CN102616893B - Wastewater Treatment System - Google Patents

Abstract

The invention provides a wastewater treatment system, which comprises a reaction tank body, an electrolysis device, an electrolysis air supply system, a catalytic material and a separation net, wherein the reaction tank body comprises a water inlet and a water outlet; the water inlet and the water outlet are formed at upper ends of two opposite side walls of the reaction tank body respectively; the electrolysis device comprises a positive plate, a negative plate and a power supply; the positive plate and the negative plate are arranged in the reaction tank body; the power supply is electrically connected to the positive plate and the negative plate; the electrolysis air supply system comprises an aeration pipe and an air pump; the aeration pipe is arranged at the bottom of the reaction tank body; the catalytic material is filled in the reaction tank body and is transition metal loaded carbon base or silicon dioxide base particles; and the separation net is arranged at the water outlet. The wastewater treatment system has the advantages of high efficiency, cleanness in a treatment process and no or less sludge production.

Description

Wastewater Treatment System

technical field

The invention belongs to the field of waste water purification, in particular to a waste water advanced treatment system.

Background technique

Saving resources and protecting the environment is a basic national policy of our country. During the "Twelfth Five-Year Plan" period, the national urban sewage treatment recycling rate should reach the goal of 10%, and more than 7 billion m ³ of fresh water resources can be saved every year, which can effectively alleviate the shortage of water resources in our country, especially in arid areas. Therefore, wastewater reuse has important practical significance.

At present, the total sewage discharge in the country is more than 70 billion tons, and the national recycled water consumption is only 1.66 billion m ³ , accounting for only 2% of the national waste/sewage discharge, which is far from the goal of 10%. Therefore, to achieve this goal not only depends on macro-control factors such as the guidance of national policies and the adjustment of market water prices, but also requires the practical application of efficient, clean, low-investment, and low-cost reliable wastewater advanced treatment and reuse technologies. Therefore, reclaimed water The future investment space is very broad.

Reclaimed water refers to the discharge water that reaches the discharge standard after pretreatment and biochemical treatment of urban domestic sewage and production wastewater. After further treatment, it reaches the water quality standard for a certain purpose, such as industrial cooling water, urban garden landscape irrigation, etc. and reuse potential water resources for the production process. However, during the wastewater treatment process, the parent compounds in the raw sewage/wastewater have undergone significant changes, not only in the composition and properties of the compounds, but also in their molecular shape and size. Therefore, if the biochemical method is continued to be used as the main purification process in the advanced treatment, the removal efficiency of key water quality indicators such as COD (chemical oxygen demand) is often very low. At present, the common treatment technologies for reclaimed water include membrane technology, MBR method, Fonton reagent oxidation method, photocatalytic oxidation method, etc., or combined processes with other physical and chemical methods, such as flocculation and filtration. However, these combined processes not only have specific problems such as long treatment process, large floor space, and high operating costs; at the same time, a large amount of sludge will be generated during the treatment process. These sludges have high moisture content and high treatment costs, especially for sludge containing Class I pollutants. The direct discharge of sludge or improper sludge management makes the sewage treatment plant that treats sewage become a new source of environmental pollution.

Therefore, it is urgent to develop an advanced wastewater treatment technology and device with high efficiency, clean treatment process, and low or no sludge generation.

Contents of the invention

In view of this, the present invention provides a wastewater treatment system, which has high efficiency, low energy consumption, low comprehensive treatment cost, clean treatment process, and no or less sludge generation.

To achieve the above object, the present invention provides the following technical solutions:

A wastewater treatment system, comprising a reaction tank and an electrolysis device, the reaction tank includes a water inlet and a water outlet, the water inlet and the water outlet are respectively arranged at the upper ends of the two opposite side walls of the reaction tank, The electrolysis device includes a positive plate, a negative plate and a power supply, the positive plate and the negative plate are arranged in the reaction tank, the power supply is electrically connected to the positive plate and the negative plate, especially, the waste water treatment The system also includes an electrolysis gas supply system, catalytic materials and a separation net. The electrolysis gas supply system includes an aeration pipe and an air pump. The aeration pipe is arranged at the bottom of the reaction tank, and the catalytic material is filled in the In the reaction tank, the catalytic material is carbon-based or silicon dioxide-based particles loaded with transition metals, and the separation net is arranged at the water outlet.

Preferably, in the above wastewater treatment system, the catalytic material is also doped with titanium dioxide.

Preferably, in the above wastewater treatment system, a plurality of positive and negative plates are arranged at a certain interval, and the positive and negative plates are arranged in parallel and adjacent to each other.

