Sewage zero-discharge cyclic utilization construction method for concrete mixing station in environment-sensitive area

Abstract

The invention discloses a sewage zero-discharge cyclic utilization construction method for a concrete mixing station in an environmentally sensitive area, and relates to the technical field of sewage zero-discharge cyclic utilization construction.The sewage zero-discharge cyclic utilization construction method for the concrete mixing station in the environmentally sensitive area comprises the following steps that 1, production sewage of the mixing station is treated; 2, mixing station domestic sewage treatment; 3, mixing station rainwater treatment; 4, recycling water is collected; 5, reuse water is reused; and step 6, retreating the recycled water after use in the mode of the step 1. The scheme solves the problems that in the aspect of drainage treatment in an existing mixing station, production sewage is generally treated only by means of facilities such as a three-stage sedimentation tank and a sand-gravel separator, but no special measure is used for treating water from other sources, the capacity of recycling water resources is limited, and the treatment cost is low. The comprehensive protection requirement on the water source is difficult to meet.

Description

Technical Field

[0001] This invention relates to the field of construction technology for zero-discharge and recycling of wastewater, specifically a construction method for zero-discharge and recycling of wastewater from concrete mixing plants in environmentally sensitive areas. Background Technology

[0002] Zero wastewater discharge refers to a technology system that achieves over 99% recycling and reuse of concentrated wastewater with high salt content and pollutants after industrial water is reused, and the final residue is treated in solid form. This technology combines physical and chemical pretreatment, membrane separation, evaporation and crystallization processes to form a closed-loop treatment system including sand carbon filtration, ultrafiltration, reverse osmosis and MVR evaporator. For example, the Chinese authorized patent with publication number CN221344263U (A High-Environmental-Friendly Zero-Emission Water Circulation System for Mixing Plants) includes a production wastewater treatment system, a living area wastewater treatment system, a plant rainwater treatment system, and a circulation system. The production wastewater treatment system includes production wastewater, a sand and gravel separator, a sedimentation tank, a raw production wastewater tank, a reclaimed production wastewater system, a transition tank, and a clear water tank. In this high-environmental-friendly zero-emission water circulation system for mixing plants, the clear water tank and the mixing water tank of the mixing plant are connected by a pump pipe, which transports treated water to the mixing water tank for the preparation of mixed materials. The clear water tank has a dedicated pumping port for use by construction site water trucks for watering operations. The clear water tank is connected to the vehicle washing machine within the plant through a concealed pipe, enabling the recycling of vehicle washing water and further conserving water resources. These measures aim to ensure the most efficient use of water resources while meeting environmental protection requirements.

[0003] In terms of existing wastewater treatment at concrete mixing plants, the current methods typically rely solely on facilities such as tertiary sedimentation tanks and sand and gravel separators to treat production wastewater. However, there are no specific measures to treat water from other sources, and the capacity for recycling water resources is limited, making it difficult to meet the requirements for comprehensive protection of water sources. Therefore, we propose a construction method for zero-discharge recycling of wastewater from concrete mixing plants in environmentally sensitive areas. Summary of the Invention

[0004] The purpose of this invention is to provide a construction method for zero-discharge recycling of wastewater from concrete mixing plants in environmentally sensitive areas, in order to solve the problem mentioned in the background art that the existing wastewater treatment in mixing plants usually only relies on facilities such as three-stage sedimentation tanks and sand and gravel separators to treat production wastewater, but there are no special measures to treat water from other sources, and the ability to recycle water resources is limited, which makes it difficult to meet the requirements for comprehensive protection of water sources.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a construction method for zero-discharge recycling of wastewater from concrete mixing plants in environmentally sensitive areas, comprising the following steps: Step 1: Wastewater treatment at the mixing plant; Step 2: Treatment of domestic sewage from the mixing plant; Step 3: Treatment of rainwater from the mixing plant; Step 4: Collect the recycled water; Step 5: Reuse the recycled water; Step 6: Reprocess the used recycled water using the method described in Step 1.

[0006] Preferably, step 1 includes the following steps: Step 1-1: Wastewater from the mixing plant is treated by a sand and gravel separator to remove coarse sand and gravel. Steps 1-2: After initial natural sedimentation in the raw water sedimentation tank, the water is pumped to the integrated equipment, where the colloids and fine suspended solids in the wastewater are coagulated into flocs by the action of coagulants. Steps 1-3: The mud and water are separated by an integrated dewatering and purification equipment. The mud cake can then be transported off-site, and the clean water can be reused.

