CN109293148B

CN109293148B - Treatment device and treatment method for sulfur-containing and salt-containing wastewater

Info

Publication number: CN109293148B
Application number: CN201811255192.5A
Authority: CN
Inventors: 刘继; 李遵陕; 金培玉; 朱晓英
Original assignee: Zhejiang Xinan Chemical Industrial Group Co Ltd
Current assignee: Zhejiang Xinan Chemical Industrial Group Co Ltd
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2021-01-29
Anticipated expiration: 2038-10-26
Also published as: CN109293148A

Abstract

The invention provides a device and a method for treating sulfur-containing salt-containing wastewater. The method carries out operations such as heat filtration, air stripping, concentration, incineration, physical and chemical treatment and biochemical treatment on the high-concentration sulfur-containing and salt-containing organic wastewater, enables the high-concentration sulfur-containing and salt-containing organic wastewater to be efficiently treated through the cooperative treatment of the unit operations, enables the treated wastewater to reach the national first-level discharge standard, enables the recovery rate of sulfur elements to reach more than 99%, enables the recovered salts to also reach the national first-level use standard of industrial salts, avoids resource waste, realizes recycling, reduces the treatment cost of the wastewater, and provides a reference for the treatment of other types of refractory organic wastewater.

Description

Treatment device and treatment method for sulfur-containing and salt-containing wastewater

Technical Field

The invention belongs to the technical field of wastewater treatment, and relates to a treatment device and a treatment method for sulfur-containing and salt-containing wastewater.

Background

In recent years, with the continuous development of economy and human society, basic industries such as dyes, medicines, pesticides and petrochemical industries are developed vigorously, and a large amount of waste water is inevitably discharged. The hydrogen sulfide has high toxicity and strong capability of killing aquatic organisms; under poor ventilation conditions, when they accumulate to a certain concentration, they can also have a toxic effect on the operators. In addition, after the wastewater containing sulfide is discharged into water, the wastewater can react with iron-based metals in the water to cause the water to smell and blacken, so that the state has strict discharge standards for the sulfur-containing wastewater.

At present, the common treatment methods for sulfur-containing wastewater include the following methods: acidification absorption method, gas stripping method, chemical flocculation method, air oxidation method, etc. Wherein the acidification recovery method is to make S under acidic condition^2-Conversion to H₂S gas enters a desulfurization device to recover sulfur in the S gas, and the hydrogen sulfide has toxicity and corrosivity and certain danger, so that the requirement on equipment is high; the air stripping method is to blow off the sulfide in the wastewater by using air, and has the limitation thatThe method has the advantages of large energy consumption, complex process, and is not suitable for wastewater with small water quantity and low sulfur content; the chemical flocculation method is to add ferrous salt or ferric salt into the waste water to react with H₂S is separated and removed after insoluble solids are generated, and when the concentration of sulfide is too high, the consumption of the medicament is high, so that the method is not suitable for wastewater with high sulfur concentration and large wastewater quantity; the air oxidation method is to oxidize sulfur ions into non-toxic thiosulfate or sulfate by using air, but because the solubility of oxygen in water is low, the gas-liquid mass transfer efficiency is extremely low, the oxidation effect is not obvious by simply introducing oxygen, and a corresponding catalyst is required to be added to improve the treatment effect, so that the cost is increased and the difficulty of subsequent treatment is increased.

At present, the components of sulfur-containing wastewater are generally complex, a single treatment method is often difficult to achieve an ideal treatment effect, and multiple treatment measures are usually adopted to treat the wastewater together. CN 106256783A discloses a method for treating sulfur-containing wastewater, firstly, the pH of the sulfur-containing wastewater is adjusted to 4-6 by adopting a pH regulator, secondly, the wastewater after the pH adjustment is input into a membrane negative pressure desulfurization unit for desulfurization treatment, the removed hydrogen sulfide gas causes atmosphere pollution through incineration treatment, the membrane method is not suitable for the treatment of wastewater with high salt content, and a membrane device is easy to block under the condition of high-concentration salt. CN 106396185A discloses a method for treating sulfide-containing wastewater, which adopts an oxidation-precipitation method, acid solution is added into an adjusting tank to adjust pH, the pH is then fed into an oxidation tank to react with an oxidant, if the concentration of sulfide is lower than 1mg/L after the reaction, the sulfur is introduced into a filter to be filtered, if the concentration of sulfide is higher than 1mg/L, a sedimentation tank is introduced to carry out precipitation reaction and then separated, so that sulfur in the wastewater is treated.

In addition, other types of waste water have higher sulfur content, higher salt content and more complicated treatment process. CN 108128983A discloses a high-sulfur and high-salt-content gas field produced water deep purification treatment process, which comprises the following steps: the method comprises the steps that produced water of a gas field sequentially enters a natural settling unit, an air floatation coagulation settling unit, an evaporation crystallization unit, a high-grade oxidation unit and a biochemical treatment unit for treatment, pollutants are separated out from sewage in the form of crystal salt and are subjected to landfill treatment or recycling, but sulfur and other salts existing in the form of ions are separated out only by the method, the separation and the use are difficult, the sulfur in other forms is not recovered, and the treatment of the wastewater is not thorough.