Preferably, in the above wastewater treatment system, a plurality of said aeration pipes are arranged at certain intervals.

Preferably, in the above wastewater treatment system, the aeration pipe is parallel to the positive plate.

Preferably, in the above wastewater treatment system, the aeration pipe is arranged between the adjacent positive and negative plates.

Preferably, in the above wastewater treatment system, the reaction tank body is formed by processing PP board or PVC board.

Compared with the prior art, in the wastewater treatment system of the present invention, carbon-based or SiO _2- based loaded transition metal doped TiO ₂ and the like are prepared, which can selectively enrich pollutants from low-concentration wastewater, and have a high degree of Environmental catalytic material with electrocatalytic activation performance; the material is filled into the reaction tank according to certain filling requirements, and combined with the electrolysis technology of wastewater; at the same time, the electrolysis gas supply system is used to provide oxygen for the negative plate in the reaction tank (DO) generates active oxygen species when activated by electricity supply, and also provides the power for the directional cycle of the catalytic material. Due to the addition of catalytic materials in the reaction tank, the treatment effect and efficiency of low-concentration refractory wastewater have been greatly improved; compared with the current three-dimensional electrolysis technology for wastewater, this technology uses a fluidized bed instead of With a fixed bed, the risk of deactivation and scaling of the catalytic material is greatly reduced, and the catalytic efficiency of the catalytic material is greatly improved with less filling. Due to the strong catalytic activity of the catalytic material for DO and the excellent mechanical stability of the catalytic material, the pollutants are almost completely degraded during the treatment process and the catalytic material itself is not easy to pulverize, so the biggest difference between this technology and traditional electrolysis or three-dimensional electrolysis technology Its energy consumption is low, the comprehensive treatment cost is low, and the treatment process is clean, and no or less sludge is generated.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows the top view of the wastewater treatment system provided in the specific embodiment of the present invention;

Fig. 2 is a front view of the wastewater treatment system provided in the specific embodiment of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Apparently, the described embodiments are only some embodiments of the present invention, rather than Full examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

An embodiment of the present invention provides a waste water treatment system, including a reaction tank and an electrolysis device. The reaction tank includes a water inlet and a water outlet, and the water inlet and water outlet are respectively arranged on two opposite sides of the reaction tank. The upper end of each side wall, the electrolysis device includes a positive plate, a negative plate and a power supply, the positive plate and the negative plate are arranged in the reaction tank, and the power supply is electrically connected to the positive plate and the negative plate, so that The wastewater treatment system also includes an electrolysis air supply system, catalytic materials and separation nets, the electrolysis air supply system includes an aeration pipe and an air pump, the aeration pipe is arranged at the bottom of the reaction tank, and the catalytic material Loaded in the reaction tank, the catalytic material is carbon-based or silicon dioxide-based particles loaded with transition metals, and the separation net is arranged at the water outlet.

Referring to FIGS. 1 and 2 , the wastewater treatment system 10 includes a reaction tank 11 , an electrolysis device 12 , an electrolysis gas supply system 13 , a catalytic material 14 and a separation net 15 .

The reaction tank body 11 is preferably arranged in a rectangular shape, which is processed by PP board or PVC board. The upper end of the left side wall of the reaction tank body 11 is provided with a water inlet 111, and the upper end of the right side wall of the reaction tank body 11 is provided with a water outlet 112, and the water outlet 112 is preferably lower than the height of the water inlet 111. The lower end of the reaction tank body 11 can also be provided with an emptying port 113, and the emptying port 113 can discharge the waste water in the reaction tank body 11 when the waste water treatment system 10 is not in use. Valves (not shown) may be provided at the water inlet 111, the water outlet 112 and the emptying port 113, respectively. In other embodiments, the shape of the reaction tank body 11 can be set to other shapes, such as a cylinder.

The electrolysis device 12 includes a positive plate 121 , a negative plate 122 and a power source 123 . The positive electrode plate 121 and the negative electrode plate 122 are installed in the reaction tank 11, and both are graphite electrode plates. A plurality of graphite electrode plates are arranged at certain intervals along the direction from left to right (the direction from the water inlet 111 to the water outlet 112) in the reaction tank body 11, and are arranged according to the interaction method of positive and negative poles and the configuration of the power supply 123 configured. The positive and negative output terminals are electrically connected, and the power supply 123 is preferably a DC power supply. The positive plate 121 and the negative plate 122 are perpendicular to the bottom plate of the reaction tank 11 . In practical applications, due to the limitation of the volume of the reaction tank 11 , the positive plate 121 and the negative plate 122 can only be arranged in one set, that is, there is only one positive plate 121 and one negative plate 122 .

