CN210150857U - Construction wastewater purification and recycling system for temporary concrete mixing station for highway construction - Google Patents

Abstract

The utility model relates to a interim concrete mixing station construction waste water purification of highway construction and recycling system belongs to the environmental protection system in the highway engineering construction. The utility model provides a construction waste water to interim concrete mixing station of highway construction carries out comprehensive purification treatment such as grid screening, natural sedimentation, oil removal, filtration and categorised collection's method and technology, process the utility model discloses mixing station waste water after the purification treatment can carry out the overflow and discharges or be used for the mixing station to wash uses such as place, washing tank car, afforestation, and categorised cyclic utilization can be realized to materials such as stone, sand, cement that categorised subregion was collected, reduces waste water and waste residue and discharges the influence to ecological environment and water environment.

Description

Construction wastewater purification and recycling system for temporary concrete mixing station for highway construction

Technical Field

The utility model provides a method and system can be used to the concrete mixing station construction waste water that the temporary set up in the highway construction, wash comprehensive purification and retrieval and utilization of waste water and field area rainwater, the quality of water purification of near sensitive water body station construction waste water to and fields such as building construction waste water and the purification treatment of the similar sewage of concrete mixing station construction waste water quality of water characteristic.

Background

Along with the rapid development of national economy, the construction of road traffic infrastructures meets new gold periods and heavy opportunities, the highway is greatly developed, simultaneously, the national and provincial trunk line transformation and the rural highway construction meet new development climax, a great part of the highway engineering projects are located in remote areas or mountain areas, and the centralized mixing and the centralized transportation of commercial concrete are difficult to realize. Therefore, in the road engineering construction, some temporary concrete mixing stations are inevitably needed to be arranged on the engineering construction site to meet the concrete mixing requirement in the engineering construction. The mixing stations are mostly located in areas with relatively good ecological environment and sensitive water environment protection, the scale of the temporary concrete mixing stations is relatively small, land resource utilization is difficult, capital investment of environmental protection facilities is limited, the level of centralized collection, purification and cyclic utilization of construction wastewater and field rainwater is not high, and the temporary concrete mixing stations become one of the main environmental problems which restrict the construction and management of the temporary concrete mixing stations in highway engineering construction in China gradually. Therefore, aiming at comprehensive factors such as construction wastewater sources, water quality characteristics, site conditions and capital conditions of the temporary concrete mixing station for highway construction, the construction wastewater purification and recycling system for the temporary concrete mixing station for highway construction, which has the advantages of simple structure, convenience in maintenance, good purification efficiency and high material classification and collection, is provided.

The concrete mixing plant wastewater mainly comes from three aspects, namely cleaning wastewater generated by cleaning concrete transport vehicles; cleaning construction wastewater generated by mixing mechanical equipment (such as a stirrer) and the like; thirdly, flushing wastewater generated by flushing a hardened site in a factory area; and fourthly, rainwater and sewage generated by concentrated convergence of rainfall in the field area range. From the water quality pollution index of the waste water, the main pollution components of the waste water are stones with larger grain sizes, suspended particulate matters (SS), particulate matter powder (including cement, mineral powder, fly ash and the like) and petroleum (including oil stains and the like generated when a transport vehicle and construction machinery are washed), and researches show that the purification treatment of the waste water of the concrete mixing plant by screening, precipitation, filtration, oil removal and the like is a feasible and effective method.

A great deal of work is carried out at home and abroad on the purification and recycling of the waste water of the concrete mixing plant, and some patent methods for treatment and purification are already proposed. These methods have also made some innovations and breakthroughs in some aspects, but still have certain defects and adaptability problems in terms of their application to the purification and reuse of wastewater from temporary concrete mixing stations for road construction, such as:

the invention has application number of 97106427, and is named as the invention patent of the comprehensive utilization process of waste water and waste residue of a concrete mixing plant, and comprises a mud and sand separation process, a pool system flow, a mud recycling process and a mechanical and electrical control system. The flow of the water tank system is that when the liquid level of the slurry flowing into the slurry tank exceeds the height of the overflow port, the slurry flows into the slurry homogenizing tank and then flows into the clean water tank, the solid in the slurry water overflows after precipitation, the water in the clean water tank can be recycled, and the slurry separated by the slurry and sand-stone separator is subjected to concentration blending in the slurry homogenizing tank and is manually measured for recycling. The mud recycling process is carried out through a mud control valve and a clean water electromagnetic valve. The method can realize no waste water and waste residue discharge, save water and building raw materials, and is beneficial to environmental protection, but has the problems of complex mechanical and electrical control system, larger floor area, higher capital investment and operation cost, and the like.

The invention discloses an invention patent with application number 201711204973.7 and named as a concrete mixing plant wastewater and waste residue comprehensive utilization process, which mainly adopts a 6-stage sedimentation tank to carry out sedimentation purification treatment on concrete mixing plant wastewater, has a better removal effect on suspended solid SS and the like in the wastewater, but the provided multistage sedimentation treatment mode has large floor area and low single sedimentation purification treatment efficiency, can not remove pollutants such as petroleum in a targeted manner, and has complex cleaning and maintenance and high cost due to too many tanks in the later-stage daily management process.