In conclusion, an efficient and low-cost method is still needed for treating the high-concentration sulfur-containing and salt-containing wastewater, so that the wastewater can be discharged after reaching the standard, and meanwhile, the effective components in the wastewater can be recycled.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a device and a method for treating sulfur-containing salt-containing wastewater, which are used for fully recovering sulfur elements and salts in the wastewater, avoiding the waste of resources, realizing the cyclic utilization of the resources, simultaneously enabling the wastewater to reach the national first-level discharge standard and reducing the treatment cost of the wastewater by sequentially carrying out operations such as thermal filtration, stripping, concentration, physicochemical treatment, biochemical treatment and the like on the high-concentration sulfur-containing salt-containing wastewater.

In order to achieve the purpose, the invention adopts the following technical scheme:

on one hand, the invention provides a treatment device for sulfur-containing salt-containing wastewater, which comprises a thermal filtering unit, a blow-off unit, a concentration unit, a physicochemical treatment unit and a biochemical treatment unit which are connected in sequence, wherein the concentration unit is also connected with an incineration unit.

In the invention, because the sulfur and salt containing wastewater is high in sulfur, salt and organic matter content, the wastewater needs to be jointly treated by multiple unit operations, sulfur element is recovered by the heat filtering unit and the air stripping unit, salt is recovered by the concentration unit, low-boiling-point and volatile organic components are treated by the physicochemical treatment unit and the biochemical treatment unit, and high-boiling-point organic matter is treated by the incineration treatment unit, so that the ordered and efficient treatment of the wastewater is realized, the wastewater is discharged up to the standard, the recovery of sulfur resources and salts can also be realized, the resource utilization of the wastewater is realized, and the device is a set of green and environment-friendly treatment device.

The following technical solutions are preferred technical solutions of the present invention, but not limited to the technical solutions provided by the present invention, and technical objects and advantageous effects of the present invention can be better achieved and achieved by the following technical solutions.

As a preferable technical scheme of the invention, the solid outlet of the hot filtering unit is connected with the first dissolving filtering unit.

Preferably, a first pH adjusting unit is further arranged between the hot filtering unit and the blow-off unit.

According to the invention, hot filtration is adopted to avoid hot-soluble solids from being brought into the elemental sulfur, after the elemental sulfur is removed by the hot filtration unit, the residual sulfur mainly exists in a sulfur ion form and needs to be blown out in a blowing-off unit in a hydrogen sulfide form, so that the temperature of the hot waste liquid is maintained to be beneficial to the subsequent blowing-off of hydrogen sulfide gas, the waste of energy is avoided, meanwhile, the pH value of the waste water is adjusted to be acidic before the blowing-off, and the hydrogen sulfide is more easily blown off under a slightly acidic condition.

Preferably, the regulator used in the first pH adjusting unit includes hydrochloric acid.

Preferably, the gas outlet of the stripping unit is connected with the hydrogen sulfide absorption unit.

Preferably, the gas used in the stripping unit is air and/or nitrogen.

Preferably, a second pH adjusting unit is further arranged between the stripping unit and the concentration unit.

Preferably, the regulator used in the second pH regulating unit is a base, preferably sodium hydroxide.

According to the invention, the pH value of the wastewater is basically adjusted to be neutral after the stripping treatment, so that the corrosion of the acidic wastewater on the evaporator in the concentration unit can be effectively avoided, and the service life of the device is prolonged.

As a preferred technical scheme of the invention, the concentration unit comprises an MVR evaporator or a multi-effect evaporator.

In the invention, the MVR evaporator is a mechanical vapor recompression evaporator, secondary vapor and energy thereof generated by an evaporation system are utilized to improve low-grade vapor into a high-grade vapor heat source through mechanical work of a compressor, and heat energy can be provided for the evaporation system in a circulating manner, so that the requirement on external energy is reduced; MVR evaporation and multiple-effect evaporation both belong to energy-saving technology, and can greatly reduce regular consumption in the evaporation process and reduce treatment cost.

Preferably, the volatile matter in the concentration unit enters a materialization treatment unit after being condensed, and the mother liquor in the concentration unit enters an incineration unit.

Preferably, the incineration unit is connected with a second dissolution filtration unit.

In the invention, the mother liquor is mainly the refractory organics with higher boiling point, the components are more complex, the heat value is higher, the direct discharge is not suitable, and the refractory organics can be effectively removed by incineration treatment.

