CN214880473U - Clean water tank of waterworks with low generation of disinfection by-products - Google Patents

Abstract

The utility model relates to a clean water basin of a water works with low generation of disinfection by-products, which comprises a clean water basin body and a plurality of vertically staggered flow guide baffles arranged along the water inlet flow direction, and the flow guide baffles are also provided with UV-LED light sources. Compared with the prior art, the utility model discloses can cut down the aquatic disinfection accessory substance production volume of dispatching from the factory by a wide margin when guaranteeing the high-efficient deactivation of microorganism, furthest reduces aquatic sodium hypochlorite consumption simultaneously.

Description

Clean water tank of waterworks with low generation of disinfection by-products

Technical Field

The utility model belongs to the technical field of water treatment, a water works clean water basin that low disinfection accessory substance generated is related to.

Background

Ultraviolet disinfection is increasingly applied to disinfection treatment of waterworks because of its good sterilization and inactivation performance, especially for chlorine-resistant microorganisms (such as giardia and cryptosporidium) and without the production of highly toxic disinfection byproducts. The current commonly used ultraviolet light source is a low-voltage and medium-voltage ultraviolet mercury lamp which is limited by the shape, installation and the like of a lamp tube, and at present, an ultraviolet disinfection reactor is usually arranged in a water plant before chlorine (amine) disinfection, namely, the ultraviolet disinfection reactor is sequentially disinfected by the chlorine (amine). In recent years, with the rapid development of semiconductor Light Emitting Diode (LED) industry, ultraviolet LED (UV-LED) is beginning to be rapidly popularized and applied in the field of disinfection as a novel ultraviolet light source. Compared with traditional low-and medium-pressure mercury lamps, UV-LEDs have the following significant advantages: 1) the UV-LED can adjust the component proportion of the semiconductor material during production to prepare any specific single-wavelength lamp bead, and the wavelength of the traditional ultraviolet mercury lamp is fixed and not adjustable; 2) the UV-LED can realize different continuous/pulse light emitting modes, and can be used on the spot without preheating; 3) the UV-LED does not contain heavy metal pollution elements such as mercury and the like, and is safe and environment-friendly; 4) the volume of the UV-LED lamp bead is very small, usually less than 1cm²And the application and installation are more various. In view of the above advantages of the UV-LED, the UV-LED is expected to be applied to water plants more flexibly.

The clean water tank of the water works is an important unit of a water supply process and has the important functions of regulating water quantity and contact reaction of disinfectants. As a main unit of disinfectant contact reaction, the hydraulic retention time of a clean water basin of a water plant is generally more than half an hour, so the volume of the clean water basin is often large. Considering that the clean water tank contains chlorine disinfectant with higher concentration, if ultraviolet radiation can be applied to the clean water tank, free chlorine in the clean water tank can be excited to generate active substances such as hydroxyl radicals with strong oxidizing property and the like, and ultraviolet/chlorine advanced oxidation reaction is formed in situ, so that the disinfection effect can be enhanced, and the generation of part of highly toxic disinfection byproducts can be reduced. However, the traditional ultraviolet mercury lamp is a glass lamp tube, the volume is large, the installation is difficult, and the safety is difficult to guarantee because the traditional ultraviolet mercury lamp contains heavy metal mercury with high toxicity.

For example, chinese patent CN109293098A discloses a method for controlling generation of disinfection byproducts in drinking water by using UV-LED light source, which specifically comprises: (1) adding sulfuric acid or sodium hydroxide into natural drinking water, adjusting the pH of the drinking water to be alkalescent, then adding free chlorine, and uniformly stirring to obtain a mixed solution; (2) and (3) placing the mixed solution under UV-LED light with the wavelength of 270-280nm for irradiation until the treatment is finished. Although the patent discloses the use of 270-280nm UV-LEDs in combination with free chlorine to control disinfection byproducts, it does not specifically consider practical application improvements in engineering, etc., making it difficult to use directly in real engineering such as clean water tanks of waterworks.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a water works clean water basin that low disinfection accessory substance generated further strengthens the disinfection efficiency of disinfectant in clean water basin to furthest cuts the disinfection accessory substance concentration of reducing control play aquatic, promotes the water quality safety of dispatching from the factory.