The invention relates to an invention patent with the application number of 201810350411.1 and the name of the invention patent is a treatment process of concrete mixing station wastewater, which mainly adopts a series of physical and chemical processes of filtration, neutralization, solid-liquid separation, oxidation and the like to treat the pH value and Ca in the mixing station wastewater₂₊Ions and the like are deeply purified and treated, so that the construction wastewater can be discharged after reaching standards, but the whole set of physical and chemical treatment procedures are complex, more detailed operations are realized, the professional requirement on chemical addition is high, and the method cannot be completely suitable for being used under the extensive management condition of a field temporary concrete mixing plant in the highway engineering construction. Application number is 201520861302.8, the name is concrete mixing plant effluent treatment plant's utility model patent mainly comprises waste water collecting tank and separating centrifuge, realizes mud-water separation through the separating centrifuge, and mud directly utilizes through stirring the pond after mixing, can realize the waste material utilization and using electricity wisely, but can't realize the categorised separation and the utilization of stone, sand, water, and it is higher to the installation of equipment and operation maintenance requirement, and waste water quality of water purifying effect does not guarantee simultaneously.

Application number is 201620052320.6, the name is concrete mixing plant effluent disposal system's utility model patent, mainly through mechanical operations such as stone screening conveyer and belt feeder, spiral sand washer and belt feeder, realized the separation of stone, sand and water, realized comprehensive utilization to stone, sand resource, through the purification treatment that natural sedimentation realized waste water, but waste water through natural sedimentation purification efficiency low, get rid of the effect poor to petroleum class pollutant, whole system area is big, comprehensive mechanical operation is more complicated.

In summary, the existing concrete mixing plant mostly adopts technologies such as mechanical screening, mud-water separation, sedimentation tank and the like to purify waste water and classify, collect and utilize materials, and the adoption of mechanical screening and mud-water separation operations mostly requires complex mechanical equipment and on-site electromechanical maintenance operations, and simultaneously requires occupation of large-area land resources and consumption of a large amount of electric power resources; the adopted sedimentation tank treatment technology is mainly focused on the design of a conventional natural sedimentation tank, and the sedimentation capacity and the pollutant removal efficiency are required to be further improved. At present, the existing related technology cannot effectively remove petroleum pollution.

In view of the above situation, the utility model discloses the designer is based on pursuing the abundant practical experience of this type of product design and manufacture many years and professional knowledge to the application of cooperation theory, actively research the innovation, provides a construction waste water purification and retrieval and utilization processing system of the interim concrete mixing station of suitable highway construction, has to concrete mixing station construction waste water multiple main pollutants treatment effect good, take up an area of few, engineering cost is low, maintain advantages such as simple and convenient.

Disclosure of Invention

The utility model aims at providing a can purify and retrieval and utilization processing system to construction waste water of interim concrete mixing station of highway construction, purification efficiency is low among the prior art can effectively be overcome to this system, area is big, engineering cost is high, it is more complicated to maintain the management, shortcoming and problem such as deoiling function lacks the position, a large amount of waste water to producing in the interim concrete mixing station of highway construction, wherein mainly to stone, sand, cement, suspended particles thing (SS), pollutants such as petroleum grease class have stable efficient and get rid of the effect, can realize stone simultaneously, sand, cement, the segmentation of water is got rid of and categorised collection and cyclic utilization.

The utility model provides a construction waste water to interim concrete mixing station of highway construction carries out comprehensive purification treatment such as grid screening, natural sedimentation, oil removal, filtration and categorised collection's method and technology, process the utility model discloses mixing station waste water after the purification treatment can carry out the overflow and discharge or be used for mixing station to wash uses such as place, washing tank car, afforestation, and categorised cyclic utilization can be realized to materials such as stone, sand, cement that divide regional collection in classification, reduces waste water and waste residue and discharges the influence to ecological environment and water environment.

The utility model relates to a construction waste water purification and recycling treatment system for a temporary concrete mixing station for highway construction, which is provided with a primary sedimentation tank 4, a primary sedimentation oil separation tank 6, a secondary sedimentation filtering tank 9, a tertiary sedimentation filtering tank 11 and a recycling tank 13 in sequence; the primary sedimentation tank 4 is communicated with a primary sedimentation oil separation tank 6 through an overflow hole 5; the primary sedimentation oil-separation tank 6 is communicated with the secondary sedimentation filtering tank 9 through a first filtering hole 8; the second-stage sedimentation filtering tank 9 is communicated with the third-stage sedimentation filtering tank 11 through a second filtering hole 10; the third-stage sedimentation filtering tank 11 is communicated with a reuse water tank 13 through a third filtering hole 12.

Further, a tank car backing stopping device is arranged outside the primary sedimentation tank and consists of a guardrail rod 2 and a fixing device 1.

Further, a grid 3 is arranged in the primary sedimentation tank 4, a gentle slope which inclines downwards is formed from one side of the grid 3 to the tank, the slope is 10-15 degrees, and the bottom end of the slope is horizontally arranged 2-3 meters away from the opposite side of the tank.

Furthermore, an overflow hole 5 is formed in the upper portion of a partition wall between the primary sedimentation tank 4 and the primary sedimentation oil separation tank 6, an oil collecting tank 7 is vertically arranged on the partition wall on the inner side of the primary sedimentation oil separation tank between the primary sedimentation oil separation tank 6 and the secondary sedimentation filtering tank 9, and a first filtering hole 8 is formed in the diagonal position of the lower portion and the overflow hole 5.

Further, a polymer oil absorption material is arranged in the oil collecting tank 7 and is periodically replaced or cleaned, the polymer oil absorption material is preferably a polystyrene electrostatic spinning fiber material, and the arrangement thickness is 20 cm.

