CN110482681A - A method of sour water containing heavy metal handles coproduction new energy - Google Patents

Abstract

The invention discloses a method for co-producing new energy by treating acid sewage containing heavy metals. The method adopts a bipolar membrane to separate a reactor into an anode chamber and a cathode chamber, and the anode and the cathode are respectively placed in the anode chamber and the cathode chamber. The mixture of bacterial suspension and nutrient solution is used as the electrolyte, and the phosphate buffer solution is used as the electrolyte in the cathode chamber. The reactor is powered on and the electrolyte is replaced regularly. When the anode potential is stabilized above 0.24V for 3 times, the anode pretreatment is completed. The electrolyte in the anode chamber of the reactor is replaced with high-concentration organic sewage, and the electrolyte in the cathode chamber is replaced with heavy metal-containing acidic sewage, and under the conditions of nitrogen and applied voltage, the heavy metal-containing acidic sewage is anaerobic treated to recover hydrogen; the method has the advantages of: It has the characteristics of low cost, high efficiency, strong versatility and good treatment effect, which effectively reduces the secondary pollution in the process of heavy metal-containing acid sewage treatment, realizes the resource utilization of waste, and obtains corresponding economic benefits.

Description

A method for co-producing new energy by treating acid sewage containing heavy metals

technical field

The invention relates to a technology for the treatment of acidic heavy metal sewage, in particular to a method for treating and degrading organic sewage by an electrochemical method while co-producing new energy.

Background technique

my country is the third largest mining country in the world and has abundant metal mine resources. Mining has made important contributions to economic development. However, mining produces a large amount of acidic mine wastewater containing heavy metal ions, which causes huge pollution to the environment. Such wastewater If it is directly discharged without treatment, the water body will be acidified. At the same time, because the acidic wastewater also contains a large amount of heavy metal ions such as copper, nickel, mercury, cadmium, lead, and chromium that cannot be degraded after discharge, so once the water body, soil and organisms are exposed to them It is difficult to remove the pollution caused by the waste water, and through bioaccumulation, it will eventually cause harm to human beings; the treatment of such wastewater is often costly and costly, and currently commonly used treatment processes such as chemical precipitation, biological methods, membrane separation methods, etc., among which chemical precipitation The emission concentration fluctuates greatly and the operating cost is high. The problem of biological method is that it has high requirements on water quality, low degree of automation and large area. The membrane separation method will encounter problems such as membrane blockage and electrode polarization in practical application. The electrochemical method has the advantages of good treatment effect, low operating cost, less sludge production, high degree of automation, easy operation and management, and simultaneous removal of various pollutants. .

In recent years, with the continuous development of society, the petrochemical energy, mainly petroleum, coal and natural gas, which once supported the rapid development of human civilization in the 20th century, has encountered an unprecedented crisis. Scientific research has found that petrochemical energy will produce a series of pollution after use. Energy shortage and environmental pollution have become two major problems faced by human beings in the process of sustainable development. Hydrogen, as a source of wide range, has a high calorific value, and its complete combustion product water will not cause any pollution to the environment. It is regarded as the most ideal energy carrier in the 21st century and has received extensive attention. At present, the most important method for hydrogen production from fossil fuels, the raw material of which is still petrochemical energy cannot meet the needs of sustainable development. Other hydrogen production methods such as water electrolysis hydrogen production are limited by excessive energy consumption, and biological hydrogen production is only in the laboratory stage.

SUMMARY OF THE INVENTION

In view of these problems, the present invention provides a high-efficiency and low-cost method for the treatment of heavy metal-containing acidic sewage and co-production of new energy, which adopts the method of combining electrochemistry with relevant special microorganisms. Since the heavy metal acidic sewage contains high concentrations of conductive ions and hydrogen ions, using this feature to solve the problem of reducing the hydrogen production performance caused by the consumption of protons while producing hydrogen, and recovering heavy metals and hydrogen at the same time.

