Device and method for improving transparency of natural water body by utilizing microalgae biological membrane

Abstract

The invention provides a device and a method for improving transparency of a natural water body by utilizing a microalgae biological membrane, and belongs to the field of water treatment, and the device comprises a water tank, rollers, a microalgae attachment matrix, a water distribution device and a lighting device. The transparency of the natural water body is effectively improved through the microalgae biological membrane. The microalgae biological membrane secretes macromolecular extracellular polymeric substances, can adsorb suspended particulate matters and soluble organic matters in water, and inhibits the reproduction of other planktons through nutrition competition, so that the turbidity is reduced. In addition, the device is designed as up-flow water inlet, so that the contact between the water body and the microalgae biological membrane is enhanced, and the treatment effect is improved. LED lamps and a heating device are adopted to keep a proper growth environment, and meanwhile, a photovoltaic power generation system is arranged, so that green and environment-friendly effects are achieved. The method is simple and easy to implement, low in cost and convenient to manage and maintain, and a novel and effective technical scheme is provided for improving the transparency of the natural water body.

Description

Technical Field

[0001] The invention belongs to the field of water treatment, and in particular relates to a device and a method for improving the transparency of natural water bodies by utilizing microalgae biofilms. Background Art

[0002] Current water environment governance efforts focus on reducing the content of organic matter and nitrogen and phosphorus in natural waters, but pay less attention to improving the transparency of natural waters. Water transparency is one of the important indicators for measuring water quality, reflecting the content of suspended matter, dissolved organic matter and plankton in water. Improving the transparency of natural waters has important significance and many positive impacts. For example, clear and transparent waters are more visually appealing and help enhance the beauty of natural landscapes; higher water transparency allows more sunlight to penetrate the water, promoting photosynthesis of underwater plants and helping to maintain the health and stability of aquatic ecosystems; clear waters facilitate more accurate monitoring and management of pollutants, helping to promptly detect and resolve water quality issues.

[0003] At present, many methods for improving water transparency have been developed, which can be divided into three categories: physical, chemical and biological methods. Common physical and chemical methods include filtration, coagulation sedimentation, adsorption, etc. These methods have high treatment efficiency and good results, but at the same time, the cost is also high, and secondary pollution to the water body may occur. Therefore, they are generally used in water treatment fields such as urban sewage and industrial wastewater. Biological method is the preferred method for improving the transparency of natural water bodies, which is green, environmentally friendly, low-cost and sustainable. At present, aquatic vegetation is mainly used to improve the transparency of water bodies. However, the growth cycle of vegetation is long, the growth state varies greatly with the seasons, and the space requirement is large, and the maintenance and management are also relatively complicated. Therefore, the use of aquatic vegetation to improve the transparency of water bodies is not widely used.

[0004] Microalgae refers to a class of tiny aquatic photosynthetic organisms that have the characteristics of tenacious vitality and rapid growth. They are widely present in natural water environments. Microalgae can form a membrane-like substance with a certain three-dimensional spatial structure by secreting high-molecular extracellular polymers and adhering to the surface of solid carriers (such as vegetation leaves, mud, etc.), which is called a biofilm. Microalgae biofilms have strong material metabolism capabilities and can consume nutrients in water bodies, thereby inhibiting the growth of suspended algae. In addition, the extracellular polymers rich in microalgae biofilms have high viscosity. On the one hand, they can act as biological flocculants to aggregate fine particles in the water into large particles. On the other hand, they also enable microalgae biofilms to capture fine particles and soluble organic matter in the water. It can be seen that microalgae biofilms have a high potential to improve the transparency of water bodies, but there is still a lack of technical means to use microalgae biofilms to improve the transparency of natural water bodies. Summary of the invention

[0005] The present invention provides a device and method for improving the transparency of natural water bodies by using microalgae biofilms, which has the advantages of good effect, low cost, simple management and maintenance, and green environmental protection, and can provide a new technical solution for improving the transparency of natural water bodies. To achieve the above purpose, the present invention adopts the following technical solution:

[0006] A device for improving the transparency of natural water bodies by using microalgae biofilms, comprising:

[0007] A water pool, used to treat the water to be treated; the water pool is provided with a water inlet and a water outlet;

[0008] A roller, wherein the roller is arranged in the pool;

[0009] A microalgae attachment matrix, the microalgae attachment matrix is ​​arranged on the roller, and the microalgae attachment matrix is ​​used for microalgae to attach and grow to form a microalgae biofilm;

[0010] A lighting device, used for illuminating the pool;

[0011] A water distribution device is used to inject the water to be treated into the water pool; the water distribution device is arranged in the water pool; the water distribution device is connected to the water inlet; the water flow of the water to be treated injected into the water pool by the water distribution device drives the roller to rotate.