[0007] Preferably, the wastewater from the mixing plant in step 1-1 mainly comes from the washing water of concrete mixer trucks, containing solid materials such as stones, sand, and cement, with very little organic matter in the water.

[0008] Preferably, in steps 1-2, the coagulant sedimentation can not only remove fine suspended particles with a particle size of 10⁻³ to 10⁻⁶ mm from the wastewater, but also remove color, oil, microorganisms, nutrients such as nitrogen and phosphorus, heavy metals, and organic matter.

[0009] Preferably, step 2 includes the following steps: Step 2-1: Through biological treatment, the raw water passes through a screen to remove impurities such as hair and large suspended solids, and then enters the equalization tank to adjust the water quality and quantity. Step 2-2: Use a water pump to lift the wastewater to the integrated equipment, and then treat it through the "anoxic + aerobic + MBR" process to make the wastewater meet the reuse standards.

[0010] Preferably, step 3 includes the following steps: Step 3-1: Collect rainwater through pipes. Before entering the storage tank, the rainwater passes through an initial diversion filtration device to divert the initial polluted rainwater to the raw wastewater sedimentation tank. Step 3-2: After the rainwater enters the storage tank, it is pumped to the integrated rainwater purification equipment for deep filtration and disinfection to meet the reuse standards.

[0011] Preferably, the reuse of water in step 5 is for watering roads and washing vehicles.

[0012] Preferably, the dehydration-purification integrated equipment in steps 1-3 requires dosing via a dosing device. The dosing agents are polyaluminum chloride and polyacrylamide. When adding the chemicals, the tank mixer is turned on and stirred until uniform. The stirring time is at least 1 hour.

[0013] Preferably, the method for preparing the polyaluminum chloride includes the following steps: S1: Operators should wear protective gloves and protective clothing; S2: Calculate the dosage of chemicals and the amount of tap water to be used according to the chemical dosing tank provided with the project; S3: Fill the chemical dosing tank with tap water to the calculated water level, close the tap water valve, and open the air valve. At the door, start by directly adding polyaluminum chloride into the box, and at the same time turn on the stirrer to stir until the drug is completely mixed to obtain polyaluminum chloride, with the concentration controlled at 5%-10%.

[0014] Preferably, the method for preparing the polyacrylamide includes the following steps: A1: First, take the calculated amount of polyacrylamide, add a certain amount of tap water, and stir until fully dissolved. Solution; A2: Add tap water to the dosing tank until the calculated mark, then add the dissolved polyacrylamide solution. When adding the liquid, the speed should be slow to ensure that the polyacrylamide dissolves completely. The amount of polyacrylamide added should be the same as that added by distilled water. 0.1%-0.3% of weight.

[0015] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention achieves three independent wastewater treatments through the treatment of production wastewater, domestic wastewater, and rainwater at the mixing plant. The treated water from the three systems is stored in a reuse pond for watering the site and washing vehicles. The water used for washing vehicles is collected and discharged into the raw wastewater sedimentation tank. The system considers all possible wastewater discharged from the mixing plant and reuses it in a comprehensive manner, thereby improving the utilization rate of water resources and minimizing the discharge of wastewater and polluted rainwater in sensitive areas. Compared with traditional methods, this method combines production wastewater, domestic wastewater, rainwater, and water resource reuse into a complete system. The wastewater generated is reused for watering the site and washing vehicles, and then treated again to achieve recycling. Zero discharge is achieved in environmentally sensitive areas, saving water resources. This method solves the problem that existing mixing plant drainage treatment usually relies only on facilities such as three-stage sedimentation tanks and sand and gravel separators to treat production wastewater, but there are no special measures to treat water from other sources, and the ability to recycle water resources is limited, making it difficult to meet the requirements for comprehensive protection of water sources. Attached Figure Description

[0016] Figure 1 This is a flow chart of the construction process for zero-discharge recycling of wastewater from the mixing plant according to the present invention. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] Please see Figure 1 The present invention provides an embodiment of a construction method for zero-discharge recycling of wastewater from concrete mixing plants in environmentally sensitive areas, comprising the following steps: Step 1: Wastewater treatment at the mixing plant; Step 2: Treatment of domestic sewage from the mixing plant; Step 3: Treatment of rainwater from the mixing plant; Step 4: Collect the recycled water; Step 5: Reuse the recycled water; Step 6: Re-treat the recycled water using the method described in Step 1; By storing the treated water from the three major treatment systems in a reuse pond, the water is used for watering the site and washing vehicles. The water used for washing vehicles is collected and discharged into the raw wastewater sedimentation pond. This method minimizes the discharge of wastewater and polluted rainwater into sensitive areas. Compared with traditional methods, this method combines the entire system of industrial wastewater, domestic sewage, rainwater, and water resource reuse. The wastewater generated is reused for watering the site and washing vehicles, achieving zero discharge in environmentally sensitive areas and saving water resources.

