阅读说明：本技术 一种协同吸附处理废水中氨氮与cod的系统及方法 (System and method for treating ammonia nitrogen and COD in wastewater through synergistic adsorption ) 是由 吴彤 岳喜龙 苗雪珮 黄河涛 谈洋 刘欣 赵阿波 沈悦 肖世健 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种协同吸附处理废水中氨氮与COD的系统,所述系统包括多个串联的滤料装置,滤料装置上端设有进水口,下端具有出水口,出水口的上部设有曝气装置,滤料装置内部填充有滤料,滤料为球状陶粒和粒状沸石,球状陶粒滤料填充在上层,粒状沸石填充在下层,球状陶粒和粒状沸石的质量比为1:1～1.5；总填充系数60-80％。本发明公开了利用上述系统进行废水处理的方法,包括以下步骤：在曝气装置的曝气量为3～10m～3/h条件下,废水从滤料装置的进水口进入,经过球状陶粒和粒状沸石过滤,吸附处理废水中的氨氮与COD,待废水达标后进行排放或回用。本发明相比生化或其他废水处理方法,具有占地面积小,处理效果显著,操作简单,成本低廉等优势。(The invention discloses a system for treating ammonia nitrogen and COD (chemical oxygen demand) in wastewater through synergistic adsorption, which comprises a plurality of filter material devices connected in series, wherein the upper ends of the filter material devices are provided with water inlets, the lower ends of the filter material devices are provided with water outlets, the upper parts of the water outlets are provided with aeration devices, filter materials are filled in the filter material devices, the filter materials are spherical ceramsite and granular zeolite, the spherical ceramsite filter material is filled in the upper layer, the granular zeolite is filled in the lower layer, and the mass ratio of the spherical ceramsite to the granular zeolite is 1: 1-1.5; the total filling factor is 60-80%. The invention discloses a method for treating wastewater by using the system, which comprises the following steps: the aeration rate of the aeration device is 3-10 m 3 Under the condition of/h, the wastewater enters from a water inlet of the filtering material device, is filtered by spherical ceramsite and granular zeolite, adsorbs ammonia nitrogen and COD in the wastewater, and is discharged after the wastewater reaches the standardAnd (4) discharging or recycling. Compared with biochemical or other wastewater treatment methods, the method has the advantages of small occupied area, obvious treatment effect, simple operation, low cost and the like.)

1. The system for treating ammonia nitrogen and COD in wastewater through synergistic adsorption is characterized by comprising a plurality of filter material devices connected in series, wherein a water inlet is formed in the upper end of each filter material device, a water outlet is formed in the lower end of each filter material device, an aeration device is arranged on the upper portion of the water outlet, a filter material is filled in each filter material device, the filter material is spherical ceramsite and granular zeolite, the spherical ceramsite filter material is filled in the upper layer, the granular zeolite is filled in the lower layer, and the mass ratio of the spherical ceramsite to the granular zeolite is 1: (1-1.5) and the total filling coefficient is 60-80%.

2. The system for the cooperative adsorption treatment of ammonia nitrogen and COD in wastewater according to claim 1, wherein the filtering material device is at least 2-stage.

3. The system for the cooperative adsorption treatment of ammonia nitrogen and COD in wastewater according to claim 1, wherein the particle size of the spherical ceramsite is 0.3-0.5 cm, and the particle size of the granular zeolite is 0.1-0.3 cm.

4. A method for treating waste water by using the system for treating ammonia nitrogen and COD in waste water through synergistic adsorption according to any one of claims 1-3, characterized in that the waste water enters from the water inlet of a filter material device, an aeration device introduces air into the filter material device, the waste water is sequentially filtered by spherical ceramsite and granular zeolite to adsorb ammonia nitrogen and COD in the waste water, and the waste water is discharged after reaching the standard.

5. The wastewater treatment method according to claim 4, wherein the aeration rate of the aeration device is 3 to 10m³/h。

6. The wastewater treatment method according to claim 4, wherein the contact reaction time of the wastewater in the filter material device is controlled to be 15-30 min.

7. The wastewater treatment method according to claim 4, wherein the pH of the wastewater at the water inlet is controlled to 6 to 8.

Technical Field

The invention relates to the field of wastewater treatment, in particular to a system and a method for cooperatively purifying ammonia nitrogen and COD in wastewater.