[0012] Optionally, the microalgae attachment substrate is a brush, and the brush is evenly arranged on the roller;

[0013] Optionally, the brush is a nylon brush;

[0014] Optionally, the rollers are provided in plurality; the rollers are arranged in a double-layer staggered manner;

[0015] Optionally, the roller is arranged horizontally, and both ends of the roller are connected to the inner wall of the pool through bearings.

[0016] Optionally, the water distribution device includes a water distribution pipe, which is arranged at the bottom of the pool; the water distribution pipe is evenly provided with water distribution holes; the water distribution pipe is connected to the water inlet; the water distribution holes output the water flow of the water body to be treated upward to drive the roller to rotate;

[0017] There are multiple water distribution pipes, which are evenly arranged at the bottom of the pool.

[0018] Optionally, the water outlet is connected to a sedimentation tank;

[0019] The water pool and the sedimentation tank are directly provided with a retaining wall, and the water outlet is arranged on the upper part of the retaining wall;

[0020] Preferably, the water outlet is located higher than the roller.

[0021] Optionally, it also includes: a heating device for heating the water in the pool;

[0022] Preferably, the heating device is arranged on the side wall of the pool.

[0023] Optionally, a photovoltaic power generation device is also included, and the photovoltaic power generation device is used to supply power to the lighting device and the heating device.

[0024] Preferably, the lighting device adopts an LED lamp;

[0025] Preferably, the lighting device is arranged on the side wall of the pool.

[0026] Optionally, the following steps are included:

[0027] Step 1) Filling water into the pool of the device for improving the transparency of natural water bodies by using microalgae biofilm, closing the water inlet and outlet of the pool, and making the water surface higher than the roller;

[0028] Step 2) adding microalgae to the water pool for cultivation, so that the microalgae adhere to the microalgae attachment substrate and grow to form a microalgae biofilm;

[0029] Step 3) Open the water inlet and outlet of the pool and let in the water to be treated for treatment.

[0030] Optionally, in the step 2), a microalgae culture solution is added to the pool; the preparation method of the microalgae culture solution is: adding dormant microalgae powder and nutrient solution, stirring evenly, to obtain a microalgae pre-culture solution; the nutrient solution contains 0.1-0.5 g / L glucose, 0.01-0.05 g / L ammonium chloride, and 0.001-0.005 g / L potassium dihydrogen phosphate.

[0031] Preferably, in step 2), every 1m 3 Add 10-20L of microalgae culture solution to the water;

[0032] Preferably, the water temperature in the pool is maintained at 20-30°C;

[0033] Preferably, the culture time in step 2) is 15 to 30 days.

[0034] Optionally, in step 3), the flow rate is maintained at 1-5 m / h when treating the water body. The flow rate is the average flow rate inside the pool, which is obtained by dividing the water inflow by the pool area.

[0035] Preferably, when treating the water body, the water flow rate is gradually increased from 0.5 m / h to 1-5 m / h.

[0036] Optionally, the method further includes:

[0037] When treating the water body, the flow rate is increased to 10-20 m / h and maintained for 6-12 hours to flush the microalgae attachment matrix, and then the flow rate is restored to 1-5 m / h.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention utilizes microalgae biofilm to improve the transparency of natural water bodies. Microalgae biofilm is a microbial aggregate formed by microalgae (such as diatoms and Chlorella) through the secretion of high-molecular-weight extracellular polymers. The principle of improving transparency mainly includes the following aspects: (1) Microalgae biofilm can absorb suspended particles (organic matter, inorganic matter and suspended microorganisms) in water, thereby improving the transparency of water bodies; (2) Microalgae biofilm is rich in extracellular polymers, which can act as biological flocculants when dispersed in water bodies, thereby promoting the aggregation of fine suspended particles into large-sized aggregates, thereby precipitating and removing. (3) Microalgae biofilm can compete with other plankton in the water body for nutrients, such as nitrogen, phosphorus, etc., thereby reducing the excessive reproduction of plankton in the water body and reducing the turbidity of the water body. (4) Microalgae biofilm can also utilize / absorb colored organic matter in the water body, thereby improving the turbidity of the water body.

