CN113603291A

CN113603291A - Wharf rainwater collecting, purifying and recycling process

Info

Publication number: CN113603291A
Application number: CN202110828604.5A
Authority: CN
Inventors: 陈宏�; 杨恩喆; 周璐; 谢敏; 邓征宇; 阮敏; 贺卫宁; 包正铎; 章乘峰; 徐哲承
Original assignee: Changsha University of Science and Technology
Current assignee: Changsha University of Science and Technology
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2021-11-05

Abstract

The invention discloses a collecting, purifying and recycling process for wharf rainwater, and relates to the field of rainwater drainage engineering. The process consists of a seepage collecting unit, a rainwater garden and a recycling unit. Rainwater is collected and converged into the spiral-flow type sand setting catch basin through the drainage ditch and the overflow rainwater port; the rainwater is discharged into a rainwater conveying channel after being preliminarily precipitated in the spiral-flow type sand setting rainwater well, and the rainwater is conveyed to a rainwater garden by the rainwater conveying channel; after being treated by the immobilized multilayer composite flora materials and the medium layer fillers in the rainwater garden, the mixture is collected into an underground water collecting tank; and finally, reusing the rainwater in the underground water collecting tank for each water using point through a reuse pump. The spiral-flow type sand setting catch basin and the rainwater conveying channel are both made of sponge concrete. The invention aims at the water quality characteristics of initial rainwater of the wharf, realizes the collection, purification and recycling of the wharf rainwater, avoids the pollution of the initial rainwater to water, and has the advantages of simple and compact structure, low operation cost, easy control, high rainwater recycling rate, environmental friendliness and the like.

Description

Wharf rainwater collecting, purifying and recycling process

Technical Field

The invention relates to a collecting, purifying and recycling process of wharf rainwater, and belongs to the field of rainwater drainage engineering.

Background

In the early stage of rainfall, a large amount of polluting gases in the air, such as acid gas, automobile exhaust, factory waste gas and the like, are dissolved in the rainwater, and after the rainwater falls to the ground, the pollution degree of the rainwater in the early stage is higher due to scouring of roofs, concrete roads and the like. The wharf has loading and unloading operations of materials such as coal, ore and the like, dust is easy to generate and is scattered on the wharf surface, and the content of suspended matters in initial rainwater is as high as 1000-3000 mg/L when the wharf is subjected to rainfall. If not properly collected and disposed of, it may cause significant environmental pollution by flowing into rivers.

The wharf collects initial rainwater generally by arranging drainage ditches transversely on the wharf, namely, the drainage ditches are arranged in a direction parallel to the cross beam of the wharf and drain water from two sides of the wharf to the middle drainage ditch. The method has low collection and utilization rate of initial rainwater on the wharf surface, so that most of the initial rainwater directly flows into the natural water body, the natural water body is polluted, and a large amount of rainwater resources are wasted. Therefore, the wharf rainwater is necessary to be collected, stored, purified and recycled from the aspects of water environment protection and rainwater comprehensive utilization.

The invention inherits the principles of green, ecological and environmental protection, and designs and develops a wharf rainwater collection, purification and recycling process aiming at the water quality characteristics of the wharf initial rainwater.

Disclosure of Invention

The problems to be solved by the invention are as follows: aiming at the problems of high concentration of suspended matters in the wharf rainwater, serious pollution to water, low utilization rate, easiness in causing flood disasters and the like, the invention provides the wharf rainwater collection, storage, purification and recycling process which is simple and compact in structure, low in operation cost, green and environment-friendly, easy to control and high in rainwater recycling rate.