Furthermore, a rectangular gabion filtering module is arranged on one side, facing the primary sedimentation oil separation tank, of the first filtering hole 8, the periphery of the rectangular gabion filtering module is formed by weaving steel bar frameworks made of iron wires, broken stones are filled in the rectangular gabion filtering module, and the particle size range of the broken stones is 1-3 cm; the second filtering hole 10 is arranged at the diagonal position of the first filtering hole 8, the third filtering hole 12 is arranged at the diagonal position of the second filtering hole 10, the rectangular gabion filtering modules are arranged on one side of the water inlet end of the second filtering hole 10 and one side of the water inlet end of the third filtering hole 12 respectively, the periphery of each rectangular gabion filtering module is formed by weaving a steel reinforcement framework made of iron wires, gravel is filled in the gabion filtering modules, stones with the particle size range of 1-2 cm and gravel with the particle size range of 0.5-1 cm are respectively filled in the gabion modules on filtering holes 10 and 12, and the particle size of the gravel filler of the filtering module is gradually reduced.

Furthermore, an overflow port 15 is arranged at the position of the tail end of the reuse water tank, which is 0.3-0.4 m away from the top of the tank, the overflow port is not provided with a control valve, and a reuse water pump 14 is arranged in or outside the reuse water tank.

Furthermore, the bottom of the first-stage sedimentation oil separation tank, the second-stage sedimentation filter tank and the third-stage sedimentation filter tank is respectively provided with a slope with the gradient of 2% -5%, the slope inclines upwards from the water outlet direction, the lower concave part of the slope is respectively provided with a sand collecting groove, and the top of each tank is provided with a stainless steel top cover with the gradient of 2%.

The technical scheme of the utility model explains as follows:

mixing station field area waste water, concrete transport vehicle's washing waste water are concentrated and are catched into the primary sedimentation pond, and the primary sedimentation pond front end is equipped with the grid and gets rid of large particle size stone, sand, cement, sets up the tank car stopping ware that backs a car outside the primary sedimentation pond, prevents that the vehicle from backing excessively and causing the damage to facilities such as grid. And other sand-containing wastewater enters the primary sedimentation oil separation tank through an overflow hole arranged at the upper part of the primary sedimentation tank after being mixed and sedimentated at the rear end of the primary sedimentation tank.

An oil collecting groove is vertically arranged on the inner side of the primary precipitation oil separation tank between the primary precipitation oil separation tank and the secondary precipitation filter tank, and a high-molecular oil absorption material, preferably a polystyrene electrostatic spinning fiber material with the thickness of 20cm, is paved in the oil collecting groove. When the mixture of oil and suspended matters contacts the surface of the polystyrene electrostatic spinning fiber material, the oil is firstly polymerized in a three-dimensional network structure, continuously coalesced and attached to the surface of the fiber, so that oil-water separation is realized; simultaneously, still reach through the experiment we, it still has better coalescence effect to the suspended solid, consequently, is used for the utility model discloses a pollution mixture such as suspended particles thing (SS), the oil and fat class in the construction waste water of highway construction concrete mixing station is that other polymer oil absorption materials have more apparent effect of getting rid of.

Still set up 1 ~ 2 wash ports in the oil trap, improve the oil absorption of oil trap, receive oil and deoiling function comprehensively to guarantee good sluicing effect, the oil absorption material needs regularly to be changed. Larger particles, petroleum grease and suspended particles (SS) in the wastewater are further purified in a primary precipitation oil separation tank, then enter a secondary precipitation filter tank through a filter hole arranged at the bottom of the primary precipitation oil separation tank, and enter a third-stage precipitation filter tank through a filter hole arranged at the top of the secondary precipitation filter tank after being settled through diagonal flow deflection and reverse water flow, wherein the SS is removed from the secondary precipitation filter tank and the third-stage precipitation filter tank, and the particle size of the particles is gradually reduced; through diagonal angle baffling with in the same direction as rivers subside the back, the rethread setting gets into the retrieval and utilization pond in the filtration pore of crossing of tertiary sedimentation filtering ponds bottom, it sets up rectangle gabion filtration module respectively to come water end one side at the filtration pore of crossing, gabion filtration module packs and adopts mixing station particle diameter stone processing to form, along with the increase of sedimentation filtering ponds progression, the particle diameter of the filler rubble of chooseing for use reduces step by step, can effectively improve the pollutant purification efficiency of sedimentation filtering ponds at different levels on the one hand, on the other hand can realize filtering module good prevent blockking up the effect. Meanwhile, the filtering holes among the primary precipitation oil separation tank, the secondary precipitation filtering tank and the tertiary precipitation filtering tank are arranged in a diagonal and up-down alternate mode, so that the zigzag flow of water flow can be effectively ensured, the hydraulic retention time is prolonged, and the precipitation and purification effects are improved. The reuse water tank is internally provided with a reuse water pump, so that the purified wastewater can be used for site mixing in time or used for flushing tank cars, flushing areas and the like, and the reuse water tank is internally provided with an overflow external discharge port. The bottom of the primary sedimentation tank is provided with an inclined gentle slope with a certain gradient, and the primary sedimentation tank is horizontal at a certain distance (for example, 2-3 meters) from the end of the primary sedimentation tank, so that the operation of a sand shoveling construction machine is facilitated. The first-stage sedimentation oil separation tank, the second-stage sedimentation filter tank and the third-stage sedimentation filter tank are respectively provided with a sand collection tank, and the sedimentary silt is collected to the sand collection tank under the action of gravity and static pressure of water, so that the silt in the tanks needs to be cleaned regularly. It should be noted that the water inlet end refers to the water flow direction from the primary sedimentation tank to the primary, secondary and tertiary filtration sedimentation tanks.