The purpose of the utility model can be realized through the following technical scheme:

one of the technical schemes of the utility model provides a clean water basin of water works that low disinfection accessory substance generated, a serial communication port, including the clear water cell body to and follow a plurality of crisscross water conservancy diversion baffles about it intake flow direction arranges, still be equipped with the UV-LED light source on the water conservancy diversion baffle.

Further, the wavelength of the UV-LED light source is 270-280 nm.

Further, the wavelength of the UV-LED light source is 275 nm.

Further, the guide baffle is provided with at least 8 blocks.

Furthermore, the UV-LED light sources are arranged on the other diversion baffles except the first diversion baffle and the second diversion baffle along the flowing direction of the inlet water of the clean water tank body.

Further, the UV-LED light source is arranged on one side, facing the water flow, of the flow guide baffle.

Furthermore, the guide baffle is provided with 8 blocks.

Further, the flow velocity of the area where the UV-LED light source is located is 0.05-0.1 m/s.

Furthermore, a water-proof layer is additionally arranged on the outer surface of the UV-LED light source. Furthermore, the water-resisting layer is a quartz layer.

The second technical scheme of the utility model provides a method for improving the disinfection treatment effect of the clean water basin of running water, and the UV-LED light source with specific wavelength is arranged in the clean water basin of running water added with chlorine disinfectant, and the operation is completed.

Further, the wavelength of the UV-LED light source is 270-280nm, and the preferable wavelength has better inactivation efficiency of the total colony number and lower consumption of the chlorine disinfectant.

Further, the wavelength of the UV-LED light source is 275 nm.

Furthermore, a plurality of guide baffles which are staggered up and down are arranged in the tap water clean water tank along the water inlet flowing direction.

Furthermore, the guide baffle is provided with at least 8 blocks.

Further, the UV-LED light source is arranged on the flow guide baffle. Preferably, the UV-LED light source is arranged on the side of the deflector facing the water flow.

Furthermore, the UV-LED light source is arranged on the flow guide baffle plate in the area with the flow velocity of 0.05-0.1m/s, so that the UV-LED/chlorine interaction and the generation amount of disinfection byproducts in the effluent are reduced under the hydraulic condition.

Furthermore, a quartz water-proof layer for separating the UV-LED light source from water is additionally arranged on the outer surface of the UV-LED light source.

Furthermore, the hydraulic retention time of the tap water clean water tank is more than 1 h.

The utility model discloses use the UV-LED of specific wavelength as the light source, lay in water works clean water basin inner wall, can reduce the aquatic disinfection accessory substance production volume of dispatching from the factory by a wide margin when guaranteeing the high-efficient deactivation of microorganism, furthest reduces aquatic sodium hypochlorite consumption simultaneously, and is simple feasible, has fine engineering using value.

Compared with the prior art, the utility model has the advantages of it is following:

1) the Ultraviolet (UV) -Light Emitting Diode (LED) with extremely small appearance is directly installed on the inner wall of the clean water tank without additionally increasing large equipment or water treatment structures, the inner space of the clean water tank is fully utilized, the modification engineering quantity is small, the cost is low, and the realization is easy.

2) The high-concentration chlorine disinfectant in the clean water tank is fully utilized to form advanced oxidation reaction in situ, the generation of high-toxicity disinfection byproducts is reduced, and meanwhile, the high-concentration chlorine disinfectant can play a role in removing other refractory micropollutants in water in an enhanced manner.

Drawings

Fig. 1 is a schematic structural view of a clean water basin of tap water incorporating ultraviolet LEDs.

Fig. 2 is a schematic view of the hydraulic state in the clean water tank.

