CN113511782B

CN113511782B - Collecting, purifying and recycling process for polluted runoff of liquid bulk cargo wharf

Info

Publication number: CN113511782B
Application number: CN202110828728.3A
Authority: CN
Inventors: 陈宏�; 罗桢; 邓征宇; 胡颖冰; 龚丽玲; 刘媛媛; 赵文玉; 禹丽娥; 袁吉成; 杨恩喆
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: 2023-04-18
Anticipated expiration: 2041-07-22
Also published as: CN113511782A

Abstract

The invention discloses a collecting, purifying and recycling process of polluted runoff of a liquid bulk cargo wharf, and belongs to the field of port wharf environmental protection. The process comprises a crude oil pollution runoff collecting and preprocessing unit, a liquefied natural gas pollution runoff collecting and preprocessing unit, a liquid chemical pollution runoff collecting and preprocessing unit, a coagulating sedimentation unit, a biological retention processing unit and a recycling unit. The polluted runoff in the crude oil tank area, the liquefied natural gas tank area and the liquid chemical tank area is collected and pretreated by a crude oil polluted runoff collecting and pretreating unit, a liquefied natural gas polluted runoff collecting and pretreating unit and a liquid chemical polluted runoff collecting and pretreating unit respectively and then enters a coagulating sedimentation unit, the coagulated, flocculated and precipitated polluted runoff enters a biological retention treatment unit, the infiltrated polluted runoff passes through a planting layer, a dielectric layer and a gravel layer and is collected and converged into a water collecting tank through a water collecting well, and finally the polluted runoff in the water collecting tank is recycled to each water using point by a recycling unit through a recycling pump. The invention is suitable for various liquid bulk cargo wharfs, and aiming at the water quality characteristics of the polluted runoff of the liquid bulk cargo wharf, the invention combines the design concept of 'artificial wetland', realizes the collection, purification and recycling of the polluted runoff of the liquid bulk cargo wharf, saves the water cost of the wharf, reduces the use of a large amount of chemical agents, avoids the pollution of the polluted runoff on a water body, and has the advantages of simple and compact structure, low operation cost, easy control, high rainwater recycling rate, environmental friendliness and the like.

Description

Collecting, purifying and recycling process for polluted runoff of liquid bulk cargo wharf

Technical Field

The invention relates to a collecting, purifying and recycling process of polluted runoff of a liquid bulk cargo wharf, and belongs to the field of port wharf environmental protection.

Background

With the continuous development of economy in China, the demands for oil gas and chemical products are continuously increased, and the development of the liquid bulk cargo sea transportation industry and the construction of corresponding ports and wharfs are promoted. The liquid bulk cargo wharf is a professional wharf for loading, unloading and conveying crude oil, finished oil, liquid chemicals, liquid natural gas and the like by using pipelines, and has the advantages of continuity, tightness, large transportation capacity and high efficiency. Among them, initial rainwater, washing water and dedusting water are generally called as polluted runoff, and if the polluted runoff is discharged without effective treatment, huge pollution is caused to the water environment.

At present, the collection of liquid bulk cargo pier to polluting runoff generally adopts the mode of transversely setting up the escape canal at the pier, is on a parallel with the direction of pier crossbeam promptly and sets up the escape canal, by the drainage of pier both sides side direction middle escape canal. However, the method has low collection utilization rate, most of the polluted runoff can not effectively flow into the drainage ditch but directly flows into the natural water body, so that the method not only causes great pollution to the natural water body, but also wastes a large amount of water resources.

With the continuous improvement of the national environmental protection requirement, a plurality of port and wharf sewage collection and treatment measures which are built according to old regulations and old requirements are difficult to reach the existing sewage discharge standard. Most old liquid wharfs have backward and long-term maintenance of sewage treatment facilities, and even wharfs with earlier production time are not provided with sewage collection and treatment devices, so that the sewage collection and treatment capacity of the wharfs on polluted runoff is seriously insufficient.

