CN105836837A - Removing device and removing method for ammonia nitrogen in wastewater and contaminated water body - Google Patents

Abstract

The invention relates to a removing device and a removing method for ammonia nitrogen in wastewater and a contaminated water body. The removing device comprises an ammonia nitrogen adsorbing unit and a regenerating unit; the ammonia nitrogen adsorbing unit comprises a water inlet pump, a water inlet valve, a filter bed and an emptying valve group which are sequentially connected, wherein the filter bed is filled with an adsorbing material; the regenerating unit comprises a regenerated liquid reserve tank and a regenerated liquid pump which are sequentially connected, regenerated liquid is contained in the regenerated liquid reserve tank, the regenerated liquid pump is further connected with a pipeline arranged between the water inlet pump and the water inlet valve, the regenerated liquid reserve tank is further connected with the filter bed and recycles regenerated liquid which flows out of the filter bed and regenerates the adsorbing material, and a regenerated liquid reflux valve is arranged between the regenerated liquid reserve tank and the filter bed. Compared with the prior art, the removing device has the advantages of being high in sewage treatment efficiency, low in operation cost, simple in regeneration and the like.

Description

Device and method for removing ammonia nitrogen in wastewater and polluted water bodies

technical field

The invention relates to a method for treating wastewater or restoring polluted water, in particular to a device and method for removing ammonia nitrogen in wastewater and polluted water.

Background technique

Ammonia nitrogen is a kind of nutrient substance. If the concentration of ammonia nitrogen in the water body is too high, it will lead to eutrophication of the water body, which will cause the microorganisms and plants in the water body, especially algae, to multiply, greatly increase the consumption of dissolved oxygen in the water body, and cause fish The species died, and the water quality became black and smelly. When the ammonia nitrogen pollution is serious, it will lead to the deterioration of the water environment and form algal blooms, which will have a negative impact on ecological balance and biodiversity. At the same time, ammonia nitrogen also increases the cost and difficulty of water treatment. The ammonia nitrogen in the water body can react with chlorine to form chloramines. Therefore, when the water body is disinfected, the ammonia nitrogen in the water body will consume a large amount of chlorine and increase the amount of disinfectant. In the presence of organic matter in the water body, cyanogen chloride and highly toxic cyanide may also be produced as disinfection by-products, which seriously threaten human health.

In the past 10 years, many experts and scholars at home and abroad have conducted a lot of research on the treatment methods of ammonia nitrogen-containing wastewater. The main methods include biological method (nitration), stripping method, chemical precipitation method, membrane treatment, breakpoint chlorination method and adsorption method. The biological method converts ammonia nitrogen into nitrite and nitrate through nitrosifying bacteria and nitrifying bacteria, which is currently the most widely used treatment method. However, the biological method is more suitable for the treatment of ammonia nitrogen wastewater with a medium concentration of ammonia nitrogen (10-100mg/L), and has higher requirements on the reaction conditions and requires a longer reaction time. The stripping method is more suitable for high ammonia nitrogen wastewater, which requires high pH and temperature, high operating costs, and has secondary pollution problems; the chemical precipitation method is also suitable for high ammonia nitrogen wastewater, which converts ammonia nitrogen into magnesium ammonium phosphate for precipitation and removal. This method also requires a higher pH value, and requires the coexistence of nitrogen and phosphorus in the sewage, and the removal effect on low and medium concentrations of ammonia nitrogen is not obvious; the membrane treatment method is more suitable for treating high concentrations with high salt content and low oily pollutant content Ammonia nitrogen wastewater, but due to the problems of power consumption and membrane pollution, the operation and maintenance costs are high, so its application range is limited to a certain extent; the breakpoint chlorination method is to pass chlorine or hypochlorite into the wastewater to make the water The ammonia nitrogen is oxidized to nitrogen, so as to achieve the purpose of removing ammonia nitrogen. However, organic substances contained in wastewater and polluted water usually consume chlorine or hypochlorite, producing toxic by-products chloramines and chlorinated organic substances, resulting in waste of raw materials and secondary pollution. Compared with the traditional method, the adsorption method has the advantages of simple process, good treatment effect, low power consumption, low operation and maintenance cost, and has a good removal effect on different concentrations of ammonia nitrogen.

