocs, accelerating sedimentation; polyacrylamide of this molecular weight has better compounding performance with the raw materials in the coagulant.

[0039] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. An integrated water treatment process for iron and manganese removal, characterized by: The process comprises the following steps: raw water aeration and coagulation treatment, iron removal, ammonia nitrogen removal, and manganese removal. The raw water aeration and coagulation treatment steps are as follows: The raw water is pre-oxidized by ozone and then aerated, and then the aerated raw water is input into a reaction tank, a coagulant is added into the reaction tank, the amount of the coagulant is 8-20 mg / L, and the contact time between the aerated raw water and the coagulant is 20-300 seconds to produce primary treated water; The coagulant comprises the following raw materials in parts by weight: 8-12 parts of polyacrylamide, 2-4 parts of organic sol and 0.4-0.8 parts of trimethylolpropane tris[β-(aziridinyl) propionate].

2. The integrated water treatment process for iron and manganese removal according to claim 1, characterized in that: The organic soluble gum is a mixture of xanthan gum and konjac gum.

3. The integrated water treatment process for iron and manganese removal according to claim 2, characterized in that: The mass ratio of the xanthan gum to the konjac gum is (3-5):

1.

4. The integrated water treatment process for iron and manganese removal according to claim 1, characterized in that: The coagulant further comprises 0.5-2 parts by weight of a terminal hydroxyl hyperbranched polyester.

5. The integrated water treatment process for iron and manganese removal according to claim 4, characterized in that: The average molecular weight of the hydroxyl-terminated hyperbranched polyester is 1100-5200.

6. The integrated water treatment process for iron and manganese removal according to claim 1, characterized in that: The average molecular weight of the polyacrylamide is 8 million.

7. The integrated water treatment process for iron and manganese removal according to claim 1, characterized in that: The iron removal and ammonia nitrogen removal steps are carried out in an iron removal tank, in which a quartz sand composite biofilm is placed. The preparation method of the quartz sand composite biofilm is as follows: Place quartz sand in the iron removal tank, and then use groundwater with high iron, high manganese and high ammonia nitrogen for water treatment. The manganese content of the groundwater is 10-14 mg / L, the iron content is 0.8-1.2 mg / L, and the ammonia nitrogen is 1.2-1.8 mg / L. The groundwater flow treatment is carried out for 25-35 days. The concentration of iron oxidizing bacteria was prepared to be (2.5-3.5)×10 9 CFU / mL, the concentration of ammonia oxidizing bacteria is (0.8-1.2)×10 9 CFU / mL, the concentration of nitrite oxidizing bacteria is (0.8-1.2)×10 9 The composite bacterial liquid with a CFU / mL was mixed with groundwater containing high iron, high manganese and high ammonia nitrogen at a volume ratio of 1: (700-900), and then transported to an iron removal tank to soak quartz sand for 40-55 hours and then released, and the process was repeated 3-6 times to obtain a quartz sand composite biofilm.

8. The integrated water treatment process for iron and manganese removal according to claim 1, characterized in that: The manganese removal step is carried out by a manganese removal tank, in which a manganese sand composite biofilm is placed. The preparation method of the manganese sand composite biofilm is as follows: Place quartz sand in the iron removal tank, and then use groundwater with high iron, high manganese and high ammonia nitrogen for water treatment. The manganese content of the groundwater is 10-14 mg / L, the iron content is 0.8-1.2 mg / L, and the ammonia nitrogen is 1.2-1.8 mg / L. The groundwater flow treatment is carried out for 25-35 days. The concentration is (3-5)×10 9 A manganese oxidizing bacteria solution with a CFU / mL content was mixed with groundwater containing high iron, high manganese and high ammonia nitrogen at a volume ratio of 1:(700-900), and then transported to an iron removal tank to soak in quartz sand for 40-55 hours and then released. The process was repeated 3-6 times to obtain a manganese sand composite biofilm.

Images