In order to solve the technical problems, the solution proposed by the invention is as follows: a wharf rainwater collection, storage, purification and recycling process is characterized by comprising a seepage collection unit (1), a rainwater garden (2) and a recycling unit (3). The seepage collecting unit (1) consists of a drainage ditch (1-1), an overflow rainwater port (1-2), a rainwater pipe (1-3), a spiral-flow type sand setting rainwater well (1-4) and a rainwater conveying channel (1-9); the recycling unit (3) consists of an underground water collecting tank (3-1), a recycling pump (3-2) and a recycling pipe network (3-7); the basic flow of the process is as follows: firstly, rainwater is collected into a rainwater pipe (1-3) through a drainage ditch (1-1) and an overflow rainwater port (1-2) of a wharf pavement (1-10) and then collected into a spiral-flow type sand setting rainwater well (1-4); in the spiral-flow type sand setting catch basin (1-4), rainwater is discharged into a rainwater conveying channel (1-9) from a water outlet pipe after primary precipitation, and the rainwater is conveyed to a rainwater garden (2) by the rainwater conveying channel (1-9); secondly, the materials are treated by a plurality of layers of immobilized composite flora materials (2-7) and medium layer fillers (2-6) in the rainwater garden (3) and collected by a water collecting pipe to enter an underground water collecting pool (3-1); and thirdly, the rainwater in the underground water collecting tank (3-1) is recycled to a storage yard water using point (3-3), a road water using point (3-4), a green belt water using point (3-5) and a living area water using point (3-6) through a recycling pump (3-2).

In the collecting, purifying and recycling process of wharf rainwater, the drainage ditch (1-1) and the overflow rainwater port (1-12) are connected with the rainwater pipe (1-3), the overflow rainwater port (1-2) adopts a flat grate type structure and is designed according to the length-width ratio of 1:0.6, and the limited length is 40-60 cm; the spiral-flow type sand setting catch basin (1-4) consists of a circular basin body (1-5), a sand collecting hopper (1-6), a water inlet pipe (1-7) and a water outlet pipe (1-8), and the volume of the spiral-flow type sand setting catch basin is 0.3-0.8 time of the local maximum daily rainfall; the circular pool body (1-5) is made of sponge concrete, the upper part of the circular pool body is cylindrical, the lower part of the circular pool body is in a circular truncated cone shape with a large upper part and a small lower part, and the lower part of the circular pool body is connected with the sand collecting hopper (1-6); the water inlet pipe (1-7) and the water outlet pipe (1-8) are tangent to the upper part of the circular tank body (1-5), and the joint of the water outlet pipe (1-8) and the circular tank body (1-5) is positioned above the joint of the water inlet pipe (1-7) and the circular tank body (1-5); the rainwater conveying channel (1-9) consists of a channel body and a cover plate; the canal body is made of sponge concrete.

In the collecting, purifying and recycling process of wharf rainwater, the rainwater garden (2) is sequentially composed of a planting layer (2-1), a medium layer (2-2) and a drainage layer (2-4) from top to bottom; the thickness of the planting layer (2-1) is 300-400 mm, soil is arranged on the planting layer (2-1) and is 100mm, emergent aquatic plants (2-5) are planted on the planting layer (2-1), and the planting layer is uniformly filled with immobilized multilayer composite flora materials (2-7) and interacts with the roots of the emergent aquatic plants (2-5) to construct a reinforced denitrification system; the emergent aquatic plant (2-5) is one or more of reed, Miscanthus sinensis or Iris pseudacorus; the immobilized multilayer composite flora material (2-7) mainly comprises anaerobic ammonia oxidation granular sludge (4-1), denitrification granular sludge (4-2), aerobic nitrification granular sludge (4-3) and embedding agents (4-4); the anaerobic ammonia oxidation granular sludge (4-1) is taken as a kernel, and the grain diameter is 3-8 mm; the denitrification granular sludge (4-2) and the aerobic nitrification granular sludge (4-3) are outer-layer embedded objects, and the denitrification granular sludge (4-2): the mass ratio of the aerobic nitrification granular sludge (4-3) is 1: 1; the embedding agent (4-4) is prepared from polyvinyl alcohol, sodium alginate and water according to the weight ratio of 6-12: 0.5-2: 100 in mass ratio; the thickness of the medium layer (2-2) is 400-500 mm, and the medium layer filler (2-6) is 90% of biological retention medium, 5% of small ceramsite and 5% of corn straw; the bioretention media includes soil, river sand and pine bark; the small ceramic particles and the corn straws are both modifiers, the small ceramic particles are easy to form films, pollutants in water can be adsorbed, the water permeability and the water retention property of the corn straws are good, and the small ceramic particles are natural, environment-friendly, water-saving and fertilizer-saving; the upper planting layer (2-1) of the rainwater garden (2) forms an oxygen-rich environment with the dissolved oxygen content of 2-3 mg/L, the lower medium layer (2-2) forms an anoxic/anaerobic environment with the dissolved oxygen content of 0.2-0.5 mg/L, and aerobic and anaerobic treatment is carried out on pollutants so as to effectively remove the pollutants; the thickness of the drainage layer (2-4) is 300-400 mm, and crushed stone with the diameter of 3-8 mm, crushed stone with the diameter of 15-30 mm and crushed stone with the diameter of 30-50 mm are sequentially filled in the drainage layer from top to bottom; a water collecting pipe (2-3) is arranged in the drainage layer (2-4); the pipe diameter of the water collecting pipe (2-3) is DN 100-DN 150.

