A comprehensive treatment system and process for organic wastewater tail gas from polluted sites

Abstract

The present invention discloses a comprehensive treatment system and treatment process for organic wastewater and tail gas in a contaminated site, and belongs to the field of soil remediation. The system of the present invention includes a wastewater treatment unit and a tail gas treatment unit, and the wastewater treatment unit includes an oxidant dosing unit, a first ultraviolet reaction unit and a second ultraviolet reaction unit connected in sequence; the oxidant dosing unit is used to add an oxidant to the wastewater to be treated; the wastewater to be treated is treated by ultraviolet photocatalytic oxidation technology, and the oxidation process includes a rapid oxidation stage and a deep oxidation stage. Through the segmented gradient oxidation process, the utilization rate and oxidation effect of the oxidant are greatly improved, and the operating cost is reduced. The tail gas treatment unit includes a plurality of adsorption towers, and the plurality of adsorption towers are connected in parallel, and the adsorption towers are filled with adsorption resin. The main purpose of the present invention is to reasonably and efficiently treat the wastewater and tail gas extracted by the extraction unit, and it occupies a small area, which is convenient for skid installation, installation, disassembly and transportation.

Description

Technical Field

[0001] The present invention relates to the field of soil remediation, and more specifically, to a comprehensive treatment system and process for organic wastewater and tail gas in a polluted site. Background Art

[0002] Contaminated plots of land with environmental risks are called contaminated sites. The multiphase extraction system is a commonly used remediation process in current contaminated site remediation projects. The group standard T / ACEF113-2023 "Technical Specifications for Remediation of Organic Contaminated Land-Multiphase Extraction" stipulates that the multiphase extraction system is mainly composed of extraction units and separation and purification units. The multiphase extraction system extracts pollutants such as soil gas and contaminated groundwater to the ground, and after gas and liquid separation, the separated pollutants in each phase are treated through the pollutant treatment device.

[0003] In the remediation of contaminated sites, the effective treatment of tail gas and wastewater after extraction and separation is crucial. In current projects, activated carbon adsorption is the simplest and most effective technology for treating organic waste gas, but due to improper management or operation, it is difficult to continuously and stably meet the emission standards and collect them; and the disposal cost of the waste activated carbon produced after adsorption is relatively high. For high-concentration wastewater to be treated, the traditional activated sludge method cannot be treated on-site, and most of them use the Fenton method or electrolysis technology for degradation. However, the Fenton method will produce Fenton iron mud, which will cause secondary pollution; electrolysis will produce flammable and explosive hydrogen, which will cause great safety hazards during on-site disposal. At the same time, the engineering equipment or systems used in the above-mentioned engineering technologies occupy a large area, and installation and disassembly are time-consuming and labor-intensive, and cannot be moved between project sites.

[0004] Therefore, there is an urgent need for a comprehensive treatment system for organic wastewater and tail gas from wastewater and tail gas pollution sites that can reasonably and efficiently treat the wastewater and tail gas extracted by the extraction unit; and a system that occupies a small area and is easy to skid, install, disassemble and transport. Summary of the invention

[0005] 1. Technical problem to be solved by the invention

[0006] In view of the problems that the on-site treatment of wastewater and tail gas extracted by the extraction unit in the remediation of contaminated sites in the prior art has secondary pollution, generation of hazardous gases, and the large footprint of the treatment device, which is inconvenient to install and disassemble, a comprehensive treatment system and treatment process for organic wastewater and tail gas from contaminated sites are provided.

[0007] 2. Technical solution

[0008] In order to achieve the above object, the technical solution provided by the present invention is:

[0009] The present invention provides a comprehensive treatment system for organic wastewater and tail gas in a polluted site, comprising a wastewater treatment unit and a tail gas treatment unit;

[0010] The wastewater treatment unit comprises an oxidant dosing unit, a first ultraviolet reaction unit and a second ultraviolet reaction unit which are connected in sequence;

[0011] The oxidant dosing unit is connected to the wastewater to be treated and is used to add the oxidant to the wastewater to be treated;

[0012] The first ultraviolet reaction unit includes a plurality of first ultraviolet reactors, and a plurality of first ultraviolet lamps are arranged in the first ultraviolet reactors; when the number of the first ultraviolet reactors is ≥2, the first ultraviolet reactors can switch between series and parallel connection modes, and the first ultraviolet reactors meet the requirement that the residence time of the wastewater to be treated in the first ultraviolet reactor is t1;

[0013] The second ultraviolet reaction unit includes a plurality of second ultraviolet reactors, and a plurality of second ultraviolet lamps are arranged in the second ultraviolet reactors; when the number of the second ultraviolet reactors is ≥2, the second ultraviolet reactors are connected in series; the second ultraviolet reactors meet the requirement that the residence time of the wastewater to be treated in the second ultraviolet reactor is t2;

[0014] The residence time t1 is shorter than the residence time t2, and the power of the first ultraviolet lamp is greater than the power of the second ultraviolet lamp;

[0015] The tail gas treatment unit comprises a plurality of adsorption towers, which are connected in parallel and filled with adsorption resin; the adsorption resin satisfies a specific surface area of ​​≥1000m 2 / g requirements.

[0016] It should be noted that the wastewater to be treated is treated by ultraviolet catalytic oxidation technology. The wastewater to be treated passes through the first ultraviolet reactor in the first ultraviolet reaction unit. Under the conditions of higher ultraviolet intensity, higher oxidant concentration and lower residence time, the organic matter in the wastewater can be quickly oxidized, which can be called a rapid oxidation stage; and then passes through the second ultraviolet reactor in the second ultraviolet reaction unit. Under the conditions of lower ultraviolet intensity, lower oxidant concentration and higher residence time, the organic matter in the wastewater is further deeply oxidized, which can be called a deep oxidation stage; through the action of the oxidant and ultraviolet light, strong oxidizing free radicals are generated to achieve thorough oxidation of organic pollutants, and generate water and carbon dioxide without secondary pollution; on the other hand, the oxidation process includes a rapid oxidation stage and a deep oxidation stage. Through the segmented gradient oxidation process, the utilization rate of the oxidant and the oxidation effect are greatly improved, and the operating cost is reduced;

[0017] The tail gas treatment unit is used to adsorb VOCs in the tail gas and treats it through adsorption resin, and has the advantages of stable operation and low replacement frequency.

[0018] Preferably, the adsorption resin can refer to the invention patent with publication number CN102391407A. The adsorption resin has stable performance, is easy to regenerate, and can be used for a long time without replacement and replenishment.

[0019] For example, the first ultraviolet reactor may be a tubular reactor, and the second ultraviolet reactor may be a tank reactor.

[0020] The wastewater to be treated is organic wastewater extracted and separated from the soil of a contaminated site by a multiphase extraction system; the tail gas is organic waste gas extracted and separated from the soil of a contaminated site by a multiphase extraction system.