The method for treating and utilizing the acid wastewater containing heavy metals of the present invention comprises the following steps:

(1) Anode pretreatment

A bipolar membrane is used to separate the reactor into an anode compartment and a cathode compartment. The anode and cathode are placed in the anode compartment and the cathode compartment respectively. The mixture of bacterial suspension and nutrient solution is used as the electrolyte in the anode compartment, and the phosphate buffer solution is used in the cathode compartment. As the electrolyte, run the reactor with power on, and replace the electrolyte in the anode chamber and the cathode chamber once a day. When the anode potential is stabilized above 0.24V three times, the anode pretreatment is completed;

The nutrient solution contains 3-5g/L sodium acetate, 50-100mL/L phosphate buffer solution, 0.30-0.4g/L ammonium chloride, 0.1-0.2g/L potassium chloride, 0.2-0.4g/L The aqueous solution of sodium chloride, 0.1-0.25g/L ferric sulfate, 0.4-0.7g/L manganese sulfate, and 0.01-0.03g/L copper sulfate, the volume ratio of bacterial suspension to nutrient solution is 1:5-30.

The bacterial suspension comes from a microbial primary battery reactor using acetate as a culture solution, and the microbial primary battery reactor using acetate as a culture solution uses a proton exchange membrane to divide the reactor into an anode chamber and a cathode chamber, The anode and cathode are placed in the anode chamber and the cathode chamber respectively, and the activated sludge and nutrient solution taken from the secondary sedimentation tank of the sewage treatment plant are added to the reactor according to the mass ratio of 1:3-5, and the mixture mass is 8-12 % pH7, 50mM phosphate buffer and mix well, the reactor is connected with a 1000 ohm resistor, and the reaction is carried out at room temperature under anaerobic conditions. When the voltage generated by the reactor drops to 0.01V, the mixed substrate in the reactor is replaced. After completing one reaction cycle, when the highest voltage generated by the reactor is above 0.1 V and three consecutive reaction cycles, the reaction solution in the reactor can be taken as the bacterial suspension; the nutrient solution contains 3-5g/L sodium acetate, 0.3 -0.4g/L ammonium chloride, 0.1-0.2g/L potassium chloride, 0.2-0.4g/L sodium chloride, 0.1-0.25g/L iron sulfate, 0.4-0.7g/L manganese sulfate, 0.01-0.03 g/L copper sulfate solution.

The bipolar membrane is a conventional commercially available product; it was purchased from Zhejiang Lanji Membrane Technology Co., Ltd.;

Described phosphate buffer solution concentration is 50mM, pH=7;

(2) Replace the electrolyte in the anode chamber of the reactor in step (1) with high-concentration organic sewage, in which the carbon source content is not less than 300 mg/L, and the electrolyte in the cathode chamber is replaced with heavy metal-containing acidic sewage. Under the condition of anaerobic treatment of acid sewage containing heavy metals, hydrogen and heavy metals are recovered;

The high-concentration organic sewage is domestic sewage, industrial wastewater or sugar-making wastewater;

A voltage of 0.45-1 V was applied across the electrodes.

The protons consumed while producing hydrogen in conventional microbial electrolysis cells often lead to an increase in pH in the cathode compartment, which negatively affects the hydrogen production performance of microbial electrolysis cells. So in most microbial electrolysis cells, phosphate buffered solution (PBS) is used as the catholyte due to its excellent property of maintaining pH balance during system operation. However, due to its high cost and the need to avoid the release of phosphates into the environment, PBS is not suitable for practical applications in microbial electrolysis cells. On the other hand, since the hydrogen production capacity of microbial electrolysis cells may be limited by wastewater with low conductivity and hydrogen ion concentration as electrolyte, acid wastewater containing heavy metals with high concentrations of conductive ions and hydrogen ions can be used in microbial electrolysis cells. At the same time, for metal species with negative standard potential, such as Pb ²⁺ , Cd ²⁺ , Zn ²⁺ and Ni ²⁺ , the oxidation performance is weak, resulting in their poor ability to bind electrons, only The removal can be achieved by applying a voltage to the external circuit, which matches the potential required for H ⁺ reduction, so _H2 precipitation should occur at the same time as the metal reduction.

