METHOD OF BORON-CONTAINED WASTEWATER TREATMENT

• US 20200131062A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: National Cheng KUNG University (Government of The Republic of China)
• Original Assignee: National Cheng KUNG University (Government of The Republic of China)
• Inventors: HUANG, Yao-Hui
• Granted Patent: US 10,850,997 B2
• Time in Patent Office: Days
• CPC Class Codes: C02F 1/5209 Regulation methods for flocculation or precipitation
• CPC Class Codes: C02F 1/5236 using inorganic agents
• CPC Class Codes: C02F 1/66 by neutralisation; pH adjustment for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58
• CPC Class Codes: C02F 1/705 Reduction by metals
• CPC Class Codes: C02F 1/722 Oxidation by peroxides
• CPC Class Codes: C02F 2101/108 Boron compounds
• CPC Class Codes: C02F 3/2833 using fluidized bed reactors
• CPC Class Codes: C02F 3/286 including two or more steps
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage

Abstract

A method of boron-contained wastewater treatment includes the following steps. Pretreatment: Mix a boron-contained wastewater with hydrogen peroxide for reaction at pH 8-12. Precipitation: Add n moles of barium compound into the pretreated boron-contained wastewater to provide perborate precipitation at pH 8.5-12. The number n is obtained from an equation of n=([B]*a+[NO₃]*0.01+[F]*0.01+[CO₃]*1+[SO₄]*1)*V wherein a is ranged from 0.6-0.9. [B], [NO₃], [F], [CO₃], and [SO₄] are molarities of boron, nitrate ion, fluoride ion, carbonate ion, and sulfate ion of the boron-container wastewater. V is the volume of the boron-container wastewater. A fluidized bed reactor is used.

Claims

1. A method of boron-contained wastewater treatment includes steps of:

pretreatment;

mixing a boron-contained wastewater with hydrogen peroxide for reaction at pH 8-12;

precipitation;

adding barium compound into the pretreated boron-contained wastewater to provide perborate precipitation at pH 8.5-12, wherein a molarity of boron of the boron-contained wastewater is defined as [B], a molarity of nitrate ion of the boron-contained wastewater is defined as [NO₃], a molarity of fluoride ion of the boron-contained wastewater is defined as [F], a molarity of carbonate ion of the boron-contained wastewater is defined as [CO₃], a molarity of sulfate ion of the boron-contained wastewater is defined as [SO₄], a volume of the boron-contained wastewater is defined as V, n moles of the barium compound is added, n is obtained from an equation that n=([B]*a+[NO₃]*0.01+[F]*0.01+[CO₃]*1+[SO₄]*1)*V wherein a is ranged from 0.6-0.9;

wherein a fluidized bed reactor having an upper section and a lower section is used, the lower section has a wastewater inlet and a coagulant inlet, the upper section has an outlet, a reflux piping is arranged between the upper section and the lower section to connect the upper section and the lower section;

hydrogen peroxide and the boron-contained wastewater are continuously injected into a mixing tank to react therein, the pretreated boron-contained wastewater and the barium compound are injected into the lower section via the wastewater inlet and the coagulant inlet respectively and are mixed in the lower section, make the boron-contained wastewater with barium compound flow from the lower section toward the upper section and flow back to the lower section via the reflux piping for circulation in order to form homogeneous particles of perborate salt.

2. The method of boron-contained wastewater treatment of claim 1, wherein the molarity of boron of the boron-contained wastewater is higher than 50 mM.

3. The method of boron-contained wastewater treatment of claim 1, wherein a mole ratio of the hydrogen peroxide to the boron of the boron-contained wastewater is ranged from 0.5 to 3.

4. The method of boron-contained wastewater treatment of claim 1, wherein the step of pretreatment is carried on at pH 9-11, the step of precipitation is carried on at pH 9-10.5.

5. The method of boron-contained wastewater treatment of claim 1, wherein a height of a granular bed is higher than 40 cm, an outflowed water has a pH ranged between 8-11.