[0021] Furthermore, the residence time t1 of the wastewater to be treated in the first ultraviolet reactor is 0.5 to 5 minutes;

[0022] The residence time t2 of the wastewater to be treated in the second ultraviolet reactor is 10 to 100 minutes.

[0023] Furthermore, the first ultraviolet lamp is arranged parallel to the water flow direction.

[0024] By arranging the first ultraviolet lamp in parallel along the water flow direction, the structure of the first ultraviolet reactor can be made more compact and its volume can be reduced.

[0025] Furthermore, the number of the first ultraviolet lamps increases as the volume of the first ultraviolet reactor increases.

[0026] Furthermore, the power of the first ultraviolet lamp is greater than 1 kW.

[0027] Furthermore, the wavelength of the ultraviolet light emitted by the first ultraviolet lamp is 200-400nm.

[0028] Furthermore, the second ultraviolet lamp is arranged perpendicular to the water flow direction.

[0029] With this arrangement, maintenance and replacement can be carried out from the top of the second UV reactor, saving space.

[0030] Furthermore, the power of the second ultraviolet lamp is less than 1 kW.

[0031] Furthermore, the wavelength of the ultraviolet light emitted by the second ultraviolet lamp is mainly 254nm.

[0032] Furthermore, the first ultraviolet lamp and the second ultraviolet lamp can both be ultraviolet lamps with adjustable power.

[0033] Furthermore, the oxidant dosing unit comprises an oxidant storage tank and a first metering pump.

[0034] The first metering pump is connected to the oxidant storage tank and the first ultraviolet reaction unit respectively.

[0035] Furthermore, the oxidant storage tank stores an oxidant, and the oxidant can generate strong oxidizing free radicals under the action of ultraviolet light.

[0036] Furthermore, the oxidant is at least one of hydrogen peroxide and persulfate.

[0037] For example, the persulfate may be sodium persulfate or potassium persulfate.

[0038] Preferably, the oxidant is hydrogen peroxide, the reduction product of which is water, which is greener and safer, and produces highly oxidizing hydroxyl radicals under the action of ultraviolet light.

[0039] Furthermore, the wastewater treatment unit further comprises the acid solution adding unit, and the acid solution adding unit comprises an acid solution storage tank and a second metering pump.

[0040] The second metering pump is connected to the acid liquid storage tank and the first ultraviolet reaction unit respectively.

[0041] It should be noted that the acid solution is used to adjust the pH value of the wastewater to be treated to enhance the oxidizing effect of the oxidant.

[0042] Furthermore, the acid solution is one or both of hydrochloric acid and sulfuric acid.

[0043] Furthermore, the acid solution adding unit may be arranged between the first reaction unit and the oxidant adding unit.

[0044] Further, the second ultraviolet reaction unit is connected to the tail gas treatment unit;

[0045] When the wastewater treated by the second ultraviolet reaction unit does not meet the standards, part of the adsorption tower in the tail gas treatment unit is used to adsorb pollutants in the wastewater.

[0046] Furthermore, a first flow meter, a temperature sensor and a pH sensor are provided between the first ultraviolet reaction unit and the wastewater to be treated;

[0047] A second flow meter is arranged between the tail gas treatment unit and the tail gas.

[0048] Furthermore, it also includes an automatic control unit, which is electrically connected to the wastewater treatment unit, the tail gas treatment unit, the oxidant dosing unit, and the acid solution dosing unit.

[0049] The automatic control unit can be a programmable logic controller. The system automatically controls each unit through the control panel on the automatic control unit, including the adjustment of the power of the ultraviolet reactor. The values ​​of all instruments and the operating status of the equipment can be viewed and controlled through the control panel of the automatic control unit, and manual control and parameter change can be performed, with a high degree of automation.

[0050] For example, based on the flow rate, temperature, pH and other water quality indicators of the wastewater to be treated monitored by the first flow meter, temperature sensor and pH sensor and the input pollutant concentration data, the required oxidant dosage is calculated according to the target oxidant concentration set by the system, and the first metering pump is intelligently controlled to add a certain amount of oxidant to the wastewater to be treated;

[0051] Based on the flow rate, temperature, pH and other water quality indicators of the wastewater to be treated monitored by the first flow meter, temperature sensor and pH sensor, as well as the input pollutant concentration data, the required ultraviolet light intensity is calculated according to the target ultraviolet light dose set by the system, and the power of the first ultraviolet lamp and the second ultraviolet lamp are intelligently controlled.

[0052] Further, the first ultraviolet reaction unit includes a first ultraviolet reactor a, a first ultraviolet reactor b and a first ultraviolet reactor c;

[0053] The first ultraviolet reactor a is provided with an interface a and an interface b.

[0054] The first ultraviolet reactor b is provided with an interface c and an interface d,

[0055] The first ultraviolet reactor c is provided with an interface e and an interface f,

[0056] Interface a, interface c, and interface e are respectively connected to the oxidant dosing unit and the wastewater to be treated through pipelines, and interface b, interface d, and interface f are connected to the second ultraviolet reaction unit through pipelines.

[0057] It should be noted that when the flow rate of the wastewater to be treated is small and the concentration of pollutants is high, the first ultraviolet reactor a, the first ultraviolet reactor b and the first ultraviolet reactor c are connected in series by adjusting the pipeline connection, etc., so as to increase the treatment time at a higher ultraviolet intensity and a higher oxidant concentration, and realize the rapid oxidation of high-concentration pollutants;

[0058] When the flow rate of the wastewater to be treated is large and the concentration is low, the first ultraviolet reactor a, the first ultraviolet reactor b and the first ultraviolet reactor c are connected in parallel by adjusting the pipeline connection, so that a large amount of wastewater to be treated can be quickly oxidized and a good oxidation effect can be maintained;

[0059] On the other hand, one or two of the first ultraviolet reactors can be cut out of the system and cleaned and maintained. Taking the cutting out of the first ultraviolet reactor a as an example, when the first ultraviolet reactor a needs to be cleaned, the first ultraviolet reactor b and the first ultraviolet reactor c are in operation, so that the wastewater does not pass through the first ultraviolet reactor a, and no wastewater flows through the first ultraviolet reactor a, so that the first ultraviolet reactor a can be repaired and cleaned under the continuous operation of the system; similarly, the other first ultraviolet reactors can be repaired and cleaned under the continuous operation of the system.

[0060] Furthermore, valves may be provided on the pipeline to achieve series-parallel switching of the first ultraviolet reactor a, the first ultraviolet reactor b and the first ultraviolet reactor c.

[0061] Furthermore, the second ultraviolet reaction unit comprises a second ultraviolet reactor a and a second ultraviolet reactor b connected in series.