The adsorption method is to use a porous solid adsorbent to adsorb ammonia nitrogen in the water body from the water body to the surface of the solid adsorbent through physical adsorption or chemical adsorption, so that the ammonia nitrogen is separated from the water body to purify the water body. Compared with other ammonia nitrogen removal technologies, the adsorption method is the most suitable technology for the treatment of low-concentration ammonia nitrogen wastewater, but the key to the application of the adsorption method is to solve the problem of adsorbent regeneration. After the solid adsorbent reaches adsorption saturation, it can be regenerated to restore its adsorption capacity and be recycled. Therefore, the regeneration of the adsorbent is a key factor affecting the comprehensive treatment effect of the adsorption method. At present, the commonly used regeneration methods include biological method, heating regeneration, wet method and so on. Biological regeneration mainly uses nitrosifying bacteria and nitrifying bacteria to oxidize ammonia nitrogen to achieve adsorbent regeneration. However, this method not only needs to solve the mass transfer problem of ammonia nitrogen diffusing from the adsorbent to the surface of microorganisms, but also needs enough reaction time to realize nitrification. Regeneration efficiency is often low. The principle of heating regeneration is based on the fact that the adsorption reaction is an exothermic reaction, so increasing the temperature can shift the adsorption balance to the reverse reaction direction, promote desorption, and restore the adsorption capacity of the adsorbent. The wet method is currently the most widely used regeneration method, and the more commonly used regeneration solution is a mixed solution of sodium hydroxide and sodium chloride. However, this method involves the treatment of the regeneration solution. Generally, it is necessary to replace the regeneration solution or add additional equipment to remove the ammonia nitrogen in the regeneration solution, which greatly increases the complexity and cost of the process.

Contents of the invention

The object of the present invention is to provide a device and method for removing ammonia nitrogen in waste water and polluted water bodies in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A device for removing ammonia nitrogen in waste water and polluted water, comprising an ammonia nitrogen adsorption unit and a regeneration unit, wherein the ammonia nitrogen adsorption unit includes a water inlet pump, a water inlet valve, a filter bed filled with adsorption materials and a venting valve group connected in sequence, the The regeneration unit includes a regeneration liquid storage tank and a regeneration liquid pump connected in sequence, the regeneration liquid storage tank is filled with regeneration liquid, and the regeneration liquid pump is also connected to the pipeline between the water inlet pump and the water inlet valve. The regenerated liquid storage tank is also connected to the filter bed, and recovers the regenerated liquid flowing out from the filter bed after regenerating the adsorbent material, and a regenerated liquid return valve is also provided between the regenerated liquid storage tank and the filter bed.

The adsorption material is at least one selected from molecular sieve, ion exchange resin, modified zeolite, natural zeolite, carbonized rice husk, charcoal, fluvo-aquic soil, volcanic rock or ceramsite.

The regeneration solution is a mixed solution of NaCl and hypochlorite, wherein the concentration of NaCl is 1-20g/L.

The vent valve group includes a vent valve A and a vent valve B sequentially connected to the filter bed, and the regeneration liquid storage tank is connected to a pipeline between the vent valve A and the vent valve B.

Adopt the removal method of the removal device of ammonia nitrogen in above-mentioned waste water and polluted water body, comprise the following steps:

(a) The sewage to be treated is driven into the filter bed by the water inlet pump, and the ammonia nitrogen is adsorbed and removed in the filter bed, and then the vent valve group is opened to discharge the sewage to the outside;

(b) Repeat the process described in step (a) until the adsorption capacity of the adsorption material in the filter bed is saturated, close the venting valve group, and the regeneration liquid is pumped into the filter bed through the regeneration liquid, so that the adsorption material in the filter bed is fully soaked in the filter bed In the regeneration liquid, regeneration treatment, and then return to the regeneration liquid storage tank, that is to complete a process of adsorption regeneration.

In step (a), the hydraulic retention time of the sewage to be treated in the filter bed is 5-40min.

The amount of the regeneration liquid sent into the filter bed satisfies that the molar ratio of the hypochlorite in the regeneration liquid to the ammonia nitrogen adsorbed by the adsorption material is 1-5:1.

The regeneration treatment time is 5-60min.

In the present invention, when the adsorption material is regenerated, the Na ⁺ in the regeneration liquid is replaced with the ammonia nitrogen adsorbed by the zeolite, so that the adsorbed ammonia nitrogen is released from the adsorption material into the water body, and then oxidized by hypochlorite into Nitrogen, released into the air, no secondary pollution.

Adsorbent-NH ₄ ⁺ +Na ⁺ →Adsorbent-Na ⁺ +NH ₄ ⁺

2NH ₄ ⁺ +3NaClO→N ₂ ↑+3H ₂ O+3NaCl+2H ⁺ .

Compared with the prior art, the present invention has the following advantages:

(1) The present invention alternates the adsorption-regeneration unit of the ammonia nitrogen adsorption material without replacing the adsorption material and regeneration solution, saves the corresponding process, and realizes the efficient removal of ammonia nitrogen in wastewater or polluted water.

(2) The regeneration solution composed of sodium chloride and hypochlorite is safe and pollution-free. After the hypochlorite reacts with ammonia nitrogen, it is converted into chloride (such as sodium chloride or calcium chloride). The regeneration solution can be recycled, so There is no problem with the treatment of flushing water and regeneration fluid, which greatly reduces operating costs and secondary pollution.