Therefore, how to realize the collection, treatment and reuse of the polluted runoff of the liquid bulk cargo wharf is a key problem to be solved. The invention combines the design concept of 'artificial wetland', inherits the principles of green, ecology and environmental protection, and designs and develops the process for collecting, purifying and recycling the polluted runoff of the liquid bulk cargo wharf aiming at the water quality characteristics of the liquid bulk cargo wharf.

Disclosure of Invention

The problems to be solved by the invention are as follows: aiming at the problems that the treatment capacity of the surface source pollution of the built old liquid bulk cargo wharf is insufficient, the wharf runoff has high concentration of suspended matters, serious water pollution, low utilization rate, various pollutants and the like, the invention provides the collection, purification and recycling process of the liquid bulk cargo wharf polluted runoff, which has the advantages of simple and compact structure, low operation cost, environmental protection, easy control and high recycling rate.

In order to solve the technical problems, the solution proposed by the invention is as follows: the collecting, purifying and recycling process of the liquid bulk cargo wharf polluted runoff is characterized by comprising a crude oil polluted runoff collecting and preprocessing unit (1), a liquefied natural gas polluted runoff collecting and preprocessing unit (2), a liquid chemical polluted runoff collecting and preprocessing unit (3), a coagulating sedimentation unit (4), a biological retention processing unit (5) and a recycling unit (6); the basic flow of the process is as follows: (1) the polluted runoff in the crude oil tank area, the liquefied natural gas tank area and the liquid chemical tank area is collected and pretreated by a crude oil polluted runoff collecting and pretreating unit (1), a liquefied natural gas polluted runoff collecting and pretreating unit (2) and a liquid chemical polluted runoff collecting and pretreating unit (3) respectively and then is conveyed to a coagulating sedimentation unit (4) through a connecting pipeline I (4-1); (2) then the sewage is treated by coagulation, flocculation and sedimentation in the coagulation sedimentation unit (4) and then is discharged into a biological retention treatment unit (5) through a connecting pipeline (4-5); (3) then the bioretention treatment unit (5) enters a recycling unit (6) through a second connecting pipeline (5-14) after the absorption and purification of plants and the adsorption treatment of fillers; (4) finally, the water is conveyed from the water collecting pool (6-1) to a water using point (6-4) in the recycling unit (6) through a recycling pump (6-3).

In the collecting, purifying and recycling process of the liquid bulk cargo wharf polluted runoff, the crude oil polluted runoff collecting and preprocessing unit (1) consists of a water catchment channel I (1-1), an adjusting oil separation tank (1-2), an adsorption tank (1-3) and a PLC control terminal I (1-4); the basic working flow of the crude oil pollution runoff collection and pretreatment unit (1) is as follows: polluted runoff near a crude oil tank area enters an adjusting oil separation tank (1-2) through a water collection channel I (1-1), the crude oil concentration in the adjusting oil separation tank (1-2) is reduced to 10-20mg/L and then enters an adsorption tank (1-3), the adsorption tank (1-3) controls the addition of an adsorbent through the detection of the crude oil concentration, and finally the crude oil concentration is conveyed to a coagulating sedimentation unit (4) through a connecting pipeline I (4-1) when being lower than 10 mg/L.

In the collecting, purifying and recycling process of the liquid bulk cargo wharf polluted runoff, the liquefied natural gas polluted runoff collecting and preprocessing unit (2) mainly comprises an overflow rainwater well cover (2-1), a water collection channel II (2-2), a lower layer water collection pipe (2-3) and an impermeable geomembrane (2-5); the basic working flow of the liquefied natural gas polluted runoff collection and pretreatment unit (2) is as follows: polluted runoff in the range of 20-35m on the left side and the right side of the water collection channel II (2-2) rapidly infiltrates into the lower layer water collection pipe (2-3), and is conveyed to the coagulating sedimentation unit (4) through the lower layer water collection pipe (2-3).