Compared with the prior art, the utility model obvious advantage and beneficial effect have. Borrow by above-mentioned technical scheme, the utility model discloses in the construction waste water purification and the retrieval and utilization processing technology of the interim concrete mixing station of highway construction that provide can reach considerable technical progress nature and practicality to have the wide use value in industry, it has following advantage at least:

1. the utility model provides a construction waste water purification and recycling treatment system of interim concrete mixing station of highway construction mainly includes the just sinking pond and deposits, oil removal, filtration purification system, and the just sinking pond can realize the effect of stone, sand separation and resource classification recovery, is the stone class before the grid, and the sand collecting tank part realizes the preliminary sedimentation of coarse sand, and follow-up technology further realizes the deep purification treatment to pollutants such as SS in the waste water;

2. the combined use of the primary sedimentation oil separation tank, the secondary sedimentation filtering tank and the tertiary sedimentation filtering tank system provided by the utility model has the comprehensive purification functions of waste water such as sedimentation, oil separation and filtration, and has good removal effect on main pollutants SS, petroleum and the like of the construction waste water of the concrete mixing station;

3. the first-level precipitation oil separation tank, the second-level precipitation filter tank and the third-level precipitation filter tank are respectively provided with gravels with proper particle sizes as fillers of the gabion filter module, so that the hydraulic retention time of water flow in the oil separation precipitation tank and the precipitation filter tank can be effectively prolonged, a better precipitation effect is achieved, and the engineering occupation can be greatly saved. Meanwhile, by the comprehensive physical and chemical purification effects of blocking, adsorption, filtration and the like of the gravel filter layers with different particle sizes, pollutants such as SS and the like in the wastewater can be effectively removed;

4. the design of the side-hung oil collecting tank of the primary sedimentation oil separation tank and the laying design of the polymer oil absorption material enable the system to realize good oil separation and removal capability, can well remove petroleum pollutants in the construction wastewater of the mixing station, and the adsorbed oil substances are accumulated in the oil collecting tank, can be cleaned and replaced once every half year, and are simple to maintain and manage; according to long-term detection and a comparison test, a high-molecular oil absorption material, namely a polystyrene electrostatic spinning fiber material, suitable for construction wastewater of a temporary concrete mixing station for highway construction is obtained, and the oil absorption multiple and the oil-water separation speed of the high-molecular oil absorption material are optimal, wherein the arrangement thickness of the high-molecular oil absorption material is 20 cm;

5. the gabion filtering module is made of local materials, graded broken stone materials with different grain sizes stored in the concrete mixing station are used as fillers, and the graded broken stone fillers have good filtering, adsorbing and other functions, so that the purifying effect of the system is effectively improved, and the construction cost is saved;

6. the front half part of the primary sedimentation tank adopts a gentle slope, the rear half part adopts a horizontal design, so that the construction operation of sand shoveling and loading machinery along the slope surface and the shoveling of settled sand on the plane are facilitated, and the cleaning construction of the primary sedimentation tank is convenient and easy to operate;

7. the bottom parts of the primary sedimentation oil separation tank, the secondary sedimentation filter tank and the tertiary sedimentation filter tank are provided with slope sand collecting grooves, so that the collection of particles through gravity stationary flow is facilitated, only the silt at the sand collecting groove part needs to be pumped and discharged during cleaning, and the maintenance is simple and convenient;

8. overflow ports and filtering holes in the primary sedimentation tank, the primary sedimentation oil separation tank, the secondary sedimentation filtering tank and the tertiary sedimentation filtering tank are arranged in a diagonal manner and are arranged in a vertically crossed manner, so that the water flow direction and the hydraulic characteristics of the system can be effectively changed, the comprehensive sedimentation effect of upper and lower multi-stage baffling is realized, the hydraulic retention time effect is improved, the sedimentation effect is better, and the engineering occupied area can be saved; each stage is unpowered and is acted on by the water level difference in each tank. The tank top of one-level sedimentation oil removal tank, second grade sedimentation filtration tank and tertiary sedimentation filtration tank sets up the stainless steel top cap, avoids taking place the incident such as personnel fall into water, and the slope is 2%, and the top cap can be opened unilateral or two sides at any time as required, is convenient for change rectangle filtration module and the clearance of deposit in the sand catch bowl.

9. The reuse water tank is provided with an overflow port and a reuse water pump, and can realize standard discharge and comprehensive utilization of purified wastewater. To sum up, the utility model provides a construction waste water purification treatment and recycling system of interim concrete mixing station of highway construction has above-mentioned a great deal of advantage and practical value, can realize construction materials's such as stone, sand and cement classification and recycle, realize high-efficient purification and cyclic utilization to construction waste water simultaneously, area is little, daily operation and maintenance are more convenient, it no matter all has the outstanding multinomial efficiency of promoting in method, procedure, thereby be suitable for the practicality more, and have the wide utilization value of industry, more traditional concrete mixing station waste water waste residue processing system etc. have apparent economic benefits and environmental benefits, and practical value has more, honest is a novelty, progress, reliable, practical new design.

Drawings

FIG. 1 is a top view of a construction wastewater purification and reuse treatment system of a temporary concrete mixing station for highway construction.