[0062] The second ultraviolet reactor a comprises a water inlet a and a water outlet a, and the second ultraviolet reactor b comprises a water inlet b and a water outlet b;

[0063] The water inlet a of the second ultraviolet reactor a is connected to the first ultraviolet reactor c, the water outlet a is connected to the water inlet b of the second ultraviolet reactor b, and the water outlet b is connected to a wastewater collection device.

[0064] The wastewater collecting device is used to collect treated wastewater that meets the standards.

[0065] For example, the wastewater collection device may be a storage tank.

[0066] Furthermore, the tail gas treatment unit comprises an adsorption tower a and an adsorption tower b connected in parallel,

[0067] The adsorption tower a includes an air inlet and an air outlet, and the adsorption tower b includes an air inlet and an air outlet;

[0068] The air inlet of the adsorption tower a and the air inlet of the adsorption tower b are connected to the tail gas, and the air outlet of the adsorption tower a and the air outlet of the adsorption tower b are both connected to the outside.

[0069] Furthermore, the adsorption tower a also includes a water inlet and a water outlet, the water inlet of the adsorption tower a is connected to the water outlet b of the second ultraviolet reactor; the water outlet of the adsorption tower a is connected to the wastewater collection device.

[0070] It should be noted that when the wastewater to be treated meets the standards after being treated by the wastewater treatment unit, it is collected by the wastewater collection device and then discharged. At this time, the adsorption tower a and the adsorption tower b are connected in parallel to treat the tail gas;

[0071] When the wastewater to be treated does not meet the standards after being treated in the wastewater treatment unit, it needs to be deeply treated by adsorption tower a to meet the standards. At this time, adsorption tower a switches to treating the wastewater to be treated, and adsorption tower b treats the exhaust gas.

[0072] It should also be noted that the wastewater compliance can be the indirect emission limit standards in Table 1 of the national standard GB 31571-2015 or the direct emission limit standards in Table 1 of the national standard GB 31571-2015.

[0073] The units and equipment reactors used in the system can be combined and applied in different quantities according to the treatment requirements and the layout can be easily changed, so the scope of application of polluted sites is wider. The system has a small footprint and is easy to skid, install, disassemble and transport; moreover, it also has the advantages of high degree of automation, good treatment effect, stable operation and low treatment cost.

[0074] The present invention also provides a process for treating wastewater and tail gas by using the above-mentioned comprehensive treatment system for organic wastewater and tail gas in contaminated sites, comprising the following process:

[0075] Adding an oxidant and an acid solution to the wastewater to be treated, and then the wastewater to be treated enters the first ultraviolet reaction unit, and then passes through the second ultraviolet reaction unit, and ultraviolet photocatalytic oxidation treatment is performed in the first ultraviolet reaction unit and the second ultraviolet reaction unit;

[0076] The tail gas is passed into the adsorption tower in the tail gas treatment unit for adsorption treatment;

[0077] After the wastewater to be treated is treated by ultraviolet photocatalytic oxidation, if it meets the standards, it will be discharged; if it does not meet the standards, it will be treated through some adsorption towers in the exhaust gas treatment unit.

[0078] 3. Beneficial effects

[0079] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0080] (1) The present invention provides a comprehensive treatment system for organic wastewater and tail gas from a contaminated site, wherein the wastewater treatment unit in the system comprises an oxidant dosing unit, a first ultraviolet reaction unit and a second ultraviolet reaction unit connected in sequence, the oxidant dosing unit is connected to the wastewater to be treated, the first ultraviolet reaction unit comprises a plurality of first ultraviolet reactors each having a plurality of first ultraviolet lamps disposed therein, the second ultraviolet reaction unit comprises a plurality of second ultraviolet reactors each having a plurality of second ultraviolet lamps disposed therein, the first ultraviolet reactor satisfies the requirement that the residence time of the wastewater to be treated in the first ultraviolet reactor is t1; the second ultraviolet reactor satisfies the requirement that the residence time of the wastewater to be treated in the second ultraviolet reactor is t2; the residence time t1 is less than the residence time t2, and the power of the first ultraviolet lamp is greater than the power of the second ultraviolet lamp;

[0081] Ultraviolet catalytic oxidation technology is used to treat the wastewater to be treated. The wastewater to be treated passes through the first ultraviolet reactor in the first ultraviolet reaction unit. Under the conditions of high ultraviolet intensity, high oxidant concentration and low residence time, the organic matter in the wastewater can be quickly oxidized; then it passes through the second ultraviolet reactor in the second ultraviolet reaction unit. Under the conditions of low ultraviolet intensity, low oxidant concentration and high residence time, the organic matter in the wastewater is further deeply oxidized. On the one hand, through the action of oxidant and ultraviolet light, strong oxidizing free radicals are generated to achieve thorough oxidation of organic pollutants, and water and carbon dioxide are generated without secondary pollution; on the other hand, in the rapid oxidation stage and the deep oxidation stage, the utilization rate and oxidation effect of the oxidant are greatly improved through the segmented gradient oxidation process, and the operating cost is reduced; ultraviolet catalytic oxidation technology is used as the core process to treat organic wastewater from contaminated sites. Through the action of ultraviolet light and oxidant, strong oxidizing free radicals are generated to thoroughly oxidize organic matter, and finally water and carbon dioxide are generated without secondary pollution; moreover, after being treated, the wastewater to be treated can meet the standards;

[0082] The tail gas treatment unit in the system includes several adsorption towers, which are filled with adsorption resins for adsorbing VOCs in the tail gas; the adsorption resins meet the specific surface area of ​​≥1000m 2 / g requirements, it has the advantage of stable performance and can be used for a long time without replacement.

[0083] (2) The comprehensive treatment system for organic wastewater and tail gas from contaminated sites of the present invention has the advantages of small footprint, easy skid installation, installation, disassembly and transportation, high degree of automation, good treatment effect, stable operation and low treatment cost.

[0084] (3) The various device units used in the comprehensive treatment system for organic wastewater and tail gas in contaminated sites of the present invention can be used in combination in different quantities according to the treatment requirements and the layout can be easily changed. It can be applied to different types of organic pollution sites such as chemical, petroleum, and pesticides, and can treat organic wastewater such as petroleum hydrocarbons, halogenated hydrocarbons, phenols, benzene series, and volatile organic tail gas, and meet the emission standards. It has a very broad application market. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0086] Figure 1 This is a schematic diagram of the structure of the coordinated treatment system for wastewater and tail gas to be treated in a contaminated site according to the present invention;

[0087] Figure 2 This is a schematic diagram of the automatic control system of the coordinated treatment system for wastewater and tail gas to be treated in a contaminated site of the present invention;

[0088] Figure 3 This is a schematic structural diagram of the first ultraviolet reaction unit of the present invention in a use state;

[0089] Figure 4 It is a structural schematic diagram of the first ultraviolet reaction unit of the present invention in another use state;

[0090] Figure 5 It is a structural schematic diagram of the first ultraviolet reaction unit of the present invention in another use state;

[0091] Figure 6 It is a schematic diagram of the top structure of the second ultraviolet reactor of the present invention.