In the collecting, purifying and recycling process of the liquid bulk cargo wharf polluted runoff, the liquid chemical polluted runoff collecting and preprocessing unit (3) consists of a water collecting channel III (3-1), a sewage pool (3-2), a PLC control terminal II (3-3) and a stirrer (3-4); the basic working flow of the liquid chemical pollution runoff collecting and preprocessing unit (3) is as follows: the contaminated runoff in liquid chemicals jar district passes through catchment channel three (3-1) gets into effluent water sump (3-2), the water inlet and the delivery port of effluent water sump (3-2) are provided with the intelligent inductive probe who connects PLC control terminal two (3-3)'s detectable toluene, n-butanol, cresol or the concentration of xylol respectively, reach 1-5mg/L as the pollutant concentration that represents with the toluene and just oxidize with ozone, pass through simultaneously agitator (3-4) assist and get rid of, discharge into coagulating sedimentation unit (4) again.

In the collecting, purifying and recycling process of the polluted runoff of the liquid bulk cargo wharf, the ground slope of the catchment channel I (1-1) is 0.5-2%; the first branch channels (1-1-1) are arranged along the pipeline of the crude oil tank area at the left and right sides at intervals of 8-12 m; the gradient of the road of the liquefied natural gas tank field is 1 percent; the second catchment channel (2-2) is arranged along a road and a sidewalk, the width of the second catchment channel is 30-50cm, and the bottom of the channel is made of renewable sponge concrete (2-2-1); the third catchment channel (3-1) is arranged along the ground of the liquefied chemical tank field, and the gradient of the ground is 1-1.5%; the distance between the third branch channels (3-1-1) is 5-8m, the width and the height are 25cm and 35cm respectively, and the specific drop is 1-1.5%; the width and the height of the third main channel (3-1-2) are respectively 35cm and 50cm, and the specific reduction is 1.5-2%.

In the collecting, purifying and recycling process of the polluted runoff of the liquid bulk cargo wharf, the coagulating sedimentation unit (4) consists of a coagulating area (4-2), a flocculating area (4-3) and a sedimentation area (4-4); coagulant is added into the coagulation area (4-2); coagulant aids are added into the flocculation area (4-3).

In the collecting, purifying and recycling process of the liquid bulk cargo wharf polluted runoff, the bioretention treatment unit (5) mainly comprises an assembled concrete outer wall (5-1), a water storage layer (5-2), a planting layer (5-3), a fine sand layer (5-4), a volcanic rock medium layer (5-5), a biological medium layer (5-6), a fine gravel layer (5-7), a coarse gravel layer (5-8), a water collecting well (5-10) and a cement partition plate (5-11).

In the collecting, purifying and recycling process of the polluted runoff of the liquid bulk cargo wharf, the planting layer (5-3) is planted with waterlogging-resistant plants (5-9); the waterlogging-resistant plant (5-9) is a combination of canna, thalictrum ramosissimum, miscanthus floridulus and Iris pseudacorus.

In the collecting, purifying and recycling process of the polluted runoff of the liquid bulk cargo wharf, soil with the thickness of 100mm is arranged on the planting layer (5-3), and a composite flora multilayer immobilized material is uniformly filled in the soil; the multilayer composite flora immobilized material consists of an inner core and an outer layer embedded matter, wherein the inner core is prepared from anaerobic ammonia oxidation granular sludge, and the outer layer embedded matter is prepared from aerobic nitrification granular sludge.

In the collecting, purifying and recycling process of the polluted runoff of the liquid bulk cargo wharf, the volcanic rock medium layer (5-6) is crushed stone with the thickness of 200-300mm and the diameter of 5-10 mm; the thickness of the biological medium layer (5-7) is 300-400mm; the biological medium layer (5-7) is internally provided with a filler; the filler is 80% of biological retention medium, 10% of small ceramsite and 10% of corn straw; the bioretention media includes soil, river sand and pine bark; the fine gravel layer (5-8) is crushed stone with the thickness of 100-200mm and the diameter of 3-8 mm; the coarse gravel layer (5-9) is crushed stone with the thickness of 200-300mm and the diameter of 15-30 mm.