As a preferred technical scheme of the invention, the materialization treatment unit comprises any one or a combination of at least two of an air catalytic oxidation device, a wet catalytic oxidation device, a Fenton oxidation device, an iron-carbon micro-electrolysis device, an ozone catalytic oxidation device or an ultraviolet oxidation device, and the combination is typically but not limited to: a combination of an air catalytic oxidation device and a wet catalytic oxidation device, a combination of a fenton oxidation device and an iron-carbon micro-electrolysis device, a combination of a wet catalytic oxidation device, an ozone catalytic oxidation device and an ultraviolet oxidation device, and the like.

According to the invention, the concentration of organic matters in the wastewater can be effectively reduced and the toxicity is eliminated through physicochemical treatment, and meanwhile, the biodegradability is obviously enhanced, so that the subsequent biochemical treatment is facilitated.

Preferably, the biochemical treatment unit comprises an anaerobic biochemical treatment device and/or a contact oxidation treatment device.

In another aspect, the invention provides a method for treating sulfur-containing salt-containing wastewater by using the above device, which comprises the following steps: carrying out thermal filtration treatment, air stripping treatment and concentration treatment on the sulfur-containing salt-containing wastewater in sequence to obtain volatile components and mother liquor, carrying out incineration treatment on the mother liquor, and carrying out physicochemical treatment and biochemical treatment on the condensed volatile components to obtain standard-reaching wastewater.

The sulfur-containing salt-containing wastewater is wastewater generated in the production process of the sulfur-containing silane coupling agent, has the remarkable characteristics of high organic matter content, high sulfur content, strong acidity, high salinity, poor biodegradability and the like, needs to be jointly treated by multiple unit operations, recovers sulfur elements through heat filtration and air stripping treatment, recovers the salinity through concentration treatment, decomposes low-boiling-point and volatile organic components through physicochemical treatment and biochemical treatment, incinerates the high-boiling-point organic matters, realizes orderly and efficient treatment and standard discharge of the wastewater, can also realize the recovery of sulfur resources and salts, realizes the resource utilization of the wastewater, and is an environment-friendly treatment method.

As a preferable technical scheme of the invention, the sulfur-containing salt-containing wastewater is organic silicon wastewater, preferably wastewater generated in the production process of a silane coupling agent.

Preferably, the COD value of the sulfur-containing salt-containing wastewater is 10000-40000 mg/L, such as 10000mg/L, 15000mg/L, 20000mg/L, 25000mg/L, 30000mg/L, 35000mg/L or 40000mg/L, etc., but not limited to the enumerated values, and other non-enumerated values in the numerical range are also applicable.

Preferably, the temperature of the sulfur-containing salt-containing wastewater is 50 to 95 ℃, for example, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃ or 95 ℃, etc., but not limited to the recited values, and other values not recited in the range of the values are also applicable; the pH is 3 to 7, for example, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 or 7, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.

Preferably, the sulfur content in the sulfur-containing salt-containing wastewater is 0.2-3 wt%, such as 0.2 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt% or 3 wt%, etc., but not limited to the recited values, and other non-recited values in the range of the values are also applicable; the salt content is 25 to 35 wt%, for example 25 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt% or 35 wt%, etc., but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the temperature of the thermal filtration treatment is 50 to 95 ℃, for example, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃ or 95 ℃, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, the solid obtained by the thermal filtration treatment is dissolved and filtered to obtain elemental sulfur, and the obtained elemental sulfur can be directly reused for production after being dried.

Preferably, the temperature of the steam condensate used for the dissolution filtration is 60 to 90 ℃, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃ or 90 ℃, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, the steam condensate used has a mass 5 to 15 times, for example 5 times, 6 times, 8 times, 10 times, 12 times, 14 times or 15 times, the amount of solids treated, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

Preferably, the pH of the wastewater is adjusted to 1 to 7, for example 1, 2, 3, 4, 5, 6 or 7, after the thermal filtration treatment, but not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the pH adjusting agent used comprises hydrochloric acid.

As a preferred technical scheme of the invention, the gas used for the stripping treatment is air and/or nitrogen.

Preferably, the flow rate ratio of the gas to the wastewater in the stripping treatment is 0.1 to 2, for example, 0.1, 0.3, 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the time of the stripping treatment is 0.5 to 5 hours, such as 0.5 hour, 1 hour, 1.5 hour, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the pressure of the stripping treatment is-0.02 to-0.01 MPa, for example, -0.02MPa, -0.018MPa, -0.016MPa, -0.014MPa, -0.012MPa or-0.01 MPa, but not limited to the values listed, and other values not listed in the numerical range are also applicable.

In the invention, the stripping treatment is carried out under the condition of micro negative pressure, which is more beneficial to the removal of hydrogen sulfide gas and can not increase the treatment cost due to overhigh vacuum degree.

Preferably, the temperature of the wastewater in the stripping treatment is 20 to 90 ℃, for example, 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃ or 90 ℃, but the temperature is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, the hydrogen sulfide gas obtained from the stripping treatment is absorbed by alkali liquor.

