TWI530459B - System and method for treating wastewater - Google Patents

Description

Wastewater treatment system and method

The present invention relates to a wastewater treatment system and method, and more particularly to a wastewater treatment system and method incorporating aeration and biological treatment.

According to the United Nations Environment Programme, if there is no immediate water resource solution, by 2025, two out of every three people in the world will feel the pressure of water shortage. Therefore, the development of diversified water resources has become an inevitable solution, and water recycling has become one of the main channels for increasing water resources. It is estimated that by 2015, recycled water will increase by 181% compared to 2005. The water recycling method with low environmental impact and sustainable development concept has become one of the main development directions. The ecological treatment system has the advantages of energy saving, simple operation, low cost and no destruction of ecology.

In the ecological treatment system, the mechanism of pollutant removal mainly includes sedimentation, adsorption, filtration, nitrification, denitrification, plant uptake and biotransformation processes, but the environment created by different types of ecological treatment systems is not the same. Not all mechanisms can be used in different types of ecological treatment systems Work properly. The reaction efficiencies of various nitrogen conversion mechanisms are also different, thus limiting the nitrogen removal efficiency of the ecological treatment system. After the general pollutants enter the ecological treatment system, they are mainly removed by oxygenation. The main removal mechanism of nitrogenous pollutants is ammonia gasification, plus nitrification and denitrification. The nitrogen in the wastewater is converted to nitrogen. When nitrification is incomplete, denitrification does not completely convert nitrogen-containing contaminants in the water to nitrogen. Therefore, nitrification must be carried out when the dissolved oxygen is above a certain limiting concentration. Therefore, the addition of aeration equipment in the ecological treatment system can strengthen the oxygen supply conditions and increase the dissolved oxygen in the water, which can significantly improve the degradation efficiency of various pollutants in the purification zone.

However, it is also found that the addition of aeration equipment in the tank can increase the dissolved oxygen in the water to improve the degradation performance of various pollutants, but it will also disturb the flow field (Flow Field), but reduce the removal efficiency of pollutants. .

The mechanisms for the current treatment of aquaculture water pollutants are summarized as follows:

1. Physical effect: Mainly remove physical solids or harmful ions in culture water by physical filtration, gravity separation, floatation, physical adsorption, ion exchange, oxygen green ray resonance, carbon rod adsorption, aeration and other mechanisms.

2. Biological effects: The main use of microorganisms to remove organic pollutants and nitrogenous pollutants in water through biological filtration, biochemical treatment, plant uptake, mineralization conversion, assimilation, predation and other mechanisms.

3. Sterilization: The possible pathogenic bacteria in the culture system can be removed by the action mechanism of ultraviolet filament and ozone sterilization, ozone oxidation and sterilization, alloy dissolved oxygen sterilization, solar radiation sterilization and the like.

Although the above-mentioned many technologies have certain effects through the verification of practical applications, they are limited by factors such as high equipment or operation cost, high demand for equipment operation and technical requirements, and high difficulty in design and operation. As a result, there are still many room for improvement in water quality improvement. . Based on the above-mentioned related shortcomings, planning a wastewater treatment system with low equipment cost, low energy consumption, simple operation, and clear target of treatment is indeed one of the important topics for improving the development of water treatment industry in China at this stage.

According to relevant research, the toxic substances of common aquaculture organisms are hydrogen sulfide, ammonia and nitrite. The toxicity of nitrite is far weaker than that of ammonia. In general water environment, the concentration of hydrogen sulfide is often much lower than that of ammonia. Easy chemical changes to non-toxic products, so aquaculture is less a source of toxicity for fish, so ammonia is the most threatening in aquaculture water. Therefore, many inventions have increased the way of dissolving oxygen in water to convert ammonia nitrogen into less toxic nitrate nitrogen by nitrification. The results of on-site monitoring also show this common phenomenon. However, high concentrations of nitrate nitrogen can contribute to the proliferation of algae in outdoor farms. Excess algae often cause biotoxicity or nighttime anti-water phenomenon, which may lead to deterioration of water quality. Fish and shrimp died. In order to reduce losses, the aquaculture industry uses pesticides to control water quality, which can increase production, but also reduce the quality of the breeding standards and market prices.