In the collecting, purifying and recycling process of the polluted runoff of the liquid bulk cargo wharf, the preparation raw materials of the renewable sponge concrete (2-2-1) comprise aggregate, cement, a binder, a foaming agent, an anti-cracking agent, a microbial agent and water; the preparation steps of the sponge concrete (2-2-1) mainly comprise aggregate screening and grading, primary coagulation and stirring, secondary coagulation and aeration and stirring, tertiary coagulation and stirring, casting molding and curing; the recycling steps of the sponge concrete (2-2-1) are mainly mechanical crushing, ultrasonic stripping, aggregate sorting and regeneration, excess material crushing and regeneration; the porosity of the sponge concrete (2-2-1) is more than 40%, wherein the ratio of the pore volume with the diameter of 0.4-2mm is more than 60%, the permeability coefficient is more than 2mm/s, and the maximum water holding rate is more than 50%.

Compared with the prior art, the invention has the beneficial effects that: the treatment effect of the polluted runoff of the liquid bulk cargo wharf can be greatly improved, the concentrations of suspended matters, heavy metals, crude oil, methylbenzene and the like in the polluted runoff are greatly reduced, the cyclic utilization is realized, and a large amount of water resources are saved.

(1) Liquid pier goods are mostly through pipeline loading and unloading, and big load removes the orbit comparatively fixed, through arranging the lateral canal and the trunk canal that catchment channel one, catchment channel two and catchment channel three constitute to realize the quick collection of pier contaminated runoff, can reduce the time of converging greatly, reduce surface ponding.

(2) The distribution of different tank areas of the liquid wharf enables the concentration of suspended matters in the polluted runoff to be high, the pollutants are various, the polluted runoff of each tank area is preprocessed by the crude oil polluted runoff collecting and preprocessing unit, the liquefied natural gas polluted runoff collecting and preprocessing unit and the liquid chemical polluted runoff collecting and preprocessing unit, and the substances such as suspended matters, heavy metals and oils contained in the polluted runoff are removed preliminarily.

(3) Utilize the coagulating sedimentation unit to coagulate, flocculate and deposit the contaminated runoff that preliminary treatment was gone on, add the coagulant when coagulating, throw the coagulant aid during flocculation, form the flocculating constituent of large granule, can effectively improve precipitation efficiency, get rid of 95% suspended solid in the contaminated runoff that preliminary treatment was gone on, avoid follow-up biological delay processing unit to take place to block up.

(4) The water treated by the coagulation precipitation unit is further treated by the biological retention treatment unit, and the water reaching the standard after absorption of plants and adsorption and purification of the medium layer enters the recycling unit and can be used as wharf road water, greening water and domestic water, so that a large amount of water resources are saved.

(5) The rainwater treatment device is simple in structure, modularized, small in occupied area, capable of adding different modules for combined arrangement according to the flow, capable of running in parallel, capable of shortening the process steps of rainwater recycling, capable of reducing the cost of subsequent rainwater treatment, good in treatment effect and capable of guaranteeing the quality of outlet water.

Drawings

FIG. 1 is a schematic view of a process flow for collecting, purifying and recycling polluted runoff of a liquid bulk cargo wharf.

FIG. 2 is a schematic diagram of a crude oil pretreatment unit configuration.

Fig. 3 is a schematic structural diagram of a water collecting channel.

Fig. 4 is a schematic structural diagram of a liquid chemical pretreatment unit.

FIG. 5 is a schematic view of the construction of a bioretention treatment unit.