FIG. 3 is a comparison of the inactivation effect of UV light of different wavelengths on the total number of colonies in the filtered water.

FIG. 4 is a comparison of the consumption of chlorine disinfectant in clean water tanks by different wavelength UV-LEDs.

FIG. 5 is a comparison of the generation of disinfection byproducts at different hydraulic flow rates.

Fig. 6 is a hydraulic state diagram of a clean water tank with different number of guide baffles.

FIG. 7 is a comparison of the generation of disinfection by-products at different hydraulic retention times.

The notation in the figure is:

1 is a clear water tank body, 2 is a flow guide baffle, 3 is a UV-LED light source, 4 is a water-resisting layer, 5 is a water inlet, and 6 is a water outlet.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

Example 1:

fig. 1 shows a schematic view of a treatment apparatus formed by UV-LEDs after being installed in a clean water tank 1, which includes the clean water tank 1, a plurality of vertically staggered flow guide baffles 2 (preferably set to more than 4) arranged along the flow direction of the inlet water of the clean water tank 1, and a wave-shaped flow channel bent in an S-shape formed in the clean water tank 1, then a UV-LED light source 3 is arranged on the flow guide baffles 2, preferably on the side facing the flow of the flow guide baffles 2, and simultaneously, in order to improve the treatment effect and reduce the generation amount of disinfection byproducts in the outlet water, the UV-LED light source 3 is arranged on the flow guide baffles 2 located in the flow velocity region of 0.05-0.1m/S, a water inlet 5 of the clean water tank 1 is arranged at the lower portion, and a water outlet 6 is arranged at the upper portion. The total hydraulic retention time of the clear water tank body 1 is more than 1 hour.

The flow velocity simulation is carried out on the hydraulic state in the clear water tank body 1 by adopting the CFD technology, the clear water tank body 1 is internally designed as shown in figure 2, the water flow states in the first gallery and the second gallery along the water inlet direction are complex, and an enough stable flow velocity area is lacked, so that the UV-LED light source is arranged in the third gallery with stable water flow and the subsequent gallery. The number of the internal diversion baffle plates 2 is set to be more than 8, so that a stable gallery with the subsequent water flow speed of 0.05-0.1m/s can be formed.

The clear water tank body 1 shown in the case of fig. 1 and 2 is 76m long, 35.1m wide and 4m deep, 8 diversion baffles 2 are arranged in the tank, the tank body is divided into 9 galleries, the first water inlet gallery is 12m wide, the rest galleries are 8m wide, the thickness of the diversion baffles 2 is very small relative to the length of the tank body, and the diversion baffles are ignored here. The pipe diameter of the water inlet and outlet pipe is 1000mm, and the flow velocity of the water inlet 5 is 1.2 m/s. The total hydraulic retention time of the clear water tank body 1 is 3.15 hours. The wavelength of the UV-LED is 275nm, the UV-LED is arranged on the wall of the flow guide baffle 2 on the right side of the 3 rd to 8 th galleries, and the hydraulic flow velocity of the area is 0.05-0.1 m/s. And a water-resisting layer 4 made of quartz is arranged on the outer side of the UV-LED lamp bead (namely the UV-LED light source 3) to ensure that the circuit is not immersed in water. The quantity of the lamp beads can be reasonably configured according to actual engineering requirements.

Example 2:

the treatment device of the embodiment 1 is adopted, the effluent of the sand filter of a water plant is taken as a research object, and the basic water quality parameters are as follows: pH 7.6, turbidity 0.389, soluble organic carbon (DOC) 1.8mg/L, Total Nitrogen (TN) 1.3mg/L, UV₂₅₄＝0.03cm^-1Total number of colonies 3.98X 10³CFU/mL. Irradiating with ultraviolet lamps of different wavelengths of 254nm (low wavelength)Mercury lamp), 265nm (UV-LED) and 275nm (UV-LED), the ultraviolet dose is controlled to be 3mJ/cm²。

As can be seen from the results of FIG. 3, the inactivation effect of 265nm and 275nm UV-LED lamps on total bacterial colonies in filtered water is 1.4Log, and the inactivation effect of 254nm low-pressure mercury lamp is 1.1Log, i.e. the bactericidal effect of 265nm and 275nm UV-LED novel light sources is superior to that of the traditional 254nm low-pressure ultraviolet mercury lamp, which proves that the light source selected by the utility model has rationality.