[0040] The present invention grows microalgae biofilm on the brush, which can greatly promote the contact area between the microalgae biofilm and the water body, thereby maximizing the effect of the microalgae biofilm on improving the transparency of the water body. By adopting upflow water inlet, the flowing water body can play a stirring role on the one hand, which can not only significantly promote the contact between the water body and the microalgae biofilm, but also make the water body oxygen-enriched, and promote the healthy growth of the microalgae biofilm. On the other hand, the flowing water body can moderately peel off the aged biofilm on the brush, so that the microalgae biofilm in the device is always maintained in a vigorous growth state. Temperature is the dominant factor affecting the growth of microalgae, and it generally grows better between 20 and 30°C, so a heating device is used to maintain the temperature between 20 and 30°C. Under the coupling effect of the above-mentioned process settings, the present invention has the advantages of good treatment effect, high efficiency and stable operation. In addition, solar panels are used to power the lighting device and the heating device, which saves energy and is green and environmentally friendly. Finally, when the treatment effect decreases, the method of increasing the flow rate is adopted to remove impurities and aged biofilms adhering to the surface of the microalgae biofilm, which is simple to operate and convenient to manage. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 This is a schematic diagram of the structure of a device for improving the transparency of natural water bodies using microalgae biofilms provided by the present invention.

[0043] Figure 2 This is a schematic diagram of the planar structure of the water distribution system at the bottom of the device.

[0044] Figure 3 Schematic diagram of the roller arrangement.

[0045] Figure 4 This is the improvement effect of the present invention on the transparency of natural water bodies. DETAILED DESCRIPTION

[0046] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0048] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0049] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0050] Example 1

[0051] A device for improving the transparency of natural water bodies by using microalgae biofilms, the device comprising a rectangular pool ( Figure 1 ). An LED light strip 3 and a constant temperature heating rod 4 are installed on the pool wall.

[0052] The pool is also provided with a roller 6, which is cylindrical, and its two ends are horizontally mounted on the pool wall through bearings so that the roller can rotate; a water distribution device is installed at the bottom of the pool. The water distribution device is used to inject the water to be treated into the pool; the water distribution device is arranged in the pool; the water distribution device is connected to the water inlet; the water flow of the water to be treated injected into the pool by the water distribution device drives the roller to rotate. Figure 3 As shown, the roller is provided with a radial water wheel plate, and the water flow impacting the water wheel plate can drive the roller to rotate.

[0053] The roller 6 is provided with a microalgae attachment matrix for microalgae to attach and grow to form a microalgae biofilm; the microalgae attachment matrix is ​​made of nylon brushes, which are evenly arranged on the roller. In this embodiment, two layers of brush rollers are arranged alternately, wherein three brush rollers are arranged on the upper layer and four brush rollers are arranged on the lower layer.

[0054] The water distribution device includes a water distribution pipe 7; water distribution holes are evenly arranged on the water distribution pipe 7; the water distribution pipe is connected to the water inlet; the water distribution holes output the water flow of the water body to be treated upward to drive the roller to rotate; there are multiple water distribution pipes, and the positions of the water distribution pipes 7 and the roller 6 correspond.

[0055] The water outlet is connected to a sedimentation tank 8; a retaining wall 10 is directly provided between the water tank and the sedimentation tank 8, and the water outlet is a plurality of water outlet holes provided on the upper part of the retaining wall. The water outlet holes are located higher than the height of the roller. A sedimentation tank outlet 9 is provided on the upper part of the sedimentation tank 8, opposite to the retaining wall 10.