In the collecting, purifying and recycling process of wharf rainwater, the recycling unit (3) is composed of an underground water collecting tank (3), a recycling pump (3-2) and a recycling pipe network (3-7).

Compared with the prior art, the invention has the advantages that:

the invention adopts the pretreatment unit and then connects the sponge facility, the design has good purification effect on the rainwater at the wharf, reduces pollutants in the rainwater, is beneficial to the recycling of the rainwater, and the spiral-flow type sand-settling catch basin is arranged at the front end of the sponge facility and is used as the pretreatment unit, thereby greatly reducing the concentration of suspended matters in the rainwater entering the sponge facility at the rear end, and avoiding the treatment capability and the over-flow capability of the sponge facility at the rear end from being greatly reduced due to the overhigh concentration of the suspended matters in the rainwater. The rear end sponge facility adopts a rainwater garden and is sequentially provided with a planting layer, a medium layer and a drainage layer from top to bottom, and pollutants in rainwater are treated by planting emergent aquatic plants and microbes in the rainwater on the planting layer; the medium layer filler adopts a novel structure of 90% of biological retention medium, 5% of small ceramsite and 5% of corn straw, the biological retention medium comprises soil, river sand and pine bark, the small ceramsite and the corn straw are used as modifiers, the small ceramsite is easy to be filmed and can adsorb pollutants in water, the corn straw has good water permeability and water retention property, and is natural, environment-friendly, water-saving and fertilizer-saving, and the filler structure is favorable for removing the pollutants in the water and keeping the soil moisture; meanwhile, the integral structure of the rainwater garden forms an upper planting layer rich in oxygen, and a lower medium layer is in an anoxic/anaerobic environment, so that pollutants are treated aerobically and anoxic/anaerobic, and the pollutants are effectively removed.

The sponge concrete adopted by the invention has a plurality of fine micropores, has good water permeability, air permeability and water retention, can purify water, absorb sound and reduce noise, can help to relieve the urban temperature and humidity imbalance caused by a heat island effect, can timely permeate rainwater into the ground when raining is concentrated, reduces surface runoff, lightens the burden of municipal drainage facilities, has an obvious improvement effect on urban waterlogging, simultaneously supplements underground water resources, maintains ecological balance of soil, has a porous structure which is more convenient when waste concrete is recycled, can be reused, is energy-saving, environment-friendly, economical and efficient.

Immobilized multilayer composite flora materials are uniformly filled in the upper layer of the soil of the rainwater garden planting layer, so that the co-immobilization culture of the anaerobic ammonia oxidation granular sludge, the aerobic nitrification granular sludge and the denitrification granular sludge in an embedding carrier is realized, the biological efficiency of the two granular sludge is coordinately exerted, and the coordinative operation of the aerobic nitrification reaction, the anaerobic ammonia oxidation reaction and the anaerobic denitrification reaction is realized; the method for preparing the immobilized multilayer composite flora material is simple and convenient, the preparation process is easy to control, and the obtained immobilized multilayer composite flora material has high water content and high mechanical strength and can be repeatedly utilized; meanwhile, the method utilizes the characteristics of high biological concentration and strong environmental adaptability of the immobilized microorganism technology, and has the advantages of low cost, high efficiency, ecology and the like.

The invention has good purification effect on initial rainwater and stable and reliable effluent quality; meanwhile, the process adopts the combination of ecology and manual technology, has high stability, easy control and wide adaptability, and can successfully realize the purification and the recycling of the wharf rainwater; the process operation process does not need to add chemical agents, does not have secondary pollution, does not need manual operation and nursing, and saves maintenance and management cost.