Based on the current aquaculture market demand considerations and the future development trend of organic aquaculture, it is urgent to propose a wastewater treatment system that can be used to improve aquaculture water quality and treat general wastewater, which can remove suspended solids, organic pollution and nitrogen in water. Nutrient salts, to solve problems related to environmental water body eutrophication and aquaculture water use. At the same time, the system has low equipment cost, low operating cost, low energy consumption and easy operation, thereby reducing water quality control. The use of drugs and promote the long-term development goals of organic aquaculture, and enhance the added value of aquaculture.

Accordingly, one aspect of the present invention is to provide a wastewater treatment system that combines aeration and biological treatment to effectively remove suspended solids, nitrogenous contaminants, and organic contaminants from wastewater.

Another aspect of the present invention is to provide a method of treating wastewater which is carried out using the above wastewater treatment system.

According to one aspect of the invention, a wastewater treatment system is provided. In one embodiment, the wastewater treatment system includes a precipitation tank, a purification tank, a rear aeration tank, a first connecting unit, and a second connecting unit, wherein the first connecting unit is connectable to the sedimentation tank and the purification tank, and the second connecting unit is connectable Purification tank and rear aeration tank. The sedimentation tank comprises a heat insulation plate covering the top of the sedimentation tank, a sediment discharge pipe is arranged at the bottom of the sedimentation tank, and a first water outlet is arranged on the side wall of the sedimentation tank.

The above-mentioned purification tank comprises an aeration zone, an aquatic plant purification zone, and a rectification zone provided in the aeration zone and the purification zone of the aquatic plants. The aeration zone includes a first aeration device and a contact material, wherein the first aeration device includes a first submersible motor and a first air compression device. The rectification zone includes a plurality of rectifiers. The aquatic plant purification area contains soil layers, water layers and water-borne plants. A first water inlet is provided on a side wall adjacent to the aeration zone, and a second water outlet is provided on a side wall adjacent to the purification zone of the aquatic plant.

The first connecting unit is used to connect the first water outlet and the first water inlet. After the above aeration tank comprises a second aeration device and a second inlet water The port, wherein the second aeration device comprises a second submersible motor and a second air compression device. The second connecting unit is for connecting the second water outlet and the second water inlet.

According to an embodiment of the invention, the nozzle of the rectifier tube is parallel to the flow direction of the wastewater.

According to an embodiment of the invention, the effluent zone is further included after the aquatic plant purification zone.

According to another aspect of the present invention, a wastewater treatment method is provided which is carried out using the above-described wastewater treatment system. In one embodiment, first, wastewater is provided. Next, the wastewater is subjected to a precipitation treatment in a sedimentation tank to form crude treated water. Then, in the aeration zone of the purification tank, the first treatment step is performed on the crude treated water, wherein the first treatment step comprises aerating the wastewater to form aerated water, and subjecting the aerated water to contact oxidation treatment To form the first treated water.

Then, in the rectification zone of the purification tank, the first treated water is subjected to a rectifying step to form a second treated water. Thereafter, in the aquatic plant purification zone of the purification tank, the second treatment water is subjected to a third treatment step to form a third treatment water. Among them, the aquatic plant purification area comprises a soil layer, a water layer and a water-borne plant. Further, in the post-aeration tank, the third treated water is subjected to post-aeration treatment to form purified water.

According to an embodiment of the invention, the method further comprises collecting the third treated water to the water discharge zone after the third processing step.

According to an embodiment of the present invention, the contact oxidation treatment described above is carried out by a strain attached to the contact material.

According to an embodiment of the invention, the third processing step comprises biologically treating the second treated water with the rhizome of the water-staining plant.

According to an embodiment of the invention, the rectifying step is performed by a plurality of rectifier tubes, and the nozzles of the rectifier tubes are arranged parallel to the flow direction of the wastewater.

According to an embodiment of the invention, the septic tank is a single tank.