Number designation in the figure: 1, a crude oil pollution runoff collection and pretreatment unit; 1-1 a water collecting channel I; 1-2 adjusting an oil separation tank; 1-3 adsorption tanks; 1-4PLC control terminal I; 1-2-1 adjusting a water inlet of the oil separation tank; 1-2-2 inlet baffle; 1-2-3 cleaning ports; 1-2-4 separator plates; 1-2-5 outlet baffles; 1-2-6 adjusting the water outlet of the oil separation tank; 1-3-1 an adsorption tank water inlet; 1-5 of a stirrer; 1-3-2) a water outlet of the adsorption tank; 2, a liquefied natural gas pollution runoff collection and pretreatment unit; 2-1, overflowing the rainwater well cover; 2-2 a water collecting channel II; 2-3 water collecting pipes; 2-4 concrete side walls; 2-2-1 of renewable sponge concrete; 2-5 of an impermeable geomembrane; 3, a liquefied chemical pollution runoff collecting and preprocessing unit; 3-1, a water collecting channel III; 3-2, a sewage tank; 3-3, a PLC control terminal II; 3-4 of a stirrer; 3-5, a water inlet of the sewage tank; 3-6, a water outlet of the sewage pool; 3-7 ozone aeration pipes; 4, a coagulating sedimentation unit; 4-1 connecting the first pipeline; 4-2 concrete channel; 4-3 flocculation area; 4-4, a sedimentation zone; 4-5 connecting a second pipeline; 5 a bioretention treatment unit; 5-1, assembling a concrete outer wall; 5-2 water storage layers; 5-3 planting layers; 5-4 fine sand layers; 5-5) volcanic rock medium layers; 5-6 biological medium layers; 5-7) a fine gravel layer; 5-8) a coarse gravel layer; 5-9) waterlogging tolerant plants; 5-10) a water collecting well; 5-11) a cement baffle; 5-12) a water inlet; 5-13) a water outlet; 5-14) connecting pipes; 6, a recycling unit; 6-1, collecting a water tank; 6-2 recycling pipelines; 6-3 recycling pump; 6-4 water points

Detailed Description

The collection, purification, reuse, collection and pretreatment process of the polluted runoff of the liquid bulk cargo wharf, which is shown in the combined drawings 1-5, comprises the following basic processes:

after rainstorm, the concentration of suspended matters in the polluted runoff of the liquid bulk cargo wharf is 1000-2000 mg/L, the concentration of crude oil in the polluted runoff near the crude oil tank area is 20-50 mg/L, and the concentration of pollutants represented by methylbenzene in the polluted runoff near the liquid chemical tank area is 1-5 mg/L. Polluted runoff near a crude oil tank area enters an adjusting oil separation tank (1-2) through a water collection channel I (1-1), the crude oil concentration in the adjusting oil separation tank (1-2) is reduced to 10mg/L and then enters an adsorption tank (1-3), the adsorption tank (1-3) controls the addition of an adsorbent through the detection of the crude oil concentration, and finally the crude oil concentration is conveyed to a coagulating sedimentation unit (4) through a connecting pipeline I (4-1) when the crude oil concentration is lower than 10 mg/L; polluted runoff in the range of 30m on the left side and the right side of a water collection channel II (2-2) of the liquefied natural gas area rapidly infiltrates into a lower-layer water collection pipe (2-3), and is conveyed to a coagulating sedimentation unit (4) through the lower-layer water collection pipe (2-3); the contaminated runoff in liquid chemicals jar district passes through catchment channel three (3-1) gets into effluent water sump (3-2), the water inlet and the delivery port of effluent water sump (3-2) are provided with the intelligent inductive probe who connects PLC control terminal two (3-3)'s detectable toluene, n-butanol, cresol or the concentration of xylol respectively, reach 3mg/L just to oxidize with ozone when the pollutant concentration that uses toluene as the representative, pass through simultaneously agitator (3-4) assist and get rid of, discharge into coagulating sedimentation unit (4) again. Then the sewage is treated by coagulation, flocculation and sedimentation in the coagulation sedimentation unit (4) and then is discharged into a biological retention treatment unit (5) through a connecting pipeline (4-5); then the bioretention treatment unit (5) enters a recycling unit (6) through a second connecting pipeline (5-14) after absorption and purification of plants and adsorption treatment of fillers; finally, the water is conveyed from the water collecting pool (6-1) to a water using point (6-4) in the recycling unit (6) through a recycling pump (6-3).