Preferably, the alkali liquor is a sodium hydroxide solution, and the feed liquid after absorbing hydrogen sulfide gas can be processed to prepare a sodium sulfide product.

Preferably, the concentration of the sodium hydroxide solution is 5 to 30 wt%, such as 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt%, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the pH of the wastewater is adjusted to 6-8, such as 6, 6.5, 7, 7.5 or 8, after the stripping treatment, but the pH is not limited to the values listed, and other values not listed in the range of the values are also applicable.

Preferably, the pH adjusting agent used comprises a base, preferably sodium hydroxide.

As a preferred technical scheme of the invention, the concentration treatment comprises MVR evaporation treatment or multi-effect evaporation treatment.

Preferably, the concentration process consumes 0.2 to 0.6 tons of steam per 1 ton of waste water evaporated, for example, 0.2 ton, 0.3 ton, 0.4 ton, 0.5 ton or 0.6 ton, but not limited to the recited values, and other values not recited in the above range are also applicable.

Preferably, the solid salt obtained by the concentration treatment comprises sodium chloride, and the obtained sodium chloride can reach the first grade use standard of national industrial salt.

Preferably, the COD value of the volatile condensate obtained by the concentration treatment is 5000 to 20000mg/L, for example 5000mg/L, 8000mg/L, 10000mg/L, 12000mg/L, 15000mg/L, 18000mg/L or 20000mg/L, etc., but not limited to the recited values, and other values not recited in the numerical range are also applicable.

In the present invention, the volatile matter obtained by the concentration treatment mainly includes low-boiling alcohols, silane coupling agents, siloxane oligomers, and the like, and the volatile matter is further treated after being condensed.

As a preferred technical scheme of the invention, the physical and chemical treatment comprises any one or combination of at least two of air catalytic oxidation, wet catalytic oxidation, Fenton oxidation, iron-carbon micro-electrolysis, ozone catalytic oxidation or ultraviolet oxidation, and typical but non-limiting examples of the combination are as follows: a combination of air catalytic oxidation and wet catalytic oxidation, a combination of iron-carbon micro-electrolysis and ozone catalytic oxidation, a combination of fenton oxidation, ozone catalytic oxidation and ultraviolet oxidation, and the like.

Through physicochemical treatment, the concentration of organic matters transferred to the wastewater is greatly reduced, the toxicity is eliminated, and the biodegradability is obviously enhanced.

Preferably, after the physicochemical treatment, the COD value of the wastewater is 500-5000 mg/L, such as 500mg/L, 1000mg/L, 2000mg/L, 3000mg/L, 4000mg/L or 5000mg/L, but not limited to the recited values, and other values not recited in the range of the values are also applicable; the sulfur content is 1.0 to 5.0mg/L, for example, 1.0mg/L, 2.0mg/L, 3.0mg/L, 4.0mg/L or 5.0mg/L, but not limited to the recited values, and other values not recited in the above range are also applicable.

Preferably, the biochemical treatment comprises an anaerobic biochemical treatment and/or a contact oxidation treatment.

Preferably, after the biochemical treatment, the COD value of the wastewater is not more than 50mg/L, such as 50mg/L, 40mg/L, 30mg/L, 20mg/L or 10mg/L, etc., but not limited to the enumerated values, and other non-enumerated values within the range are also applicable; the sulfur content is not more than 1.0mg/L, for example, 1.0mg/L, 0.8mg/L, 0.6mg/L, 0.4mg/L, or 0.2mg/L, etc., but is not limited to the recited values, and other values not recited within the range of values are also applicable.

According to the invention, the COD value and the sulfur content of the wastewater after biochemical treatment reach the national primary discharge standard of wastewater (Integrated wastewater discharge Standard GB 8978-1996).

In a preferred embodiment of the present invention, the temperature of the incineration treatment is 300 to 600 ℃, for example, 300 ℃, 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃ or 600 ℃, but the temperature is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, the mother liquor is subjected to dissolution filtration after incineration treatment, the obtained filtrate is used for adjusting the pH of the wastewater after thermal filtration treatment, and the obtained filter residue is treated as solid waste.

In the invention, most of the mother liquor is high boiling point siloxane polymer, also comprises unreacted raw materials and the like, the components are relatively complex, if the mother liquor is directly discharged to be dangerous waste, the environmental load is increased, the organic matter can be fully decomposed by burning treatment, and the heat in the burning process can be fully utilized due to the higher heat value.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method has the advantages that the high-concentration sulfur-containing salt-containing organic wastewater is efficiently treated through the cooperative treatment of unit operations, the treated wastewater reaches the national first-level discharge standard, the recovery rate of sulfur element reaches more than 99%, and the recovered salt can also reach the national first-level use standard of industrial salt;

(2) the recovery of sulfur and salt in the wastewater of the invention not only avoids the waste of resources and can realize the recycling of the resources, but also reduces the difficulty and energy consumption of the post-treatment of the wastewater;

(3) the incineration treatment of the invention avoids the generation of a large amount of dangerous solid wastes, and greatly reduces the sewage treatment cost;

(4) the effective treatment of the sulfur-containing and salt-containing organic silicon wastewater can provide reference and reference for the treatment of other organic silicon wastewater difficult to treat.

