TREATMENT METHOD OF WASTEWATER CONTAINING HIGH-CONCENTRATION BORON

Abstract

A treatment method of wastewater containing high-concentration boron includes steps as follows: pouring wastewater containing high-concentration boron into a PH value adjusting tank; pouring an alkaline solution into the PH value adjusting tank; pouring the wastewater containing boron into a boron-removing electrocoagulation tank, and an electric conducting electrolyte being provided for performing an electrocoagulation procedure; discharging sludge generated by the electrocoagulation procedure into a boron-contained sludge dewatering tank; outputting the wastewater containing boron into a first absorbing tank provided with a first absorbing material to perform an absorbing and filtering procedure; outputting the wastewater containing boron into a second absorbing tank provided with a second absorbing material to perform another absorbing and filtering procedure; and outputting the wastewater containing boron into a filtering tank to perform another filtering procedure for outputting the wastewater containing boron with a lower concentration.

Claims

1. A treatment method of wastewater containing high-concentration boron, including steps as follows: pouring wastewater of fuel-gas desulfurization generated by a coal-fired power plant into a first tank containing fly ash and bottom ash and stay still for a period of time to generate first processed wastewater having an alkaline PH level; performing an electrocoagulation procedure on the first processed wastewater in a second tank to generate and discharge second processed wastewater; and using a binder to mix with saturated coal ashes derived from the first tank to generate a concrete product.

2. The treatment method of wastewater containing high-concentration boron as claimed in claim 1, wherein the binder is cement.

3. The treatment method of wastewater containing high-concentration boron as claimed in claim 1, wherein an additional alkaline solution is poured into the second tank to accelerate the electrocoagulation procedure.

4. A treatment method of wastewater containing high-concentration boron, including steps as follows: pouring wastewater containing high-concentration boron into a PH value adjusting tank, wherein said wastewater containing high-concentration boron is wastewater of fuel-gas desulfurization generated by a coal-fired power plant; pouring an alkaline solution into said PH value adjusting tank to adjust a PH value of said wastewater containing high-concentration boron to generate first processed wastewater; pouring said first processed wastewater into a boron-removing electrocoagulation tank having an electric conducting electrolyte for performing an electrocoagulation procedure on the first processed wastewater to generate second processed wastewater; discharging sludge generated by said electrocoagulation procedure from a bottom portion of said boron-removing electrocoagulation tank into a boron-contained sludge dewatering tank for dewatering; outputting said second processed wastewater into a first absorbing tank having a first absorbing material for performing an absorbing and filtering procedure on said second processed wastewater to generate third processed wastewater, wherein said first absorbing material is bottom ash; outputting said third processed wastewater into a second absorbing tank having a second absorbing material for performing another absorbing and filtering procedure on said third processed wastewater to generate fourth processed wastewater, wherein said second absorbing material is fly ash; and outputting said fourth processed wastewater into a filtering tank for performing another filtering procedure on the fourth processed wastewater to provide low boron concentration water; wherein said first absorbing tank, said filtering tank and said second absorbing tank absorb saturated coal ashes provided in said boron-contained sludge dewatering tank, and a binder is provided to mix with the saturated coal ashes to form a concrete product.

5. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein said wastewater containing high-concentration boron has a boron concentration of 500 mg/L.

6. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein said alkaline solution is NaOH, and a PH value, after being adjusted, of said wastewater containing high-concentration boron is 8˜10.

7. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein said electric conducting electrolyte is seawater for increasing an electric conductivity of said wastewater containing high-concentration boron and reducing power consumption during said electrocoagulation procedure.

8. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein a power source adopted in said boron-removing electrocoagulation tank is a direct-current power source with 30˜1000V, and said direct-current is from an energy storage battery or solar power.

9. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein said boron-removing electrocoagulation tank further has an electrode, and said electrode is pure aluminum, nickel, iron or an alloy consisted of pure aluminum, nickel and iron.

10. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein when said bottom ash is provided with an amount of 100˜500 g/L, an absorbing period of 20˜180 minutes is required.

11. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein said filtering tank further has ultrafine hollow fibers with less than 0.5 micron as a filtering material, which is used for purifying said wastewater after being performed said electrocoagulation procedure.

12. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein when said fly ash is provided with an amount of 100˜500 g/L, an absorbing period of 20˜180 minutes is required.

13. The treatment method of wastewater containing high-concentration boron as claimed in claim 4, wherein said binder is cement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a flowchart illustrating a treatment method of wastewater containing high-concentration boron according to one preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Please refer to FIG. 1, which is a flowchart illustrating a treatment method of wastewater containing high-concentration boron according to one preferred embodiment of the present invention

[0029] As show in FIG. 1, the present invention provides a treatment method of wastewater containing high-concentration boron, which including steps as follows: pouring wastewater containing high-concentration boron into a PH value adjusting tank (a step 1); pouring an alkaline solution into the PH value adjusting tank to adjust a PH value of the wastewater containing high-concentration boron (a step 2); pouring the wastewater containing boron after the PH value being adjusted into a boron-removing electrocoagulation tank, and an electric conducting electrolyte being provided for performing an electrocoagulation procedure (a step 3); discharging sludge generated by the electrocoagulation procedure from a bottom portion of the tank into a boron-contained sludge dewatering tank for dewatering (a step 4); outputting the wastewater containing boron processed by the electrocoagulation procedure into a first absorbing tank, and a first absorbing material being provided into the first absorbing tank to perform an absorbing and filtering procedure on the wastewater containing boron (a step 5); outputting the wastewater containing boron after being filtered through the first absorbing tank into a second absorbing tank, and a second absorbing material being provided into the second absorbing tank to perform another absorbing and filtering procedure on the wastewater containing boron (a step 6); outputting the wastewater containing boron after being absorbed and filtered through the second absorbing tank into a filtering tank to perform another filtering procedure for outputting the wastewater containing boron with a lower concentration (a step 7).

[0030] In the step 1, the wastewater containing high-concentration boron is poured into the PH value adjusting tank. Wherein, the wastewater containing high-concentration boron is, for example but not limited to, wastewater of fuel-gas desulfurization generated by a coal-fired power plant, and the boron concentration thereon is, for example but not limited to, 500 mg/L.

[0031] In the step 2, the alkaline solution is poured into the PH value adjusting tank to adjust the PH value of the wastewater containing high-concentration boron. Wherein, the alkaline solution is, for example but not limited to, NaOH, and the PH value, after being adjusted, of the wastewater containing high-concentration boron is, for example but not limited to, PH8˜10.

[0032] In the step 3, the wastewater containing boron after the PH value being adjusted is poured into the boron-removing electrocoagulation tank, and the electric conducting electrolyte is provided for performing the electrocoagulation procedure. Wherein, the electric conducting electrolyte is, for example but not limited to, seawater, so that the electric conductivity of the wastewater containing high-concentration boron is increased, and power consumption during the electrocoagulation procedure is reduced. Wherein, the boron-removing electrocoagulation tank further has an electrode, and the electrode is, for example but not limited to, pure aluminum, nickel, iron or an alloy consisted of pure aluminum, nickel and iron.

[0033] In the step 4, the sludge generated by the electrocoagulation procedure from the bottom portion of the tank is discharged into the boron-contained sludge dewatering tank for dewatering. Wherein, a power source adopted in the boron-removing electrocoagulation tank is, for example but not limited to, a direct-current power source with 30˜1000V, and the direct-current is from an energy storage battery or solar power.

[0034] In the step 5, the wastewater containing boron processed by the electrocoagulation procedure is discharged into the first absorbing tank, and the first absorbing material is provided into the first absorbing tank to perform the absorbing and filtering procedure on the wastewater containing boron. Wherein, when the amount of the first absorbing material, for example but not limited to 100˜500 g/L, is provided, an absorbing period is set to, for example but not limited to 20˜180 minutes.