The crude oil pollution runoff collection and pretreatment unit (1) consists of a catchment channel I (1-1), an adjusting oil separation tank (1-2), an adsorption tank (1-3) and a PLC control terminal I (1-4); the liquefied natural gas pollution runoff collection and pretreatment unit (2) mainly comprises an overflow rainwater well cover (2-1), a water collection channel II (2-2), a lower layer water collection pipe (2-3) and an anti-seepage geomembrane (2-5); the liquid chemical product polluted runoff collecting and preprocessing unit (3) is composed of a catchment channel III (3-1), a sewage pool (3-2), a PLC control terminal II (3-3) and a stirrer (3-4).

The ground gradient of the first catchment channel (1-1) is 1%; the first branch channels (1-1-1) are arranged along the pipeline 1m of the crude oil tank area at intervals of 10m; the gradient of the road of the liquefied natural gas tank field is 1 percent; the second catchment channel (2-2) is arranged along a road and a sidewalk, the width of the second catchment channel is 40cm, and the bottom of the channel is made of renewable sponge concrete (2-2-1); the third water catchment channel (3-1) is arranged along the ground of the liquefied chemical tank field, and the slope of the ground is 1%; the distance between the third branch channels (3-1-1) is 6m, the width and the height are respectively 25cm and 35cm, and the specific drop is 1%; the width and the height of the third main channel (3-1-2) are respectively 35cm and 50cm, and the specific reduction is 2%.

The coagulating sedimentation unit (4) consists of a coagulating area (4-2), a flocculating area (4-3) and a sedimentation area (4-4); the coagulating area (4-2) is added with polyaluminium chloride as a coagulant; and polyacrylamide is added into the flocculation area (4-3) as a coagulant aid.

The bioretention treatment unit (5) mainly comprises an assembled concrete outer wall (5-1), a water storage layer (5-2), a planting layer (5-3), a fine sand layer (5-4), a volcanic rock medium layer (5-5), a biological medium layer (5-6), a fine gravel layer (5-7), a coarse gravel layer (5-8), a water collecting well (5-10) and a cement partition plate (5-11); the planting layer (5-3) is planted with waterlogging-resistant plants (5-9); the waterlogging-resistant plant (5-9) is a combination of canna, thalictrum ramosissimum, miscanthus gracilis and acorus calamus; soil with the thickness of 100mm is arranged on the planting layer (5-3), and a composite flora multilayer immobilized material is uniformly filled in the soil; the multilayer immobilized material of the composite flora consists of an inner core and an outer layer embedded substance, wherein the inner core is prepared from anaerobic ammonia oxidation granular sludge, and the outer layer embedded substance is prepared from aerobic nitrification granular sludge.

The volcanic medium layer (5-6) is crushed stone with the thickness of 200 and the diameter of 5 mm; the thickness of the biological medium layer (5-7) is 300mm; the biological medium layer (5-7) is internally provided with a filler; the filler is 80% of biological retention medium, 10% of small ceramsite and 10% of corn straw; the bioretention media comprises soil, river sand and pine bark; the fine gravel layer (5-8) is crushed stone with the thickness of 200mm and the diameter of 5 mm; the coarse gravel layer (5-9) is crushed stone with the thickness of 300mm and the diameter of 20 mm.