(3) The equipment has a simple structure and is easy to operate and maintain.

(4) When the regeneration liquid regenerates the adsorption material, it can also modify it to a certain extent at the same time, thereby increasing the adsorption capacity and rate of the adsorption material, and improving the removal rate of ammonia nitrogen in the effluent by the regenerated adsorption material.

Description of drawings

Fig. 1 is the flowchart of removal method of the present invention;

In the figure, 1-filter bed, 2-water inlet pump, 3-water inlet valve, 4-vent valve A, 5-vent valve B, 6-regeneration liquid storage tank, 7-regeneration liquid pump, 8-regeneration liquid return valve .

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

Specific treatment process for ammonia nitrogen-containing wastewater or polluted water bodies

As shown in Figure 1, the water to be treated is pumped into the filter bed 1 by the water inlet pump 2 through the water inlet valve 3. The hydraulic retention time of the filter bed 1 is 5-40min, and the adsorption material (molecular sieve) in the filter bed 1 is fully absorbed in the water body. of ammonia nitrogen. After reaching the preset running time, turn off the water inlet pump 2, open the vent valve A4 and the vent valve B5, and discharge all the treated water for regeneration. During regeneration, close the vent valve A4 and the vent valve B5, and pump the regeneration liquid from the regeneration liquid storage tank 6 into the filter bed 1 by the regeneration liquid pump 7. When the filter bed 1 is filled with the regeneration liquid, close the regeneration liquid pump 7 to make the adsorption The material is fully immersed in the regeneration solution. After 5-60 minutes, open the vent valve A4 and the regeneration fluid return valve 8 to allow the regeneration fluid to flow back into the regeneration fluid storage tank 6 to complete the regeneration. After the regeneration is completed, the cycle enters the ammonia nitrogen adsorption stage of the water to be treated.

Example 2

A device for removing ammonia nitrogen from polluted waste water and polluted water bodies, including an ammonia nitrogen adsorption unit and a regeneration unit, the ammonia nitrogen adsorption unit includes a water inlet pump 2 connected in sequence, a water inlet valve, a filter bed 1 filled with adsorption materials, a vent valve A4 and a vent valve A4. Valve B5, the regeneration unit includes a regeneration liquid return valve 8, a regeneration liquid storage tank 6 and a regeneration liquid pump 7 connected in sequence, the regeneration liquid storage tank 6 is filled with regeneration liquid, and the regeneration liquid pump 7 is also connected to the water inlet pump 2 and the water inlet valve 3 The regeneration liquid return valve 8 is also connected to the pipeline between the vent valve A4 and the vent valve B5. The adsorption material is an ion exchange resin, and the regeneration solution is a mixed solution of NaCl and hypochlorite, wherein the concentration of NaCl is 10g/L. During regeneration, the molar ratio of the hypochlorite in the regeneration solution to the ammonia nitrogen adsorbed by the adsorption material It is 3:1.

Example 3

Compared with Example 2, except that the adsorption material is a mixture of modified zeolite and natural zeolite at a mass ratio of 1:1, the rest are the same.

Example 4

Compared with Example 2, except that the adsorption material is carbonized rice husk and charcoal mixed in 1:1, the rest are the same.

Example 5

Compared with Example 2, except that the adsorption material is fluvo-aquic soil, the rest are the same.

Example 6

Compared with Example 2, except that the adsorption material is a mixture of volcanic rock and ceramsite at a mass ratio of 1:3, the rest are the same.

Example 7

Compared with Example 2, except that the concentration of NaCl is 1g/L, during regeneration, the molar ratio of hypochlorite in the regeneration solution to ammonia nitrogen adsorbed by the adsorbent is 4:1, and the rest are the same.

Example 8

Compared with Example 2, except that the concentration of NaCl is 20g/L, during regeneration, the molar ratio of hypochlorite in the regeneration solution to ammonia nitrogen adsorbed by the adsorbent is 5:1, and the rest are the same.

Example 9

Compared with Example 2, except that the concentration of NaCl is 5g/L, the molar ratio of the hypochlorite in the regeneration solution to the ammonia nitrogen adsorbed by the adsorbent is 1:1 during regeneration, and the rest are the same.

Example 10

Compared with Example 2, except that the concentration of NaCl is 12g/L, during regeneration, the molar ratio of hypochlorite in the regeneration solution to ammonia nitrogen adsorbed by the adsorbent is 2:1, and the rest are the same.

