Process information
| Key Data Set Information | |
| Location | IT |
| Geographical representativeness description | This study is based on indoor experiments, where the author's hometown is filled in. |
| Reference year | 2023 |
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| Use advice for data set | When utilizing data from this study, consider its laboratory-scale context and the exclusion of maintenance and inoculum cultivation in the assessment. The findings should be applied cautiously outside of laboratory conditions, with considerations to scale-up processes which may require more consumables, materials, and energy input. Researchers must also validate the applicability of MET process in in-situ conditions and assess the system's robustness over a longer timeframe and variable environmental conditions. It is advisable to investigate the environmental impact comprehensively including the use phase behavior and end-of-life scenarios when scaling up. |
| Technical purpose of product or process | The double-chambered MET described is primarily used for laboratory-scale research, focusing on the remediation of soil contaminated with total petroleum hydrocarbons (TPH). This MET process is specifically designed for the bioelectrochemical treatment of TPH polluted soil, showing potential for application in environmental engineering, particularly soil remediation. Its use in analytical or pilot studies can provide insights into the feasibility of microbial electrochemical technologies for degrading harmful environmental contaminants, particularly hydrocarbons in soil. |
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| General comment on data set | Microbial electrochemical technologies (MET) are a bioelectrochemical system that uses microbial catalytic (metabolic) activity to convert the chemical energy of organic compounds into electrical energy. The doublechambered MET is a type of MET with an anode and cathode separated by a proton exchange membrane. Electrons and protons are produced in the anode chamber when microorganisms metabolize chemicals (the substrate) through oxidation reactions. The ion-selective permeable membrane (in this case, the soil itself) allows the protons generated by micro bial oxidation to pass through into the cathode chamber. Meanwhile, the microorganisms' released electrons are gathered by the anode and flow through an external circuit into the cathode, where they are absorbed and reduced by chemical species with high positive redox potentials, such as oxygen, ferricyanide, and other oxidizing chemical agents. |
| Copyright | No |
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| Functional Unit | The functional unit for this study is related to treated soil polluted with petroleum hydrocarbons using MET (100 g, 0.5 kWh). The initial concentration of total petroleum hydrocarbons is 4500 mg/kg. |
| Technological representativeness | |
| Technology description including background system | A double chamber BES microbial electrochemical technology (MET) was used based on previous studies (Ambaye et al., 2022a, 2022b, 2022c, 2022d). Moreover, two similar Plexi-glass bottles were detached by a cation exchange membrane (CEM) with an inner diameter of 7 cm, having 250 mL volume with a working volume space of 200 mL was used. Two rubber gaskets with a metal clip holder for glass bottles were used to keep the bioreactor air-tight. The anode (graphite) and cathode (titanium) electrodes (6 cm length, 5 cm width) were utilized. These electrodes were fastened with titanium electric wires wrapped with a heat-shrink tube. Ag/AgCl assay was employed as a reference electrode. Anolyte media was poured into the anode chamber. In the cathode chamber, sterile phosphate buffer (0.5 M PBS) solution having (i) Na2HPO4∙12H2O, 7.56 g L−1 ; (ii) KH2PO4, 1.5 g L−1 ; (iii) 0.31 g L−1 NH4Cl; (iv) 0.13 g L−1 KCl was added, and pH 7.0 was maintained as described by Rabaey et al. (2005). The MET reactor was sterilized by autoclave for 30 min at maintaining a temperature of 121 °C. Then a sterile anolyte was aseptically added to the anode chamber. All the experiments of this study were carried out in a semi-batch mode. Before the MET process began, the anode chamber was purged with 100 % nitrogen for 15 min to maintain anaerobic conditions. All experiments connected electrodes to a single resistor (R = 1000 Ω), and the MET system, which contains the PAHs polluted soil sample, was run in a long-term fed-batch mode at 20 °C for 20 days. (i.e., four cycles) in one set of experiments. The effect of the biosurfactant dose on the degradation of petroleum hydrocarbon in the MET system anode was investigated. Three different biosurfactant concentrations in the anolyte feed solutions were used and selected based on previous studies at 10, 50, and 100 mg/L (Ambaye et al., 2022a, 2022b, 2022c, 2022d). In addition, a negative control was included with the same conditions as biotic systems but without biosurfactants in the medium. A maximum reduction of petroleum hydrocarbons was found to be up to 72.5 %, while the current density reached 9.5 Am−2 for the MET reactor having a dose of 100 mg/L within 20 days of the operational period. |
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Modelling and validation
Administrative information
Inputs and Outputs