[0056] In addition, the device also includes a photovoltaic power generation device 1, which is used to power the LED light strip 3 and the constant temperature heating rod 4; the photovoltaic power generation device 1 is also connected to a controller 2; the controller 2 is connected to the lighting device and the heating device; a water inlet pipe 5, a perforated water distribution wall 10, a sedimentation unit 8, and a water outlet 9. The water inlet pipe 5 is connected to the perforated water distribution pipe 7, and its plane structure is shown in FIG. Figure 2 .

[0057] The LED light strip provides white or yellow light, with a light intensity of 5000 to 10000 Lux.

[0058] Example 2

[0059] In this embodiment, a pond water body located in a rural area of ​​Chongming, Shanghai is taken as an example to implement a method for improving the transparency of natural water bodies using microalgae biofilms.

[0060] The steps include:

[0061] S1. Add dormant algae powder of Chlorella and diatoms to deionized water and add nutrient salts. Then, place it on a magnetic stirrer and stir for 48 hours to obtain a microalgae pre-culture solution. The addition ratio of microalgae powder to deionized water is: 5g dormant algae powder is added to 1L deionized water. The proportion of nutrient salts is as follows: 0.1g / L glucose, 0.01g / L ammonium chloride, 0.001g / L potassium dihydrogen phosphate;

[0062] S2. Add the microalgae pre-culture solution obtained in step S1 to the device of Example 1. Add natural water to the device at a rate of 1 m 3 10L of microalgae pre-culture solution was added to the natural water. The LED light strip was turned on to provide illumination, and the light intensity was controlled to 5000Lux. The LED light strip was turned on for 12 hours and off for 12 hours, and was automatically turned on and off by the timer switch controller. Since the implementation season was summer and the ambient temperature was above 20°C, a constant temperature heating rod was not used. Then, the culture was allowed to stand for 15 days. A mature microalgae biofilm was formed on the brush roller 6 in the device;

[0063] S3. Open the water inlet pipe of the device, and the water flows into the perforated water distribution pipe through the water inlet pipe, and passes through the brush with microalgae biofilm on the roller in an ascending manner. Then, it enters the sedimentation tank through the outlet hole on the upper part of the retaining wall. In the sedimentation tank, some large-sized sediments are precipitated and removed, such as detached biofilms, fine-grained sediments that are agglomerated together, etc. Then, the water flows out of the device in the form of a waterfall from the outlet of the sedimentation tank. In the initial stage, by controlling the water inlet flow rate, the flow rate in the device is increased from 0.5m / h to 2m / h at intervals of 0.5m / h, and stays at each speed for 2 days. After that, the flow rate is maintained at 2m / h and operated in the above manner.

[0064] S4. After 60 days of normal operation, the treatment effect gradually decreased. Therefore, by controlling the influent flow rate, the flow rate in the device was increased to 10m / h and operated for 6h, after which the flow rate was restored to 2m / h.

[0065] During the operation of the device, the change in the transparency of the pond water was measured by the industry standard of the People's Republic of China - Determination of transparency (disc method, SL 87-1994). Each measurement was repeated three times, and the average of the three times was taken as the final result. Figure 4It can be seen that the initial value of the transparency of the pond water is 42cm, and the transparency is relatively low. This is because the high temperature in summer causes a large number of plankton in the water body. In addition, rainfall and sewage discharge are also the reasons for the low transparency. After the device was put into operation, the transparency of the water body rose rapidly. After 30 days of operation, the transparency of the water body rose to 74cm, an increase of 76% over the initial value. Subsequently, it remained at around 74cm. The above results show that the present invention can quickly and effectively improve the transparency of the water body. After running for 60 days, the treatment effect began to decline due to the interception of a large amount of particulate matter and the aging of the microalgae biofilm. For this reason, by increasing the water flow, this part of the particulate matter adhering to the microalgae biofilm is removed, and at the same time, the aged biofilm is removed. Afterwards, the operating effect of the device increased again and returned to the state before the effect declined. It can be seen that the operating effect of the present invention is stable and the management and operation are simple. In general, the present invention can efficiently improve the transparency of natural water bodies, and has the advantages of simple management and operation, low cost, and green environmental protection.