[0092] Explanation of the symbols in the schematic diagram:

[0093] 100. Wastewater treatment unit;

[0094] 110. Oxidant dosing unit; 111. Oxidant storage tank; 112. First metering pump;

[0095] 120, first ultraviolet reaction unit; 121a, first ultraviolet reactor a; 121b, first ultraviolet reactor b; 121c, first ultraviolet reactor c; 1211, first ultraviolet lamp;

[0096] 130, second ultraviolet reaction unit; 131a, second ultraviolet reactor a; 131b, second ultraviolet reactor b; 1311, second ultraviolet lamp;

[0097] 14. A first flow meter;

[0098] 15. Temperature sensor;

[0099] 16. pH sensor;

[0100] 171, valve a; 172, valve b; 173, valve c; 174, valve d; 175, valve e; 176, valve f; 177, valve g; 178, valve h; 179, valve i;

[0101] 180. Acid solution dosing unit; 181. Acid solution storage tank; 182. Second metering pump;

[0102] 200. Exhaust gas treatment unit;

[0103] 21. Adsorption tower a;

[0104] 22. Adsorption tower b;

[0105] 23. A second flow meter;

[0106] 241, valve j; 242, valve k; 243, valve L; 244, valve m; 245, valve n; 246, valve o;

[0107] 300. Automatic control unit. DETAILED DESCRIPTION

[0108] The present disclosure may be more easily understood by reference to the following description in conjunction with examples, all of which constitute a part of the present disclosure. It should be understood that the present disclosure is not limited to the specific products, methods, conditions or parameters described and / or illustrated herein. Further, the terms used herein are only used for the purpose of describing specific embodiments by way of example and are not intended to be limiting unless otherwise indicated.

[0109] It should also be understood that, for the sake of clarity, certain features of the present disclosure may be described herein in the context of separate embodiments, but may also be provided in combination with each other in a single embodiment. That is, unless clearly incompatible or specifically not included, each separate embodiment is considered to be combinable with any other embodiment, and the combination is considered to represent another different embodiment. Conversely, for the sake of simplicity, the various features of the present disclosure described in the context of a single embodiment may also be provided individually or in any sub-combination. Finally, although a particular embodiment may be described as part of a series of steps or part of a more general structure, each step or substructure itself may also be considered to be an independent embodiment.

[0110] Unless otherwise indicated, it should be understood that each individual element in a list and each combination of individual elements in the list will be interpreted as a different embodiment. For example, a list of embodiments represented as "A, B, or C" should be interpreted to include embodiments "A", "B", "C", "A or B", "A or C", "B or C", or "A, B, or C".

[0111] In the present disclosure, the singular forms of the articles "a," "an," and "the" also include the corresponding plural references, and a reference to a specific value includes at least that specific value unless the context clearly indicates otherwise. Thus, for example, a reference to "a substance" is a reference to at least one of that substance and equivalents thereof.

[0112] The terms including ordinal numbers such as "first" and "second" can be used to explain various components or fluids, but these components and fluids are not limited by these terms. Therefore, without departing from the teachings of the present disclosure, these terms are only used to distinguish the component / fluid from another component / fluid.

[0113] When items are described by using the conjunction terms "... and / or...," etc., the description should be understood to include any one of the associated listed items and all combinations of one or more thereof.

[0114] In general, the use of the term "about" indicates an approximate value that can vary depending on the desired properties obtained by the disclosed subject matter, and will be interpreted in a context-dependent manner based on function. Therefore, one of ordinary skill in the art will be able to interpret a certain degree of difference on a case-by-case basis. In some cases, the number of significant figures used when expressing a particular value can be a representative technique for determining the difference allowed by the term "about". In other cases, a gradient in a range of values ​​can be used to determine the range of differences allowed by the term "about". Further, all ranges in this disclosure are inclusive and combinable, and reference to a value in a range includes each value within that range.

[0115] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs; the terms used herein and / or include any and all combinations of one or more of the associated listed items.

[0116] In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if no manufacturer is specified, are all conventional products that can be purchased commercially.

[0117] The present invention is further described below in conjunction with specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. The essential characteristics and remarkable effects of the present invention can be reflected from the following examples, and the described embodiments are part of the embodiments of the present invention, rather than all the embodiments, and therefore, they do not limit the present invention in any way, and those skilled in the art make some non-essential improvements and adjustments based on the content of the present invention, which all belong to the protection scope of the present invention.

[0118] Example 1

[0119] Combination Figure 1 The present embodiment provides a comprehensive treatment system for organic wastewater and tail gas in a contaminated site, comprising a wastewater treatment unit 100 and a tail gas treatment unit 200. The wastewater treatment unit 100 comprises an oxidant dosing unit 110, a first ultraviolet reaction unit 120 and a second ultraviolet reaction unit 130 connected in sequence. The oxidant dosing unit 110 is connected to the wastewater to be treated, i.e., the organic wastewater obtained after extraction and separation, and is used to add an oxidant to the wastewater to be treated. The oxidant can generate strong oxidizing free radicals, such as hydrogen peroxide, persulfate, etc., under the action of ultraviolet light.

[0120] The first ultraviolet reaction unit 120 includes a plurality of first ultraviolet reactors, and a plurality of first ultraviolet lamps 1211 are arranged in the first ultraviolet reactors. The first ultraviolet reactors may be one or more. Usually, the number of the first ultraviolet reactors is not less than 2. At this time, the first ultraviolet reactors may switch the connection mode of series and parallel connection to cope with the treatment of wastewater to be treated with different concentrations and different flow rates. The first ultraviolet reactor should meet the requirement that the residence time of the wastewater to be treated in the first ultraviolet reactor is t1.

[0121] The second ultraviolet reaction unit 130 includes a plurality of second ultraviolet reactors, and a plurality of second ultraviolet lamps 1311 are arranged in the second ultraviolet reactors. The second ultraviolet reactor may be one or more. Usually, the number of the first ultraviolet lamps 1211 is not less than 2, and at this time, the second ultraviolet reactors are connected in series. The second ultraviolet reactor should meet the requirement that the residence time of the wastewater to be treated in the second ultraviolet reactor is t2. The residence time t1 is less than the residence time t2, and the power of the first ultraviolet lamp 1211 is greater than the power of the second ultraviolet lamp 1311. In order to meet the above-mentioned residence time condition, the first ultraviolet reactor may be a tubular reactor, and the second ultraviolet reactor may be a tank reactor.

