Sediment Microbial Fuel Cells Research Articles

On-Line Monitoring of Minor Oil Spills in Seawater Using Sediment Microbial Fuel Cells: A Preliminary Study

In recent years microbial fuel cells have been studied for their biosensing properties. Consequently, sediment microbial fuel cells (sMFCs) have been found to be able to detect minor oil spills in freshwater. However, it was previously unknown whether sMFC properties as a biosensor would be able to produce the same results in a saltwater environment. Therefore, sMFCs at various external resistances (220 Ω, 300 Ω, 430 Ω, 510 Ω, 1000 Ω and 2000 Ω) were assembled to assess their ability to detect oil in seawater. The results indicated that an ER of 1k Ω is optimal for sMFC power generation, and that as oil was added to the cathode of the sMFCs, there was a clear and gradual decrease in the voltage output due to the oil’s interference with oxygen dissolvability in seawater; However, the relationship between the change in voltage and change in time was less linear than the change observed in previous studies, and inconsistent across the different voltages. The variation observed may be due to the absence of a catalyst, such as platinum, which would have sped up the rate of the decrease in voltage. This study illustrates that sMFCs provide a cost effective and environmentally friendly method to detect minor oil spills in seawater.

Sediment microbial fuel cell with biochar-modified cathode for remediation of black-odorous water sediments and analysis of microbial community

Sediment microbial fuel cells (SMFCs) generate electricity through microbial degradation of organic matter in sediments, and the cathode catalyst used for the oxygen reduction reaction is a key factor affecting the performance of SMFCs. To improve power production in SMFCs and remediate black-odorous water sediments, this study modifies the cathode carbon felt of the SMFC system with Enteromorpha prolifera (EP) biochar with high N and P content. The study demonstrated that the SMFC system with the modified cathode carbon felt (C-800℃/CF) exhibited superior power generation capabilities, achieving a maximum power density of 219.44 mW·m−2. Over 25 days of operation, the anode biofilm effectively degraded around 78.15% of total organic carbon, 79.55% of acid volatile sulfide, 74.78% of total nitrogen, 80.58% of ammonia nitrogen, and 77.46% of total phosphorus in the sediment. In addition, microbial community analysis showed that functional bacteria Thiobacillus, Acidaminobacter, Sulfurimonas, Bacteroidetes_vadinHA17, and Sideroxydans were the dominant genera in the anode biofilm.

Sediment microbial fuel cell monitoring repeated Cr(VI) shocks in different wetlands for a year: Performance and mechanism

Cr(VI) is a major heavy metal contaminant that poses great threats to aquatic ecosystems and human health. To guarantee the safety of water quality, the development of in-situ and online sensors for monitoring Cr(VI) contamination events is crucial. In this work, sediment microbial fuel cell (SMFC) based sensors using floating cathode as sensing element were operated in outdoor environment for one year to monitor repeated Cr(VI) shocks in wetlands constructed with coastal alkaline soil (YC), paddy of acidic soil (YT), and paddy of neutral soil (NJ). K2CrO4 solutions were added to the cathode four times in January, March, June, and September, respectively. Results showed that each Cr(VI) addition triggered a voltage peak and the voltage increments were linearly correlated with Cr(VI) concentrations within the range of 5–120 mg L−1 Cr(VI). The highest sensitivity was observed for YC (1.2 mV L mg−1) and YT (1.4 mV L mg−1) in June and for NJ (1.2 mV L mg−1) in September. XPS analysis demonstrated the reduction reaction of Cr(VI) to Cr(III) on the cathode might contribute to the generation of voltage peaks. Despite repeated shocks, Cr(VI) was immobilized in the soil and completely reduced to low-toxic Cr(III) with the consumption of soil organic matter, and the diversity and abundance of exoelectrogenic bacteria-associated genera were not inhibited. As a result, stable operation of the SMFC sensors was ensured. The SMFC sensors exhibited great potential for in-situ and online monitoring of Cr(VI) contamination events across various wetlands.

Utilization of Spent Coffee Grounds for Bioelectricity Generation in Sediment Microbial Fuel Cells.

