Treatment agent and treatment method for wet desulphurization wastewaterTechnical Field
The invention relates to the technical field of tea tree planting, in particular to a treatment agent and a treatment method for wet desulphurization wastewater.
Background
The impurities contained in the desulfurization wastewater mainly comprise suspended matters, supersaturated sulfite, sulfate and heavy metals, wherein a lot of pollutants are the first pollutants which are required to be strictly controlled in the national environmental protection standard, and the desulfurization wastewater has the characteristics of high salinity, high heavy metal content, corrosivity, low chroma, high hardness and the like, and has the characteristics of specificity, complexity, strong corrosivity and the like, and the treatment and recycling difficulty is extremely high. At present, domestic and foreign enterprises carry out certain treatment on the desulfurization wastewater, but mainly adopt a chemical precipitation method for treatment, and the treated desulfurization wastewater is difficult to recycle. If the treated wastewater is directly discharged, not only water resources are wasted, but also the physicochemical properties of soil and water are changed, secondary pollution is caused, and the ecological environment is damaged. With the tightening of the regulations on the flue gas desulfurization wastewater, the zero discharge treatment of the desulfurization wastewater becomes a necessary trend.
At present, the zero discharge technology of wastewater in China is still in the initial stage, and the technology mainly adopts the combination of flue gas waste heat drying and membrane concentration with MVR evaporation crystallization. The flue gas waste heat drying method has the problems that a spray drying system is easy to scale and block, the system cannot stably run for a long time, and the dried solid substance is soluble miscellaneous salt which is solid dangerous waste, so that the subsequent treatment difficulty is high.
Disclosure of Invention
The invention provides a treatment agent and a treatment method for wet desulphurization wastewater, which aim to solve the problems in the background art.
The invention provides a treatment agent for wet desulphurization wastewater, which comprises the following components: lime milk solution with the concentration of 5 percent is 25-30mg/L, organic sulfide with the concentration of 15 percent is 40-60mg/L, ferric chloride sulfate with the concentration of 40 percent is 35-45mg/L, PAM with the concentration of 0.05 percent is 9-10mg/L and hydrochloric acid with the concentration of 3 percent is 2-3 mg/L.
The invention also provides a treatment method of the wet desulphurization wastewater, which comprises the following steps:
s1: feeding the desulfurization wastewater into a neutralization tank, adding a lime milk solution for neutralization, and increasing the pH value of the wastewater to be more than 9.0 so that most heavy metal ions in the wastewater generate insoluble hydroxide precipitate in an alkaline environment;
s2: sending the wastewater subjected to neutralization treatment in the S1 into a settling tank for settling, adding organic sulfide into the wastewater, and reacting the organic sulfide with residual heavy metal to form insoluble sulfide for settling;
s3: sending the wastewater subjected to the sedimentation treatment in the S2 into a flocculation box, adding ferric chloride sulfate to enable colloidal particles and suspended matter particles to be coagulated and aggregated, and coagulating fine particles in the wastewater into large particles to be deposited and then carrying out liquid phase separation;
s4: adding PAM at a wastewater outlet of the flocculation tank, and sending the PAM into a clarification tank for sedimentation;
s5: and in the precipitated wastewater, the precipitate is concentrated into sludge at the bottom of a clarification tank, and dechlorinating agent is added into the upper layer liquid at the separation part, so that treated effluent can be obtained.
Preferably, the organic sulfide in S2 is one of thiol, ethanethiol, thioether, ethanethiolsulfonic acid, sulfonate or sulfonyl chloride.
Preferably, the PH value and the turbidity of effluent are monitored, and the PH value and the turbidity reach the drainage standard for discharging; otherwise, adding acid to adjust the pH value or sending the pH value back to the neutralization tank for continuous treatment until the pH value is qualified.
Preferably, the dechlorination agent in S5 comprises the following components: 20-30 parts of ferrous sulfate, 20-40 parts of calcium oxide and 10-25 parts of attapulgite clay.
Preferably, the preparation of the dechlorination agent comprises the following steps:
a 1: mixing ferrous sulfate, calcium oxide and attapulgite clay, and fully kneading;
a 2: adding a binder into the uniformly mixed material of the a1, and mixing and grinding the material into paste;
a 3: the paste in a2 is dried at the temperature of 160-180 ℃ to prepare the dechlorinating agent.
Preferably, the binder in a2 is silica sol or hydroxymethyl cellulose.
The invention provides a treatment agent and a treatment method for wet desulphurization wastewater, which have the beneficial effects that: the method is suitable for treating the waste water containing corrosive chloride ions, and firstly, heavy metals and a small amount of chloride ions in the waste water are separated in a lime milk solution mode in the waste water containing the chloride ions; and removing residual metal ions in the wastewater by a method of generating precipitates through a chemical reaction, and finally adding a dechlorinating agent for dechlorinating, so that the removal of the chloride ions in the wastewater is realized, and the subsequent thorough harmless treatment of the wastewater is conveniently realized.