[0019] Furthermore, step 1 includes the following steps: Step 1-1: Wastewater from the mixing plant is treated by a sand and gravel separator to remove coarse sand and gravel. Steps 1-2: After initial natural sedimentation in the raw water sedimentation tank, the water is pumped to the integrated equipment, where the colloids and fine suspended solids in the wastewater are coagulated into flocs by the action of coagulants. Steps 1-3: The mud and water are separated by an integrated dewatering-purification device. The mud cake can then be transported off-site, and the clean water can be reused. This enables independent treatment of wastewater from the mixing plant, improving wastewater treatment efficiency and cleanliness.

[0020] Furthermore, the wastewater from the mixing plant in step 1-1 mainly comes from the washing water of concrete mixer trucks, which contains solid materials such as stones, sand, and cement, and very little organic matter.

[0021] Furthermore, in steps 1-2, the coagulant sedimentation can not only remove fine suspended particles with a particle size of 10⁻³ to 10⁻⁶ mm from the wastewater, but also remove color, oil, microorganisms, nutrients such as nitrogen and phosphorus, heavy metals, and organic matter.

[0022] Furthermore, step 2 includes the following steps: Step 2-1: Through biological treatment, the raw water passes through a screen to remove impurities such as hair and large suspended solids, and then enters the equalization tank to adjust the water quality and quantity. Step 2-2: Use a water pump to lift the wastewater to the integrated equipment, and then treat it through the "anoxic + aerobic + MBR" process to make the wastewater meet the reuse standards. This allows for the independent treatment of domestic sewage from the mixing plant, preventing it from being mixed with industrial wastewater, thus improving treatment efficiency and the cleanliness of the treated wastewater.

[0023] Furthermore, step 3 includes the following steps: Step 3-1: Collect rainwater through pipes. Before entering the storage tank, the rainwater passes through an initial diversion filtration device to divert the initial polluted rainwater to the raw wastewater sedimentation tank. Step 3-2: After the rainwater enters the storage tank, it is pumped to the integrated rainwater purification equipment for deep filtration and disinfection to meet the reuse standards. This method achieves independent treatment of rainwater from the mixing plant, preventing it from being mixed with domestic sewage and production wastewater. It implements three independent wastewater treatment systems, storing the treated water in a reuse pond for watering the site and washing vehicles. Water used for washing vehicles is collected and discharged into a sedimentation pond for raw production wastewater. This minimizes the discharge of wastewater and polluted rainwater into sensitive areas. Compared to traditional methods, this approach integrates production wastewater, domestic sewage, rainwater, and water resource reuse into a comprehensive system. Wastewater generated is reused for watering the site and washing vehicles, achieving zero discharge in environmentally sensitive areas and conserving water resources.

[0024] Furthermore, in step 5, the recycled water is used for watering roads and washing vehicles.

[0025] Furthermore, the dehydration-purification integrated equipment in steps 1-3 requires chemical dosing during use. The chemicals used are polyaluminum chloride and polyacrylamide. When adding chemicals, turn on the tank mixer and stir until uniform. The stirring time should be at least 1 hour.

[0026] Furthermore, the preparation method of polyaluminum chloride includes the following steps: S1: Operators should wear protective gloves and protective clothing; S2: Calculate the dosage of chemicals and the amount of tap water to be used according to the chemical dosing tank provided with the project; S3: Fill the chemical dosing tank with tap water to the calculated water level, close the tap water valve, and open the air valve. At the door, start by directly adding polyaluminum chloride into the box, and at the same time turn on the stirrer to stir until the drug is completely mixed to obtain polyaluminum chloride, with the concentration controlled at 5%-10%.