Drawings

FIG. 1 is a connection diagram of a sulfur-containing and salt-containing wastewater treatment plant provided in example 1 of the present invention;

FIG. 2 is a connection diagram of a sulfur-containing and salt-containing wastewater treatment device provided in example 2 of the present invention;

FIG. 3 is a connection diagram of a sulfur-containing and salt-containing wastewater treatment device provided in example 3 of the present invention;

FIG. 4 is a connection diagram of a sulfur-containing and salt-containing wastewater treatment device provided in example 4 of the present invention.

Detailed Description

In order to better explain the present invention and to facilitate the understanding of the technical solutions of the present invention, the present invention is further described in detail with specific embodiments below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.

The invention provides a device and a method for treating sulfur-containing and salt-containing wastewater.

The processing method comprises the following steps: carrying out thermal filtration treatment, air stripping treatment and concentration treatment on the sulfur-containing salt-containing wastewater in sequence to obtain volatile components and mother liquor, carrying out incineration treatment on the mother liquor, and carrying out physicochemical treatment and biochemical treatment on the condensed volatile components to obtain standard-reaching wastewater.

The following are typical but non-limiting examples of the invention:

example 1:

the embodiment provides a device and a method for treating sulfur-containing salt-containing wastewater, wherein the device is connected with a connection relation diagram shown in fig. 1 and comprises a thermal filtering unit, a blowing-off unit, a concentration unit, a physicochemical treatment unit and a biochemical treatment unit which are connected in sequence, and the concentration unit is also connected with an incineration unit.

The solid outlet of the hot filtering unit is connected with the first dissolving and filtering unit, a first pH adjusting unit is further arranged between the hot filtering unit and the blowing-off unit, the gas outlet of the blowing-off unit is connected with the hydrogen sulfide absorption unit, and a second pH adjusting unit is further arranged between the blowing-off unit and the concentration unit.

The concentration unit comprises an MVR evaporator, the materialization treatment unit comprises an iron-carbon micro-electrolysis device, the biochemical treatment unit comprises a contact oxidation treatment device, and the incineration unit is connected with the second dissolution and filtration unit.

The method for treating the sulfur-containing salt-containing wastewater by adopting the device comprises the following steps:

(1) performing thermal filtration treatment on 1000kg of silane coupling agent production wastewater with the temperature of 80 ℃, the COD value of 20000mg/L, the sulfur content of 2 wt%, the sodium chloride content of 35 wt% and the pH value of 6 to obtain 5kg of filter residue, adding 30kg of steam condensate water into the filter residue to perform dissolution filtration to obtain insoluble substances, namely elemental sulfur, and feeding the filtrate into an MVR evaporator;

(2) adjusting the pH value of the hot filtered wastewater to be 4 by using industrial hydrochloric acid with the concentration of 30 wt%;

(3) carrying out air stripping treatment on the wastewater with the pH value adjusted in the step (2), wherein the system pressure is ensured to be-0.01 MPa and the air flow rate is ensured to be 1L min in the air stripping process^-1The stripping time is 3 hours, the water temperature is 70-80 ℃, hydrogen sulfide gas obtained by stripping is absorbed by liquid caustic soda, and the sulfur content of the wastewater after stripping treatment is 15 mg/L;

(4) adjusting the pH value of the wastewater after the stripping treatment to 7.5 by using alkali liquor;

(5) carrying out MVR evaporation concentration treatment on the wastewater with the pH adjusted in the step (4), and condensing evaporated water and organic volatile to obtain condensate; the salt obtained by concentration can be used as industrial salt; burning the residual mother liquor at 500 ℃, dissolving and filtering, and using the obtained filtrate for adjusting the pH value of the wastewater in the step (2);

(6) carrying out iron-carbon micro-electrolysis treatment on the condensate with the COD of 15000mg/L obtained in the step (5), wherein the COD of the treated wastewater is 5000mg/L, and the sulfur content is 2.0 mg/L;

(7) and (4) carrying out contact oxidation treatment on the wastewater treated in the step (6), wherein the COD (chemical oxygen demand) of the treated wastewater is 48mg/L, the sulfur content is 0.8mg/L, and the treated wastewater reaches the national first-grade discharge standard.

Example 2:

the embodiment provides a device and a method for treating sulfur-containing salt-containing wastewater, wherein the device is connected with a heat filtering unit, a blowing-off unit, a concentration unit, a physicochemical treatment unit and a biochemical treatment unit which are connected in sequence, and the concentration unit is also connected with an incineration unit, as shown in fig. 2.