Detailed Description
The invention is further illustrated by the following examples.
Example 1
The invention provides a treatment agent for wet desulphurization wastewater, which comprises the following components: lime milk solution with the concentration of 5% 25mg/L, organic sulfide with the concentration of 15% 40mg/L, ferric chloride sulfate with the concentration of 40% 35/L, PAM9mg/L with the concentration of 0.05% and hydrochloric acid with the concentration of 3% 2 mg/L;
a method for treating wet desulphurization wastewater comprises the following steps:
s1: when the desulfurization wastewater enters the neutralization tank, a certain amount of lime milk solution is added to increase the pH value of the wastewater to be more than 9.0, so that most heavy metal ions generate insoluble hydroxide precipitate in an alkaline environment.
S2: after lime milk is added into the sedimentation desulfurization wastewater of the heavy metal ion compound, most heavy metal ions can form insoluble hydroxide when the pH value reaches 9.0-9.5; meanwhile, Ca2+ in the lime milk reacts with part of F-in the wastewater to generate insoluble calcium fluoride, so that the effect of removing fluorine is achieved; in the neutralized wastewater, the contents of Cd2+ and Hg2+ still exceed the standard, so organic sulfide is added into a settling tank to react with residual Cd2+ and Hg2+ to form insoluble sulfide for deposition.
S3: the content of suspended matters in the desulfurization wastewater is large, and the desulfurization wastewater mainly contains gypsum particles, SiO2, Al3+ and Fe3+ hydroxide. The flocculation method is adopted to lead the colloid particles and the suspended particles to be coagulated and aggregated, thereby separating from the liquid phase, and ferric chloride sulfate is added into a flocculation box to lead the fine particles in the wastewater to be coagulated into large particles and deposited.
S4: PAM is added at the wastewater outlet of the flocculation tank and is sent into a clarification tank for precipitation, so that the growth process of particles is further strengthened, and fine flocculates slowly become thick solid flocculating constituents easier to deposit.
S5: and (3) after the flocculated wastewater enters a clarification tank and is treated by adding a dechlorinating agent, precipitates are deposited at the bottom and are concentrated into sludge, the upper part is treated effluent, and an online monitoring instrument is used for monitoring the pH value and the turbidity of the effluent. If the PH value and the turbidity reach the drainage design standard, discharging the wastewater through a water outlet pump; otherwise, hydrochloric acid is added to adjust the pH value or the pH value is sent back to the neutralization tank for continuous treatment until the pH value is qualified.
The dechlorination agent comprises the following components: 20-30 parts of ferrous sulfate, 20-40 parts of calcium oxide and 10-25 parts of attapulgite clay by weight, and the preparation of the dechlorinating agent comprises the following steps:
a 1: mixing ferrous sulfate, calcium oxide and attapulgite clay, and fully kneading;
a 2: adding a binder into the uniformly mixed material of the a1, and mixing and grinding the material into paste, wherein the binder is silica sol or hydroxymethyl cellulose;
a 3: the paste in a2 is dried at the temperature of 160-180 ℃ to prepare the dechlorinating agent.
Example 2
The invention provides a treatment agent for wet desulphurization wastewater, which comprises the following components: lime milk solution with concentration of 5% 28mg/L, organic sulfide with concentration of 15% 50mg/L, ferric chloride sulfate with concentration of 40% 40mg/L, PAM9.5mg/L with concentration of 0.05% and hydrochloric acid with concentration of 3% 2.5 mg/L.
A method for treating wet desulphurization wastewater comprises the following steps:
s1: when the desulfurization wastewater enters the neutralization tank, a certain amount of lime milk solution is added, the pH value of the wastewater is increased to be more than 9.0, and most heavy metal ions generate insoluble hydroxide precipitate in an alkaline environment.
S2: after lime milk is added into the sedimentation desulfurization wastewater of the heavy metal ion compound, most heavy metal ions can form insoluble hydroxide when the pH value reaches 9.0-9.5; meanwhile, Ca2+ in the lime milk reacts with part of F-in the wastewater to generate insoluble calcium fluoride, so that the effect of removing fluorine is achieved; in the neutralized wastewater, the contents of Cd2+ and Hg2+ still exceed the standard, so 50mg/L of organic sulfide with the concentration of 15% is added into a settling tank, and the organic sulfide reacts with residual Cd2+ and Hg2+ to form insoluble sulfide for deposition.