[0066] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A device for improving the transparency of natural water bodies using microalgae biofilms, characterized in that: include: A water pool, used for treating the water to be treated; the water pool is provided with a water inlet and a water outlet; a roller, the roller is arranged in the water pool; A microalgae attachment matrix, the microalgae attachment matrix is ​​arranged on the roller, and the microalgae attachment matrix is ​​used for microalgae to attach and grow to form a microalgae biofilm; A lighting device, used for illuminating the pool; A water distribution device is used to inject the water to be treated into the water pool; the water distribution device is arranged in the water pool; the water distribution device is connected to the water inlet; the water flow of the water to be treated injected into the water pool by the water distribution device drives the roller to rotate.

2. The device for improving the transparency of natural water bodies using microalgae biofilm according to claim 1, characterized in that: The microalgae attachment substrate adopts a brush, and the brush is evenly arranged on the roller; Preferably, the brush is a nylon brush; Preferably, the rollers are provided in plurality; the rollers are arranged in a double-layer staggered manner; Preferably, the roller is arranged horizontally, and both ends of the roller are connected to the inner wall of the pool through bearings.

3. The device for improving the transparency of natural water bodies using microalgae biofilm according to claim 1, characterized in that: The water distribution device comprises a water distribution pipe, which is arranged at the bottom of the pool; the water distribution pipe is evenly provided with water distribution holes; the water distribution pipe is connected to the water inlet; the water distribution holes output the water flow of the water body to be treated upward to drive the roller to rotate; There are multiple water distribution pipes, which are evenly arranged at the bottom of the pool.

4. The device for improving the transparency of natural water bodies using microalgae biofilm according to claim 1, characterized in that: The water outlet is connected to a sedimentation tank; The water pool and the sedimentation tank are directly provided with a retaining wall, and the water outlet is arranged on the upper part of the retaining wall; Preferably, the water outlet is located higher than the roller.

5. The device for improving the transparency of natural water bodies using microalgae biofilm according to claim 1, characterized in that: Also includes: A heating device, used for heating the water in the pool; Preferably, the heating device adopts an electric heating rod; Preferably, the heating device is arranged on the side wall of the pool.

6. The device for improving the transparency of natural water bodies using microalgae biofilm according to claim 5, characterized in that: It also includes a photovoltaic power generation device, which is used to power the lighting device and the heating device; Preferably, the photovoltaic power generation device is further connected to a controller; the controller is connected to the lighting device and the heating device; Preferably, the lighting device adopts an LED lamp; the LED lamp is white light or yellow light, and the light intensity is 5000-10000 Lux; Preferably, the lighting device is arranged on the side wall of the pool.

7. A method for improving the transparency of natural water bodies using microalgae biofilms, characterized in that: The steps include: Step 1) Filling water into the pool of the device for improving the transparency of natural water bodies by using microalgae biofilms according to any one of claims 1 to 6, closing the water inlet and outlet of the pool, and making the water surface higher than the roller; Step 2) adding microalgae to the water pool for cultivation, so that the microalgae adhere to the microalgae attachment substrate and grow to form a microalgae biofilm; Step 3) Open the water inlet and outlet of the pool and let in the water to be treated for treatment.

8. The method for improving the transparency of natural water bodies by using microalgae biofilm according to claim 7, characterized in that: In the step 2), a microalgae culture solution is added to the pool; the preparation method of the microalgae culture solution is: dormant microalgae powder is added to a nutrient solution, and stirred evenly to obtain a microalgae pre-culture solution; the nutrient solution contains 0.1-0.5 g / L glucose, 0.01-0.05 g / L ammonium chloride, and 0.001-0.005 g / L potassium dihydrogen phosphate; Preferably, in step 2), every 1m 3 Add 10-20L of microalgae culture solution to the water; Preferably, the water temperature in the pool is maintained at 20-30°C; Preferably, the culture time in step 2) is 15 to 30 days.

9. The method for improving the transparency of natural water bodies by using microalgae biofilm according to claim 7, characterized in that: In the step 3), the flow rate is maintained at 1 to 5 m / h when treating the water body; Preferably, when treating the water body, the water flow rate is gradually increased from 0.5 m / h to 1-5 m / h.

10. The method for improving the transparency of natural water bodies by using microalgae biofilm according to claim 7, characterized in that: The method further comprises: When treating the water body, the flow rate is increased to 10-20 m / h and maintained for 6-12 hours to flush the microalgae attachment matrix, and then the flow rate is restored to 1-5 m / h.

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