In conclusion, the invention inherits the design concept of green, ecological and environmental protection aiming at the water quality characteristics of the initial rainwater of the wharf, realizes the collection, purification and reuse of the rainwater of the wharf, saves the water cost of the wharf, reduces the drainage pressure of a river channel and avoids the pollution of the initial rainwater to the water body; the process has the advantages of simple and compact structure, low operation cost, easy control, high rainwater reuse rate, environmental friendliness and the like.

Drawings

Fig. 1 is a schematic view of a wharf rainwater collection, storage, purification and reuse process.

Fig. 2 is a schematic structural view of a cyclone type sand setting catch basin.

Fig. 3 is a schematic view of a rain garden structure.

FIG. 4 shows an immobilized multi-layered composite bacterial material.

Illustration of the drawings:

Detailed Description

The present invention will be described in detail below by way of specific examples.

A wharf rainwater collection, storage, purification and recycling process mainly comprises a seepage collection unit (1), a rainwater garden (2) and a recycling unit (3).

The seepage collecting unit (1) consists of a drainage ditch (1-1), an overflow rainwater port (1-2), a rainwater pipe (1-3), a spiral-flow type sand setting rainwater well (1-4) and a rainwater conveying channel (1-9); the drainage ditch (1-1) and the overflow rain water port (1-2) are connected with a rain water pipe (1-3), the overflow rain water port (1-2) adopts a flat grate type structure and is designed according to the length-width ratio of 1:0.6, and the length is limited to be 50cm, and the width is 30 cm; the spiral-flow type sand setting catch basin (1-4) consists of a circular basin body (1-5), a sand collecting hopper (1-6), a water inlet pipe (1-7) and a water outlet pipe (1-8), and the volume of the spiral-flow type sand setting catch basin is 0.5 time of the local maximum daily rainfall; the circular pool body (1-5) is made of sponge concrete, the upper part of the circular pool body is cylindrical, the lower part of the circular pool body is in a circular truncated cone shape with a large upper part and a small lower part, and the lower part of the circular pool body is connected with the sand collecting hopper (1-6); the water inlet pipe (1-7) and the water outlet pipe (1-8) are tangent to the upper part of the circular tank body (1-5), and the joint of the water outlet pipe (1-8) and the circular tank body (1-5) is positioned above the joint of the water inlet pipe (1-7) and the circular tank body (1-5); the rainwater conveying channel (1-9) consists of a channel body and a cover plate; the canal body is made of sponge concrete.

After rainstorm, the concentration of suspended matters in initial rainwater of the wharf is 2000mg/L, at the moment, rainwater on the wharf pavement (1-10) is collected into a rainwater pipe (1-3) through a drainage ditch (1-1) and an overflow rainwater port (1-2), the rainwater is collected into a rotational flow type sand-settling rainwater well (1-4) through the rainwater pipe (1-3), the rainwater is preliminarily precipitated in the rotational flow type sand-settling rainwater well (1-4), then is discharged into a rainwater conveying channel (1-9) from a water outlet pipe (1-8), and is conveyed to a rainwater garden (2) through the rainwater conveying channel (1-9);