[0027] Furthermore, the preparation method of polyacrylamide includes the following steps: A1: First, take the calculated amount of polyacrylamide, add a certain amount of tap water, and stir until fully dissolved. Solution; A2: Add tap water to the dosing tank until the calculated mark, then add the dissolved polyacrylamide solution. When adding the liquid, the speed should be slow to ensure that the polyacrylamide dissolves completely. The amount of polyacrylamide added should be the same as that added by distilled water. 0.1%-0.3% of weight.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An environmental sensitive area concrete mixing plant sewage zero discharge recycling construction method, characterized in that, The method comprises the following steps: Step 1: mixing station production sewage treatment; Step 2: mixing station domestic sewage treatment; Step 3: mixing station rainwater treatment; Step 4: collecting reclaimed water; Step 5: using the reclaimed water; Step 6: treating the used reclaimed water by the method of step 1.

2. The method according to claim 1, wherein the method is characterized in that: The step 1 comprises the following steps: Step 1-1: removing coarse sand from the mixing station production sewage by a sand separator; Step 1-2: performing preliminary natural sedimentation on the raw water in a raw water sedimentation tank, pumping to an integrated device, and coagulating colloids and fine suspended solids in the wastewater into flocculation bodies under the action of a coagulant; Step 1-3: separating the mud and water by a dehydration-purification integrated device, then the mud cake can be transported out, and the clear water is reused.

3. The method according to claim 2, wherein the method is characterized in that: The mixing station production sewage in the step 1-1 mainly comes from the washing water of a concrete tank truck, containing solid substances such as stones, sand and cement, and having little organic matter in the water.

4. The construction method for zero-discharge recycling of wastewater from concrete mixing plants in environmentally sensitive areas according to claim 2, characterized in that: In the step 1-2, the coagulant precipitation can not only remove the fine suspended particles with a particle size of 10-3~10-6mm in the wastewater, but also remove color, oil, microorganisms, nitrogen and phosphorus, heavy metals and organic matter.

5. The method according to claim 1, wherein the method is characterized in that: The step 2 comprises the following steps: Step 2-1: treating by a biological method, removing impurities such as hair and large particle suspended solids in the water by a grid, and adjusting the water quality and quantity in a regulating tank; Step 2-2: lifting to an integrated device by a water pump, and then treating by an "anaerobic+ aerobic+MBR" process to make the sewage meet the reuse standard.

6. The method according to claim 1, wherein the method is characterized by: The step 3 comprises the following steps: Step 3-1: collecting rainwater by a pipeline, and discarding the initial contaminated rainwater to the production sewage raw water sedimentation tank by an initial discarding and filtering device before the rainwater enters a water storage tank; Step 3-2: then lifting to a rainwater purification integrated device by a water pump after the rainwater enters the water storage tank, and performing deep filtration and disinfection to meet the reuse standard.

7. The method according to claim 1, wherein the method further comprises: 7.

1. collecting the wastewater from the concrete mixing plant; 7.

2. treating the wastewater to remove the contaminants; 7.

3. recycling the treated wastewater to the concrete mixing plant; and 7.

4. repeating steps 7.1 to 7.

3. The reclaimed water in the step 5 is used for sprinkling roads and washing vehicles.

8. The method according to claim 2, wherein the method is characterized in that: The dehydration-purification integrated device in the step 1-3 needs to be dosed by a dosing device when used, and the dosing agent is polyaluminum chloride and polyacrylamide, and the dosing is started by opening the stirring machine of the dosing barrel, and the stirring is performed until uniform, and the stirring time is at least 1h.

9. A construction method for zero-discharge recycling of wastewater from a concrete mixing plant in an environmentally sensitive area, as described in claim 8, is characterized in that: The preparation method of the polyaluminum chloride comprises the following steps: S1: an operator wears protective gloves and protective clothing; S2: calculating the dosing amount and tap water amount according to the dosing box matched with the project; S3: injecting tap water into the dosing box to the calculated water level, closing the tap water valve, and opening the air valve, starting to directly add polyaluminum chloride into the box, and simultaneously opening the stirrer, and stirring until the medicine is completely mixed, to obtain polyaluminum chloride, and the concentration is controlled to be 5%-10%.

10. The method of claim 8, wherein the method further comprises: The preparation method of the polyacrylamide comprises the following steps: A1: first taking a calculated amount of polyacrylamide, adding a certain amount of tap water, and stirring until fully dissolved; A2: adding tap water into the dosing barrel to the calculated scale, and adding the dissolved polyacrylamide solution, the adding speed is slow to make the polyacrylamide fully dissolved, and the amount of the added polyacrylamide is 0.1%-0.3% of the weight of the water.

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