The concentration unit comprises an MVR evaporator, the materialization treatment unit comprises a wet catalytic oxidation device, the biochemical treatment unit comprises a contact oxidation treatment device, and the incineration unit is connected with the second dissolution filtering unit.

(1) carrying out hot filtration treatment on 1000kg of silane coupling agent production wastewater with the temperature of 60 ℃, the COD value of 40000mg/L, the sulfur content of 3 wt%, the sodium chloride content of 30 wt% and the pH value of 7 to obtain 2kg of filter residue, adding 30kg of steam condensate water into the filter residue to dissolve and filter, wherein the obtained insoluble substance is a sulfur simple substance, and feeding the filtrate into an MVR evaporator;

(2) adjusting the pH value of the hot filtered wastewater to 3 by using industrial hydrochloric acid with the concentration of 30 wt%;

(3) carrying out air stripping treatment on the wastewater with the pH value adjusted in the step (2), wherein the system pressure is ensured to be-0.02 MPa and the air flow rate is ensured to be 0.5L min in the air stripping process^-1The stripping time is 2 hours, the water temperature is 40-50 ℃, hydrogen sulfide gas obtained by stripping is absorbed by liquid caustic soda, and the sulfur content of the wastewater after stripping treatment is 15 mg/L;

(4) adjusting the pH value of the wastewater after the stripping treatment to 7 by using alkali liquor;

(5) carrying out MVR evaporation concentration treatment on the wastewater with the pH adjusted in the step (4), and condensing evaporated water and organic volatile to obtain condensate; the salt obtained by concentration can be used as industrial salt; burning the residual mother liquor at the temperature of 600 ℃, dissolving and filtering, and using the obtained filtrate for adjusting the pH value of the wastewater in the step (2);

(6) carrying out wet catalytic oxidation treatment on the condensate with the COD of 20000mg/L obtained in the step (5), wherein the COD of the treated wastewater is 500mg/L, and the sulfur content is 3.5 mg/L;

(7) and (4) carrying out contact oxidation treatment on the wastewater treated in the step (6), wherein the COD (chemical oxygen demand) of the treated wastewater is 20mg/L, the sulfur content is 0.5mg/L, and the treated wastewater reaches the national first-grade discharge standard.

Example 3:

the embodiment provides a device and a method for treating sulfur-containing salt-containing wastewater, wherein the device is connected with a heat filtering unit, a blowing-off unit, a concentration unit, a physicochemical treatment unit and a biochemical treatment unit which are connected in sequence, and the concentration unit is also connected with an incineration unit, as shown in fig. 3.

The solid outlet of the hot filtering unit is connected with the first dissolving and filtering unit, the gas outlet of the stripping unit is connected with the hydrogen sulfide absorption unit, and a pH adjusting unit is further arranged between the stripping unit and the concentration unit.

The concentration unit comprises a four-effect evaporator, the materialization treatment unit comprises a Fenton oxidation device, the biochemical treatment unit comprises an anaerobic biochemical treatment device and a contact oxidation treatment device, and the incineration unit is connected with the second dissolution and filtration unit.

(1) performing thermal filtration treatment on 1000kg of silane coupling agent production wastewater with the temperature of 50 ℃, the COD value of 10000mg/L, the sulfur content of 1 wt%, the sodium chloride content of 25 wt% and the pH value of 3 to obtain 3kg of filter residue, adding 27kg of steam condensate water into the filter residue for dissolving and filtering to obtain insoluble substances, namely elemental sulfur, and feeding the filtrate into a four-effect evaporator;

(2) carrying out air stripping treatment on the hot filtered wastewater, wherein the system pressure is ensured to be-0.016 MPa and the air flow rate is ensured to be 2L min in the air stripping process^-1The stripping time is 1h, the water temperature is 20-30 ℃, hydrogen sulfide gas obtained by stripping is absorbed by liquid alkali, and the hydrogen sulfide gas is subjected to stripping treatmentThe sulfur content of the wastewater is 50 mg/L;

(3) adjusting the pH value of the wastewater after the stripping treatment to 6 by using alkali liquor;

(4) performing four-effect evaporation concentration treatment on the wastewater with the pH adjusted in the step (3), and condensing evaporated water and organic volatile to obtain condensate; the salt obtained by concentration can be used as industrial salt; burning the residual mother liquor at 400 ℃, dissolving and filtering, and using the obtained filtrate for adjusting the pH value of the wastewater in the step (3);

(5) performing Fenton oxidation treatment on the condensate with COD of 5000mg/L obtained in the step (4), wherein the treated wastewater has COD of 3500mg/L and sulfur content of 3.0 mg/L;

(6) and (4) sequentially carrying out anaerobic biochemical treatment and contact oxidation treatment on the wastewater treated in the step (5), wherein the COD (chemical oxygen demand) of the treated wastewater is 42mg/L, the sulfur content is 1.0mg/L, and the treated wastewater reaches the national first-class emission standard.