FIG. 2 is a longitudinal cross-sectional view of side b-b of the purification and reuse treatment system of FIG. 1.

FIG. 3 is a longitudinal sectional view of the side of the primary sedimentation tank c-c of FIG. 2.

Illustration of the drawings:

1. guardrail bar 2. fixing device

3. Grating 4. preliminary sedimentation tank

5. Overflow hole 6, first-stage sedimentation oil separation tank

7. Oil sump 8, first filtering hole

9. A second filtering hole of the second-stage sedimentation filtering tank 10

11. Third filtering holes of the third-stage sedimentation filtering tank 12

13. Reuse pool 14, reuse water pump

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

The utility model provides a system of comprehensive purification treatment and retrieval and utilization such as interim concrete mixing station construction waste water screening of highway construction, oil removal, sediment, filtration.

Fig. 1 is a top view of a construction wastewater purification and recycling treatment system of a temporary concrete mixing station for road construction, and fig. 2b-b are longitudinal sectional views of the side surfaces, as can be seen from fig. 1 and fig. 2, wastewater in a mixing station field area and flushing wastewater of a concrete transport vehicle are gathered into a primary sedimentation tank 4, a tank car backing stopping device is arranged outside the primary sedimentation tank and consists of a guard rail 2 and a fixing device 1, the damage to facilities such as a grid caused by excessive backing of the vehicle is prevented, and the system can be opened at any time according to the working requirements of sand shoveling construction mechanical operation and the like. The front end of the primary sedimentation tank 4 is provided with a grid 3 for screening and removing stones with large particle size, and other sand-containing wastewater enters a primary sedimentation oil separation tank 6 through an overflow hole 5 arranged at the upper part of the primary sedimentation tank after being mixed and sedimentated at the rear end of the primary sedimentation tank 4. Fig. 3 is a sectional view of the c-c side of the primary sedimentation tank of fig. 2, a gentle slope inclining downwards is formed within a distance of 3-5 m from the grid 3 to the direction in the tank, the slope is 10% -15%, the slope bottom of the gentle slope is set to be horizontal (the horizontal distance shown in fig. 1 and fig. 3 a-a) within a distance range of 2-3 m from the opposite side of the primary sedimentation tank, and the operations of construction operation of a sand shoveling construction machine along a slope surface, shoveling settled sand on a plane and the like are facilitated.

The oil collecting tank 7 is arranged on the inner side of a partition wall of the primary sedimentation oil separation tank 6 in a side-hanging fixing mode, a high-polymer oil absorption material is laid in the oil collecting tank 7, 1-2 drain holes (visible in the bottom end of the oil collecting tank 7 in the figure 2) are designed in the bottom of the oil collecting tank along the direction of a central line, the oil absorption, oil collection and oil removal capabilities and the level of the oil collecting tank 7 are comprehensively improved, a good water drainage effect is guaranteed, collected floating oil is stored in the oil absorption material in the oil collecting tank, and the oil collection tank needs to be replaced every half year or one year.

The bigger particulate matter and the petroleum class material in the waste water obtain further sediment in one-level precipitation oil interceptor 6, after comprehensive purification treatment such as absorption, get into second grade precipitation filtration pond 9 through setting up the first filtration pore 8 that filters in one-level precipitation oil interceptor 6 bottoms, first filtration pore 8 sets up rectangle gabion filter module in water end one side, it is by 6 millimeters stainless steel reinforcing bars do the skeleton, weave the netting with stainless steel wire all around, the mesh is not more than 1 centimetre, rectangle skeleton size is long, wide, the height is 0.5 meters respectively, 0.2 meters and 0.5 meters, set up the lug of grabbing of mechanical jack-up transfer such as the excavator of being convenient for on the rectangle steel bar skeleton, in order to do benefit to construction hoist and mount and later stage clearance. The mesh cage is filled with crushed stones as filter layer fillers, and the crushed stones can be selected from 1-3 stones (the particle size range of the corresponding crushed stones is about 1-3 cm) stored in a mixing station bin.

Particulate matter in the waste water obtains further baffling sediment and filters the back in second grade sedimentation filtering ponds 9, gets into tertiary sedimentation filtering ponds 11 through setting up the second filtration pore 10 at second grade sedimentation filtering ponds 9 top, and second filtration pore 10 sets up rectangle gabion filter module in water end one side equally, and filter module size can be the same with the size in second grade sedimentation filtering ponds 9, and the gabion intussuseption is filled with 1-2 stones (the particle size scope that corresponds the rubble is 1 centimetre ~ 2 centimetres) of rubble for the feed bin deposit of mix station.

After the particles in the wastewater are further precipitated and filtered in the third-level precipitation filtering tank 11, the particles enter a reuse water tank 13 through a third filtering hole 12 formed in the bottom of the third-level precipitation filtering tank 11, a rectangular gabion filtering module is also arranged on one side of a water inlet end of the third filtering hole 12, the size of the filtering module can be the same as that of the second-level precipitation filtering tank 9, meshes are not larger than 0.5 cm, and typical particle size of a mixing station for filling is 5-1 stone (the particle size range of corresponding crushed stones is 0.5-1 cm). The gabion filtering module with the crushed stones with the proper particle sizes as the filler can effectively prolong the hydraulic retention time of water flow in each pool, improve the sedimentation effect and save land. Meanwhile, SS in the wastewater and pollutants such as petroleum attached to the SS can be effectively removed through the comprehensive effects of blocking, adsorption, filtration and the like of the gravel filter layers with different particle sizes.