With the waste water treatment system of the present invention, suspended solids, nitrogen-containing contaminants and organic contaminants in the wastewater can be removed simply and economically.

100‧‧‧Waste treatment system

101, 103‧‧‧ arrows

110‧‧‧Sedimentation tank

111‧‧‧Drain pipe

113‧‧‧ Thermal insulation board

120‧‧‧Septic tank

121‧‧‧Aeration zone

121A‧‧‧First aeration device

121B‧‧‧Contact material

122a‧‧‧First air compression device

122b‧‧‧First submersible motor

123‧‧‧Rectifier

123A‧‧‧Rectifier

124‧‧‧Sun cover

125‧‧‧Aquatic plant purification area

125A‧‧‧ very waterborne plants

125B‧‧ soil layer

127‧‧‧Water area

130‧‧‧After aeration tank

131A‧‧‧Second aeration device

132a‧‧‧Second air compression device

132b; second submersible motor

140‧‧‧First connection unit

141‧‧‧ first outlet

143‧‧‧ first water inlet

150‧‧‧Second connection unit

151‧‧‧Second outlet

153‧‧‧Second water inlet

160‧‧‧ water level

201, 203, 205‧‧‧ Biochemical Oxygen Demand

211, 213‧‧‧ average removal rate of biochemical oxygen demand

301, 303, 305‧‧‧ ammonium nitrogen concentration

311, 313‧‧ ‧ average removal rate of ammonium nitrogen concentration

401, 403, 405‧ ‧ total ammonium nitrogen concentration

411, 413‧‧ ‧ average ammonium nitrogen concentration average removal rate

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; FIG. 2A is a diagram showing the biochemical oxygen demand of a wastewater treatment system according to an embodiment of the present invention and a comparative example; FIG. 2B is a diagram showing an embodiment of the present invention and a comparative example. The average removal rate of biochemical oxygen demand of the wastewater treatment system over time; [Fig. 3A] shows the ammonium nitrogen concentration of the wastewater treatment system according to an embodiment of the present invention and the comparative example as a function of time; [Fig. 3B] The average removal rate of ammonium nitrogen concentration according to time of the wastewater treatment system according to an embodiment of the present invention and a comparative example; 4A is a graph showing the total ammonium nitrogen concentration of a wastewater treatment system according to an embodiment of the present invention and a comparative example; FIG. 4B is a diagram showing wastewater treatment according to an embodiment of the present invention and a comparative example. The average removal rate of total ammonium nitrogen concentration over time in the system.

It is an object of the present invention to provide a wastewater treatment method and system for simply and economically removing suspended solids, nitrogenous contaminants and organic contaminants from wastewater. The suspended solids referred to herein may include sediment, clay, protozoa, algae, bacteria, viruses, and high molecular organic substances, etc., and the nitrogen-containing pollutants referred to herein may include ammonium nitrogen, nitrite nitrogen, and nitrate nitrogen. The organic pollutants referred to herein may include humic acid, fulvic acid, hydrophilic acid, carbohydrates, carboxylic acids, amino acids or hydrocarbons.

The wastewater treatment system of the present invention will be described below using Fig. 1 . As shown in FIG. 1 , the wastewater treatment system 100 includes a precipitation tank 110 , a purification tank 120 , and a rear aeration tank 130 . The first connection unit 140 can be connected to the precipitation tank 110 and the purification tank 120 , and the second connection unit 150 can be connected to the purification tank. 120 and the rear aeration tank 130 are described below. In addition, the symbol 160 in FIG. 1 represents the water level, and the water level in the sedimentation tank 110, the purification tank 120, and the rear aeration tank 130 is only slightly different (for example, the water level of the sedimentation tank 110 is higher than the purification tank 120, and the water level of the purification tank 120 Higher than the rear aeration tank 130), but this difference is not shown in FIG.

As shown in Figure 1, the wastewater enters the settling tank 110 of the wastewater treatment system 100 in the direction of arrow 101, at which time the wastewater may be referred to as influent water. Precipitation tank The main structure of the 110 is an artificial tank, and the top of the tank of the sedimentation tank 110 is covered with a heat insulating plate 113, which helps the collection of suspended solids and is provided with a drain pipe 111. In addition, the precipitation tank 110 further includes a first water outlet 141 on the side wall thereof.