Background

The adsorption treatment method of waste water is a method of purifying waste water by adsorbing one or more contaminants (adsorbates) in the waste water using a porous solid (called adsorbent) to recover or remove some of the contaminants. Common adsorption materials comprise activated carbon adsorbents (activated carbon, carbon fibers and the like), humic acid adsorbents (natural weathered coal, lignite, humic acid resin and the like), mineral adsorbents (zeolite, bentonite, sepiolite, vermiculite, bauxite, calcite and the like), high molecular adsorbents (ion exchange resin, ion exchange fiber and the like), and industrial waste adsorbents (fly ash, scrap iron, steel slag and the like), and an adsorption method is mainly used for removing trace pollutants in water in wastewater treatment, and comprises decolorization, deodorization, heavy metal removal, organic matter removal and the like. In the treatment process, the adsorption method can be used as pretreatment of methods such as ion exchange, membrane separation and the like to remove organic matters, colloid, residual chlorine and the like; can also be used as an advanced treatment means after secondary treatment to meet the requirements of standard-lifting discharge or recycling. At present, an ideal comprehensive treatment effect cannot be achieved depending on the treatment capacity of the current single filter material. Even if the combined filter material is adopted, the effect of removing ammonia nitrogen and COD (organic pollutants) is not good.

Disclosure of Invention

The invention aims to provide a system and a method for cooperatively purifying ammonia nitrogen and COD (organic pollutants) in wastewater, so as to realize standard discharge or reuse of the wastewater.

In order to achieve the purpose, the invention provides the following technical scheme:

a system for cooperatively purifying and treating ammonia nitrogen and COD in wastewater comprises a plurality of filter material devices connected in series, wherein the upper ends of the filter material devices are provided with water inlets, the lower ends of the filter material devices are provided with water outlets, the upper parts of the water outlets are provided with aeration devices, filter materials are filled in the filter material devices and are spherical ceramsite and granular zeolite, the spherical ceramsite filter material is filled in the upper layer, the granular zeolite is filled in the lower layer, and the mass ratio of the spherical ceramsite to the granular zeolite is 1: 1-1.5; the total filling coefficient is 60-80%, the grain diameter of the spherical ceramsite is 0.3-0.5 cm, and the grain diameter of the granular zeolite is 0.1-0.3 cm.

According to the concentration of ammonia nitrogen and COD in the wastewater to be treated, the filter material device is at least 2 grades.

A method for treating wastewater by using the system comprises the following steps: wastewater enters from a water inlet of the filter material device, the aeration device introduces air into the filter material device, and the aeration amount is 3-10 m³And h, filtering the wastewater by spherical ceramsite and granular zeolite in sequence, adsorbing ammonia nitrogen and COD in the wastewater, controlling the contact reaction time of the wastewater and a filter material to be 15-30 min, and discharging or recycling the wastewater after the wastewater reaches the standard.

Further, the pH value of the wastewater at the water inlet is controlled to be 6-8.

The invention has the following beneficial effects:

first, the invention adopts the cascade filter material device to treat the wastewater, compared with biochemical or other methods, the device has small occupied area, obvious treatment effect, simple operation and low cost, and the filter material after saturated adsorption can be directly regenerated and treated on line. The regeneration treatment method comprises the following steps: and (3) closing the water inlet, emptying the wastewater in the filter material device, and then analyzing and regenerating by using 1.5-2.0 mol/L of salt solution.

Secondly, in the invention, ceramsite and zeolite are adopted to treat ammonia nitrogen and COD in the waste, so that the effect of deep purification is achieved, and the effect of upgrading the waste water is remarkable.

Thirdly, the ceramsite filter material and the zeolite filter material selected in the invention also have good removal effect on pollutants such as heavy metal, phosphorus, fluorine, chromaticity and the like in the wastewater.

Drawings

FIG. 1 is a schematic view of a wastewater treatment system according to the present invention.