Fig. 2 shows that the overflow port 5 and the first filtering holes 8, 10 and 12 in the primary sedimentation tank, the primary sedimentation oil-separating tank, the secondary sedimentation filtering tank and the tertiary sedimentation filtering tank are arranged in a diagonal and up-down cross manner, so that the water flow direction and the hydraulic characteristics of the system can be effectively changed, the comprehensive sedimentation effect of up-down multi-stage baffling is realized, and a better sedimentation effect is achieved. A reuse water pump 1 is arranged in the reuse water tank 13, the purified wastewater is pressurized by the water pump and then is used for a mixing plant or used for flushing a tank car, a flushing field area and the like, an overflow external discharge port 15 is arranged at the position of the tail end of the reuse water tank, which is 0.3-0.4 meter away from the center of the tank top, and a control valve is not arranged at the overflow port.

Fig. 2 shows that the bottom of the first-stage sedimentation oil separation tank, the second-stage sedimentation filter tank and the third-stage sedimentation filter tank is respectively provided with a slope with a gradient of 2% -5%, the slope inclines upwards from the water outlet direction, and the lower concave part of the slope is respectively provided with a sand collecting groove, so that the collection of particles through gravity stationary flow is facilitated, and only the silt in the sand collecting groove part needs to be pumped and discharged during cleaning. Set up a cat ladder in one-level precipitation oil interceptor, second grade sedimentation filtration pond and the tertiary sedimentation filtration pond respectively, conveniently observe maintenance and bottom of the pool grit clearance etc..

The tank top of one-level sedimentation oil removal tank, second grade sedimentation filtration tank and tertiary sedimentation filtration tank sets up the stainless steel top cap, avoids taking place the incident such as personnel fall into water, and the slope is 2%, and the top cap can be opened unilateral or two sides at any time as required, is convenient for change rectangle filtration module and the clearance of deposit in the sand catch bowl.

It should be noted that the water inlet end refers to the water flow direction from the primary sedimentation tank to the primary, secondary and tertiary filtration sedimentation tanks. It should be noted that fig. 3 is a sectional view of the c-c side of the primary sedimentation tank of fig. 2, and the distance indicated by the arrow a-a in the figure is the distance a-a in fig. 1, where it is understood that the grid 3 may also be arranged as a gentle slope sloping upward from one side of the tank to the other side of the tank.

The constructed system for purifying and recycling construction wastewater of the temporary concrete mixing station for highway construction has a good removal effect on main pollutants SS, petroleum and the like in initial rainwater runoff, and each water quality index of effluent can meet the requirements of 'water quality standard for farmland irrigation' (GB5084-2005) or 'water quality standard for urban miscellaneous water for recycling of urban sewage' (GB/T18920-2002).

Example 1

A construction wastewater purification and recycling treatment method for a temporary concrete mixing station for highway construction specifically comprises the following steps: waste water of a mixing station area and flushing waste water of a concrete transport vehicle are collected into a primary sedimentation tank 4 after large-particle-size stones are removed through a grating 3, then enter a primary sedimentation oil separation tank 6 through an overflow hole 5, are added with a flocculating agent, enter a secondary sedimentation filtering tank 9 through a first filtering hole 8 after sedimentation and oil separation purification, enter a tertiary sedimentation filtering tank 11 through a second filtering hole 10 after reprecipitation and filtration, enter a reuse water tank 13 through a third filtering hole 12 after further sedimentation and filtration, and are comprehensively utilized after being treated through a reuse water pump 14, wherein the primary sedimentation tank 4 is communicated with the primary sedimentation oil separation tank 6 through the overflow hole 5; the primary sedimentation oil-separation tank 6 is communicated with the secondary sedimentation filtering tank 9 through a first filtering hole 8; the second-stage sedimentation filtering tank 9 is communicated with the third-stage sedimentation filtering tank 11 through a second filtering hole 10; the three-stage sedimentation and filtration tank 11 is communicated with a reuse water tank 13 through a third filtration hole 12, a tank car backing stopping device is arranged outside the primary sedimentation tank and consists of a guard rail 2 and a fixing device 1, a grid 3 is arranged in the primary sedimentation tank 4, a downward inclined gentle slope is formed from one side of the grid 3 into the tank, the slope is 10 degrees, an overflow hole 5 is arranged at the upper part of a partition wall between the primary sedimentation tank 4 and a primary sedimentation oil separation tank 6, an oil collecting tank 7 is vertically arranged on the partition wall on the inner side of the primary sedimentation oil separation tank between the primary sedimentation oil separation tank 6 and a secondary sedimentation and filtration tank 9, a first filtration hole 8 is arranged at the diagonal part of the lower part and the overflow hole 5, and a polymer oil absorbing material is arranged in the oil collecting tank 7 and is periodically replaced or cleaned; a rectangular gabion filtering module is arranged on one side, facing the primary sedimentation oil separation tank, of the first filtering hole 8, the periphery of the rectangular gabion filtering module is formed by weaving steel reinforcement frameworks made of iron wires, broken stones are filled in the rectangular gabion filtering module, and the particle size range of the broken stones is 3 cm; a second filtering hole 10 is arranged at a diagonal position with the first filtering hole 8, a third filtering hole 12 is arranged at a diagonal position with the second filtering hole 10, rectangular gabion filtering modules are respectively arranged at one water inlet end sides of the second filtering hole 10 and the third filtering hole 12, the periphery of each rectangular gabion filtering module is formed by weaving steel bar frameworks which are woven by iron wires, broken stones are filled in the gabion filtering modules on the second filtering hole 10 and the third filtering hole 12, and stones with the particle size range of 2 cm and broken stones with the particle size range of 1 cm are respectively filled in the gabion filtering modules on filtering holes 10 and the third filtering hole 12; the overflow port 15 is arranged at the position of the tail end of the reuse water tank, which is 0.3 meter away from the tank top, the control valve is not arranged at the overflow port, the reuse water pump 14 is arranged in or outside the reuse water tank, the bottom of the primary precipitation oil separation tank, the secondary precipitation filter tank and the tertiary precipitation filter tank is respectively provided with a slope with the gradient of 4%, the slope inclines upwards from the water outlet direction, the lower recess of the slope is respectively provided with a sand collecting groove, and the top of each tank is provided with a stainless steel top cover.