The advantages and characteristics of the present invention lie in: using the method of electrochemically combining microorganisms to treat the acid wastewater containing heavy metals, the steps are simple, the cost is low, and the treatment effect is obvious; While treating sewage, it can not only recover heavy metals, but also produce hydrogen at low cost, and provide carbon source and energy for microorganisms through high-concentration organic wastewater such as domestic wastewater and industrial wastewater. The purpose is to achieve a double harvest of economic and environmental benefits at the same time.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited to the content.

Example 1:

(1) Collect the bacterial suspension in the microbial primary battery reactor cultivated with sodium acetate, and mix the bacterial suspension with the nutrient solution in a volume ratio of 1:5 to obtain an electrolyte in the anode chamber. The nutrient solution contains 3g/L acetic acid. Sodium, 100mL/L phosphate buffer solution (50mM, pH=7), 0.3g/L ammonium chloride, 0.1g/L potassium chloride, 0.2g/L sodium chloride, 0.25g/L iron sulfate, 0.4g /L manganese sulfate, 0.01g/L copper sulfate aqueous solution;

The bacterial suspension comes from a microbial primary battery reactor with acetate as a culture solution, the reactor is divided into an anode compartment and a cathode compartment by a proton exchange membrane, and the anode and the cathode are placed in the anode compartment and the cathode compartment respectively, Activated sludge and nutrient solution (containing 3g/L sodium acetate, 0.3g/L ammonium chloride, 0.1g/L potassium chloride, 0.2g/L sodium acetate, 0.1g/L potassium chloride, 0.2g /L sodium chloride, 0.25g/L ferric sulfate, 0.4g/L manganese sulfate, 0.01g/L copper sulfate aqueous solution) was added to the reactor, and at the same time 10% of the mixture was added with pH7, 50mM phosphate buffer mixed The reactor is connected with a 1000 ohm resistor, and the reaction is carried out at room temperature and under anaerobic conditions. When the voltage generated by the reactor drops to 0.01V, replace the mixed substrate in the reactor to complete a reaction cycle. When the voltage is above 0.1 V for three consecutive reaction cycles, the reaction solution in the reactor can be taken as the bacterial suspension;

(2) A bipolar membrane (Zhejiang Lanji Membrane Technology Co., Ltd.) was used to separate the reactor into an anode chamber and a cathode chamber, the anode and cathode were placed in the anode chamber and the cathode chamber respectively, and the mixture in step (1) was used in the anode chamber as an electrolysis The cathode chamber uses 50mM, pH=7 phosphate buffer solution as the electrolyte, the reactor is powered on, and the electrolyte in the anode chamber and the cathode chamber is replaced once a day. When the anode potential is stabilized above 0.24V for 3 times, the anode pretreatment is completed. ;

(3) Replace the electrolyte in the anode chamber of the reactor in step (2) with sugar-making wastewater, in which the carbon source content is 350 mg/L, and the electrolyte in the cathode chamber is replaced with acid wastewater (Cu ² ) containing heavy metals from a copper mine in Yunnan. ⁺ concentration of 17g/L, Ni ²⁺ concentration of 5g/L), under nitrogen, 0.5V, anaerobic treatment of acid sewage containing heavy metals, recovery of hydrogen and heavy metals; after 24h reaction, the removal rate of Cu ²⁺ was 95% %, the removal rate of Ni was 78%, and the maximum cumulative hydrogen production was 136mL/100mL.