Detailed Description

The invention will be further explained with reference to the schematic diagram, and the specific structure of the wastewater treatment system of the invention is shown in fig. 1, and comprises a filter material device (primary, secondary to N-level), and an aeration device. The filter material devices are sequentially connected in series, the upper end of each stage of filter material device is provided with a water inlet, the lower end of each stage of filter material device is provided with two water outlets, one water outlet is connected with the water inlet of the next stage of filter material device, and the other water outlet is used for discharging qualified wastewater; the upper part of the water outlet of each stage of filter material device is provided with an aeration device; each level of filter material device is filled with spherical ceramsite and granular zeolite in a layered mode, wherein the ceramsite is arranged on the upper layer, and the zeolite is arranged on the lower layer. The aeration in the invention is to fully contact the waste water with the filter material and improve the synergistic treatment effect of ammonia nitrogen and COD, and all devices with aeration function in the market can be used in the invention.

In the technical scheme of the invention, the selected ceramsite filter material is a novel water treatment filter material, the main chemical components of the ceramsite filter material are shown in table 1, the performance of the ceramsite filter material is shown in table 2, the ceramsite filter material is spherical particles, uniform in granularity, reddish brown in appearance, microporous on the surface, and criss-cross internal pore networks, and has a certain specific surface area, so that the ceramsite filter material has outstanding electrostatic adsorption capacity and surface adsorption capacity (represented by various van der Waals forces). In the wastewater treatment, the ceramsite filter material can perform electrolysis reaction on water and other series of micro-electrochemical reactions (catalysis, decomposition, adsorption, electron donation and the like), and simultaneously has extremely strong chemical adsorption capacity, is favorable for improving the dissolved oxygen content of the water body, further removes pollutants in the water body, and particularly has a strong purification treatment effect on COD. Under the condition of aeration and oxygenation, the filter material has a self-cleaning function, so that the continuous purification treatment effect of the filter material on pollutants such as COD (chemical oxygen demand) is ensured.

TABLE 1 main chemical composition of ceramsite filter material

TABLE 2 physicochemical properties of ceramsite filter materials

	Porosity of the material	Density of	Bulk density	Specific surface area	Pore diameter
						Index (I)	40％～50％	1.4～1.8g/cm3	0.9～1.0g/cm3	0.244m2/g	2.748nm

The selected zeolite filter material is light green granular natural zeolite, the main chemical components of which are shown in table 3, and the performances of which are shown in table 4. Zeolite is a porous aluminosilicate crystal made of Silica (SiO)₄) Tetrahedron and aluminum oxide (AlO)₄) The tetrahedral units being staggered by oxygen atoms at the vertices of the tetrahedronForming a space network structure. Has large specific surface area and charge performance, and a large number of holes are arranged in the crystal structure, and movable water molecules and cations are distributed in the holes. The structure features make zeolite possess selective adsorption, catalysis and ion exchange, and especially have strong adsorption to ammonium ion in waste water.

TABLE 3 main chemical composition of zeolite

TABLE 4 physicochemical properties of the zeolitic filter material

Example 1:

after the leachate of a certain hazardous waste landfill is pretreated, the ammonia nitrogen concentration of the wastewater is 67mg/L, the COD concentration is 475mg/L, and the discharge standard cannot be met. 50L of wastewater was taken for treatment, and the pH of the wastewater was adjusted to 6. 5kg of spherical ceramsite and 5kg of granular zeolite are respectively filled in the filtering material device, the total filling coefficient is 60 percent, and the contact residence time of the wastewater in each stage of filtering material device is controlled to be 20 min; controlling aeration quantity to be 5m³And/min. After the first-stage adsorption, the ammonia nitrogen of the effluent can be reduced to 24mg/L, and the COD can be reduced to 231 mg/L; through the secondary adsorption, the ammonia nitrogen of the effluent is reduced to 6mg/L, and the COD is reduced to 121 mg/L. After the secondary purification treatment, the removal rate of COD reaches 74.5 percent; the removal rate of ammonia nitrogen reaches 91 percent, and the method conforms to the indirect discharge standard of the discharge limit value of the wastewater pollutants of the hazardous waste landfill in the hazardous waste landfill pollution control standard GB 18598-2019.

Example 2:

after the cleaning wastewater of a certain electroplating enterprise is pretreated, the ammonia nitrogen concentration is 139mg/L, the COD concentration is 416mg/L, and the requirement of the discharge standard is not met. 50L of wastewater was taken for treatment, and the pH of the wastewater was adjusted to 7.