Experiment-selection comparison experiment of different polymer oil absorption materials in oil sump

Experimental example 1

The concrete road construction temporary concrete mixing station construction wastewater purification and recycling system refers to example 1, wherein an acrylate-based porous hydrophobic/oleophilic material is selected as a high-molecular oil absorption material in the oil collecting tank.

The preparation method of the specific oil absorption material comprises the following steps: and (3) soaking the acrylate-based porous material in absolute ethyl alcohol for 1h, taking out and naturally drying. Taking a proper amount of aminated silicon dioxide and deionized water, and dispersing by ultrasonic treatment for 20min to obtain a suspension with the weight percent of 1%. And (3) placing the cleaned acrylate-based porous material into the suspension for soaking for 4h, taking out, and drying at 60 ℃. Preparing an octadecyl trimethoxy silane/absolute ethyl alcohol solution with the volume ratio of 2/100, soaking the model in the solution, keeping the temperature at 60 ℃ for 4 hours, and finally drying at 60 ℃.

Experimental example 2

The concrete road construction temporary concrete mixing station construction wastewater purification and recycling system refers to example 1, wherein polyurethane sponge is selected as a polymer oil absorption material in the oil collecting tank. Wherein polyurethane sponge is commercially available.

Experimental example 3

The concrete road construction temporary concrete mixing station construction wastewater purification and recycling system refers to example 1, wherein a polystyrene electrostatic spinning fiber material is selected as a high-molecular oil absorption material in an oil collecting tank.

The preparation method of the specific oil absorption material comprises the following steps: the raw materials adopt polystyrene and N, N-dimethylformamide as a solvent, a certain amount of polystyrene is dissolved in the N, N-dimethylformamide, stirred for 3 hours and aged for 12 hours to obtain a spinning solution with the mass fraction of 20%; and (3) injecting the spinning solution into a micro pump of a KH-08 type electrostatic spinning machine, adjusting spinning process parameters (spinning voltage is 16,20 and 24KV respectively, receiving distance is 18,21 and 24cm respectively, propelling speed is 0.318,0.636 and 0.954mL/h respectively) to carry out electrostatic spinning, and after the spinning is finished, placing the obtained fiber membrane in a drying box for drying for 24 hours at 40 degrees to obtain the polystyrene electrostatic spinning fiber material.

The experimental method comprises the following steps: important indexes of an oil-water separation material are measured, and the oil absorption multiple and the oil-water separation rate of the material are selected.

Oil absorption multiple calculation formula: the mass difference of the adsorbing material before and after adsorption and the mass ratio of the adsorbing material,

expressed as Eq: eq ═ W2-W1)/W1

Wherein, W1- - -the mass of the adsorbent/(g) W2- - -the mass of the adsorbent after the equilibrium is reached/(g) Eq- - -the oil absorption multiple/(g/g)

The oil-water separation rate is expressed in terms of the volume of oil collected per unit time.

And (3) adsorbing and removing grease from 10L of water sample by using a polymer oil absorption material, and determining the oil absorption multiple and the oil-water separation rate of the oil-water separation material after adsorption, wherein the water sample is taken from the wastewater in the primary precipitation oil separation tank in the example 1, and each experimental group is repeated for 3 times to obtain an average value.

The experimental results are as follows: the oil-water separation rate is related to the water filtering speed of the oil recovery system, and the higher the oil-water separation rate is, the higher the oil stain adsorption speed is. As shown in table 1, when the polystyrene electrospun fiber material is used in a way of being arranged in a 20cm thick oil and grease removing and collecting tank of a primary sedimentation tank in the temporary concrete mixing station wastewater for highway construction, the oil-water separation rate is optimal, which is 32.6% and 30.6% higher than polypropylene (PP) absorbent cotton and polyurethane sponge respectively, and meanwhile, when the polystyrene electrospun fiber material is increased in thickness again, namely exceeding 20cm, the oil-water separation rate is reduced on the contrary, which indicates that the polystyrene electrospun fiber material with a thickness of 20cm is best in the oil-water separation rate arranged in the temporary concrete mixing station wastewater collecting tank for highway construction. The oil-water separation rate of polyurethane sponge and polypropylene (PP) adsorption cotton is not the same as that of polystyrene electrostatic spinning fiber materials, and the polyurethane sponge and the polypropylene (PP) adsorption cotton are easy to deform during oil-water separation experiments due to poor strength and toughness, so that the oil-water separation rate is influenced.