The raw materials for preparing the renewable sponge concrete (2-2-1) comprise aggregate, cement, a binder, a foaming agent, an anti-cracking agent, a microbial agent and water; the preparation steps of the sponge concrete (2-2-1) mainly comprise aggregate screening and grading, primary coagulation and stirring, secondary coagulation and aeration and stirring, tertiary coagulation and stirring, casting molding and curing; the recycling steps of the sponge concrete (2-2-1) are mainly mechanical crushing, ultrasonic stripping, aggregate sorting and regeneration, excess material crushing and regeneration; the porosity of the sponge concrete (2-2-1) is 50%, wherein the pore volume of the sponge concrete with the diameter of 0.4-2mm accounts for 60%, the permeability coefficient is 3mm/s, and the maximum water holding rate is 60%.

Claims

1. The collecting, purifying and recycling process of the liquid bulk cargo wharf polluted runoff is characterized by comprising a crude oil polluted runoff collecting and preprocessing unit (1), a liquefied natural gas polluted runoff collecting and preprocessing unit (2), a liquid chemical polluted runoff collecting and preprocessing unit (3), a coagulating sedimentation unit (4), a biological retention processing unit (5) and a recycling unit (6); the process comprises the following steps: (1) the polluted runoff of the crude oil tank area, the liquefied natural gas tank area and the liquid chemical tank area is collected and pretreated by a crude oil polluted runoff collecting and pretreating unit (1), a liquefied natural gas polluted runoff collecting and pretreating unit (2) and a liquid chemical polluted runoff collecting and pretreating unit (3) respectively and then is conveyed to a coagulating sedimentation unit (4) through a connecting pipeline I (4-1); (2) then the mixed solution is treated by coagulation, flocculation and sedimentation in the coagulating sedimentation unit (4) and then is discharged into a biological retention treatment unit (5) through a second connecting pipeline (4-5); (3) after the biological retention treatment unit (5) is subjected to absorption purification of plants and adsorption treatment of fillers, the biological retention treatment unit enters a recycling unit (6) through a connecting pipeline (5-14); (4) finally, the water is conveyed from the water collecting pool (6-1) to a water using point (6-4) in the recycling unit (6) through a recycling pump (6-3); the liquefied natural gas polluted runoff collection and pretreatment unit (2) mainly comprises an overflow rainwater well cover (2-1), a catchment channel II (2-2), a water collecting pipe (2-3) and an impermeable geomembrane (2-5); the basic working flow of the liquefied natural gas pollution runoff collecting and preprocessing unit (2) is as follows: polluted runoff in the range of 20-35m on the left side and the right side of the water collection channel II (2-2) quickly infiltrates into the water collection pipes (2-3), and is conveyed to the coagulating sedimentation unit (4) through the water collection pipes (2-3); the gradient of the road of the liquefied natural gas tank field is 1 percent; the second water catchment channel (2-2) is arranged along the road and the sidewalk and has the width of 30-50cm; the bottom of the catchment channel II (2-2) is made of renewable sponge concrete (2-2-1); the raw materials for preparing the renewable sponge concrete (2-2-1) comprise aggregate, cement, a binder, a foaming agent, an anti-cracking agent, a microbial agent and water; the preparation steps of the renewable sponge concrete (2-2-1) mainly comprise aggregate screening and grading, primary coagulation and stirring, secondary coagulation and aeration and stirring, tertiary coagulation and stirring, casting molding and curing; the recycling steps of the renewable sponge concrete (2-2-1) mainly comprise mechanical crushing, ultrasonic stripping, aggregate sorting and regeneration, excess material crushing and regeneration; the porosity of the renewable sponge concrete (2-2-1) is more than 40%, wherein the ratio of the pore volume with the diameter of 0.4-2mm is more than 60%, the permeability coefficient is more than 2mm/s, and the maximum water holding rate is more than 50%; the bioretention treatment unit (5) mainly comprises an assembled concrete outer wall (5-1), a water storage layer (5-2), a planting layer (5-3), a fine sand layer (5-4), a volcanic rock medium layer (5-5), a biological medium layer (5-6), a fine gravel layer (5-7), a coarse gravel layer (5-8), a water collecting well (5-10) and a cement partition plate (5-11); soil with the thickness of 100mm is arranged on the planting layer (5-3), and a composite flora multilayer immobilized material is uniformly filled in the soil; the multilayer composite flora immobilized material consists of an inner core and an outer layer embedded matter, wherein the inner core is prepared from anaerobic ammonia oxidation granular sludge, and the outer layer embedded matter is prepared from aerobic nitrification granular sludge.