S3: the content of suspended matters in the desulfurization wastewater is large, and the desulfurization wastewater mainly contains gypsum particles, SiO2, Al3+ and Fe3+ hydroxide. The flocculation method is adopted to lead the colloid particles and the suspended particles to be coagulated and aggregated, thereby separating from the liquid phase, and ferric chloride sulfate is added into a flocculation box to lead the fine particles in the wastewater to be coagulated into large particles and deposited.
S4: PAM is added at the wastewater outlet of the flocculation tank and is sent into a clarification tank for precipitation, so that the growth process of particles is further strengthened, and fine flocculates slowly become thick solid flocculating constituents easier to deposit.
S5: and (3) after the flocculated wastewater enters a clarification tank and is treated by adding a dechlorinating agent, precipitates are deposited at the bottom and are concentrated into sludge, the upper part is treated effluent, and an online monitoring instrument is used for monitoring the pH value and the turbidity of the effluent. If the PH value and the turbidity reach the drainage design standard, discharging the wastewater through a water outlet pump; otherwise, the pH value is adjusted by adding hydrochloric acid or sent back to the neutralization box for continuous treatment until the pH value is qualified.
The dechlorination agent comprises the following components: 20-30 parts of ferrous sulfate, 20-40 parts of calcium oxide and 10-25 parts of attapulgite clay, and the preparation of the dechlorinating agent comprises the following steps:
a 1: mixing ferrous sulfate, calcium oxide and attapulgite clay, and fully kneading;
a 2: adding a binder into the uniformly mixed material of the a1, and mixing and grinding the material into paste, wherein the binder is silica sol or hydroxymethyl cellulose;
a 3: the paste in a2 is dried at the temperature of 160-180 ℃ to prepare the dechlorinating agent.
Example 3
The invention provides a treatment agent for wet desulphurization wastewater, which comprises the following components: 30mg/L of lime milk solution with the concentration of 5 percent, 60mg/L of organic sulfide with the concentration of 15 percent, 45mg/L of ferric chloride sulfate with the concentration of 40 percent, 10mg/L of PAM with the concentration of 0.05 percent and 3mg/L of hydrochloric acid with the concentration of 3 percent.
A method for treating wet desulphurization wastewater comprises the following steps:
s1: when the desulfurization wastewater enters the neutralization tank, a certain amount of lime milk solution is added to increase the pH value of the wastewater to be more than 9.0, so that most heavy metal ions generate insoluble hydroxide precipitate in an alkaline environment.
S2: after lime milk is added into the sedimentation desulfurization wastewater of the heavy metal ion compound, most heavy metal ions can form insoluble hydroxide when the pH value reaches 9.0-9.5; meanwhile, Ca2+ in the lime milk reacts with part of F-in the wastewater to generate insoluble calcium fluoride, so that the effect of removing fluorine is achieved; in the neutralized wastewater, the contents of Cd2+ and Hg2+ still exceed the standard, so organic sulfide is added into a settling tank to react with residual Cd2+ and Hg2+ to form insoluble sulfide for deposition.
S3: the content of suspended matters in the desulfurization wastewater is large, and the desulfurization wastewater mainly contains gypsum particles, SiO2, Al3+ and Fe3+ hydroxide. The flocculation method is adopted to lead the colloid particles and the suspended particles to be coagulated and aggregated, thereby separating from the liquid phase, and ferric chloride sulfate with concentration is added into a flocculation box, so that the fine particles in the wastewater are coagulated into large particles and deposited.
S4: PAM is added at the wastewater outlet of the flocculation tank and is sent into a clarification tank for precipitation, so that the growth process of particles is further strengthened, and fine flocculates slowly become thick solid flocculating constituents easier to deposit.
S5: and (3) after the flocculated wastewater enters a clarification tank and is treated by adding a dechlorinating agent, precipitates are deposited at the bottom and are concentrated into sludge, the upper part is treated effluent, and an online monitoring instrument is used for monitoring the pH value and the turbidity of the effluent. If the PH value and the turbidity reach the drainage design standard, discharging the wastewater through a water outlet pump; otherwise, hydrochloric acid is added to adjust the pH value or the pH value is sent back to the neutralization tank for continuous treatment until the pH value is qualified.
The dechlorination agent comprises the following components: 20-30 parts of ferrous sulfate, 20-40 parts of calcium oxide and 10-25 parts of attapulgite clay, and the preparation of the dechlorinating agent comprises the following steps:
a 1: mixing ferrous sulfate, calcium oxide and attapulgite clay, and fully kneading;
a 2: adding a binder into the uniformly mixed material of the a1, and mixing and grinding the material into paste, wherein the binder is silica sol or hydroxymethyl cellulose;
a 3: the paste in a2 is dried at the temperature of 160-180 ℃ to prepare the dechlorinating agent.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.