AU2021103475A4

AU2021103475A4 - A method and system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell

Info

Publication number: AU2021103475A4
Application number: AU2021103475A
Authority: AU
Inventors: Rajeshbanu Jeyakumar; Gopalakrishnan KUMAR; Devi Selvaraj; Adishkumar Somanathan
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-06-19
Filing date: 2021-06-19
Publication date: 2022-03-24
Anticipated expiration: 2029-06-19

Abstract

The present disclosures relates to method and system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell. In the present disclosure a stable current along with the COD removal is successfully achieved using the dual chamber MFC treatment system. The MFC consists of electrodes, anodic and cathodic chamber, and salt bridge or proton exchange membrane (PEM). This treatment system has produced a maximum power density of 146 and 152 mWm-2 with coulombic energy of 25% and 60% for pretreated latex processing and production wastewater respectively. The treatment efficiency of 96% and 88.5% COD removal was achieved for pretreated latex processing and production wastewater respectively. The proposed MFC treatment generated electrical energy of 1.57 and 1.04 Wh/L for latex processing and production wastewater respectively and the energy is utilized to drive the electro-Fenton rector. 13 0 -0 0 NC7 0 u L 00 $- U0 L 0 0- 4-1 4- 4-D x ~ cu E m L E r CO > 0) ~ ~ s ocu

Description

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A METHOD AND SYSTEM FOR GENERATING ELECTRICITY BY DEGRADATION OF PRETREATED LATEX WASTEWATER USING DOUBLE CHAMBER MICROBIAL FUEL CELL FILED OF THE INVENTION

The present disclosure relates to a method and system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell.

BACKGROUND OF THE INVENTION

The increasing amount of the industries causing a problem of larger amount of wastewater and due to that it has become a great challenge to treat that water. The current trend of the global energy supply and consumption are not suitable to the ecosystem, economy and society. The global demand of energy is expected to grow by 30% by 2040. Due to rising energy demand, the world has recognized the need of renewable energy to uphold sustainable economic growth. The cost of current well known sources of renewable energy is really expensive such as hydro, wind and biomass. The higher demand of renewable energy has increased the researcher's attentions.

Microbial fuel cell (MFC) is an environmental-friendly and promising technology on the generation of renewable energy from the industrial wastewater. MFC transforms the chemical energy into electrical energy during the process of degradation and use some selective microorganisms as catalyst. The MFC process is generally performed under anaerobic condition.

However, the discharge of large volumes of wastewater from the industries to environment poses lot of danger to environment, and also there is increasing demand of energy and due to that there is need for effective renewable energy source. Therefore there is need for a method and system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell.

SUMMARY OF THE INVENTION

The present disclosure relates to a method and system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell. In the present invention a double chamber microbial fuel cell (MFC) reactor with anode and cathode chamber which are separated by a nafion proton exchange membrane is developed and the performance for the treatment of electro fenton pretreated latex wastewater is evaluated. The wastewater contains chemical oxygen demand (COD) of 2660 and 780 mgL for latex processing and production of wastewater respectively. After 12 days, MFC treatment, the COD reduces to 133 mg/L (96%) and 86 mg/L (88.5%) for latex processing and production wastewater respectively, The proposed system generated electric energy of 1.57 and 1.04 Wh/L for latex processing and production wastewaters respectively. The generated energy is utilized to drive the electro-fenton reactor. The results indicated that the effective wastewater treatment, energy production and discharge standards could be obtained in the system.

The present disclosure seeks to provide a system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell. The system comprises: a double chamber microbial fuel cell (MFC) reactor for treatment of electro Fenton pretreated latex processing and production wastewater comprises of: a anode chamber of working volume of 750 mL and length and diameter of 0.15m and 0.08m respectively and provided with three ports; a cathode chamber of working volume of 750 mL and length and diameter of 0.15m and 0.08m respectively and provided into two ports; a salt bridge or proton exchange membrane (PEM) to separate the anode chamber and cathode chamber; a activated carbon fiber felt of size 0.13 x 0.07m used as both cathode and anode electrode spaced at a distance of 0.05m; and an external circuit containing a multimeter which measures the voltage and current and a single resistor connected with two electrodes via copper wire.

The present disclosure also seeks to provide a method for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell. The method comprises: collecting the anaerobic sludge in the municipal wastewater treatment plant; feeding the latex wastewater through a injection port or inlet port of the anode chamber using peristaltic pump; adding 2mM bromoethanesulfonate in the anode chamber to prevent the methanogenic bacterial growth; maintaing the pH of wastewater in the range of 7.03-7.17 in the MFC; establishing a external circuit by connecting a multimeter to measure the voltage and current across the cell; monitoring the developed voltage in the fuel cell periodically using a digital mulimeter; and conducting the polarization study after attaining a state of stable power generation.

An objective of the present disclosure is to provide a method and system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell.

Another object of the present disclosure is to develop a double microbial fuel cell reactor with anode and cathode chamber.

Another object of the present disclosure is to evaluate the performance for treatment of electro fenton pretreated latex processing and production wastewater.

Another object of the present disclosure is to reduce the chemical oxygen demand (COD) for latex processing and production wastewater.

Another object of the present disclosure is to generate electrical energy using MFC treatment.

Another object of the present disclosure is to used the generated electrical energy to drive the electro-fenton reactor.

To further clarify advantages and features of the present disclosure, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF FIGURES

These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

Figure 1 illustrates a block diagram of a system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell in accordance with an embodiment of the present disclosure;

Figure 2 illustrates a flow chart of a method for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell in accordance with an embodiment of the present disclosure;

Figure 3 illustrates the experimental setup of dual chamber MFC in accordance with an embodiment of the present disclosure;

Figure 4 illustrates the performance of MFC treatment on pretreated latex processing and production wastewater in accordance with an embodiment of the present disclosure;

Figure 5 illustrates the generation of current from the MFC treatment of pretreated latex processing and production wastewater in accordance with an embodiment of the present disclosure;

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present disclosure. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises...a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

Embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings.

Figure 1 illustrates a block diagram of a system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell in accordance with an embodiment of the present disclosure. The system 100 consists of a double chamber microbial fuel cell (MFC) 102 reactor for treatment of electro Fenton pretreated latex processing and production wastewater wherein the MFC comprises of: a anode chamber 104 of working volume of 750 mL and length and diameter of 0.15m and 0.08m respectively and provided with three ports; a cathode chamber 106 of working volume of 750 mL and length and diameter of 0.15m and 0.08m respectively and provided into two ports; a salt bridge or proton exchange membrane (PEM) 108 to separate the anode chamber and cathode chamber; a activated carbon fiber felt 110 of size 0.13 x 0.07m used as both cathode and anode electrode spaced at a distance of 0.05m; and an external circuit 112 containing a multimeter which measures the voltage and current and a single resistor connected with two electrodes via copper wire.

Figure 2 illustrates a flow chart of a method for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell in accordance with an embodiment of the present disclosure. At step 202 the method 200 includes, collecting the anaerobic sludge in the municipal wastewater treatment plant. The anaerobic sludge contains highly various bacterial consortia consisting electrochemically active strains of bacteria and used for inoculation to oxidize organic matter and generate electric potential and is acclimated at the organic loading rate of 250 mg COD/L and sequentially increased to 2660 mg COD/L for the period of 30 days.

At step 204 the method 200 includes, feeding the latex wastewater through an injection port or inlet port of the anode chamber using peristaltic pump. The anode chamber is sealed with a cork which is impermeable to atmospheric oxygen.

At step 206 the method 200 includes, adding 2mM bromoethanesulfonate in the anode chamber to prevent the methanogenic bacterial growth.

At step 208 the method 200 includes, maintaining the pH of wastewater in the range of 7.03-7.17 in the MFC. The MFC is operated at room temperature varying from 33 to 37 °C and their performance & effectiveness in term of power generation depends on factors such as pH of anolyte/ catholyte, temperature, materials of anode/cathode, membrane type, and etc.

At step 210 the method 200 includes, establishing a external circuit by connecting a multimeter to measure the voltage and current across the cell. The external circuit contains a multimeter which measures the voltage and current and a single resistor connected with two electrodes via copper wire. The average potential assessed for 17 days and 12 days for the processing and production of wastewater respectively.

At step 212 the method 200 includes, monitoring the developed voltage in the fuel cell periodically using a digital multimeter.

At step 214 the method 200 includes, conducting the polarization study after attaining a state of stable power generation. The term "polarization" is the transformation of electrode potential from its steady state of equilibrium due to a flow of current.

Figure 3 illustrates the experimental setup of dual chamber MFC in accordance with an embodiment of the present disclosure. The MFC is developed with an anode chamber and a cathode chamber and those chambers are of working volume 750 mL and they are separated by a nafion proton exchange membrane (PEM). The length and the diameter of anode and cathode chamber are 0.15m and 0.08 respectively. The anode chamber is divided in three ports i.e. inlet port, outlet port and port of electrode and in cathode chamber two ports are provided at the top, one is for aeration and other is for electrode. In the cathode chamber a phosphate buffer containing NH 4 Cl, NaH 2 PO 4 H20, Na 2HPO4H2 0, KCl, minerals, and vitamins solution is used as catholyte in the cathode chamber and it is aerated at the rate of 1 L/min using an aquarium aerator to provide dissolved oxygen of 4mg/L at the cathode. The nafion is used as a proton exchange membrane between anode and cathode chamber. Activated carbon fiber felt of size 0.13 x 0.07m is used as both anode and cathode electrode. Both the electrodes are spaced at a distance of 10.05m and were connected via copper wire to an external circuit containing a single resistor.

Figure 4 illustrates the performance of MFC treatment on pretreated latex processing and production wastewater in accordance with an embodiment of the present disclosure. The figure (a) represents the pretreated latex processing and figure (b) represents the pretreated latex production. The degradation efficiency in terms of COD removal for both latex processing and production wastewater is shown in this figure. The initial COD of electron-fenton treated effluent was 2660 and 780 mg/L for latex processing and production wastewater. After the treatment the COD reduced to 133 mg/L (96%) and 86 mg/L(88.5%) was achieved for latex processing and production wastewater respectively. These results established that latex wastewater could produce electricity in the MFC during the degradation of organic matters.

Figure 5 illustrates the generation of current from the MFC treatment of pretreated latex processing and production wastewater in accordance with an embodiment of the present disclosure. The figure (a) represents the pretreated latex processing and figure (b) represents the pretreated latex production. The total current recovered from MFC was calculated every day for both processing and production sector wastewater and graphically represented in these figures. The total coloumbic energy recovered from the MFC was obtained by multiplying the average current generated with time for both latex processing and production wastewater as 5787 and 3768 C. The total coulombic energy available was 23250 and 6249 C for latex processing and production wastewater respectively. The CE of latex processing and production wastewater was % and 60% respectively.

The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.

Claims

WE CLAIM

1. A system for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell, the system comprises:

a double chamber microbial fuel cell (MFC) reactor for treatment of electro Fenton pretreated latex processing and production wastewater comprises of:

an anode chamber of working volume of 750 mL and length and diameter of 0.15m and 0.08m respectively and provided with three ports;

a cathode chamber of working volume of 750 mL and length and diameter of 0.15m and 0.08m respectively and provided into two ports;

a salt bridge or proton exchange membrane (PEM) to separate the anode chamber and cathode chamber;

an activated carbon fiber felt of size 0.13 x 0.07m used as both cathode and anode electrode spaced at a distance of 0.05m; and

an external circuit containing a multimeter which measures the voltage and current and a single resistor connected with two electrodes via copper wire.

2. The system as claimed in claim 1, wherein said MFC is operated at room temperature varying from 33 to 37 °C and their performance & effectiveness in term of power generation depends on factors such as pH of anolyte/catholyte, temperature, materials of anode/cathode, membrane type, and etc.

3. The system as claimed in claim 1, wherein the three ports in anode chamber are inlet port, outlet port for samples, and a port for electrode.

4. The system as claimed in claim 1, wherein the two ports are provided at the top in the cathode chamber, one is for aeration and the other is for electrode.

5. The system as claimed in claim 1, wherein a phosphate buffer containing NH 4 Cl

4.H 20 (2.75 g/L ), KCl (0.13 g/L ), and (0.31g/L), NaH 2 PO 4 H20 (4.97 g/L), Na 2HPO minerals (12.5 mL) and vitamins (12.5 mL) solution is used as catholyte in the cathode chamber

6. The system as claimed in claim 1, wherein, a latex wastewater is used as anolyte in the anode chamber which is inoculated with anaerobic sludge.

7. The system as claimed in claim 4, wherein the catholyte is continuously aerated at a rate of iL/min using an aquarium aerator to provide dissolved oxygen of 4mg/L at the cathode.

8. The system as claimed in claim 1 , wherein a nafion 117 of size 0.05 x0.05m is used as the proton exchange membrane (PEM) between the cathode and anode chamber, wherein the nafion was pretreated and stored in deionized water.

9. A method for generating electricity by degradation of pretreated latex wastewater using double chamber microbial fuel cell, the method comprises:

collecting the anaerobic sludge in the municipal wastewater treatment plant;

feeding the latex wastewater through an injection port or inlet port of the anode chamber using peristaltic pump;

adding 2mM bromoethanesulfonate in the anode chamber to prevent the methanogenic bacterial growth;

maintaining the pH of wastewater in the range of 7.03-7.17 in the MFC; establishing the external circuit by connecting a multimeter to measure the voltage and current across the cell; monitoring the developed voltage in the fuel cell periodically using a digital mulimeter; and conducting the polarization study after attaining a state of stable power generation, wherein the method is performed at room temperature and left undisturbed, wherein a batch configuration was employed and the rise and decline were taken at 3 hour interval for the entire period and averaged for every day, and wherein the average potential assessed for 17 days and 12 days for the processing and production of wastewater respectively.

10. The method as claimed in claim 9, wherein the anaerobic sludge contains highly various bacterial consortia consisting electrochemically active strains of bacteria and used for inoculation to oxidize organic matter and generate electric potential, wherein the anaerobic sludge is acclimated at the organic loading rate of 250 mg COD/L and sequentially increased to 2660 mg COD/L for the period of 30 days, wherein a cork is used to seal the anode chamber and is impermeable to atmospheric oxygen.

Double chamber MFC 102

anode chamber 104

cathode chamber 106

salt bridge 108

activated carbon fiber felt 110

external circuit 112

Figure 1

Figure 3