[0122] It should be noted that when ultraviolet catalytic oxidation technology is used to treat wastewater, the wastewater passes through the first ultraviolet reactor in the first ultraviolet reaction unit 120. Under the conditions of higher ultraviolet intensity, higher oxidant concentration and lower residence time, the organic matter in the wastewater can be quickly oxidized, which can be called a rapid oxidation stage; then the wastewater passes through the second ultraviolet reactor in the second ultraviolet reaction unit 130. Under the conditions of lower ultraviolet intensity, lower oxidant concentration and higher residence time, the organic matter in the wastewater is further deeply oxidized, which can be called a deep oxidation stage; through the action of the oxidant and ultraviolet light, strong oxidizing free radicals are generated, thereby achieving complete oxidation of organic pollutants, generating water and carbon dioxide, and no secondary pollution is generated; on the other hand, the oxidation process includes a rapid oxidation stage and a deep oxidation stage. Through the segmented gradient oxidation process, the wastewater can meet the standards, greatly improving the utilization rate and oxidation effect of the oxidant, and reducing the operating cost.

[0123] The tail gas treatment unit 200 includes a plurality of adsorption towers connected in parallel. The adsorption towers are filled with adsorption resins for adsorbing VOCs in the tail gas, i.e., VOCs in the organic waste gas obtained by extraction and separation. The adsorption resins meet the specific surface area of ​​≥1000m 2 / g condition. VOCs in tail gas can be effectively removed by adsorption resin, and tail gas can meet the standard. Preferably, the adsorption resin can refer to the invention patent with publication number CN102391407A. The adsorption resin has stable performance and can be used for a long time without replacement and replenishment. In addition, the particle size of the adsorption resin can be 0.6 to 1.25 mm.

[0124] Furthermore, the wastewater to be treated is organic wastewater extracted and separated from the soil of a contaminated site by a multiphase extraction system; the tail gas is organic waste gas extracted and separated from the soil of a contaminated site by a multiphase extraction system.

[0125] As a specific implementation method, the wastewater meeting the standard may be meeting the indirect emission limit standard in Table 1 of the national standard GB 31571-2015 or the direct emission limit standard in Table 1 of the national standard GB 31571-2015; the wastewater not meeting the standard may be not meeting the indirect emission limit standard in Table 1 of the national standard GB 31571-2015;

[0126] The exhaust gas compliance can be achieved by meeting the third-level standard in Table 2 of the national standard GB 16297-1996 and the standard of the concentration limit of unorganized emissions.

[0127] For example, after being treated by the first ultraviolet reaction unit 120 and the second ultraviolet reaction unit 130, the wastewater to be treated can meet the indirect emission limit standards in Table 1 of the national standard GB 31571-2015. At this time, the wastewater that meets the standards will be indirectly discharged, for example, it will be collected and transported to a sewage treatment plant for reprocessing; when the concentration of the wastewater to be treated is low, the treated wastewater can further meet the direct emission limit standards in Table 1 of GB 31571-2015 on the basis of meeting the indirect emission limit standards in Table 1 of the national standard GB 31571-2015. At this time, the wastewater that meets the standards will be directly discharged, for example, it can be discharged locally into the urban sewage network.

[0128] Specifically, the residence time t1 of the wastewater to be treated in the first ultraviolet reactor is 0.5 to 5 minutes; the residence time t2 of the wastewater to be treated in the second ultraviolet reactor is 10 to 100 minutes.

[0129] Furthermore, the first ultraviolet lamp 1211 is arranged in parallel along the water flow direction in the first ultraviolet reactor. By arranging the first ultraviolet lamp 1211 along the axis of the water flow direction, the structure of the first ultraviolet reactor can be made more compact, and its volume can be reduced, which is conducive to reducing the overall footprint of the system. On the other hand, in order to achieve the effect of rapid oxidation, the power of the first ultraviolet lamp 1211 should be greater than 1kW. Moreover, the wavelength of the ultraviolet light emitted by the first ultraviolet lamp 1211 is 200 to 400nm. In addition, the number of the first ultraviolet lamps 1211 can be adjusted according to the volume of the first ultraviolet reactor. Generally, the number of the first ultraviolet lamps 1211 increases as the volume of the first ultraviolet reactor increases.

[0130] Combination Figure 6 , the second ultraviolet lamp 1311 is arranged perpendicularly to the direction of water flow, and the power of the second ultraviolet lamp 1311 is less than 1kW. Through this arrangement, maintenance and replacement can be carried out from the top of the second ultraviolet reactor, saving space. On the other hand, the wavelength of the ultraviolet light emitted by the second ultraviolet lamp 1311 is mainly 254nm. In addition, the number of the second ultraviolet lamps 1311 can also be adjusted according to the volume of the second ultraviolet reactor. Furthermore, the first ultraviolet lamp 1211 and the second ultraviolet lamp 1311 can be selected with adjustable power, and their power can be adjusted according to the concentration and flow rate of the wastewater to be treated.

[0131] The oxidant dosing unit 110 includes an oxidant storage tank 111 and a first metering pump 112, and the first metering pump 112 is connected to the oxidant storage tank 111 and the first ultraviolet reaction unit 120, respectively. The oxidant is stored in the oxidant storage tank 111, and the oxidant can generate strong oxidizing free radicals under the action of ultraviolet light. Preferably, the first metering pump 112 can add the oxidant to the wastewater to be treated before the wastewater to be treated enters the first ultraviolet reactor. The oxidant is at least one of hydrogen peroxide and persulfate. For example, the persulfate can be sodium persulfate or potassium persulfate. Preferably, the oxidant is hydrogen peroxide, and its reduction product is water, which is more green and safe.

[0132] In order to strengthen the oxidizing effect of the oxidant, acid can be added to the wastewater to be treated. The acid is used to adjust the pH value of the wastewater to be treated. It can be one, two or more of hydrochloric acid or sulfuric acid. In practical applications, dilute sulfuric acid or dilute hydrochloric acid with a lower concentration can be used. Specifically, the acid is added by the acid adding unit 180 in the wastewater treatment unit 100. The acid adding unit 180 includes an acid storage tank 181 and a second metering pump 182, and the second metering pump 182 is connected to the acid storage tank 181 and the first ultraviolet reaction unit 120 respectively.

[0133] Moreover, a mixer, such as a pipeline mixer, can be installed between the pipeline of the first ultraviolet reaction unit 120 and the acid liquid adding unit 180. After the oxidant and the acid liquid are added to the wastewater to be treated, they are evenly mixed with the wastewater to be treated through the mixer, which is conducive to achieving the desired oxidation effect after subsequent ultraviolet photocatalytic oxidation.