the rainwater garden (2) is sequentially composed of a planting layer (2-1), a medium layer (2-2) and a drainage layer (2-4) from top to bottom; the thickness of the planting layer (2-1) is 400mm, soil is arranged on the planting layer (2-1) and is 100mm, emergent aquatic plants (2-5) are planted on the planting layer (2-1), and immobilized multilayer composite flora materials (2-7) are uniformly filled in the planting layer and interact with the roots of the emergent aquatic plants (2-5) to construct a reinforced denitrification system; the emergent aquatic plant (2-5) is one or more of reed, Miscanthus sinensis or Iris pseudacorus; the immobilized multilayer composite flora material (2-7) mainly comprises anaerobic ammonia oxidation granular sludge (4-1), denitrification granular sludge (4-2), aerobic nitrification granular sludge (4-3) and embedding agents (4-4); the anaerobic ammonia oxidation granular sludge (4-1) is taken as a core, and the grain diameter is 5 mm; the denitrification granular sludge (4-2) and the aerobic nitrification granular sludge (4-3) are outer-layer embedded objects, and the denitrification granular sludge (4-2): the mass ratio of the aerobic nitrification granular sludge (4-3) is 1: 1; the embedding agent (4-4) is prepared from polyvinyl alcohol, sodium alginate and water according to the weight ratio of 12: 2: 100 in mass ratio; the thickness of the medium layer (2-2) is 500mm, and the medium layer filler (2-6) is 90% of biological retention medium, 5% of small ceramsite and 5% of corn straw; the bioretention media includes soil, river sand and pine bark; the small ceramic particles and the corn straws are both modifiers, the small ceramic particles are easy to form films, pollutants in water can be adsorbed, the water permeability and the water retention property of the corn straws are good, and the small ceramic particles are natural, environment-friendly, water-saving and fertilizer-saving; the upper planting layer (2-1) of the rainwater garden forms an oxygen-rich environment with the dissolved oxygen content of 2.45mg/L, the lower medium layer (2-2) forms an anoxic/anaerobic environment with the dissolved oxygen content of 0.32mg/L, and aerobic and anaerobic treatment is carried out on pollutants so as to effectively remove the pollutants; the thickness of the drainage layer (2-4) is 400mm, and phi 3-8 mm broken stone with the thickness of 75mm, phi 15-30 mm broken stone with the thickness of 75mm and phi 30-50 mm broken stone with the thickness of 250mm are sequentially filled in the drainage layer from top to bottom; a water collecting pipe (2-3) is arranged in the drainage layer (2-4); the pipe diameter of the water collecting pipe (2-3) is DN 100; after being treated by the rainwater garden (2), the rainwater is collected by the water collecting pipe (2-3) and enters the underground water collecting tank (3-1); .

And finally, the rainwater in the underground water collecting tank (3-1) is recycled to a storage yard water using point (3-3), a road water using point (3-4), a green belt water using point (3-5) and a living area water using point (3-6) through a recycling pump (3-2) and is recycled as storage yard spraying dust removal water, road and green belt spraying water and wharf living toilet flushing water.

Claims

1. A wharf rainwater collection, storage, purification and recycling process is characterized by comprising a seepage collection unit (1), a rainwater garden (2) and a recycling unit (3); the seepage collecting unit (1) consists of a drainage ditch (1-1), an overflow rainwater port (1-2), a rainwater pipe (1-3), a spiral-flow type sand setting rainwater well (1-4) and a rainwater conveying channel (1-9); the recycling unit (3) consists of an underground water collecting tank (3-1), a recycling pump (3-2) and a recycling pipe network (3-7); the basic flow of the process is as follows: firstly, rainwater is collected into a rainwater pipe (1-3) through a drainage ditch (1-1) and an overflow rainwater port (1-2) of a wharf pavement (1-10) and then collected into a spiral-flow type sand setting rainwater well (1-4); in the spiral-flow type sand setting catch basin (1-4), rainwater is discharged into a rainwater conveying channel (1-9) from a water outlet pipe after primary precipitation, and the rainwater is conveyed to a rainwater garden (2) by the rainwater conveying channel (1-9); secondly, the materials are treated by a plurality of layers of immobilized composite flora materials (2-7) and medium layer fillers (2-6) in the rainwater garden (3) and collected by a water collecting pipe to enter an underground water collecting pool (3-1); and thirdly, the rainwater in the underground water collecting tank (3-1) is recycled to a storage yard water using point (3-3), a road water using point (3-4), a green belt water using point (3-5) and a living area water using point (3-6) through a recycling pump (3-2).

2. The wharf rainwater collecting, storing, purifying and recycling process according to claim 1, characterized in that: the spiral-flow type sand setting catch basin (1-4) consists of a circular basin body (1-5), a sand collecting hopper (1-6), a water inlet pipe (1-7) and a water outlet pipe (1-9), and the volume of the spiral-flow type sand setting catch basin is 0.3-0.8 time of the local maximum daily rainfall; the circular pool body (1-5) is made of sponge concrete, the upper part of the circular pool body is cylindrical, the lower part of the circular pool body is in a circular truncated cone shape with a large upper part and a small lower part, and the lower part of the circular pool body is connected with the sand collecting hopper (1-6); the water inlet pipe (1-7) and the water outlet pipe (1-8) are tangent to the upper part of the circular tank body, and the water outlet pipe (1-8) and the circular tank body interface are positioned above the water inlet pipe (1-7) and the circular tank body interface.