Example 2:

(1) Collect the bacterial suspension in the microbial primary battery reactor cultivated with sodium acetate, and mix the bacterial suspension with the nutrient solution in a volume ratio of 1:15 to obtain the anode chamber electrolyte, and the nutrient solution contains 4g/L acetic acid. Sodium 70mL/L phosphate buffer solution (50mM, pH=7), 0.4g/L ammonium chloride, 0.2g/L potassium chloride, 0.3g/L sodium chloride, 0.1g/L iron sulfate, 0.5g/L Aqueous solution of L manganese sulfate and 0.02g/L copper sulfate;

The bacterial suspension comes from a microbial primary battery reactor with acetate as a culture solution, the reactor is divided into an anode compartment and a cathode compartment by a proton exchange membrane, and the anode and the cathode are placed in the anode compartment and the cathode compartment respectively, Activated sludge and nutrient solution (containing 4g/L sodium acetate, 0.4g/L ammonium chloride, 0.2g/L potassium chloride, 0.3g/L potassium chloride, 0.3g /L sodium chloride, 0.1g/L ferric sulfate, 0.5g/L manganese sulfate, 0.02g/L copper sulfate aqueous solution) was added to the reactor, and at the same time 11% of the mixture was added with pH7, 50mM phosphate buffer mixed The reactor is connected with a 1000 ohm resistor, and the reaction is carried out at room temperature and under anaerobic conditions. When the voltage generated by the reactor drops to 0.01V, replace the mixed substrate in the reactor to complete a reaction cycle. When the voltage is above 0.1 V for three consecutive reaction cycles, the reaction solution in the reactor can be taken as the bacterial suspension;

(2) A bipolar membrane (Zhejiang Lanji Membrane Technology Co., Ltd.) was used to separate the reactor into an anode chamber and a cathode chamber, the anode and cathode were placed in the anode chamber and the cathode chamber respectively, and the mixture in step (1) was used in the anode chamber as an electrolysis The cathode chamber uses 50mM, pH=7 phosphate buffer solution as the electrolyte, the reactor is powered on, and the electrolyte in the anode chamber and the cathode chamber is replaced once a day. When the anode potential is stabilized above 0.24V for 3 times, the anode pretreatment is completed. ;

(3) Replace the electrolyte in the anode chamber of the reactor in step (2) with aquaculture wastewater, wherein the carbon source content is 378 mg/L, and the electrolyte in the cathode chamber is replaced with heavy metal-containing acid wastewater from a silver mine in Yunnan (Ag ⁺ concentration is 9 g/L), under nitrogen and 0.7V, anaerobic treatment of acid sewage containing heavy metals, recovery of hydrogen and heavy metals; after 24 hours of reaction, the removal rate of Ag ⁺ was 96%, and the maximum cumulative hydrogen production obtained was 122mL/100mL.

Example 3:

(1) Collect the bacterial suspension in the microbial primary battery reactor cultivated with sodium acetate, and mix the bacterial suspension (the same source as in Example 1) with the nutrient solution at a volume ratio of 1:15 to obtain an electrolyte in the anode chamber. The solution contains 5g/L sodium acetate 50mL/L phosphate buffer solution (50mM, pH=7), 0.35g/L ammonium chloride, 0.15g/L potassium chloride, 0.4g/L sodium chloride, 0.25g/L L ferric sulfate, 0.7g/L manganese sulfate, 0.03g/L copper sulfate aqueous solution;

(2) A bipolar membrane (Zhejiang Lanji Membrane Technology Co., Ltd.) was used to separate the reactor into an anode chamber and a cathode chamber, the anode and cathode were placed in the anode chamber and the cathode chamber respectively, and the mixture in step (1) was used in the anode chamber as an electrolysis The cathode chamber uses 50mM, pH=7 phosphate buffer solution as the electrolyte, the reactor is powered on, and the electrolyte in the anode chamber and the cathode chamber is replaced once a day. When the anode potential is stabilized above 0.24V for 3 times, the anode pretreatment is completed. ;

(3) Replace the electrolyte in the anode chamber of the reactor in step (2) with leather wastewater, in which the carbon source content is 400 mg/L, and the electrolyte in the cathode chamber is replaced with acid wastewater (Fe ²⁺ ) containing heavy metals from an iron mine in Guizhou. The content of 12 g/L), under nitrogen and 1V, anaerobic treatment of acid sewage containing heavy metals, recovery of hydrogen and heavy metals;

After 24 h of reaction, the removal rate of Fe ²⁺ was 84%, and the maximum cumulative hydrogen production was 113 mL/100 mL.

Claims (7)

1. a kind of method of the processing of sour water containing heavy metal coproduction new energy, it is characterised in that: specific step is as follows,

(1) anode pre-processes

Reactor is divided by anode chamber and cathode chamber using Bipolar Membrane, anode and cathode is respectively placed in anode chamber and cathode chamber It is interior, use the mixture of bacterial suspension and nutrient solution as electrolyte in anode chamber, cathode chamber use phosphate buffer solution as Electrolyte, be powered operation reactor, the electrolyte of replacement in one day an anode chamber and cathode chamber, when anode potential stabilization exists 0.24V or more 3 times, complete anode pretreatment；

(2) electrolyte in step (1) reactor anode chamber is replaced with into high concentration organic sewage, wherein carbon source content is not less than 300mg/L, cathode chamber electrolyte replace with sour water containing heavy metal, and under nitrogen, application voltage conditions, Anaerobic Treatment is containing weight Metal sour water recycles hydrogen and heavy metal.

2. the method for the processing of sour water containing heavy metal coproduction new energy according to claim 1, it is characterised in that: step (1) nutrient solution is to include 3-5g/L sodium acetate, 50-100mL/L phosphate buffer solution, 0.3-0.4g/L ammonium chloride, 0.1- 0.2g/L potassium chloride, 0.2-0.4g/L sodium chloride, 0.1-0.25g/L ferric sulfate, 0.4-0.7g/L manganese sulfate, 0.01-0.03g/L The volume ratio 1:5-30 of the aqueous solution of copper sulphate, bacterial suspension and nutrient solution.

3. the method for the processing of sour water containing heavy metal coproduction new energy according to claim 1 or 2, it is characterised in that: Phosphate buffer solution concentration is 50mM, pH=7.

4. the method for the processing of sour water containing heavy metal coproduction new energy according to claim 1, it is characterised in that: pass through Electrode applies voltage 0.45-1V.

5. the method for the processing of sour water containing heavy metal coproduction new energy according to claim 1, it is characterised in that: highly concentrated Degree organic sewage is sanitary sewage, industrial wastewater or sugar production wastewater.

6. the method for the processing of sour water containing heavy metal coproduction new energy according to claim 1, it is characterised in that: bacterium Suspension is from using acetate as the microorganism galvanic interaction device of culture solution, using acetate as the former electricity of the microorganism of culture solution Pond reactor is that reactor is divided into anode chamber and cathode chamber with proton exchange membrane, anode and cathode be respectively placed in anode chamber and In cathode chamber, the ratio of 1:3-5 reacts the activated sludge for being derived from secondary sedimentation tank of sewage treatment work with nutrient solution addition in mass ratio In device, while the phosphate buffer that pH7,50mM of mixture quality 8-12% is added mixes, the external 1000 ohm of electricity of reactor Resistance, is reacted under room temperature, anaerobic condition, when the voltage that reactor generates is down to 0.01V, mixes bottom in replacement reactor Object completes a reaction time, when the ceiling voltage that reactor generates is in 0.1 V or more and continuous three reaction times, reaction Reaction solution in device is used as bacterial suspension.

7. the method for the processing of sour water containing heavy metal coproduction new energy according to claim 6, it is characterised in that: nutrition Liquid is to contain 3-5g/L sodium acetate, 0.3-0.4g/L ammonium chloride, 0.1-0.2g/L potassium chloride, 0.2-0.4g/L sodium chloride, 0.1- 0.25g/L ferric sulfate, 0.4-0.7g/L manganese sulfate, 0.01-0.03g/L copper sulphate aqueous solution.