Example 3:

the basic water quality parameters of the treatment device of example 1 and the effluent of the sand filter of a water plant are the same as those of example 2. Adding 1mg/L (in Cl) into the water sample₂Sodium hypochlorite disinfectant), controlling the hydraulic flow rate to be 0.06m/s (equivalent G value is 2.1 s)^-1) Ultraviolet irradiation is carried out by adopting 265nm and 275nm UV-LEDs with different wavelengths, and the ultraviolet irradiation intensity is controlled to be 135 mu W/cm²The residual chlorine concentrations were sampled and analyzed at the reaction times of 0, 15, 30, 60 and 120min to calculate the chlorine consumption, and the results are shown in FIG. 4.

From example 2, it can be seen that 265nm UV-LED and 275nm UV-LED have similar inactivation effects on total colony number in filtered water, and are both 1.4Log, but from the chlorine consumption shown in FIG. 4, the chlorine consumption of 275nm UV-LED is smaller, and the advantage is more obvious when the retention time is more than 1 hour.

The utility model discloses in be arranged in the clean water basin with UV-LED, on the one hand be in order to promote the disinfection effect of disinfecting, and on the other hand is the high toxicity disinfection accessory substance of part of cutting down, nevertheless guarantees as far as simultaneously to throw the sodium hypochlorite disinfectant that throws and not consumed by too much photodissociation. Therefore, the utility model discloses propose select UV-LED of wavelength 270-.

Example 4:

the basic water quality parameters of the treatment device of example 1 and the effluent of the sand filter of a water plant are the same as those of example 2. Adding 1mg/L (in Cl) into the water sample₂Sodium hypochlorite disinfectant), controlling hydraulic flow rate at 0, 0.06 and 0.40m/s (equivalent G values of 0, 2.1 and 16.4s, respectively)^-1) Ultraviolet irradiation is carried out by adopting a 275nm UV-LED, and the ultraviolet irradiation intensity is controlled to be 135 mu W/cm²Controlling the reaction time to be 30min, and measuring the concentration of conventional Trihalomethanes (THMs) and emerging highly toxic nitrogen-containing disinfection byproducts (N-DBPs) in the water after the reaction, wherein the result is shown in figure 5.

As can be seen in fig. 5, a total of four THMs were detected, including Trichloromethane (TCM), dichloromonobromomethane (BDCM), monochlorodibromomethane (DBCM) and Tribromomethane (TBM); a total of four N-DBPs were detected, including Trichloronitromethane (TCNM), Dichloroacetonitrile (DCAN), Bromochloroacetonitrile (BCAN), and Dibromoacetonitrile (DBAN). From the total disinfection by-product, when the flow rate is higher than 0.06m/s, the application of 275nm wavelength UV-LED illumination (i.e. UV-LED/chlorine combination) in the clear water tank containing chlorine disinfectant is lower than the total disinfection by-product in the chlorine-disinfected effluent alone, and the faster the flow rate the lower the concentration. However, considering the design standard of the clean water tank, the flow velocity is too large, the tank body is too large on the basis of ensuring the retention time, the tank is not economical and practical enough, and a large high flow velocity area is difficult to appear in the actual clean water tank.

Comprehensively, the utility model discloses propose to lay 270 mang 280nm UV-LED in 0.05-0.1m/s velocity of flow region, can obtain good disinfection accessory substance reduction effect.

