A device and method for removing arsenic in water by electrochemical synergistic oxidation-flocculation with low energy consumption

A synergistic oxidation and electrochemical technology, applied in the field of water pollution remediation, can solve the problems of high pre-oxidation cost, high energy consumption of electrode reaction, etc., and achieve the effect of saving system energy consumption and eliminating the aeration link

Active Publication Date: 2019-01-29
TSINGHUA UNIV
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Problems solved by technology

[0008] In order to overcome the disadvantages of high pre-oxidation cost and high energy consumption of electrode reaction in the above-mentioned prior art, the object of the present invention is to provide a device and method for removing arsenic in water by electrochemical synergistic oxidation-flocculation with low energy consumption. Basically, an air cathode is used instead of an iron cathode. Under the action of atmospheric partial pressure, the air passes through the PVDF waterproof membrane, and an oxygen reduction reaction occurs on the surface of the catalytic layer to generate H in situ. 2 o 2 Enter the water phase to oxidize As(III) to As(V), and the metal ions (iron ions, aluminum ions or zinc ions) generated at the anode are hydrolyzed to form a large number of flocs, and As(V) is removed by adsorption

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  • A device and method for removing arsenic in water by electrochemical synergistic oxidation-flocculation with low energy consumption
  • A device and method for removing arsenic in water by electrochemical synergistic oxidation-flocculation with low energy consumption
  • A device and method for removing arsenic in water by electrochemical synergistic oxidation-flocculation with low energy consumption

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Embodiment 1

[0051] The groundwater has a pH of 7, a conductivity of 1500 μs / cm, and an As(III) content of 500 μg / L. The air cathode-electroflocculation reactor is powered by a DC stabilized power supply (the schematic diagram of the reactor is shown in figure 2 ), fixed voltage 1V. Take 1 mL of water sample every 10 minutes, and measure As(III) and total arsenic changes after passing through a 45 μm water filter membrane, as shown in Figure 5 , 6 shown. The energy consumption of the air cathode-electrocoagulation system can be calculated by P=UIt, wherein the current I is the real-time record of the automatic data acquisition system, and t is the time when the total arsenic reaches 10 μg / L, such as Figure 9 shown.

Embodiment 2

[0053] The groundwater has a pH of 7, a conductivity of 1500 μs / cm, and an As(III) content of 500 μg / L. The air cathode-electroflocculation reactor is powered by a DC stabilized power supply (the schematic diagram of the reactor is shown in figure 2 ), fixed voltage 2V. Take 1 mL of water sample every 10 minutes, and measure As(III) and total arsenic changes after passing through a 45 μm water filter membrane, as shown in Figure 7 , 8 shown. The energy consumption of the air cathode-electrocoagulation system can be calculated by P=UIt, wherein the current I is the real-time record of the automatic data acquisition system, and t is the time when the total arsenic reaches 10 μg / L, such as Figure 9 shown.

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Abstract

The invention provides a low energy consumption device and method for removal of arsenic from water by electrochemistry coordinated oxidation-flocculation. The method employs a gas diffusion type air cathode to replace an iron cathode in common electric flocculation, utilizes the passive diffusion of oxygen in air to achieve in-situ formation of H2O2 on the surface of a catalyst layer, promotes the generation of active species (.OH and Fe(IV)), and rapidly oxidizes As(III) into As(V), anode generated metal ions (iron ions, aluminum ions or zinc ions) are hydrolyzed to generate a large number of flocs, and adsorption is carried out to remove As(V). Compared with traditional electric flocculation, the method not only can achieve efficient oxidation of As(III) and up-to-stand removal of total arsenic, also saves aeration energy consumption by about 200Wh.m<-3>, and reduces the electrode reaction energy consumption by 30-40%.

Description

technical field [0001] The invention belongs to the technical field of water pollution remediation, and in particular relates to a device and method for removing arsenic in a water body through electrochemical synergistic oxidation and flocculation with low energy consumption. Background technique [0002] There are more than 70 countries in the world that have high-arsenic groundwater distribution, and hundreds of millions of people are facing the threat of high-arsenic groundwater. Chronic arsenic poisoning is a major endemic disease caused by drinking high-arsenic groundwater, and China is one of the countries most seriously affected by arsenic endemic diseases. According to the safe standard of arsenic content in drinking water (10 μg / L) recommended by WHO, there are more than 15 million people exposed to arsenic pollution in China, which poses a great threat to the safety of drinking water for residents. To do a good job in the prevention and control of endemic arsenic...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F1/463C02F1/467C02F1/74C02F103/06
CPCC02F1/463C02F1/467C02F1/74C02F2101/103C02F2103/06C02F2201/461
Inventor 张芳司艳晓李广贺张旭侯德义冯晨刘波
Owner TSINGHUA UNIV
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