The electrolysis air supply system 13 includes an aeration pipe 131 and an air pump 132 . There are multiple aeration tubes 131, which are distributed in parallel at the bottom of the reaction tank body 11. The aeration tubes 131 are preferably arranged parallel to the positive plate 121 or the negative plate 122. Further, the aeration tubes 131 are preferably arranged on adjacent between the positive plate 121 and the negative plate 122. The air pump 132 is connected to the aeration pipe 131, which can provide oxygen for the negative plate 122 in the reaction tank 11 to generate active oxygen species during power supply and activation, and also provide the catalytic material 14 with the power of directional circulation, thereby making the catalytic material 14 inactive. The risk of activity and fouling is greatly reduced, and the catalytic efficiency of the catalytic material 14 is greatly improved. The electrolysis gas supply system 13 may also include an air flow meter or an air valve. In other embodiments, only one aeration tube 131 may be provided.

The catalytic material 14 is carbon-based or silicon dioxide-based particles loaded with transition metals, and the catalytic material 14 may also be doped with titanium dioxide. The catalytic material 14 can not only selectively enrich pollutants from low-concentration wastewater, but also has high electrocatalytic activation performance. The catalytic material 14 is added in the reaction tank body 11, so that the treatment effect and treatment efficiency of low-concentration refractory wastewater are greatly improved.

The filling amount of the catalytic material 14 is preferably 30%-60% of the volume of the reaction tank body 11 .

The separation net 15 is arranged at the water outlet 122 to intercept the catalytic material 14 and prevent the catalytic material 14 from being taken away by water and lost.

In the process of using the above-mentioned wastewater treatment system 10 to treat wastewater, the pump is driven to transport the wastewater to the water inlet 111. After being measured by the flow meter, it enters the reaction tank 11 for electrocatalytic oxidation treatment. The average reaction time (i.e. The hydraulic retention time) is 20 minutes. The effluent quality of the treated wastewater can meet the requirements of the design standards. The discharge standard is implemented in accordance with the current urban sewage treatment plant discharge standard (GB18918-2002) Class I (A standard) (that is, COD is lower than 50mg/L).

According to the actual needs, the user can adjust the reaction time or adjust the electrolysis parameters and the loading amount of the catalytic material 14 when it is used for different wastewater or to meet different application requirements. After parameter optimization, it can meet the treatment requirements of different types of industrial wastewater.

The effects of the wastewater treatment system 10 provided by the present invention will be described in detail below in conjunction with examples.

Example 1

Analysis of the treatment effect of the effluent after biochemical treatment of oil refinery wastewater.

Refining wastewater is refractory wastewater. The refining process consumes a lot of water, and the water quality of the discharged wastewater is complex and highly volatile. Using the above-mentioned wastewater treatment system 10 with a treatment capacity of 60 L/h, a 30-day on-site continuous operation test was carried out on the biochemical discharge water of an oil refinery wastewater. The results show that: when the influent water quality index COD fluctuates between 80.0-360mg/L, the average value is 220mg/L; when the ammonia nitrogen concentration is around 40.0mg/L, the control reaction time is 20min, and the COD of the system effluent after the reaction is lower than 50mg/L, the average removal rate can reach 80.1%; the concentration of ammonia nitrogen in the effluent is lower than 4mg/L, and the removal rate of ammonia nitrogen reaches more than 90%; the average sludge production of the system at the end of electrolysis is lower than 50mg per liter of wastewater. Moreover, the effluent quality is good and the change is stable, which shows that the system has good impact resistance to organic matter.

Example 2

Analysis of the treatment effect of printing and dyeing wastewater after biochemical treatment.

The printing and dyeing industry consumes a lot of water, the water quality is complicated, and the concentration of pollutants fluctuates greatly. Using the above-mentioned wastewater treatment system 10 with a treatment capacity of 60 L/h, a 3-week on-site continuous operation test was carried out on the discharged water after biochemical treatment of printing and dyeing wastewater. The main water quality indicators of the experimental water are: the COD fluctuation of the influent water quality index is between 80-120mg/L, and the average value is 100mg/L; the chroma is 40-80, and the average value is 60. The reaction time was controlled at 20 min during the experiment. The effluent results show that the average COD removal rate of the device can still reach 60%, the effluent COD is lower than 50mg/L, and the chroma removal rate is close to 100%; the average sludge production of the system at the end of electrolysis is lower than 60mg per liter of wastewater . The water quality of the effluent is stable and the effect is good, which can meet the water quality standard requirements of the reused water.