Example 11

The ammonia nitrogen and water were treated with the removal device of Example 2, and the ammonia nitrogen concentration of the river water containing ammonia nitrogen was 2.65mg/L. The river water enters the filter bed 1 through the water inlet valve 3, and the filter bed 1 has a volume of 2m ³ and is filled with 3.2t of natural zeolite. The hydraulic retention time is 2min, the adsorption operation time is 7h, the water volume that can be treated in one operation is 160m ³ , the water volume that can be treated per hour is 23m ³ /h, and the water volume that can be treated per day is 506m ³ /d (calculated according to 22h), reaching the preset After the running time, close the water inlet pump 2, open the vent valve A4 and vent valve B5, and discharge all the treated water for regeneration. When regenerating, close the vent valve A4 and vent valve B5, and pump the regeneration liquid from the regeneration liquid storage tank 6 into the filter bed 1 by the regeneration liquid pump 7. When the filter bed 1 is filled with the regeneration liquid, close the regeneration liquid inlet pump 7 to make the adsorption The material is fully immersed in the regeneration solution. After 20 minutes, open the vent valve 4 and the regenerating liquid return valve 8 to allow the regenerating liquid to flow back into the regenerating liquid reserve tank 6 to complete the regeneration. After the regeneration is completed, it enters the ammonia nitrogen adsorption stage.

After the river water containing ammonia nitrogen with a concentration of 2.65mg/L is treated by filter bed 1, the concentration of ammonia nitrogen in the effluent is 1.52mg/L, and the removal rate is 42.7%; after one regeneration, the concentration of ammonia nitrogen in the effluent is 0.44mg/L, and the removal rate is 83.3% %; After secondary regeneration, the concentration of ammonia nitrogen in the effluent is 0.05mg/L, and the removal rate is 98.0%. This is because during regeneration, the sodium chloride and hypochlorite in the regeneration solution will have a certain modification effect on the natural zeolite, increasing the adsorption capacity and rate of the natural zeolite, and improving the removal rate of ammonia nitrogen in the effluent.

The above description of the embodiments is for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (8)

1. the removal device of ammonia nitrogen in a waste water and polluted-water, it is characterised in that include ammonia nitrogen absorption unit And regeneration unit, described ammonia nitrogen absorption unit includes the intake pump (2) being sequentially connected with, water intaking valve (3), loads Having filter bed (1) and the emptying valve group of adsorbing material, described regeneration unit includes the regenerated liquid storage being sequentially connected with Standby case (6) and regeneration liquid pump (7), described regenerated liquid reserve tank (6) is built with regenerated liquid, described regeneration Liquid pump (7) is also connected with pipeline between intake pump (2) and water intaking valve (3), described regenerated liquid reserve tank (6) It is also connected with filter bed (1), and reclaims the regenerated liquid after the Regeneration Treatment adsorbing material that filter bed (1) flows out, again It is additionally provided with regenerated liquid reflux inlet (8) between raw liquid reserve tank (6) and filter bed (1).

The removal device of ammonia nitrogen in a kind of waste water the most according to claim 1 and polluted-water, its feature exists In, described adsorbing material selected from molecular sieve, ion exchange resin, modified zeolite, natural zeolite, carbonization rice husk, At least one in Linesless charcoal, moisture soil, volcanic rock or haydite.

The removal device of ammonia nitrogen in a kind of waste water the most according to claim 1 and polluted-water, its feature exists In, described regenerated liquid is the mixed solution of NaCl and hypochlorite, and wherein, the concentration of NaCl is 1-20g/L.

The removal device of ammonia nitrogen in a kind of waste water the most according to claim 1 and polluted-water, its feature exists In, described emptying valve group includes emptying valve A (4) and the emptying valve B being sequentially connected with filter bed (1) (5), described regenerated liquid reserve tank (6) connects manages between emptying valve A (4) and emptying valve B (5) Road.

5. use the removal of the removal device of ammonia nitrogen in the waste water as described in claim 1-4 is arbitrary and polluted-water Method, it is characterised in that comprise the following steps:

A () treatment sewage is squeezed into filter bed (1) by intake pump (2), remove ammonia nitrogen at filter bed (1) internal adsorption, Opening emptying valve group the most again, sewage is expelled to outside；

B () repeats step (a) described process, until the adsorption capacity of filter bed (1) internal adsorption material is saturated, Closing emptying valve group, regenerated liquid, in filter bed (1) is sent in regeneration liquid pump (7), makes the suction in filter bed (1) Enclosure material is substantially immersed in regenerated liquid, Regeneration Treatment, then is back in regenerated liquid reserve tank (6), i.e. completes The process of one absorption regeneration.

Minimizing technology the most according to claim 5, it is characterised in that in step (a), treatment sewage Hydraulic detention time in filter bed (1) is 5-40min.

Minimizing technology the most according to claim 5, it is characterised in that regenerated liquid is sent in filter bed (1) Amount meets: the hypochlorite in regenerated liquid is 1-5:1 with the mol ratio of the ammonia nitrogen of adsorbing material absorption.

Minimizing technology the most according to claim 5, it is characterised in that the time of Regeneration Treatment is 5-60min.