In one embodiment, the wastewater first enters the precipitation tank 110 for precipitation treatment. In the precipitation treatment, a large volume of suspended solids, such as sediment, is deposited by physical sedimentation to the bottom of the sedimentation tank 110 and discharged through the sludge discharge pipe 111. The crude treated water subjected to the precipitation treatment is discharged through the first water outlet 141 and flows through the first water inlet 143 to the purification tank 120.

The purification tank 120 is a single tank and may be a rectangular tank. The purification tank 120 includes an aeration zone 121, an aquatic plant purification zone 125, and a rectification zone 123 disposed between the aeration zone 121 and the aquatic plant purification zone 125. In addition, the septic tank 120 further includes a first water inlet 143 disposed on a side wall adjacent to the aeration zone 121, and a second water outlet 151 disposed on a side wall adjacent to the aquatic plant purification zone 125 to facilitate the space between the tanks. Wastewater transportation.

The aeration zone 121 described above is provided with a first aeration device 121A and a uniformly distributed contact material 121B for performing the first processing step. The first aeration device 121A includes a first air compression device 122a and a first submersible motor 122b. The first processing step described above includes increasing the amount of dissolved oxygen in the wastewater with the first aeration device 121A to form aerated water, and using the contact material 121B as a substrate for contact growth of the nitrifying bacteria in contact with the oxidation treatment. Since the nitrifying bacteria are aerobic bacteria, in the wastewater with a high dissolved oxygen amount, the contact material 121B as a substrate is combined to perform treatment including nitrification and contact oxidation to remove nitrogen-containing contaminants in the wastewater to form a first treatment. water. At the same time, in order to enhance the nitrifying bacteria The processing performance, a sunshade cover 124 may be disposed above the aeration zone 121. In one embodiment, the contact material 121 is uniformly distributed in the aeration zone 121 and the rectification zone 123 (not shown) described later.

The contact material 121B referred to in the present invention may be any conventional or commercially available contact material. For example, the contact material may be a biofilm having a large specific surface area and growth adhesion, and may be a wave board, a honeycomb board, or a rope. Filter material, mesh filter or float. The nitrifying bacteria referred to herein may be self-operating nitrifying bacteria or heterotrophic nitrifying bacteria, and are aerobic bacteria.

Next, the first treated water is rectified by the rectifier 123A provided in the rectifying zone 123 to form second treated water and enter the aquatic plant purification zone 125. The rectifying section 123 includes a plurality of rectifying tubes 123A, and the nozzles of the rectifying tubes 123A are arranged in a direction parallel to the flow of the first treated water, and are arranged in a honeycomb shape. Further, the rectifier 123A may have a nozzle diameter of, for example, 3 mm to 5 mm and a length of 15 cm to 20 cm. The material of the rectifier 123A may include, but is not limited to, ceramic, concrete, plastic or any corrosion-resistant material.

The rectification via the rectifier 123A allows the disturbance to the first treated water during the aeration process to be smoothed to form the second treated water, facilitating the processing steps after entering the aquatic plant purification zone.

The bottom of the aquatic plant purification area 125 is provided with a soil layer 125B, and the aquatic plant purification area 125 also includes a water layer (not shown) for the water-borne plant 125A (for example: reed, rush, cattail, pennisetum, windmill grass, Petrigreeum, etc.) grows.

In the aquatic plant purification zone 125, a second processing step is performed on the second treated water. The third treatment step comprises the bottom of the plant or the sand Biological treatment such as mineralization, nitrification, denitrification and assimilation of organic matter is performed to remove organic pollutants or nitrogen-containing pollutants in the second treatment water. On the other hand, suspended solids, nitrogen-containing pollutants, organic pollutants, and microorganisms can also be removed by physical sedimentation, adsorption, filtration, and the like. Furthermore, the uptake of aquatic plants can also remove nitrogenous contaminants or heavy metals from the water. In addition, the radiation of sunlight and the predation of protozoa also have the effect of removing pathogens. The wastewater treated by the aquatic plant purification zone 125 is referred to as the third treated water.