2. The process for collecting, purifying and recycling the polluted runoff of the liquid bulk cargo wharf according to claim 1, wherein the process comprises the following steps: the crude oil pollution runoff collection and pretreatment unit (1) consists of a catchment channel I (1-1), an adjusting oil separation tank (1-2), an adsorption tank (1-3) and a PLC control terminal I (1-4); the basic working flow of the crude oil pollution runoff collection and pretreatment unit (1) is as follows: polluted runoff near a crude oil tank area enters an adjusting oil separation tank (1-2) through a water collection channel I (1-1), the crude oil concentration in the adjusting oil separation tank (1-2) is reduced to 10-20mg/L and then enters an adsorption tank (1-3), the adsorption tank (1-3) controls the addition of an adsorbent through the detection of the crude oil concentration, and finally the crude oil concentration is conveyed to a coagulating sedimentation unit (4) through a connecting pipeline I (4-1) when being lower than 10 mg/L; the ground gradient of the catchment channel I (1-1) is 0.5-2%; the first branch channels are arranged along the pipeline of the crude oil tank area at the left and right sides at the interval of 8-12m.

3. The process of claim 1, wherein the process comprises the steps of: the liquid chemical product polluted runoff collecting and preprocessing unit (3) consists of a catchment channel III (3-1), a sewage pool (3-2), a PLC control terminal II (3-3) and a stirrer (3-4); the basic working flow of the liquid chemical pollution runoff collecting and preprocessing unit (3) is as follows: polluted runoff in the liquid chemical tank area enters a sewage tank (3-2) through a water collection channel III (3-1), an intelligent sensing probe which is connected with a PLC control terminal II (3-3) and can detect the concentration of toluene, n-butyl alcohol, cresol or xylene is respectively arranged at a water inlet and a water outlet of the sewage tank (3-2), when the concentration of pollutants represented by toluene reaches 1-5mg/L, ozone is used for oxidation, and meanwhile, the pollutants are removed in an auxiliary way through a stirrer (3-4) and then discharged into a coagulating sedimentation unit (4); the third catchment channel (3-1) is arranged along the ground of the liquefied chemical tank field, and the gradient of the ground is 1-1.5%; the distance between the third branch channels is 5-8m, the width and the height are respectively 25cm and 35cm, and the specific reduction is 1-1.5%; the width and height of the third main canal are 35cm and 50cm respectively, and the specific reduction is 1.5-2%.

4. The process of claim 1, wherein the process comprises the steps of: the planting layer (5-3) is planted with waterlogging-resistant plants (5-9); the waterlogging-resistant plant (5-9) is a combination of canna, thalictrum ramosissimum, miscanthus gracilis and acorus calamus; the volcanic medium layer (5-5) is crushed stone with the thickness of 200-300mm and the diameter of 5-10 mm; the thickness of the biological medium layer (5-6) is 300-400mm; the biological medium layer (5-6) is internally provided with a filler; the filler is 80% of biological retention medium, 10% of small ceramsite and 10% of corn straw; the bioretention media comprises soil, river sand and pine bark; the fine gravel layer (5-7) is crushed stone with the thickness of 100-200mm and the diameter of 3-8 mm; the coarse gravel layer (5-8) is crushed stone with the thickness of 200-300mm and the diameter of 15-30 mm.