This study examined the utilization of spent coffee grounds with different aqueous extraction methods for the bioelectricity generation from coastal benthic sediment through a sediment microbial fuel cell (SMFC) system. Different methods for the aqueous extraction of SCGs were evaluated, including rinsing and drying of the SCG (SMFC-CRD), immersion, rinsing and drying (SMFC-CRID), drying alone (SMFC-CD), and untreated SCG (SMFC-C). The caffeine concentration in the SCG was significantly reduced using pretreatments, with SMFC-CRID achieving the lowest concentration of 0.021 ± 0.001 mg/g. SMFC-CRD contributed to the generation of the highest current density of 213.7 mA/m2 during closed-circuit operation and exhibited the highest power density of 96.9 mW/m2 in the polarization test, due to the suitable caffeine content of 0.275 ± 0.001 mg/g in the SCG. This study could provide a cost-effective method for reusing SCGs (i.e., 128 g) while generating bioelectricity as an alternative energy source. These results suggest that pretreatment with SCGs is essential for achieving optimal power density and reducing the caffeine concentration in the SMFC system.

Effect of submerged and floating cathodes on sustainable bioelectricity generation and benthic nutrient removal in sediment microbial fuel cells

Sediment microbial fuel cells (SMFC) are a potential alternative for benthic sediment remediation in bioelectricity generation. The cathodic oxygen reduction rate is an important limiting factor in SMFC. This study aims to evaluate the effects of submerged and floating cathodes on bioelectricity generation and benthic nutrient removal in SMFC. Based on the generated current density, SMFC with a wick-air cathode, 10 cm from the top sediment surface and partially submerged in water and exposed to air (SMFC-CW) was found to be superior to those with bottom cathode, 1 cm from the top sediment surface (SMFC-C1), a middle cathode, 5 cm from the top sediment surface (SMFC-C5), and a floating cathode, 10 cm from the top sediment surface and placed under the overlying surface water (SMFC-C10). In the polarization test, SMFC-CW contributed to the lowest concentration loss with a maximum current density of 236.4 mA/m2. The overshoot phenomenon in SMFC-C1 is not a good indicator of the SMFC system, despite the generation of a high maximum power density. This study has shown that a large pH difference between the anodic and cathodic regions in SMFC-CW is important for bioelectricity generation as it was observed that the internal resistance of SMFCs changes. SMFC-CW showed the largest reduction in phosphate concentration, from 0.61 mg/L to 0.14 mg/L. These results provide a simple strategy for sustainable bioelectricity generation in SMFC systems while remediating benthic sediments.

On-Line Monitoring of Minor Oil Spills in Seawater Using Sediment Microbial Fuel Cells: A Preliminary Study

In recent years microbial fuel cells have been studied for their biosensing properties. Consequently, sediment microbial fuel cells (sMFCs) have been found to be able to detect minor oil spills in freshwater. However, it was previously unknown whether sMFC properties as a biosensor would be able to produce the same results in a saltwater environment. Therefore, sMFCs at various external resistances (220 Ω, 300 Ω, 430 Ω, 510 Ω, 1000 Ω and 2000 Ω) were assembled to assess their ability to detect oil in seawater. The results indicated that as oil was added to the cathode of the microbial fuel cells, there was a clear and gradual decrease in the voltage output due to the oil’s interference with oxygen dissolvability in seawater; However, the relationship between the change in voltage and change in time was less linear than the change observed in previous studies, and inconsistent across the different voltages. The variation observed may be due to the absence of a catalyst, such as platinum, which would have sped up the rate of the decrease in voltage. This study illustrates that sediment microbial fuel cells provide a cost effective and environmentally friendly method to detect minor oil spills in seawater.

The Effect of Illumination, Electrode Distance, and Illumination Periods on the Performance of Phototrophic Sediment Microbial Fuel Cells (PSMFCs)

Microbial fuel cells (MFCs) can potentially be used to overcome issues with battery powered light buoys and their frequent maintenance. In this study, a phototrophic sediment microbial fuel cell (PSMFC) was chosen, as the microalgae provide oxygen to be reduced on the cathode and to release the necessary nutrients for the bacteria on the anode. To achieve this, we studied the effect of illumination, the period of the illumination, and the distance between 9-cm2 stainless steel mesh electrodes on the performance of the MFC. The illuminated cells were able to produce higher OCP (max. 205.2 mV) and higher power density (max. 0.68 mW/m2). However, the highest current was achieved during the unilluminated variation (max. 5.3 μA unilluminated and 3.3 μA illuminated). Prolonged illumination produced a higher OCP, current, and power density. A longer electrode distance produced a higher OCP, power density, and current. SEM analysis showed that biofilm formation tended to be scattered at lower electrode distance and more clumped (filling the anode area) at higher electrode distance. Through FTIR analysis, it was found that all MFC variations had the same organic matter, but a more concentrated organic content was found in the MFC at longer electrode distances.