In addition, the septic tank 120 may selectively include a water discharge area 127 to collect the third treated water and connect the rear aeration tank 130.

The first water outlet 141 and the first water inlet 143 are connected by a first connecting unit 140 for discharging the waste water in the sedimentation tank 110 into the purification tank 120. The first connecting unit 140 and the second connecting unit 150 described later may be, for example, a water pipe having a valve.

The main structure of the rear aeration tank 130 is an artificial tank. The rear aeration tank 130 can be coupled to the purification tank 120 by a second connecting unit 150 provided with a valve, and the second water inlet 151 on the side wall of the purification tank 120 and the second water inlet 153 on the side wall of the rear aeration tank 130. The third treated water is introduced into the rear aeration tank 130 from the second connecting unit 150. A second aeration device 131A is disposed in the rear aeration tank 130, and the second aeration device 131A includes a second air compression device 132a and a second submersible motor 132b. The function of the post-aeration tank 130 is mainly to enhance the dissolved oxygen of the treated water by the aeration of the second aeration device 131A to meet the needs of the subsequent pool. The water treated by the above process is referred to herein as purified water.

Thereafter, as shown in FIG. 1, the purified water flows out of the wastewater treatment system 100 in the direction of arrow 103. Whether or not the wastewater treatment is completed is based on the water quality standards for water demand, such as the land environment water body standards according to the Environmental Protection Agency's classification of surface water bodies and water quality standards. The above provisions are well known to those of ordinary skill in the art and will not be further described herein.

Preferably, the upper and lower positions of the first connecting unit 140 and the second connecting unit 150 in the wastewater treatment system 100 are diagonally arranged (as shown in FIG. 1) to control the flow of water. In an embodiment of the invention, the first connection unit 140 is disposed near the top of the tank body of the wastewater treatment system, and the second connection unit 150 is disposed adjacent to the bottom of the tank body of the wastewater treatment system.

In this embodiment, since the first water inlet 141 of the first connecting unit is closer to the position where the wastewater flows into the sedimentation tank 110, the wastewater that has just flowed in is prevented from flowing out of the sedimentation tank 110 before the precipitation treatment has been completely performed. A vertical baffle (not shown) is disposed between the waste water inlet position of the sedimentation tank 110 and the first water inlet 141, but the sedimentation tank 110 is not completely partitioned into two spaces, so that the coarse treated water after the sedimentation can pass. And it is input to the purification tank 120.

It is to be noted that the first air compressing device 122a and the second air compressing device 132a of the first aeration device 121A and the second aeration device 131A used in the present invention are disposed in the purification tank 120 and the rear aeration tank 130. In addition, any conventional air compression device can be used. Specific examples may include, but are not limited to, a reciprocating air compressor, a rotary air compressor, or a centrifugal air compressor.

The first submersible motor 122b and the second submersible motor 132b are submersible aeration motors. By the high-speed agitation of the turbine blades of the submersible aeration motor, the air input from the air compressing device (for example, the first air compressing device 122a and the second air compressing device 132a) is made into minute bubbles, which can be greatly improved. The rate of dissolved oxygen in water and the amount of dissolved oxygen can also prolong the time of bubbles in the water. At the same time, the blades of the turbine also mix the gas with the water, so that a better aeration efficiency can be achieved. Compared with the pontoon type aeration motor, the invention cooperates with the air compression device and the submersible aeration motor disposed outside the tank to achieve better aeration efficiency.

It is to be noted that there is no additional compartment between the aeration zone 121, the rectification zone 123 and the aquatic plant purification zone 125 (or the further water discharge zone 127) in the purification tank 120 of the present invention. The crude treated water outputted from the sedimentation tank 110 is flowed into the purification tank 120 at a slow flow rate (for example, the flow rate of the crude treated water in the rectification zone 123 and the aquatic plant purification zone 125 for about 1 to 4 days). The aeration zone 121, the rectification zone 123, and the aquatic plant purification zone 125 in the purification tank have a slight water level difference (i.e., gravity flow) such that the flow of the crude treated water is from the aeration zone 121 toward the aquatic plant purification zone 125.