3. The wharf rainwater collecting, storing, purifying and recycling process according to claim 1, characterized in that: the rainwater conveying channel (1-9) consists of a channel body and a cover plate; the canal body is made of sponge concrete.

4. The wharf rainwater collecting, storing, purifying and recycling process according to claim 1, characterized in that: the rainwater garden (2) is sequentially composed of a planting layer (2-1), a medium layer (2-2) and a drainage layer (2-4) from top to bottom; the thickness of the planting layer (2-1) is 300-400 mm, emergent aquatic plants (2-5) are planted on the planting layer (2-1), and the planting layer is uniformly filled with multiple layers of immobilized composite flora materials (2-7); the emergent aquatic plant (2-5) is one or more of reed, Miscanthus sinensis or Iris pseudacorus; the thickness of the medium layer (2-2) is 400-500 mm, and the medium layer filler (2-6) is 90% of biological retention medium, 5% of small ceramsite and 5% of corn straw; the bioretention media includes soil, river sand and pine bark; the thickness of the drainage layer (2-4) is 300-400 mm, and crushed stone with the diameter of 3-8 mm, crushed stone with the diameter of 15-30 mm and crushed stone with the diameter of 30-50 mm are sequentially filled in the drainage layer from top to bottom; a water collecting pipe (2-3) is arranged in the drainage layer (2-4); the pipe diameter of the water collecting pipe (2-3) is DN 100-DN 150.

5. The wharf rainwater collecting, storing, purifying and recycling process according to claim 1, characterized in that: the immobilized multilayer composite flora material (2-7) mainly comprises anaerobic ammonia oxidation granular sludge (4-1), denitrification granular sludge (4-2), aerobic nitrification granular sludge (4-3) and embedding agents (4-4); the anaerobic ammonia oxidation granular sludge (4-1) is taken as a kernel, and the grain diameter is 3-8 mm; the denitrification granular sludge (4-2) and the aerobic nitrification granular sludge (4-3) are outer-layer embedded objects, and the denitrification granular sludge (4-2): the mass ratio of the aerobic nitrification granular sludge (4-3) is 1: 1; the embedding agent (4-4) is prepared from polyvinyl alcohol, sodium alginate and water according to the weight ratio of 6-12: 0.5-2: 100 mass ratio.

6. The wharf rainwater collection, storage, purification and recycling process according to claims 1, 2 and 3, wherein the process comprises the following steps: the preparation raw materials and the weight fraction of the sponge concrete comprise 100-150 g mass parts of aggregate, 10-20 g mass parts of cement, 3-8 g mass parts of binder, 0.5-2 g mass parts of foaming agent, 0.2-1 g mass part of anti-cracking agent and 2-20 g mass parts of water; the aggregate is mainly zeolite, limestone, vermiculite, furnace slag, quartz stone or gravel; the cement is one or more of magnesite material and silico-calcic material cement; the binder is one or more of epoxy resin adhesive, unsaturated polyester resin adhesive, styrene-butadiene rubber, acrylic resin adhesive and polyurethane adhesive; the foaming agent is mainly a physical foaming agent comprising a compound foaming agent and a biosurfactant or a chemical foaming agent comprising two or more of hydrogen peroxide, calcium carbide and ammonium salt; the anti-cracking agent is one or more of polypropylene fiber, polyethylene fiber, carbon fiber, glass fiber and oil palm fiber; the preparation steps of the sponge concrete mainly comprise aggregate screening and grading, primary mixing and stirring, secondary mixing, aeration and stirring, tertiary mixing and stirring, casting molding and curing; the recycling step of the sponge concrete mainly comprises mechanical crushing, ultrasonic stripping, aggregate sorting and regeneration, and excess material crushing and regeneration; the porosity of the sponge concrete is more than 40%, wherein the volume of the pores with the diameter of 0.4-2 mm accounts for more than 60%, the water permeability coefficient is more than 2mm/s, and the maximum water retention rate is more than 50%.