Energy harvesting from plants using hybrid microbial fuel cells; potential applications and future exploitation.

Microbial Fuel Cells (MFC) can be fuelled using biomass derived from dead plant material and can operate on plant produced chemicals such as sugars, carbohydrates, polysaccharides and cellulose, as well as being "fed" on a regular diet of primary biomass from plants or algae. An even closer relationship can exist if algae (e.g., prokaryotic microalgae or eukaryotic and unicellular algae) can colonise the open to air cathode chambers of MFCs driving photosynthesis, producing a high redox gradient due to the oxygenic phase of collective algal cells. The hybrid system is symbiotic; the conditions within the cathodic chamber favour the growth of microalgae whilst the increased redox and production of oxygen by the algae, favour a more powerful cathode giving a higher maximum voltage and power to the photo-microbial fuel cell, which can ultimately be harvested for a range of end-user applications. MFCs can utilise a wide range of plant derived materials including detritus, plant composts, rhizodeposits, root exudates, dead or dying macro- or microalgae, via Soil-based Microbial Fuel Cells, Sediment Microbial Fuel Cells, Plant-based microbial fuel cells, floating artificial islands and constructed artificial wetlands. This review provides a perspective on this aspect of the technology as yet another attribute of the benevolent Bioelectrochemical Systems.

Simultaneous degradation of NSAIDs in aqueous and sludge stages by an electron-Fenton system derived from sediment microbial fuel cell based on a novel Fe@Mn biochar GDC

Electro-Fenton (e-Fenton) reactions boosted using microbial fuel cells (MFCs) can degrade contaminants with high efficiency, the treatment is generally performed in the aqueous phase and the sludge pollution is ignored in such MFCs. In this study, a sediment MFC e-Fenton (SMFC-e-Fenton) system was proposed for the degradation of nonsteroidal anti-inflammatory drugs (NSAIDs) in both aqueous and solid phases. A Fe@Mn-codoped biochar gas diffusion cathode was fabricated to produce hydroxyl radicals without any additional power input. The studied NSAIDs of ibuprofen (IBU), naproxen (NPX), and diclofenac (DCF) exhibited total degradation efficiencies (including aqueous and sludge phase) of 99.1%, 98.5%, and 80.6%, respectively, in the SMFC-e-Fenton system. Compared with sludge anaerobic digestion, the residual amounts of IBU, NPX, and DCF reduced from 10.2%, 24.6%, and 32.2% to 2.7%, 4.4%, and 8.5%, respectively, in the sludge phase. Moreover, the electricity generation and sludge reduction improved owing to the e-Fenton process. Using the SMFC-e-Fenton system, the effects of NSAIDs were reduced and the richness and diversity of the microbial community are maintained, improving the overall system performance. These results demonstrate that the SMFC-e-Fenton method is a high-efficiency, economic and environmental friendly technology for simultaneously treating NSAIDs in the aqueous and sludge phases.

Effect of NH2-MWCNTs/CF anodes on the power generation performance of SMFCs

The carbon nanotube-modified anodes have been widely recognized as one of the most effective methods to improve the conductivity of the anode and enhance the performance of microbial fuel cells. And there are few studies on the effect of amino-functionalized carbon nanotube-modified anodes on the performance of sediment microbial fuel cells (SMFCs) systematically. In this paper, we prepared amino-functionalized carbon nanotube-modified electrodes and constructed SMFCs using them to study the effect of amino-functionalized carbon nanotubes on the power generation performance of SMFCs. The results showed that the highest output voltage of NH2-functionalized multi-walled carbon nanotube (NH2-MWCNT)-modified carbon felt (CF) SMFCs (529.15 mV) was significantly higher than that of CF (474.5 mV). And the power density of SMFCs with 10% NH2-MWCNTs/CF reached a maximum of 58.3 mW/m3. There are because NH2-MWCNTs surface has a larger specific surface area and a porous structure, enhancing electron conduction pathway helps to improve the conductivity of the anode. Therefore, the modification of CF surfaces with NH2-MWCNTs can be used to improve the interfacial properties and positively enhance the power generation performance of SMFCs. This study provides a novel and effective approach to enhance the performance of SMFCs and contributes to the international research on carbon nanotube-modified anodes for energy and environmental applications.