In addition, since the aeration effect of the aeration zone 121 makes the first treated water uniformly mixed and has no temperature difference, the circulation caused by the temperature difference is less likely to occur, and the consistency of the water flow direction is further improved.

Furthermore, the aquatic plants in the aquatic plant purification zone 125 grow in a direction perpendicular to the direction of the water flow, and thus have a function of blocking the flow of water.

The treatment efficiency of the wastewater treatment system of the present invention was evaluated by the following examples and comparative examples.

In order to evaluate the efficacy of the wastewater treatment system of the present invention, the following experimental studies were conducted. The wastewater treatment systems of the examples and comparative examples were set in the wastewater treatment plant of Jianan University of Pharmacy, with the campus wastewater as the source of wastewater, and the wastewater treatment systems of the examples and comparative examples were stabilized after about 2 months and planted. , carry out various sampling, monitoring and analysis work. The sampling frequency is once a week, and the sampling time is about 8:00 am to 10:00 am on each sampling day. It should be noted that the evaluation methods and evaluation results of the present invention are carried out in accordance with the detection method announced by the Environmental Protection Agency of the Executive Yuan. The relevant evaluation results will be described later.

Example

The embodiment uses a wastewater treatment system 100 as shown in FIG. 1, wherein the purification tank 120 is a single tank, and the length, width, and height of the tank are 176 cm, 30 cm, and 46 cm, respectively. In an embodiment, the operating flow rate of the wastewater treatment system is planned to be 108 liters/day, the water depth is about 30 cm, and the hydraulic load is 0.204 cubic meters per square meter per day (m ³ /m ² /d). The residence time is approximately 1.47 days.

Comparative example

The comparative example uses the same wastewater treatment system as the embodiment, but the wastewater treatment system of the comparative example does not contain an aeration zone and a rectification zone, and all the purification tanks are planted with aquatic plants.

Evaluation method 1. The amount of dissolved oxygen

Since nitrifying bacteria are aerobic bacteria, if the amount of dissolved oxygen in the wastewater is higher, the efficiency of using the nitrifying bacteria or the rhizomes of the aquatic plants for biological treatment is better. In addition, if applied to aquaculture, the higher the amount of dissolved oxygen in the water, the better. Therefore, the evaluation standard of the dissolved oxygen amount is as high as possible.

2. Biochemical oxygen demand and its average removal rate

Biochemical oxygen demand is the amount of dissolved oxygen required by the aerobic microorganisms in the water to decompose the organic pollutants in the water into inorganic substances at a certain temperature for a certain period of time. If the lower the biochemical oxygen demand, the less organic pollutants in the water, the lower the biochemical oxygen demand, the better. In addition, the average removal rate of biochemical oxygen demand represents the ratio of biochemical oxygen demand reduction after wastewater treatment, so the higher the average removal rate of biochemical oxygen demand, the better.

3. Ammonium nitrogen concentration and its average removal rate

The nitrogenous pollutants in general waste water include ammonium nitrogen (NH ₄ ⁺ -N), nitrite-nitrogen (NO ₂ ^- -N) and nitrate nitrogen (nitrate-nitrogen; NO ₃ ^- - N). The mechanism for removing the above substances is mainly to convert ammonium nitrogen into nitrite nitrogen by nitrification, and then oxidize nitrogen nitrite to nitrogen nitrate. Therefore, the lower the ammonium nitrogen concentration, the better. In addition, the higher the average removal rate corresponding to the ammonium nitrogen concentration, the better.

4. Total ammonium nitrogen concentration and its average removal rate

Here, the sum of ammonium nitrogen, nitrite nitrogen and nitrogen nitrate of wastewater is referred to as total ammonium nitrogen (TAN). Therefore, the lower the total ammonium nitrogen concentration, the better. In addition, the higher the average removal rate corresponding to the total ammonium nitrogen concentration, the better.