Example 3

Analysis of the advanced treatment effect of effluent after biochemical treatment of domestic wastewater.

The production of domestic wastewater has now exceeded the discharge of industrial wastewater, becoming the main source of wastewater in my country's wastewater treatment industry, and it is also the most important potential water source in the field of reuse in the future. According to the current domestic sewage discharge standards in our country, the COD of the treated discharge water is required to be lower than the standard of 50 or 60mg/L. In the Taihu Lake Basin in Jiangsu Province, COD is required to be lower than 50, and ammonia nitrogen is lower than 5 or 8mg/L. But this standard is for some old sewage treatment plants, the COD requirement is lower than 80 or 120mg/L in the process design, and there is no standard requirement for ammonia nitrogen. Therefore, this technology is suitable for the technical transformation of old sewage treatment plants and the future wastewater reuse basin. Utilize the above-mentioned waste water treatment system 10 that processing capacity is 60L/h, to an old sewage treatment plant 30 days field test, test water quality is: the influent water quality index COD fluctuation changes between 60-150mg/L, average value 105mg/L When L; ammonia nitrogen is 20-60mg/L, and the average value is 40mg/L. The reaction time was controlled at 20 min during the experiment. The effluent results show that the device can still achieve an average COD removal rate of 70%, and the ammonia nitrogen removal rate is close to 100%. At the end of electrolysis, the average sludge production of the system is lower than 30 mg per liter of wastewater. The effluent water quality is good and the change is stable, and the effect is good, which can meet the water quality standard requirements of reuse water.

The above results show that the wastewater treatment system 10 of the present invention can be widely used in different wastewater treatments, and has good treatment effect, low sludge production, clean process and low treatment cost, and has great market prospects.

As mentioned above, in the wastewater treatment system of the present invention, carbon-based or _SiO2- based loaded transition metals doped with _TiO2 , etc. are prepared to selectively enrich pollutants from low-concentration wastewater, and have a high degree of electrocatalysis Environmental catalytic material with activation performance; the material is filled into the reaction tank according to a certain filling amount, and combined with the electrolysis technology of wastewater; at the same time, the electrolysis gas supply system is used to provide oxygen for the negative plate in the reaction tank (DO ) to generate active oxygen species when activated by power supply, and also provide the power of directional circulation for the catalytic material. Due to the addition of catalytic materials in the reaction tank, the treatment effect and efficiency of low-concentration refractory wastewater have been greatly improved; compared with the current three-dimensional electrolysis technology for wastewater, this technology uses a fluidized bed instead of With a fixed bed, the risk of deactivation and fouling of the catalytic material is greatly reduced, and the catalytic efficiency of the catalytic material is greatly improved. Due to the strong catalytic activity of the catalytic material for DO and the excellent mechanical stability of the catalytic material, the pollutants are almost completely degraded during the treatment process and the catalytic material itself is not easy to pulverize, so the biggest difference between this technology and traditional electrolysis or three-dimensional electrolysis technology It has low energy consumption, low comprehensive treatment cost, clean treatment process, and no or less sludge generation.

Moreover, the field test results of a variety of production wastewater show that the technical system has high equipment volume efficiency, good treatment effect, low or There are many technical advantages such as no sludge generation, stable effluent quality, low operating cost, low energy consumption, high degree of automation, simple operation, and good compatibility with the original water treatment system.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (2)

1. A waste water treatment system, comprising a reaction tank body and an electrolysis device, the reaction tank body comprising a water inlet and a water outlet, the water inlet and the water outlet being respectively arranged on two opposite side walls of the reaction tank body At the upper end, the electrolysis device includes a positive plate, a negative plate and a power supply, the positive plate and the negative plate are arranged in the reaction tank, and the power supply is electrically connected to the positive plate and the negative plate, and it is characterized in that: The wastewater treatment system also includes an electrolysis air supply system, catalytic materials and a separation net, the electrolysis air supply system includes an aeration pipe and an air pump, the aeration pipe is arranged at the bottom of the reaction tank, and the aeration There are a plurality of tubes, which are distributed in parallel at the bottom of the reaction tank, and the aeration tube is arranged parallel to the positive plate or the negative plate, and the aeration tube is set between the adjacent positive plate and the negative plate, and the catalytic material Loaded in the reaction tank, the catalytic material is carbon-based or silicon dioxide-based particles loaded with transition metals, the catalytic material is doped with titanium dioxide, and the separation net is arranged at the water outlet. 2. The wastewater treatment system according to claim 1, characterized in that: the reaction tank body is formed by processing PP board or PVC board.

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