Phosphorus Release from Agricultural Drainage Sediments with Iron-Added Sediment Microbial Fuel Cells

Phosphorus Release from Agricultural Drainage Sediments with Iron-Added Sediment Microbial Fuel Cells

Integrating plant microbial fuel cells and permeable O2-releasing rods to enhance copper removal and electricity generation in sediment

The high mass transfer resistance of the sediment limits the migration of copper (Cu) ions generated from the operation of a sediment microbial fuel cell (SMFC), causing difficulty in obtaining high removal efficiencies of Cu ions through the SMFC. Therefore, approaches are required to reduce the internal resistance of the system and to increase the power generation of the SMFC. In this study, the anode zone of SMFCs was planted with water spinach, which produces root exudates to activate the microorganisms. A permeable oxygen release rod (POR) was installed in the cathode zone of the SMFC to slowly release a small amount of oxygen to enhance power generation, prompting copper ions to migrate to the cathode for a reduction reaction to remove copper. Under the condition of growing water spinach and setting POR simultaneously, the power density (94.9 mW/m3) of SMFC was increased by 14.1 times, significantly increasing the removal efficiency of Cu ions (from 20.9 % to 84.9 %). The abundance of electro-producing bacteria (e.g., Clostridium, Bacillus, and Thiobacillus) was increased when the anode zone of the SMFC was planted with water spinach. This suggests that the root exudates of water spinach and trace oxygen from POR promoted the electricity production of SMFC and accelerated the migration of Cu ions.

Sediment Microbial Fuel Cells with Algae-Assisted Cathodes for Electricity Generation and Bio-Treatment of Sewage Sludge

In this study, an algal–bacterial symbiotic consortium was integrated with the sediment microbial fuel cell (SMFC) to construct an algal–bacterial cathode SMFC (AC-SMFC) for excess sewage sludge treatment and electricity generation. A bacterial cathode SMFC (BC-SMFC) and a static settling system (SS-system) were used as controls. Electrochemical analysis confirmed that the algal–bacterial biofilm on the cathode improved electricity production. The maximum power density of AC-SMFC was 75.21 mW/m2, which was 65.70% higher than that of the BC-SMFC (45.39 mW/m2). After 60 days of treatment, AC-SMFC achieved much higher removal efficiencies of the total chemical oxygen demand (TCOD) (59.60%), suspended solids (SS) (62.42%), and volatile suspended solids (VSS) (71.44%) in the sediment, compared to BC-SMFC and the SS-system, exhibiting an effective degradation of the organic matter in the sediment sludge. Moreover, the lower concentration of total nitrogen (TN) and total phosphorus (TP) in the overlying water of AC-SMFC demonstrated that the algae on the cathode could inhibit the accumulation of nitrogen and phosphorus released from the sediments. The three-dimensional excitation–emission matrix (EEM) fluorescence spectroscopy revealed that the tryptophan protein and aromatic protein in the loosely bound extracellular polymeric substances (LB-EPS) of the sediment sludge in the AC-SMFC were significantly decreased. Additionally, the abundance of functional microbiota in the AC-SMFC increased, such as Trichococcus, Alphaproteobacteria, and Clostridia, which contributed to electricity generation and sludge degradation. The combined application of microalgae and the SMFC provided a promising approach for excess sludge reduction and energy recovery.

Promoting electricity generated from sediment-based microbial fuel cells and remediation of copper-containing sediments using plant radial oxygen loss and root exudates

This study uses root exudates and radial oxygen loss (ROL) produced by plants to increase the amount of power produced by sediment microbial fuel cells (SMFCs) and improve copper removal. Among the three plants tested, which are commonly found in wetlands, Ipomoea aquatica produces the highest yield of root exudates and ROL, with respective values of 8.54 mg/(g‧d) and 2.1 μmol/(g‧h) at 50-mg/L Cu inhibition. The maximum power density of an SMFC with 450 mg/kg of copper-containing sediment and Ipomoea aquatica planted at the anode is 58.4 mW/m3, which is three times greater than that of an SMFC with Ipomoea aquatica planted at the cathode. This demonstrates that plant root exudates provide anodic microorganisms with easily decomposed organic matter, which increases the amount of power. The presence of a bioelectrochemical process is demonstrated by the presence of Cu(II) reduction deposits on the cathode surface. According to the findings, planting Ipomoea aquatica at the anode produces more electricity and removes slightly less copper than planting it at the cathode. It is concluded that planting Ipomoea aquatica at the anode is more effective than planting it at the cathode.