Referring to Table 1, Table 1 contains the dissolved oxygen content of each part of the wastewater treatment systems of the examples and comparative examples. According to Table 1, it can be seen that by adding the aeration zone and the rectification zone, the dissolved oxygen amount of the wastewater in the treatment process of the wastewater treatment system can be effectively increased.

Next, please refer to FIG. 2A. 2A is a graph showing the biochemical oxygen demand concentration of untreated wastewater (line segment 201), example (line segment 203), and comparative example (line segment 205) as a function of time. Since the untreated wastewater is directly used as the influent water in the examples and comparative examples, the biochemical oxygen demand (BOD) of the influent water changes greatly. The maximum biochemical oxygen demand of untreated wastewater is 27.75mg/L, the minimum biochemical oxygen demand of untreated wastewater is 1.3mg/L, and the average biochemical oxygen demand of untreated wastewater is 12.22mg/L, as shown in Figure 2A. Shown. The average biochemical oxygen demand of the purified water of the example was 2.11 mg/L, and the average biochemical oxygen demand of the purified water of the comparative example was 4.51 mg/L.

Next, please refer to FIG. 2B. 2B is an average removal rate of biochemical oxygen demand of the embodiment (line segment 211) and the comparative example (line segment 213) as a function of time. The average biochemical oxygen demand removal rates of the examples and comparative examples were 83% and 63%, respectively, indicating that rectification aeration can effectively improve the removal efficiency of organic pollutants. Obviously, rectification aeration can effectively reduce the biochemical oxygen demand of wastewater.

Next, please refer to FIG. 3A. 3A is a graph showing the ammonium nitrogen concentration as a function of time for untreated wastewater (line segment 301), example (line segment 303), and comparative example (line segment 305). According to the results of Fig. 3A, the maximum ammonium nitrogen concentration of the untreated wastewater was found to be 49.78 mg/L, the minimum ammonium nitrogen concentration was 4.67 mg/L, and the average ammonium nitrogen concentration was 27.32 mg/L. The average ammonium nitrogen concentration of the purified water of the example is lowered. It was 5.95 mg/L, and the average ammonium nitrogen concentration of the purified water of the comparative example was 19.78 mg/L.

Figure 3B shows the average removal rate of ammonium nitrogen over time. The average ammonium nitrogen removal rates of the examples (line 311) and the comparative example (line 313) were 78% and 31%, respectively, indicating that rectifying aeration can effectively enhance ammonium nitrogen. Removal efficiency.

Further, the examples and comparative examples were used to evaluate the nitrogen-containing pollutant removal efficiency as a whole. 4A is a graph showing the total ammonium nitrogen concentration as a function of time for untreated wastewater (line segment 401), example (line segment 403), and comparative example (line segment 405). According to the results of FIG. 4A, the maximum total ammonium nitrogen concentration of the untreated wastewater was 50.74 mg/L, the minimum total ammonium nitrogen concentration was 4.96 mg/L, and the average total ammonium nitrogen concentration was 27.83 mg/L. The average total ammonium nitrogen concentration of the purified water of the example was lowered to 8.50 mg/L, and the average total ammonium nitrogen concentration of the purified water of the comparative example was 19.78 mg/L.

4B is the average ammonium nitrogen removal rate as a function of time. The average removal rates of the example (line 411) and the comparative example (line 413) are 69.5% and 30.6%, respectively, indicating that the rectification aeration can effectively increase the total ammonium nitrogen. Removal efficiency.

Based on the results of FIG. 2A to FIG. 4B, the wastewater treatment system of the present invention can effectively reduce the biochemical oxygen demand, the ammonium nitrogen concentration and the total ammonium nitrogen concentration of the wastewater, so that the nitrogen-containing pollutants in the wastewater can be effectively removed. Organic pollutants and suspended solids. In addition, the wastewater treatment system of the present invention has the advantages of simple operation, low cost, and the like, and is beneficial to aquaculture or other industries that require wastewater treatment.