Example 4:

the embodiment provides a device and a method for treating sulfur-containing salt-containing wastewater, wherein a connection relation diagram of the device is shown in fig. 4, the device comprises a thermal filtering unit, a blowing-off unit, a concentration unit, a physicochemical treatment unit and a biochemical treatment unit which are connected in sequence, and the concentration unit is also connected with an incineration unit.

The concentration unit comprises a double-effect evaporator, the materialization treatment unit comprises an air catalytic oxidation device and an ozone catalytic oxidation device, the biochemical treatment unit comprises a contact oxidation treatment device, and the incineration unit is connected with the second dissolution filtering unit.

(1) carrying out thermal filtration treatment on 1000kg of silane coupling agent production wastewater with the temperature of 95 ℃, the COD value of 30000mg/L, the sulfur content of 0.5 wt%, the sodium chloride content of 33 wt% and the pH value of 5 to obtain 3kg of filter residue, adding 36kg of steam condensate water into the filter residue for dissolution and filtration to obtain insoluble substances, namely elemental sulfur, and feeding the filtrate into a double-effect evaporator;

(2) adjusting the pH value of the hot filtered wastewater to 1 by using industrial hydrochloric acid with the concentration of 30 wt%;

(3) carrying out air stripping treatment on the wastewater with the pH value adjusted in the step (2), wherein the system pressure is ensured to be-0.012 MPa and the air flow rate is ensured to be 0.2L min in the air stripping process^-1The stripping time is 5 hours, the water temperature is 80-90 ℃, hydrogen sulfide gas obtained by stripping is absorbed by liquid caustic soda, and the sulfur content of the wastewater after stripping treatment is 20 mg/L;

(4) adjusting the pH value of the wastewater after the stripping treatment to 8 by using alkali liquor;

(5) carrying out double-effect evaporation concentration treatment on the wastewater with the pH adjusted in the step (4), and condensing evaporated water and organic volatile to obtain condensate; the salt obtained by concentration can be used as industrial salt; burning the residual mother liquor at the temperature of 300 ℃, dissolving and filtering, and using the obtained filtrate for adjusting the pH value of the wastewater in the step (2);

(6) carrying out air catalytic oxidation treatment on the condensate with the COD of 9000mg/L obtained in the step (5), wherein the COD of the treated wastewater is 4000mg/L, and the sulfur content is 3.0 mg/L;

(7) carrying out catalytic ozonation treatment on the wastewater treated in the step (6), wherein the COD (chemical oxygen demand) of the treated wastewater is 800mg/L, and the sulfur content is 2.0 mg/L;

(8) and (4) carrying out contact oxidation treatment on the wastewater treated in the step (7), wherein the COD (chemical oxygen demand) of the treated wastewater is 47mg/L, the sulfur content is 0.9mg/L, and the treated wastewater reaches the national first-grade discharge standard.

It can be seen from the above embodiments that the sulfur-containing and salt-containing wastewater can be efficiently treated only by the joint treatment of the sulfur-containing and salt-containing wastewater by the operation of each main unit, such as thermal filtration, air stripping, concentration, physicochemical treatment, biochemical treatment, incineration and the like, the treated wastewater reaches the national first-level discharge standard, the recovery rate of sulfur element reaches more than 99%, and the recovered salt also can reach the national first-level use standard of industrial salt; and the lack of any one of the two causes the wastewater to fail to reach the discharge standard or generate a large amount of dangerous solid wastes, thereby increasing the treatment cost of the wastewater.

The applicant states that the present invention is illustrated by the above examples to describe the detailed apparatus and process of the invention, but the present invention is not limited to the above apparatus and process, i.e. it is not meant to imply that the present invention must be implemented by means of the above apparatus and process. It will be apparent to those skilled in the art that any modifications to the present invention, equivalents of the unit operations of the invention and additions of ancillary operations, choices of details, and the like, are within the scope and disclosure of the present invention.

Claims

1. The method for treating the sulfur-containing salt-containing wastewater is characterized by adopting a sulfur-containing salt-containing wastewater treatment device, wherein the device comprises a thermal filtering unit, a blowing-off unit, a concentration unit, a physicochemical treatment unit and a biochemical treatment unit which are sequentially connected, and the concentration unit is also connected with an incineration unit; the solid outlet of the hot filtering unit is connected with the first dissolving filtering unit;

a first pH adjusting unit is arranged between the thermal filtering unit and the air stripping unit, volatile components in the concentrating unit are condensed and then enter the physicochemical treatment unit, and mother liquor in the concentrating unit enters the incineration unit;

the processing method of the device comprises the following steps: sequentially carrying out thermal filtration treatment, air stripping treatment and concentration treatment on the sulfur-containing salt-containing wastewater to obtain volatile components, solid salt and mother liquor, carrying out incineration treatment on the mother liquor, and sequentially carrying out physicochemical treatment and biochemical treatment on the condensed volatile components to obtain standard wastewater;