[0134] Furthermore, the second ultraviolet reaction unit 130 is connected to the tail gas treatment unit 200; when the wastewater to be treated that passes through the second ultraviolet reaction unit 130 does not meet the standards, part of the adsorption tower in the tail gas treatment unit 200 is used to adsorb pollutants in the wastewater to make the wastewater meet the standards. Specifically, a detector can be set on the outlet pipe of the second ultraviolet reaction unit 130 to monitor and obtain the concentration of pollutants in the wastewater to be treated, so as to determine whether the wastewater needs to be passed into the adsorption tower for treatment.

[0135] A first flow meter 14, a temperature sensor 15 and a pH sensor 16 are arranged between the first ultraviolet reaction unit 120 and the wastewater to be treated; a second flow meter 23 is arranged between the exhaust gas treatment unit 200 and the exhaust gas, which can monitor the real-time flow, temperature and pH of the wastewater to be treated and the real-time flow of the exhaust gas, so as to make timely adjustments to the system, such as reducing the flow rate, etc.

[0136] Combination Figure 2 The system also includes an automatic control unit 300, which is electrically connected to the wastewater treatment unit 100, the tail gas treatment unit 200, the oxidant dosing unit 110, and the acid solution dosing unit 180.

[0137] The automatic control unit 300 can be a programmable logic controller. The system automatically controls each unit through the control panel on the automatic control unit 300, including the adjustment of the power of the ultraviolet reactor. The values ​​of all instruments and the operating status of the equipment can be viewed and controlled through the control panel of the automatic control unit 300, and manual control and parameter change can be performed, with a high degree of automation.

[0138] For example, based on the flow rate, temperature, pH and other water quality indicators of the wastewater to be treated monitored by the first flow meter 14, the temperature sensor 15, and the pH sensor 16, and the input pollutant concentration data, the dosage of the oxidant and the acid solution to be added can be calculated according to the target oxidant concentration set by the system, and the first metering pump 112 and the second metering pump 182 can be intelligently controlled to add a certain amount of oxidant and acid solution to the wastewater to be treated, respectively, which can effectively avoid waste caused by excessive addition of reagents;

[0139] It is also possible to calculate the required ultraviolet light intensity based on the target ultraviolet light dose set by the system, based on the flow rate, temperature, pH and other water quality indicators of the wastewater to be treated monitored by the first flow meter 14, temperature sensor 15 and pH sensor 16, as well as the input pollutant concentration data, and intelligently control the power of the first ultraviolet lamp 1211 and the second ultraviolet lamp 1311, thereby avoiding energy waste.

[0140] The comprehensive treatment system for organic wastewater and tail gas from contaminated sites of this embodiment has the advantages of small footprint, easy skid installation, installation, disassembly and transportation, high degree of automation, good treatment effect, stable operation and low treatment cost.

[0141] Moreover, it can be combined and applied in different quantities according to the treatment requirements and the layout can be easily changed. It can be applied to different types of organic pollution sites such as chemical, petroleum, pesticides, etc., and treat organic wastewater such as petroleum hydrocarbons, halogenated hydrocarbons, phenols, benzene series, and volatile organic tail gas, and meet the emission standards. In addition, the system has the advantages of small footprint, high degree of automation, stable operation, and low treatment cost.

[0142] As a specific implementation, the first ultraviolet reaction unit 120 includes a first ultraviolet reactor a121a, a first ultraviolet reactor b121b and a first ultraviolet reactor c121c; the first ultraviolet reactor a121a is provided with an interface a and an interface b, the first ultraviolet reactor b121b is provided with an interface c and an interface d, and the first ultraviolet reactor c121c is provided with an interface e and an interface f.

[0143] Interface a, interface c, and interface e are respectively connected to the oxidant dosing unit 110 and the wastewater to be treated through pipelines, and interface b, interface d, and interface f are connected to the second ultraviolet reaction unit 130 through pipelines.

[0144] It should be noted that when the flow rate of the wastewater to be treated is small and the concentration of pollutants is high, by adjusting the pipe connection and the like, for example, by removing the pipes connected to the wastewater to be treated by interface c and interface e and the pipes connected to the second ultraviolet reaction unit 130 by interface b and interface d, and adding pipes connected to interface b and interface c, and pipes connected to interface d and interface e, so that the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c are in series, the treatment time at higher ultraviolet intensity and higher oxidant concentration can be increased, and rapid oxidation of high-concentration pollutants can be achieved;

[0145] When the flow rate of the wastewater to be treated is large and the concentration is low, the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c are connected in parallel, and multiple first ultraviolet reactors are processed simultaneously, which can complete the rapid oxidation of a large amount of wastewater to be treated and maintain a good oxidation effect;

[0146] On the other hand, one of the first ultraviolet reactors can be cut out of the system and cleaned and maintained by adjusting the connection of the pipeline. For example, the aforementioned method of removing and adding pipelines can be adopted, which will not be repeated here. Taking the cutting out of the first ultraviolet reactor a121a as an example, when the first ultraviolet reactor a121a needs to be cleaned, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c are in operation, so that the wastewater does not pass through the first ultraviolet reactor a121a, and no wastewater flows through the first ultraviolet reactor a121a, so that the first ultraviolet reactor a121a can be repaired and cleaned under the continuous operation of the system; similarly, other first ultraviolet reactors can be repaired and cleaned under the continuous operation of the system. When the first ultraviolet reaction unit 120 is provided with 4 or more first ultraviolet reactors, the connection method can be analogous, which will not be repeated here.

[0147] The second ultraviolet reaction unit 130 includes a second ultraviolet reactor a131a and a second ultraviolet reactor b131b connected in series, the second ultraviolet reactor a131a includes a water inlet a and a water outlet a, and the second ultraviolet reactor b131b includes a water inlet b and a water outlet b; the water inlet a of the second ultraviolet reactor a131a is connected to the first ultraviolet reactor c121c, the water outlet a is connected to the water inlet b of the second ultraviolet reactor b131b, and the water outlet b is connected to the wastewater collection device. The wastewater collection device is used to collect wastewater that meets the standards after treatment. For example, the wastewater collection device can be a storage tank. After collection, it is convenient to store and transport to a sewage treatment plant, and can also be used for sampling, testing and analyzing the concentration of pollutants in the wastewater that meets the standards. The second ultraviolet reaction unit 130 can also be provided with 3 or more second ultraviolet reactors connected in series, which will not be repeated here.

[0148] The tail gas treatment unit 200 includes an adsorption tower a21 and an adsorption tower b22 connected in parallel. The adsorption tower a21 includes an air inlet and an air outlet, and the adsorption tower b22 includes an air inlet and an air outlet; the air inlet of the adsorption tower a21 and the air inlet of the adsorption tower b22 are connected to the tail gas, and the air outlet of the adsorption tower a21 and the air outlet of the adsorption tower b22 are connected to the outside world. Usually, the air inlets of the adsorption tower a21 and the adsorption tower b22 are respectively arranged at their bottoms, and the air outlets are respectively arranged at their tops. After the tail gas is treated and meets the standards, it can be directly discharged into the atmosphere. Specifically, a gas detector or the like can be set on the pipeline connected to the air outlet of the adsorption tower to monitor and obtain the VOCs concentration in the treated tail gas, etc.