The present invention has been disclosed in the above embodiments, and is not intended to limit the present invention. Any one of ordinary skill in the art to which the present invention pertains can make various changes without departing from the spirit and scope of the invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

100‧‧‧Waste treatment system

101, 103‧‧‧ arrows

110‧‧‧Sedimentation tank

111‧‧‧Drain pipe

113‧‧‧ Thermal insulation board

120‧‧‧Septic tank

121‧‧‧Aeration zone

121A‧‧‧First aeration device

121B‧‧‧Contact material

122a‧‧‧First air compression device

122b‧‧‧First submersible motor

123‧‧‧Rectifier

123A‧‧‧Rectifier

124‧‧‧Sun cover

125‧‧‧Aquatic plant purification area

125A‧‧‧ very waterborne plants

125B‧‧ soil layer

127‧‧‧Water area

130‧‧‧After aeration tank

131A‧‧‧Second aeration device

132a‧‧‧Second air compression device

132b‧‧‧Second submersible motor

140‧‧‧First connection unit

141‧‧‧ first outlet

143‧‧‧ first water inlet

150‧‧‧Second connection unit

151‧‧‧Second outlet

153‧‧‧Second water inlet

160‧‧‧ water level

Claims (9)

A wastewater treatment system comprising: a sedimentation tank, wherein a heat insulation plate covers a top of the sedimentation tank, a drain pipe is arranged at a bottom of the sedimentation tank, and a first water outlet is arranged on one side wall of the sedimentation tank; The septic tank comprises: an aeration zone comprising a first aeration device and a contact material, wherein the first aeration device comprises a first submersible motor and a first air compression device; and an aquatic plant purification zone, The aquatic plant purification zone comprises a soil layer, a water layer and an aqueous plant; and a rectification zone is disposed in the aeration zone and the aquatic plant purification zone, wherein the rectification zone comprises a plurality of rectifiers, wherein a first water inlet is disposed on a side wall adjacent to the aeration zone, and a second water outlet is disposed on a side wall adjacent to one of the aquatic plant purification zones; a first connecting unit is configured to connect the first water outlet and the first water outlet a first water inlet; a rear aeration tank comprising a second aeration device and a second water inlet, wherein the second aeration device comprises a second submersible motor and a second air compression device; Two connection list For connecting the second outlet and the second inlet. The wastewater treatment system of claim 1, wherein the nozzles of the rectifier tubes are parallel to a flow direction of one of the wastewaters. The wastewater treatment system of claim 1, wherein the effluent zone is further included after the aquatic plant purification zone. A wastewater treatment method, which is carried out by using a wastewater treatment system according to any one of claims 1 to 3, wherein the wastewater treatment method comprises: providing a wastewater; and performing a precipitation treatment on the wastewater in a sedimentation tank; Forming a rough treated water; performing a first processing step on the crude treated water in an aeration zone of a septic tank, wherein the first treating step comprises: performing an aeration treatment on the wastewater to form a Aerating water; and subjecting the aerated water to a contact oxidation treatment to form a first treated water; in a rectifying zone of the septic tank, performing a rectifying step on the first treated water to form a second Treating water; performing a third treatment step on the second treated water in the aquatic plant purification zone of the purification tank to form a third treated water, wherein the aquatic plant purification zone comprises a soil layer and a water layer And a watery plant; The third treated water is subjected to a post-aeration treatment in a post-aeration tank to form a purified water. The wastewater treatment method of claim 4, further comprising collecting the third treated water to a water discharge zone after the third treatment step. The wastewater treatment method according to claim 4, wherein the contact oxidation treatment is carried out by adhering to one of the contact materials. The wastewater treatment method according to claim 4, wherein the third treatment step comprises subjecting the second treated water to a biological treatment using the rhizome of the water-based plant. The wastewater treatment method according to claim 4, wherein the rectifying step is performed by a plurality of rectifier tubes, and the nozzles of the rectifier tubes are disposed in a flow direction parallel to one of the wastewaters. The wastewater treatment method of claim 4, wherein the purification tank is a single tank.