the sulfur-containing and salt-containing wastewater is organic silicon wastewater, the sulfur content in the sulfur-containing and salt-containing wastewater is 0.2-3 wt%, the salt content is 25-35 wt%, the temperature of the thermal filtration treatment is 50-95 ℃, the solid obtained by the thermal filtration treatment is dissolved and filtered to obtain elemental sulfur, and the obtained elemental sulfur can be directly reused for production after being dried; the pH value of the waste water is adjusted to 1-7 after the thermal filtration treatment, the COD value of the volatile condensate obtained by the concentration treatment is 5000-20000 mg/L, and the temperature of the incineration treatment is 300-600 ℃.

2. The method of claim 1, wherein the adjusting agent used in the first pH adjusting unit comprises hydrochloric acid.

3. The method according to claim 1, characterized in that the gas outlet of the stripping unit is connected to a hydrogen sulfide absorption unit.

4. The method according to claim 1, characterized in that the gas used in the stripping unit is air and/or nitrogen.

5. The method according to claim 1, wherein a second pH adjusting unit is further provided between the stripping unit and the concentration unit.

6. The method according to claim 1, wherein the adjusting agent used in the second pH adjusting unit is a base.

7. The method according to claim 6, wherein the adjusting agent used in the second pH adjusting unit is sodium hydroxide.

8. The method of claim 1, wherein the concentration unit comprises an MVR evaporator or a multiple effect evaporator.

9. The method of claim 1, wherein the incineration unit is connected to a second dissolution filtration unit.

10. The method according to claim 1, wherein the physicochemical treatment unit comprises any one of an air catalytic oxidation device, a wet catalytic oxidation device, a Fenton oxidation device, an iron-carbon micro-electrolysis device, an ozone catalytic oxidation device or an ultraviolet oxidation device or a combination of at least two of the above devices.

11. The method of claim 1, wherein the biochemical treatment unit comprises an anaerobic biochemical treatment device and/or a contact oxidation treatment device.

12. The method as claimed in claim 1, wherein the sulfur-containing salt-containing wastewater is wastewater generated in a silane coupling agent production process.

13. The method according to claim 1, wherein the COD value of the sulfur-containing salt-containing wastewater is 10000-40000 mg/L.

14. The method as claimed in claim 1, wherein the temperature of the wastewater containing sulfur and salt is 50-95 ℃ and the pH value is 3-7.

15. The method according to claim 1, wherein the temperature of the steam condensate for dissolution filtration is 60 to 90 ℃.

16. The method according to claim 15, characterized in that the mass of steam condensate used is 5-15 times the amount of solids treated.

17. The method according to claim 1, wherein the flow rate ratio of the gas to the waste water in the stripping treatment is 0.1 to 2.

18. The method according to claim 1, wherein the time of the stripping treatment is 0.5-5 h.

19. The method according to claim 1, characterized in that the pressure of the stripping treatment is-0.02 to-0.01 MPa.

20. The method according to claim 1, wherein the temperature of the wastewater during the stripping treatment is 20-90 ℃.

21. The method of claim 1, wherein hydrogen sulfide gas obtained from the stripping treatment is absorbed by an alkaline solution.

22. The method of claim 21, wherein the lye is a sodium hydroxide solution.

23. The method according to claim 22, wherein the concentration of the sodium hydroxide solution is 5 to 30 wt%.

24. The method according to claim 1, wherein the pH of the wastewater is adjusted to 6-8 after the stripping treatment.

25. The method of claim 1, wherein the concentration process comprises an MVR evaporation process or a multi-effect evaporation process.

26. The method according to claim 1, wherein the concentration process consumes 0.2 to 0.6 ton of steam per 1 ton of wastewater evaporated.

27. The method of claim 1, wherein the solid salt from the concentration process comprises sodium chloride.

28. The method according to claim 1, wherein the physicochemical treatment comprises any one of air catalytic oxidation, wet catalytic oxidation, Fenton oxidation, iron-carbon micro-electrolysis, ozone catalytic oxidation or ultraviolet oxidation or a combination of at least two of the above.

29. The method according to claim 1, wherein after the physicochemical treatment, the COD value of the wastewater is 500-5000 mg/L, and the sulfur content is 1.0-5.0 mg/L.

30. The method of claim 1, wherein the biochemical treatment comprises an anaerobic biochemical treatment and/or a contact oxidation treatment.

31. The method according to claim 1, wherein after the biochemical treatment, the COD value of the wastewater is not more than 50mg/L, and the sulfur content is not more than 1.0 mg/L.

32. The method according to claim 1, characterized in that the mother liquor is subjected to dissolution filtration after incineration treatment, and the obtained filtrate is used for adjusting the pH of the wastewater after thermal filtration treatment.