[0149] The adsorption tower a21 also includes a water inlet and a water outlet. The water inlet of the adsorption tower a21 is connected to the water outlet b of the second ultraviolet reactor; the water outlet of the adsorption tower a21 is connected to the wastewater collection device.

[0150] It should be noted that when the wastewater to be treated meets the standard after being treated by the wastewater treatment unit 100, it is discharged in compliance with the standard. At this time, the adsorption tower a21 and the adsorption tower b22 are connected in parallel to treat the organic waste gas; in addition, the discharge in compliance with the standard can refer to the aforementioned standard for discharge, which will not be repeated here. When the wastewater to be treated does not meet the standard after being treated by the wastewater treatment unit 100, it needs to be deeply treated by the adsorption tower a21 to meet the standard. At this time, the adsorption tower a21 switches to treat organic wastewater, and the adsorption tower b22 treats organic waste gas.

[0151] A plurality of adsorption towers connected in parallel may be arranged in the exhaust gas treatment unit 200, and a water inlet and a water outlet may be respectively opened in the plurality of adsorption towers for treating the untreated wastewater which does not meet the standards. However, it should be ensured that a certain number of adsorption towers can be used to treat the exhaust gas, which will not be elaborated one by one here.

[0152] Furthermore, valves can be provided on the connecting pipes of the equipment to realize the series-parallel switching of the plurality of first ultraviolet reactors and the switching of the wastewater to be treated entering the adsorption tower a21 or being discharged in compliance with the standards.

[0153] As another specific implementation, the first ultraviolet reactor a121a is provided with interface a and interface b, the first ultraviolet reactor b121b is provided with interface c and interface d, the first ultraviolet reactor c121c is provided with interface e and interface f, interface a on the first ultraviolet reactor a121a is connected to valve a171, interface b is connected to valve b172, interface c on the first ultraviolet reactor b121b is connected to valve c173, interface d is connected to valve d174, interface e on the first ultraviolet reactor c121c is connected to valve e175, and interface f is connected to valve f176.

[0154] Valve a171, valve c173, and valve e175 are connected to the wastewater to be treated through an inlet pipe, and valve b172, valve d174, and valve f176 are connected to the second ultraviolet reaction unit 130 through an outlet pipe; a valve g177 is provided between valve a171 and valve c173 on the inlet pipe, and a valve h178 is provided between valve d174 and valve e175 on the outlet pipe.

[0155] like Figure 3 As shown in the figure, when valve a171, valve b172, valve c173, valve d174, valve e175 and valve f176 are opened, valve g177 and valve h178 are closed, the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c are in series connection, and the flow direction of the wastewater to be treated is shown by the arrow in the figure, and needs to flow through the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c in sequence;

[0156] like Figure 4 As shown, when valve a171, valve b172, valve c173, valve d174, valve e175, valve f176, valve g177 and valve h178 are all opened, the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c are in parallel, and the flow direction of the wastewater to be treated is shown by the arrows, and is divided into three streams flowing through the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c respectively;

[0157] like Figure 5 As shown in the figure, when valve a171 and valve b172 are closed, valve c173, valve d174, valve e175, valve f176, valve g177 and valve h178 are all open, the first ultraviolet reactor a121a is cut out, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c are in parallel, and the flow direction of the wastewater to be treated is shown by the arrow in the figure. At this time, no wastewater to be treated flows through the first ultraviolet reactor a121a, and it can be cleaned or repaired, etc. The first ultraviolet reactor b121b and the first ultraviolet reactor c121c treat the wastewater to be treated normally.

[0158] In addition, a valve i179 is provided on the pipe connecting the interface f of the first ultraviolet reactor c121c and the wastewater collection device;

[0159] The air inlet of adsorption tower a21 is connected to valve j241, and the air outlet is connected to valve k242;

[0160] The water inlet of adsorption tower a21 is connected to valve L243, and the water outlet is connected to valve m244;

[0161] The air inlet of the adsorption tower b22 is connected to a valve n245, and the air outlet is connected to a valve o246;

[0162] When the wastewater meets the standards after being treated by the ultraviolet catalytic oxidation unit, valve i179 is opened, valve L243 and valve m244 are closed for discharge. At this time, adsorption tower a21 and adsorption tower b22 are opened in parallel to treat the exhaust gas.

[0163] When the wastewater does not meet the standards after being treated by the ultraviolet catalytic oxidation unit, valve i179 is closed, valve j241, valve k242, valve n245, valve o246, valve L243, and valve m244 are opened, adsorption tower a21 treats the wastewater to be treated, and adsorption tower b22 treats the exhaust gas.

[0164] Moreover, each of the above-mentioned valves can be a solenoid valve and is electrically connected to the automatic control unit 300 to automatically control the opening and closing of the valve.

[0165] Example 2

[0166] The present embodiment provides a treatment process for treating wastewater and tail gas by using the comprehensive treatment system for organic wastewater and tail gas of a contaminated site in Embodiment 1, comprising the following processes: the organic wastewater after extraction and separation enters the first ultraviolet reaction unit 120 through a pipeline, and before entering the first ultraviolet reaction unit 120, an oxidant and an acid solution are added to the wastewater to be treated by the first metering pump 112 and the second metering pump 182 in the oxidant adding unit 110 and the acid solution adding unit 180, and after entering the first ultraviolet reaction unit 120, under the conditions of higher ultraviolet intensity, higher oxidant concentration and lower residence time, the organic matter in the wastewater can be quickly oxidized, and then the wastewater to be treated enters the second ultraviolet reaction unit 130, and under the conditions of lower ultraviolet intensity, lower oxidant concentration and higher residence time, the organic matter in the wastewater is further deeply oxidized, and strong oxidizing free radicals are generated by the action of the oxidant and ultraviolet light, and the organic pollutants are completely oxidized into water and carbon dioxide without generating secondary pollution; through the segmented gradient oxidation process, the utilization rate and oxidation effect of the oxidant are improved, and the operating cost is reduced.

[0167] When the flow rate of the wastewater to be treated is small and the concentration of organic matter is too high, the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c in the first ultraviolet reaction unit 120 can be switched to a series connection mode to extend the time of rapid oxidation to achieve a better oxidation effect; when the flow rate of the wastewater to be treated is large and the concentration of organic matter is low, the first ultraviolet reactor a121a, the first ultraviolet reactor b121b and the first ultraviolet reactor c121c in the first ultraviolet reaction unit 120 can be switched to a parallel connection mode, and the three reactors are processed simultaneously to complete the treatment of a large amount of wastewater to be treated.