5kg of spherical ceramsite and 6kg of granular zeolite are respectively filled in the filtering material device, the total filling coefficient is 66 percent, and the wastewater is controlled to be filtered at each levelThe contact residence time in the device is 15min, and the aeration rate is 4m³And/min. After the first-stage adsorption, the ammonia nitrogen of the effluent is reduced to 73mg/L, and the COD is reduced to 202 mg/L; after the secondary adsorption, the ammonia nitrogen of the effluent is reduced to 16mg/L, and the COD is reduced to 97 mg/L; after three-stage adsorption, the ammonia nitrogen of the effluent is reduced to 4mg/L, and the COD is reduced to 29 mg/L. Through three-stage purification treatment, the ammonia nitrogen removal rate reaches 97.1 percent, and the COD removal rate reaches 93.0 percent, which meets the requirements of electroplating pollutant discharge standard GB 21900-2008.

Example 3:

after the wastewater of a certain chemical synthesis pharmaceutical enterprise is pretreated, the concentration of ammonia nitrogen in the wastewater is 261mg/L, the concentration of COD in the wastewater is 659mg/L, and the wastewater does not meet the discharge standard. 50L of wastewater is taken for treatment, and the pH value of the wastewater is adjusted to 6.

5.8kg of spherical ceramsite and 7.53kg of granular zeolite are respectively filled in the filtering material device, the total filling coefficient is 80 percent, the retention time of the wastewater in each stage of filtering material device is controlled to be 30min, and the aeration quantity is 10m³And/min. After the first-stage adsorption, the ammonia nitrogen of the effluent is reduced to 200mg/L, the COD is reduced to 506mg/L, after the second-stage adsorption, the ammonia nitrogen of the effluent is reduced to 135mg/L, the COD is reduced to 352mg/L, after the third-stage adsorption, the ammonia nitrogen of the effluent is reduced to 70mg/L, and the COD is reduced to 204 mg/L; after four-stage adsorption, the ammonia nitrogen in the effluent is reduced to 18mg/L, and the COD is reduced to 61 mg/L. Through four-stage purification treatment, the removal rate of ammonia nitrogen reaches 93.1%, the removal rate of COD reaches 90.7%, and the water pollutant emission concentration limit value of newly-built enterprises in chemical synthesis pharmaceutical industry water pollutant emission standard GB 21904-2008 is met.

Example 4:

after the wastewater of a certain urban sewage treatment plant is pretreated, the ammonia nitrogen concentration in the wastewater is 20mg/L, the COD concentration is 80mg/L, and the wastewater does not meet the I-grade discharge standard. 50L of wastewater is taken for treatment, and the pH value of the wastewater is adjusted to 8.

5kg of spherical ceramsite and 7.5kg of granular zeolite are respectively filled in the filtering material device, the total filling coefficient is 75 percent, the contact time of the wastewater in each stage of filtering material device is controlled to be 15min, and the aeration quantity is 3m³And/min. After the first-stage adsorption, the ammonia nitrogen in the effluent is reduced to 6mg/L, and the COD is reduced to 34 mg/L; the ammonia nitrogen removal rate reaches 70 percent, and the COD removal rate reaches 57.5 percent; after the secondary adsorption treatment, the ammonia nitrogen in the effluent is reduced to 2.0mg/L, and CO is removedD is reduced to 16mg/L, the removal rate of ammonia nitrogen reaches 90 percent, the removal rate of COD reaches 80 percent, and the limit value reaches the first-class standard of pollutant emission concentration of GB 18918-2002 pollutant emission standard of urban sewage treatment plant.

The static adsorption comparison test of the wastewater filter material is shown in the following table 5, and it can be seen that the synergistic treatment effect is obviously superior to the treatment effect of the single filter material.

TABLE 5 static adsorption comparative test

The spherical ceramsite filter material and the granular zeolite filter material are subjected to synergistic treatment, so that the advantage of COD removal of the ceramsite filter material is exerted, the advantage of ammonia nitrogen adsorption of the zeolite is exerted, and the spherical ceramsite filter material and the zeolite have strong promoting effects, so that the effect of synergistic purification treatment is achieved. When the wastewater flows through the ceramsite filter layer, the COD purification treatment is rapidly completed, and when the wastewater flows through the zeolite filter layer, the ammonia nitrogen purification treatment is rapidly completed, and meanwhile, the adverse effect of the COD on the zeolite is avoided.