In addition, the higher the oil absorption multiple, the better the oil-water separation material performance. As shown in Table 2, when the polystyrene electrospun fiber material is distributed in a 20 cm-thick oil removing and collecting tank of a primary sedimentation tank in the temporary concrete mixing plant wastewater in highway construction, the polystyrene electrospun fiber material has the highest oil absorption multiple and the best oil absorption effect. When the re-thickness of the polystyrene electrospun fiber material is increased, namely, the re-thickness exceeds 20cm, the oil-water oil absorption capacity is not increased continuously, but is decreased, because the oil-water passing resistance of the high-molecular oil absorption material is increased along with the increase of the thickness, the oil-water has certain viscosity, and the effective passing and absorption efficiency is prevented after the thickness is increased.

TABLE 1 oil-water separation rate comparison experiment of different polymer oil-absorbing materials

Table 2 oil absorption multiple comparison experiment of different polymer oil absorption materials

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above description, and although the present invention has been disclosed with the preferred embodiment, but not limited to the above description, any skilled person in the art can make modifications or changes equivalent to the equivalent embodiment without departing from the scope of the present invention, and any simple modification, equivalent change and modification made to the above embodiments by the technical spirit of the present invention still fall within the scope of the technical solution of the present invention.

Claims (8)

1. A construction wastewater purification and recycling system of a temporary concrete mixing station for highway construction is characterized in that the system is sequentially provided with a primary sedimentation tank (4), a primary sedimentation oil separation tank (6), a secondary sedimentation filtering tank (9), a tertiary sedimentation filtering tank (11) and a recycling water tank (13); the primary sedimentation tank (4) is communicated with the primary sedimentation oil separation tank (6) through an overflow hole (5); the primary sedimentation oil separation tank (6) is communicated with the secondary sedimentation filtering tank (9) through a first filtering hole (8); the secondary sedimentation and filtration tank (9) is communicated with the tertiary sedimentation and filtration tank (11) through a second filtration hole (10); the three-stage sedimentation filtering tank (11) is communicated with the reuse water tank (13) through a third filtering hole (12).

2. The construction wastewater purification and reuse system for the temporary concrete mixing station for road construction according to claim 1, wherein a tank car backing stopping device is arranged outside the primary sedimentation tank, and the backing stopping device is composed of a guard rail (2) and a fixing device (1).

3. The construction wastewater purification and reuse system for temporary concrete mixing station for road construction according to claim 1, wherein a grating (3) is installed in the primary sedimentation tank (4), and a gentle slope is formed from one side of the grating (3) to the interior of the tank and is inclined downward, and the slope is 10 ° to 15 °.

4. A construction waste water purification and reuse system for a temporary concrete mixing station for highway construction according to any one of claims 1 to 3, wherein an overflow hole (5) is formed in the upper portion of a partition wall between the primary sedimentation tank (4) and the primary sedimentation oil-separating tank (6), an oil collecting tank (7) is vertically formed in the partition wall on the inner side of the primary sedimentation oil-separating tank between the primary sedimentation oil-separating tank (6) and the secondary sedimentation filtering tank (9), and a first filtering hole (8) is formed in the lower portion of the oil collecting tank at a diagonal line with the overflow hole (5).

5. The construction wastewater purification and reuse system for the temporary concrete mixing station in road construction according to claim 4, wherein the oil collection tank (7) is vertically suspended above the upper portion of the inner partition wall of the first-stage sedimentation oil separation tank, and the oil collection tank (7) is internally provided with a polymer oil absorption material which is a polystyrene electrospun fiber material and is arranged with a thickness of 20 cm.

6. The construction wastewater purification and reuse system for the temporary concrete mixing station for road construction according to claim 1,2, 3 or 5, wherein the first filtering hole (8) is provided with a rectangular gabion filtering module at one side facing the primary sedimentation oil separation tank, the periphery of the rectangular gabion filtering module is formed by weaving a steel reinforcement framework made of iron wires, and crushed stones are filled in the rectangular gabion filtering module, and the particle size of the crushed stones is 1-3 cm; it sets up second filtration hole (10) to be diagonal department with first filtration hole (8), it sets up third filtration hole (12) to be diagonal department with second filtration hole (10), second filtration hole (10) and third filtration hole (12) come water end one side and set up rectangle gabion filter module respectively, this rectangle gabion filter module is woven by the steel reinforcement skeleton that the iron wire was woven all around and is constituteed, the intussuseption rubble, be equipped with respectively in the gabion module on that second filtration hole (10) and third filtration hole (12) that the particle diameter scope is 1 centimetre ~ 2 centimetres stone and the particle diameter scope is 0.5 centimetre ~ 1 centimetre rubble, the particle diameter that filter module rubble was packed reduces step by step.

7. The construction wastewater purification and reuse system for the temporary concrete mixing station for road construction according to claim 6, wherein an overflow port (15) is arranged at the position of the tail end of the reuse water pool 0.3-0.4 m from the top of the pool, the overflow port is not provided with a control valve, and a reuse water pump (14) is arranged in or outside the reuse water pool.

8. The construction wastewater purification and reuse system for the temporary concrete mixing station for road construction according to claim 7, wherein a slope with a gradient of 2% -5% is respectively arranged at the bottom of the first-stage sedimentation oil-separation tank, the second-stage sedimentation filtration tank and the third-stage sedimentation filtration tank, the slope is inclined upwards from the water outlet direction, a sand collecting groove is respectively arranged at the lower recess of the slope, and a stainless steel top cover is arranged at the top of each tank.

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