[0168] On the other hand, the organic waste gas after extraction and separation enters the adsorption tower in the tail gas unit and is adsorbed by the adsorption resin filled in the adsorption tower. The adsorption resin can refer to the invention patent with publication number CN102391407A. The adsorption resin has stable performance and is easy to regenerate. It can be used for a long time without replacement and replenishment.

[0169] Moreover, if the wastewater to be treated still does not meet the standards after being treated by the first ultraviolet reaction unit 120 and the second ultraviolet reaction unit 130, it can be introduced into some adsorption towers in the tail gas treatment unit 200 to remove organic matter by adsorption to achieve the standards.

[0170] Furthermore, a first flow meter 14, a temperature sensor 15 and a pH sensor 16 are provided between the first ultraviolet reaction unit 120 and the wastewater to be treated; and a second flow meter 23 is provided between the tail gas treatment unit 200 and the tail gas.

[0171] The system further includes an automatic control unit 300 , which is electrically connected to the wastewater treatment unit 100 , the tail gas treatment unit 200 , the oxidant dosing unit 110 , and the acid solution dosing unit 180 .

[0172] The automatic control unit 300 can be a programmable logic controller, and the system can realize automatic control of each unit, including the adjustment of the ultraviolet lamp power. The values ​​of each instrument and the operating status of the equipment in each unit can be viewed and controlled through the control panel of the automatic control unit 300, and the operating parameters can be adjusted, and the operating status of the system can be adjusted.

Claims

1. A comprehensive treatment system for organic wastewater and tail gas from polluted sites, characterized by: It comprises a wastewater treatment unit (100) and an exhaust gas treatment unit (200), The wastewater treatment unit (100) comprises an oxidant dosing unit (110), a first ultraviolet reaction unit (120) and a second ultraviolet reaction unit (130) which are connected in sequence; The oxidant dosing unit (110) is connected to the wastewater to be treated and is used to add the oxidant to the wastewater to be treated; The first ultraviolet reaction unit (120) comprises a plurality of first ultraviolet reactors, wherein a plurality of first ultraviolet lamps (1211) are arranged in the first ultraviolet reactors; the number of the first ultraviolet reactors is ≥ 2, the first ultraviolet reactors can be switched between series and parallel connection modes, and the first ultraviolet reactors meet the requirement that the residence time of the wastewater to be treated in the first ultraviolet reactor is t1; The second ultraviolet reaction unit (130) comprises a plurality of second ultraviolet reactors, wherein a plurality of second ultraviolet lamps (1311) are arranged in the second ultraviolet reactors, the number of the second ultraviolet reactors is ≥ 2, and the second ultraviolet reactors are connected in series; the second ultraviolet reactors meet the requirement that the residence time of the wastewater to be treated in the second ultraviolet reactor is t2; The residence time t1 is shorter than the residence time t2, and the power of the first ultraviolet lamp (1211) is greater than the power of the second ultraviolet lamp (1311); The tail gas treatment unit (200) comprises a plurality of adsorption towers, which are connected in parallel. The adsorption towers are filled with adsorption resin. The adsorption resin needs to meet the specific surface area of ​​≥1000m 2 / g Required.

2. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 1 is characterized by: The first ultraviolet lamp (1211) is arranged parallel to the water flow direction.

3. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 1 is characterized by: The second ultraviolet lamp (1311) is arranged perpendicular to the water flow direction.

4. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to any one of claims 1 to 3, characterized in that: The oxidant dosing unit (110) comprises an oxidant storage tank (111) and a first metering pump (112). The first metering pump (112) is connected to the oxidant storage tank (111) and the first ultraviolet reaction unit (120) respectively.

5. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 4 is characterized by: The wastewater treatment unit (100) further comprises an acid solution dosing unit (180), wherein the acid solution dosing unit (180) comprises an acid solution storage tank (181) and a second metering pump (182). The second metering pump (182) is connected to the acid liquid storage tank (181) and the first ultraviolet reaction unit (120) respectively.

6. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 5 is characterized by: The second ultraviolet reaction unit (130) is connected to the tail gas treatment unit (200); When the wastewater treated by the second ultraviolet reaction unit (130) does not meet the standards, part of the adsorption tower in the tail gas treatment unit (200) is used to adsorb pollutants in the wastewater.

7. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 6 is characterized by: It also includes an automatic control unit (300), wherein the automatic control unit (300) is electrically connected to the wastewater treatment unit (100), the tail gas treatment unit (200), the oxidant dosing unit (110), and the acid solution dosing unit (180).

8. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 7 is characterized by: The first ultraviolet reaction unit (120) comprises a first ultraviolet reactor a (121a), a first ultraviolet reactor b (121b) and a first ultraviolet reactor c (121c); The first ultraviolet reactor a (121a) is provided with an interface a and an interface b. The first ultraviolet reactor b (121b) is provided with an interface c and an interface d, The first ultraviolet reactor c (121c) is provided with an interface e and an interface f. Interface a, interface c, and interface e are respectively connected to the oxidant dosing unit (110) and the wastewater to be treated through pipelines, and interface b, interface d, and interface f are connected to the second ultraviolet reaction unit (130) through pipelines.

9. The comprehensive treatment system for organic wastewater and tail gas from contaminated sites according to claim 7 is characterized by: The tail gas treatment unit (200) comprises an adsorption tower a (21) and an adsorption tower b (22) connected in parallel; The adsorption tower a (21) includes an air inlet, an air outlet, a water inlet and a water outlet, and the adsorption tower b (22) includes an air inlet and an air outlet; The air inlet of the adsorption tower a (21) and the air inlet of the adsorption tower b (22) are connected to the tail gas, and the air outlet of the adsorption tower a (21) and the air outlet of the adsorption tower b (22) are both connected to the outside; The water inlet of the adsorption tower a (21) is connected to the second ultraviolet reaction unit (130), and the water outlet of the adsorption tower a (21) is connected to a wastewater collection device.

10. A process for treating wastewater and tail gas using the comprehensive treatment system for organic wastewater and tail gas from a contaminated site as claimed in any one of claims 1 to 9, characterized in that: The process includes: An oxidant and an acid solution are added to the wastewater to be treated, and then the wastewater to be treated enters a first ultraviolet reaction unit (120), and then passes through a second ultraviolet reaction unit (130), and is subjected to ultraviolet photocatalytic oxidation treatment in the first ultraviolet reaction unit (120) and the second ultraviolet reaction unit (130); The tail gas is passed into an adsorption tower in the tail gas treatment unit (200) for adsorption treatment; After the wastewater to be treated is treated by ultraviolet catalytic oxidation, if it meets the standards, it is discharged; if it does not meet the standards, it is further treated by some adsorption towers in the tail gas treatment unit (200).

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