In order to guarantee the disinfection contact time, the clean water tank with the disinfection function is usually provided with the flow guide baffles inside so as to form a plurality of galleries, but the design of the number of the flow guide baffles influences the combined effect of the UV-LED disinfection device and the UV-LED disinfection device. Fig. 6 shows three designs of clean water pools with the same size data and different number of baffles, wherein fig. 6(a) shows the designs used in examples 1-3, the number of baffles is 8, fig. 6(b) shows the number of baffles is 6, and fig. 6(c) shows the number of baffles is 18. Comparing and knowing that in the three schemes, only the large flow velocity in the areas of 0.05-0.1m/s appears in fig. 6(a) and (c) and is suitable for arrangement of the UV-LED, while in the fig. 6(b), because the number of the flow guide baffles is not enough, the flow velocity in the gallery is generally lower than 0.02m/s, according to the result in fig. 5, the risk of generating disinfection byproducts is higher when the UV-LED is arranged in the area with the flow velocity lower than 0.02m/s, and therefore, no less than 8 flow guide baffles are arranged in the clear water tank.

Example 5:

the basic water quality parameters of the treatment device of example 1 and the effluent of the sand filter of a water plant are the same as those of example 2. Adding 1mg/L (in Cl) into the water sample₂Sodium hypochlorite disinfectant), controlling the hydraulic flow rate to be 0.06m/s (equivalent G value is 2.1 s)^-1) Ultraviolet irradiation is carried out by adopting a 275nm UV-LED, and the ultraviolet irradiation intensity is controlled to be 135 mu W/cm²The reaction time was controlled at 0.5, 1 and 2h, and the concentration of conventional Trihalomethanes (THMs) and emerging highly toxic nitrogen-containing disinfection by-products (N-DBPs) in the reacted water was determined, the results of which are shown in FIG. 7.

From the results of FIG. 7, it can be seen that by prolonging the hydraulic retention time, i.e., increasing the hydraulic retention time, the UV-LED/chlorine combination application can further reduce the generation of THMs and N-DBPs, especially the generation of N-DBPs with stronger toxicity approaches 0 μ g/L when the retention time is prolonged to more than 1 h; while for chlorine alone disinfection, there was a slight decrease in the total amount of THMs, but a significant increase in the more toxic N-DBPs.

Therefore, the utility model discloses when the UV-LED of 270-.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims (10)

1. A clean water tank with low generation of disinfection byproducts for a water works is characterized by comprising a clean water tank body and a plurality of guide baffles which are staggered up and down and are arranged along the flowing direction of inlet water, wherein UV-LED light sources are also arranged on the guide baffles.

2. The clean water basin for waterworks with low generation of disinfection byproducts as claimed in claim 1, wherein the wavelength of said UV-LED light source is 270-280 nm.

3. The clean water plant basin with low generation of disinfection by-products of claim 1, wherein said UV-LED light source has a wavelength of 275 nm.

4. The clean water plant basin with low generation of disinfection byproducts as claimed in claim 1, wherein said deflector is provided with at least 8 pieces.

5. The clean water basin of water works with low generation of disinfection byproducts as claimed in claim 4, wherein said UV-LED light sources are disposed on the remaining diversion baffles except the first and second diversion baffles along the flow direction of the inlet water of the clean water basin body.

6. The clean water factory basin with low generation of disinfection byproducts as claimed in claim 1 or 5, wherein said UV-LED light source is arranged on the side of the diversion baffle facing the water flow.

7. The clean water factory basin with low generation of disinfection byproducts as claimed in claim 1 or 4, wherein said flow guide baffle is provided with 8 pieces.

8. The clean water factory basin with low generation of disinfection byproducts as claimed in claim 1, wherein the flow rate of the area where said UV-LED light source is located is 0.05-0.1 m/s.

9. The clean water basin of claim 1, wherein the UV-LED light source further comprises a water barrier layer on the outer surface of the UV-LED light source.

10. The clean water plant basin of claim 9 wherein said water barrier is a quartz layer.

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