[0035] In the step 6, the wastewater containing boron after being filtered through the first absorbing tank is discharged into the second absorbing tank, and the second absorbing material is provided into the second absorbing tank to perform another absorbing and filtering procedure on the wastewater containing boron. Wherein, when the amount of the second absorbing material, for example but not limited to 100˜500 g/L, is provided, an absorbing period is set to, for example but not limited to 20˜180 minutes.

[0036] In the step 7, the wastewater containing boron after being absorbed and filtered through the second absorbing tank is discharged into the filtering tank to perform another filtering procedure for outputting the wastewater containing boron with a lower concentration. Wherein, the filtering tank further has ultrafine hollow fibers with less than 0.5 micron as a filtering material, which is used for purifying the wastewater after being processed by the electrocoagulation procedure.

[0037] Moreover, according to the treatment method of wastewater containing high-concentration boron, the first absorbing tank, the filtering tank and the second absorbing tank are able to absorb saturated coal ashes which are provided in the boron-contained sludge dewatering tank, and a binder is provided after the dewatering procedure. Wherein, the binder is, for example but not limited to, cement, so that a concrete product containing coal ashes is formed.

[0038] The treatment of wastewater containing high-concentration boron of the present invention is applied in a testing sample of original wastewater containing high-concentration boron generated by the Taipower Company fired power plant located in Taichung, Taiwan, a 40% NaOH is firstly provided to adjust a PH value of the testing sample to PH8˜10, the testing sample is electrolyzed with a constant current for 30 minutes, and filtered through the first absorbing tank and the second absorbing tank, then the PH value is adjusted again and electrolyzed for another 30 minutes, the above-mentioned operations are repeatedly processed for 3 hours, so that the wastewater containing high-concentration boron with a concentration of 600 ppm is lowered to 13 ppm, a removing rate thereof is about 97.8%, meanwhile a magnesium removing rate is 99.55%, and a Calcium removing rate is about 65.2%;

[0039] the technical feature disclosed in the present invention is a continuous treatment method to effectively treating a large amount of wastewater containing high-concentration boron, and the operation process is simple, thereby being able to be automated. Accordingly, the treatment method of wastewater containing high-concentration boron provided by the present invention is novel and more practical in use comparing to prior arts.

[0040] Based on what has been disclose above, advantages achieved by the treatment method of wastewater containing high-concentration boron disclosed in the present invention, comparing with conventional treatment methods of wastewater containing high-concentration boron, are as follows: 1. the direct-current power source from the energy storage battery or the solar power is adopted; 2. the coal ashes are used as the absorbent for treating the fuel material with wastewater containing high-concentration boron; and 3. the coal ashes can be solidified to form a concomitant concrete product. Accordingly, the treatment method of wastewater containing high-concentration boron provided by the present invention is novel and more practical in use comparing to the conventional treatment methods of wastewater containing high-concentration boron.

[0041] While the invention has been described by way of example and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. For example, before going through the electrocoagulation procedure, the wastewater of fuel-gas desulfurization generated by a coal-fired power plant can be poured into a tank containing fly ash and bottom ash and stay still for a period of time to increase the PH level thereof to alkaline values, which can be up to 10. When the PH level becomes more alkaline, more of the magnesium ions (Mg.sup.+2) in the wastewater of fuel-gas desulfurization will hydrolyze to form Mg(OH).sup.2 precipitation. As the magnesium hydroxides can absorb borons, the boron concentration of the wastewater of fuel-gas desulfurization will reduce considerably, thereby reducing the cost of the electrocoagulation procedure. That is, the invention can be embodied alternatively as: pouring wastewater of fuel-gas desulfurization generated by a coal-fired power plant into a first tank containing fly ash and bottom ash and stay still for a period of time to generate first processed wastewater having an alkaline PH level (step A); performing an electrocoagulation procedure on the first processed wastewater in a second tank to generate and discharge second processed wastewater (step B); and using a binder to mix with saturated coal ashes derived from the first tank to generate a concrete product, where the binder can be cement (step C). Besides, in step B, an additional alkaline solution is poured into the second tank to support the electrocoagulation procedure.

[0042] In summation of the above description, the present invention herein enhances the performance over the conventional structure and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights.