Plant microbial fuel cell in paddy field : A power source for rural area

As an energy carrier, electricity access is one of important aspect for human development. There is a positive correlation between electricity consumption per capita and human development index (HDI) and also gross domestic product (GDP).  However, the world electrification is not equally distributed. Most of those who do not have electricity access live in rural areas and located in developing countries. In these area, some people use polluted kerosene lamps as their light source or expensive gasoline generator as their electricity source. Other than that, battery is also widely used as a power source. In addition to the unequal electrification, the world electricity generation is still dominated by fossil fuel sources that have a negative impact on the environment, increased health risk and global climate change. Therefore, it is important to shift from conventional energy source to low-carbon renewable electricity sources. This thesis “Plant Microbial Fuel Cell in Paddy Field: a power source for rural area“ aims to assess the applicability of the plant  microbial fuel cell (Plant-MFC) as a low power off-grid power source in a rural area for a theoretical Indonesian case. To achieve this, a technical design was made for a household in rural area of Indonesia based on the latest research developments. Then, the applicability was assessed on technical, social, and environmental safety and health criteria as well as economics and some scenarios were suggested which could improve the real application. Values for a plant-MFC system to fulfil basic electricity needs were calculated. The main highlights and findings on this work are summarized in accordance with the chapters outlined in this thesis as following. Chapter 2 “Marine Sediment Mixed with Activated Carbon Allows Electricity Production and Storage from Internal and External Energy Sources: A New Rechargeable Bio-Battery with Bi-Directional Electron Transfer Properties” investigates the abilities of marine sediment and activated carbon to store and generate electricity in a bio-battery. In this work, several mixture of marine sediment and activated carbon were studied in a bio electrochemical system (BES). When operated in the MFC mode, the system generated electricity with solely marine sediment as the anode electron donor, resulted in the creation of a bio-battery. The results show that by usage of marine sediment and activated carbon (AC) electricity was generated and stored. The internal electrical storage density is 0.3 mWh/kg AC marine anode.  These insights give opportunities to apply such BES systems as e.g. ex-situ bio-battery to store and use electricity for off-grid purpose in remote areas. Chapter 3 “Activated Carbon Mixed with Marine Sediment is Suitable as Bioanode Material for Spartina anglica Sediment/Plant Microbial Fuel Cell: Plant Growth, Electricity Generation, and Spatial Microbial Community Diversity” aims to investigate the suitability of a mixture of activated carbon and marine sediment as a bioanode in a plant-MFC system with Spartina anglica. This work focused on study how different mixtures of the activated carbon (AC) and the marine sediment (MS) as an anode material affected the plant vitality, electricity generation and spatial microbial community. Results show that Spartina anglica grew in all of the plant-MFCs, although the growth was less fertile in the 100% activated carbon Plant-MFC. On long-term (2 weeks) performance, mixture of 33% and 67% marine sediment outperformed other Plant-MFCs in terms of current density (16.1 mA/m2 plant growth area) and power density (1.04 mW/m2 plant growth area). Results also show a high diversity of microbial communities dominated by Proteobacteria and indicates that the bacterial communities were affected by the anode composition. These findings show that the mixture of activated carbon and marine sediment are suitable material for bioanodes and could be useful for the application of Plant-MFC in a real wetland. Chapter 4 “Performance and Long Distance Data Acquisition via LoRa Technology of a Tubular Plant Microbial Fuel Cell Located in a Paddy Field in West Kalimantan, Indonesia” provide an insight about the field performance of tubular Plant-MFC. In this study, one-meter tubular Plant-MFC with graphite felt anode and cathode were installed in triplicates in a paddy field for four rice growth seasons. An online data acquisition using LoRa technology was developed to investigate the performance of the tubular Plant-MFC over the final whole rice paddy growing season. The result revealed that the Plant-MFC do not negatively affect the rice growth. A continuous electricity generation was achieved during a wet period in the crop season. On average the Plant-MFC generated power of 6.6 mW/m2 plant growth area (0.4mW per meter tube). The Plant-MFC also shows a potential to be used as a bio sensor, e.g. rain event indicator, during a dry period between the crop seasons. Chapter 5 “A Thin Layer of Activated Carbon Deposited on Polyurethane Cube Leads to New Conductive Bioanode for (Plant) Microbial Fuel Cell” exploits the potential of electrochemically active self-assembled biofilms to fabricate three-dimensional bio electrodes for of (plant) microbial fuel cells with minimum use of electrode materials. For this purpose, polyurethane foams coated with activated carbon was prepared and studied as platform bio anodes for harvesting electric current in lab microbial fuel cells (MFCs) and field Plant-MFCs. Results show that electric conductivity of the PU/AC electrode enhance over time during bioanode development. The maximum current and power density of an acetate fed MFC reached 3mA/m2 projected surface area of anode compartment and 22mW/m3 anode compartment. The field test of the Plant-MFC reached a maximum performance of 0.9 mW/m2 plant growth area at a current density of 5.6 mA/ m2 PGA. A rice paddy field test showed that the PU/AC electrode was suitable as anode material in combination with a graphite felt cathode.  Finally, the main findings of this thesis are summarized and discussed in Chapter 6, “General Discussion”. In this chapter, a theoretical available power for Plant-MFC system from a paddy field is presented to give an insight how far performance of current Plant-MFC meets theoretical understanding. Based on the experimental results, this chapter answers the thesis goal to discuss the applicability of the Plant-MFC as an off-grid power source in a rural area by assessing its technical, economic, social, and environmental safety and health criteria. Finally, an outlook for future Plant-MFC application is provided

Marine Sediment Mixed With Activated Carbon Allows Electricity Production and Storage From Internal and External Energy Sources: A New Rechargeable Bio-Battery With Bi-Directional Electron Transfer Properties

Marine sediment has a great potential to generate electricity with a bioelectrochemical system (BES) like the microbial fuel cell (MFC). In this study, we investigated the potential of marine sediment and activated carbon (AC) to generate and store electricity. Both internal and external energy supply was validated for storage behavior. Four types of anode electrode compositions were investigated. Two types were mixtures of different volumes of AC and Dutch Eastern Scheldt marine sediment (67% AC and 33% AC) and the others two were 100% AC or 100% marine sediment based. Each composition was duplicated. Operating these BES’s under MFC mode with solely marine sediment as the anode electron donor resulted in the creation of a bio-battery. The recharge time of such bio-battery does depend on the fuel content and its usage. The results show that by usage of marine sediment and AC electricity was generated and stored. The 100% AC and the 67% AC mixed with marine sediment electrode were over long term potentiostatic controlled at -100 mV vs. Ag/AgCl which resulted in a cathodic current and an applied voltage. After switching back to the MFC operation mode at 1000 Ω external load, the electrode turned into an anode and electricity was generated. This supports the hypothesis that external supply electrical energy was recovered via bi-directional electron transfer. With open cell voltage experiments these AC marine bioanodes showed internal supplied electric charge storage up to 100 mC at short self-charging times (10 and 60 s) and up to 2.4°C (3,666 C/m3 anode) at long charging time (1 h). Using a hypothetical cell voltage of 0.2 V, this value represents an internal electrical storage density of 0.3 mWh/kg AC marine anode. Furthermore it was remarkable that the BES with 100% marine sediment based electrode also acted like a capacitor similar to the charge storage behaviors of the AC based bioanodes with a maximum volumetric storage of 1,373 C/m3 anode. These insights give opportunities to apply such BES systems as e.g., ex situ bio-battery to store and use electricity for off-grid purpose in remote areas

A thin layer of activated carbon deposited on polyurethane cube leads to new conductive bioanode for (plant) microbial fuel cell

Large-scale implementation of (plant) microbial fuel cells is greatly limited by high electrode costs. In this work, the potential of exploiting electrochemically active self-assembled biofilms in fabricating three-dimensional bioelectrodes for (plant) microbial fuel cells with minimum use of electrode materials was studied. Three-dimensional robust bioanodes were successfully developed with inexpensive polyurethane foams (PU) and activated carbon (AC). The PU/AC electrode bases were fabricated via a water-based sorption of AC particles on the surface of the PU cubes. The electrical current was enhanced by growth of bacteria on the PU/AC bioanode while sole current collectors produced minor current. Growth and electrochemical activity of the biofilm were shown with SEM imaging and DNA sequencing of the microbial community. The electric conductivity of the PU/AC electrode enhanced over time during bioanode development. The maximum current and power density of an acetate fed MFC reached 3 mA·m−2 projected surface area of anode compartment and 22 mW·m−3 anode compartment. The field test of the Plant-MFC reached a maximum performance of 0.9 mW·m−2 plant growth area (PGA) at a current density of 5.6 mA·m−2 PGA. A paddy field test showed that the PU/AC electrode was suitable as an anode material in combination with a graphite felt cathode. Finally, this study offers insights on the role of electrochemically active biofilms as natural enhancers of the conductivity of electrodes and as transformers of inert low-cost electrode materials into living electron acceptors.</p

Activated Carbon mixed with marine sediment suits as bioanode material for Spartina anglica Sediment/Plant Microbial Fuel Cell: plant growth, electricity generation and spatial less microbial community diversity

This study is part of paper: "Activated Carbon mixed with marine sediment suits as bioanode material for Spartina anglica Sediment/Plant Microbial Fuel Cell: plant growth, electricity generation and spatial microbial community diversity" In this study, eight lab-wetlands systems in the shape of flat-plate Plant-MFC were constructed. Spartina anglica model plant was planted in the anode chamber of the Plant-MFC reactors. Here, four wetlands compositions with activated carbon and/or marine sediment functioning as anodes were investigated for their suitability as a bioanode in a Plant-MFC system.Four different anode compositions were used to fill the anode compartments (650ml). Plant-MFC 1 and Plant-MFC 2, this duplicate was named as AC100, were filled with 100% activated carbon (AC); Plant-MFC 3 and Plant-MFC 4, this duplicate was named as MS100, were only filled with marine sediment; Plant-MFC 5 and Plant-MFC 6, this duplicate was named as AC67, were filled with a mixture of 67 % AC and 33% marine sediment; and Plant-MFC 7 and Plant-MFC 8, this duplicate was named as AC33, were filled with a mixture of 33% AC and 67% marine sediment. The utilized AC is granular activated carbon PK 1-3(Cabot Norit Netherlands BV, with apparent density of 290 g/L)At the end of the experiment (day 190), about 3 ml biomass samples from anode components (mixture of marine sediment, AC and plant roots) were taken for DNA analysis. Samples were taken from the MS100 (Plant-MFC 3 & Plant-MFC 4) and the AC33 (Plant-MFC 7 & Plant-MFC 8). For every reactor, five biomass samples were collected. Biomass samples were taken from five different locations in the anode. These five sample locations were clustered in two zones: upper zone (until 5cm below the anode surface) and lower zone (from 5 until 20 cm below the anode surface). The upper zone(UZ) sample points were (A) UZ-AN (anode) and (C) UZ-CC (current collector). The lower zone sample points were (B) LZ-RO (roots), (D) LZ-AN (anode), and (E) LZ-CC (current collector). In the MS100 plant-MFC, the anode biomass samples (UZ-AN and LZ-AN) contained marine sediment; the current collector biomass samples (UZ-CC and LZ-CC) contained marine sediment that were attached on the current collector. While, in the AC33 plant-MFC, the anode biomass samples (UZ-AN and LZ-AN) contained AC and marine sediment; the current collector biomass samples (UZ-CC and LZ-CC) contained AC and marine sediment that were attached on the current collector. In total 20 samples were collected. The samples were stored immediately in -80 Centigrade freezer after collection before the DNA sequencing was performed.Further detail information can be found in the above mentioned paper

Soil Microbial Communities on the anode and 2-m distance of Tubular Plant Microbial Fuel Cell in a Paddy Field in West Kalimantan, Indonesia

Soil samples were collected (on 30 June 2018) from 6 different locations for microbial community analysis from a paddy field in West Kalimantan, Indonesia (0.919215N, 109.468182E; elevation 100m above sea level). Sample A: Soil that attached on the anode from mid of Plant-MFC 1Sample B: soil that attached on the anode from end of the plant-MFC 1Sample C: Soil that attached on the anode from mid of Plant-MFC 2Sample D: soil that attached on the anode from end of the plant-MFC 2Sample E: soil from 2 m distance at northen side of plant-MFC 1 & 2Sample F: soil from 2 m distance at southern side of plant-MFC 1 & 2Samples were grouped into 3: Group I (Samples A and C) was soil that attached on the anode from mid plant-MFC; Group II (samples B and D) was soil that attached on the anode from end of the plant-MFC; and Group III (samples E and F) was from soil with 2 m distance from plant-MFC 1 and 2. After collection, samples were kept in a 30ml-tube container and keep in 40C fridge. The next day samples were transported for 48hours with a cool-ice box for DNA extraction to Genetika Lab, Jakarta (PT. Genetika Science Indonesia), a partner company from 1st BASE Axil Scientific Pte Ltd, Singapore. Sequencing steps were performed by 1st BASEas following: the universal primers that targeted the V3V4 regions were used for amplification. The quantity and quality of the PCR product that targeted the V3V4 regions were measured using Tapestation 4200, picogreen and nanodrop. All the samples passed the QC measurement and proceed straight for a library preparation. The libraries were prepared using Illumina 16s metagenomics library prep kit and their quality and quantity were determine using Agilent Tapestation 4200, Picogreen and qPCR. These libraries were then pooled according to the protocol recommended by the Illumina and proceed straight to sequencing using MiSeq platform at 2x301PE format by 1st BASE Axil Scientific Pte Ltd, Singapore

Marine Sediment Mixed With Activated Carbon Allows Electricity Production and Storage From Internal and External Energy Sources: A New Rechargeable Bio-Battery With Bi-Directional Electron Transfer Properties

Marine sediment has a great potential to generate electricity with a bioelectrochemical system (BES) like the microbial fuel cell (MFC). In this study, we investigated the potential of marine sediment and activated carbon (AC) to generate and store electricity. Both internal and external energy supply was validated for storage behavior. Four types of anode electrode compositions were investigated. Two types were mixtures of different volumes of AC and Dutch Eastern Scheldt marine sediment (67% AC and 33% AC) and the others two were 100% AC or 100% marine sediment based. Each composition was duplicated. Operating these BES’s under MFC mode with solely marine sediment as the anode electron donor resulted in the creation of a bio-battery. The recharge time of such bio-battery does depend on the fuel content and its usage. The results show that by usage of marine sediment and AC electricity was generated and stored. The 100% AC and the 67% AC mixed with marine sediment electrode were over long term potentiostatic controlled at -100 mV vs. Ag/AgCl which resulted in a cathodic current and an applied voltage. After switching back to the MFC operation mode at 1000 Ω external load, the electrode turned into an anode and electricity was generated. This supports the hypothesis that external supply electrical energy was recovered via bi-directional electron transfer. With open cell voltage experiments these AC marine bioanodes showed internal supplied electric charge storage up to 100 mC at short self-charging times (10 and 60 s) and up to 2.4∘C (3,666 C/m3 anode) at long charging time (1 h). Using a hypothetical cell voltage of 0.2 V, this value represents an internal electrical storage density of 0.3 mWh/kg AC marine anode. Furthermore it was remarkable that the BES with 100% marine sediment based electrode also acted like a capacitor similar to the charge storage behaviors of the AC based bioanodes with a maximum volumetric storage of 1,373 C/m3 anode. These insights give opportunities to apply such BES systems as e.g., ex situ bio-battery to store and use electricity for off-grid purpose in remote areas

Activated carbon mixed with marine sediment is suitable as bioanode material for Spartina anglica sediment/plant microbial fuel cell: Plant growth, electricity generation, and spatial microbial community diversity

Wetlands cover a significant part of the world's land surface area. Wetlands are permanently or temporarily inundated with water and rich in nutrients. Therefore, wetlands equipped with Plant-Microbial Fuel Cells (Plant-MFC) can provide a new source of electricity by converting organic matter with the help of electrochemically active bacteria. In addition, sediments provide a source of electron donors to generate electricity from available (organic) matters. Eight lab-wetlands systems in the shape of flat-plate Plant-MFC were constructed. Here, four wetland compositions with activated carbon and/or marine sediment functioning as anodes were investigated for their suitability as a bioanode in a Plant-MFC system. Results show that Spartina anglica grew in all of the Plant-MFCs, although the growth was less fertile in the 100% activated carbon (AC100) Plant-MFC. Based on long-term performance (2 weeks) under 1000 ohm external load, the 33% activated carbon (AC33) Plant-MFC outperformed the other Plant-MFCs in terms of current density (16.1 mA/m2 plant growth area) and power density (1.04 mW/m2 plant growth area). Results also show a high diversity of microbial communities dominated by Proteobacteria with 42.5-69.7% relative abundance. Principal Coordinates Analysis shows clear different bacterial communities between 100% marine sediment (MS100) Plant-MFC and AC33 Plant-MFC. This result indicates that the bacterial communities were affected by the anode composition. In addition, small worms (Annelida phylum) were found to live around the plant roots within the anode of the wetland with MS100. These findings show that the mixture of activated carbon and marine sediment are suitable material for bioanodes and could be useful for the application of Plant-MFC in a real wetland. Moreover, the usage of activated carbon could provide an additional function like wetland remediation or restoration, and even coastal protection.</p

Soil Microbial Communities on the anode and 2-m distance of Tubular Plant Microbial Fuel Cell in a Paddy Field in West Kalimantan, Indonesia

Soil samples were collected (on 30 June 2018) from 6 different locations for microbial community analysis from a paddy field in West Kalimantan, Indonesia (0.919215N, 109.468182E; elevation 100m above sea level). Sample A: Soil that attached on the anode from mid of Plant-MFC 1Sample B: soil that attached on the anode from end of the plant-MFC 1Sample C: Soil that attached on the anode from mid of Plant-MFC 2Sample D: soil that attached on the anode from end of the plant-MFC 2Sample E: soil from 2 m distance at northen side of plant-MFC 1 & 2Sample F: soil from 2 m distance at southern side of plant-MFC 1 & 2Samples were grouped into 3: Group I (Samples A and C) was soil that attached on the anode from mid plant-MFC; Group II (samples B and D) was soil that attached on the anode from end of the plant-MFC; and Group III (samples E and F) was from soil with 2 m distance from plant-MFC 1 and 2. After collection, samples were kept in a 30ml-tube container and keep in 40C fridge. The next day samples were transported for 48hours with a cool-ice box for DNA extraction to Genetika Lab, Jakarta (PT. Genetika Science Indonesia), a partner company from 1st BASE Axil Scientific Pte Ltd, Singapore. Sequencing steps were performed by 1st BASEas following: the universal primers that targeted the V3V4 regions were used for amplification. The quantity and quality of the PCR product that targeted the V3V4 regions were measured using Tapestation 4200, picogreen and nanodrop. All the samples passed the QC measurement and proceed straight for a library preparation. The libraries were prepared using Illumina 16s metagenomics library prep kit and their quality and quantity were determine using Agilent Tapestation 4200, Picogreen and qPCR. These libraries were then pooled according to the protocol recommended by the Illumina and proceed straight to sequencing using MiSeq platform at 2x301PE format by 1st BASE Axil Scientific Pte Ltd, Singapore

Soil Microbial Communities on the anode and 2-m distance of Tubular Plant Microbial Fuel Cell in a Paddy Field in West Kalimantan, Indonesia

Soil samples were collected (on 30 June 2018) from 6 different locations for microbial community analysis from a paddy field in West Kalimantan, Indonesia (0.919215N, 109.468182E; elevation 100m above sea level). Sample A: Soil that attached on the anode from mid of Plant-MFC 1Sample B: soil that attached on the anode from end of the plant-MFC 1Sample C: Soil that attached on the anode from mid of Plant-MFC 2Sample D: soil that attached on the anode from end of the plant-MFC 2Sample E: soil from 2 m distance at northen side of plant-MFC 1 & 2Sample F: soil from 2 m distance at southern side of plant-MFC 1 & 2Samples were grouped into 3: Group I (Samples A and C) was soil that attached on the anode from mid plant-MFC; Group II (samples B and D) was soil that attached on the anode from end of the plant-MFC; and Group III (samples E and F) was from soil with 2 m distance from plant-MFC 1 and 2. After collection, samples were kept in a 30ml-tube container and keep in 40C fridge. The next day samples were transported for 48hours with a cool-ice box for DNA extraction to Genetika Lab, Jakarta (PT. Genetika Science Indonesia), a partner company from 1st BASE Axil Scientific Pte Ltd, Singapore. Sequencing steps were performed by 1st BASEas following: the universal primers that targeted the V3V4 regions were used for amplification. The quantity and quality of the PCR product that targeted the V3V4 regions were measured using Tapestation 4200, picogreen and nanodrop. All the samples passed the QC measurement and proceed straight for a library preparation. The libraries were prepared using Illumina 16s metagenomics library prep kit and their quality and quantity were determine using Agilent Tapestation 4200, Picogreen and qPCR. These libraries were then pooled according to the protocol recommended by the Illumina and proceed straight to sequencing using MiSeq platform at 2x301PE format by 1st BASE Axil Scientific Pte Ltd, Singapore