Probing the effect of distance between sediment microbial fuel cells and sediment storage on electricity generation and organic matter removal in open channels

In this study, influence of distance between two sediment microbial fuel cells (SMFCs) and storage of sediment for several months in an open channel were investigated in different configurations. Results indicated that SMFCs with the largest distance outperformed the neighboring SMFCs in terms of voltage and power output in different configurations. In addition, it was shown that long-term sediment storage weakened SMFC performance. Maximum power densities of 39 and 50 mW m−2 were achieved for the two SMFCs with the largest distance, while 30 and 26 mW m−2 were obtained for the two adjacent SMFCs operating with fresh sediment. Furthermore, loss on ignition (LOI) removal was enhanced with a sufficient increase in SMFC distances, so that LOI removal of 49.8 % and 21.4 % in the SMFCs with the largest distance was considerably higher than the neighboring SMFCs (18.2 % and 12.9 %). On the other hand, employing the stored sediment, SMFCs with the largest distance produced the highest maximum power densities of 35 and 32 mW m−2 whereas 23 and 22 mW m−2 were obtained by the neighboring SMFCs. Power density of the SMFCs with the largest distances was higher than the neighboring cells in both series and parallel connections as well.

Study of voltage reversal of stacked sediment microbial fuel cells

Sediment microbial fuel cell (SMFC) is a renewable energy source with a wide range of raw materials. They have a simple structure, low cost, and broad application prospects in the field of self-power supply, attracting the attention of many researchers. However, the output current of SMFC is weak and the output voltage is low, which does not meet the power supply requirements of general electronic devices. Therefore, it is necessary to connect multiple SMFCs to obtain the required voltage and current. Series operation can increase the output voltage, while parallel operation can increase the output current. However, voltage reversal occurs in series operation, which can affect the output performance of the battery. In this work, voltage reversal was studied by two SMFCs respectively connected in series and in parallel after their output voltage stabilized. External load of the series and parallel batteries were connected to 330 ohms, 680 ohms, 1000 ohms, 2000 ohms, and 380K ohms, respectively. It was found that batteries with poor performance in series battery packs experienced voltage reversal, which occurred at 330 ohms, 680 ohms, and 1000 ohms. When the resistances became 2000 ohms and 380K ohms, parallel battery packs did not experience similar phenomena. The reason for voltage reversal was provided in this article. In addition, voltage reversal occurred in the stage of low resistances, which indicating that the greater the current, the greater the possibility of voltage reversal.

Performance Evaluation of Aquaponics-Waste-Based Biochar as a Cathode Catalyst in Sediment Microbial Fuel Cells for Integrated Multitrophic Aquaculture Systems

The sustainable development of aquaculture faces a significant challenge due to the need for the frequent treatment of aquacultural waste. This research presents a pioneering solution by concurrently utilizing aquacultural waste to produce biochar and enhancing a sediment microbial fuel cell (SMFC)’s treatment efficacy for waste generated from the integrated multitrophic aquaculture (IMTA) system. The water quality parameters of the aquacultural pond water were analyzed, and synthetic wastewater was prepared to validate the system’s efficiency. Over a period of more than 50 days, the SMFC was operated and monitored, yielding an average chemical oxygen demand (COD) removal efficiency of 86.31 ± 2.18%. The maximum operating voltage of the SMFC reached 0.422 V on the 21st day of operation when connected to an external resistance of 975 Ω. A novel-activated aquacultural biochar catalyst was synthesized from aquaponics waste and used as a cathode catalyst, substantially improving the SMFC’s performance. Characterization studies demonstrated that the aquacultural biochar catalyst was an active electrocatalyst, accelerating the oxygen reduction reaction rate and leading to increased power output and overall efficiency of the SMFC. The SMFC utilizing the aquacultural-waste-based biochar cathode catalyst showcased the highest maximum power density, with a range of 101.63 mW/m2 (1693.83 mW/m3), and the lowest internal resistance, indicating superior performance. These results validate the reliability of implementing SMFCs in actual aquaculture systems. A novel modular design for SMFC reactor-assisted small-scale integrated poultry–fish culture systems is proposed for further practical application in real-life aquaculture settings. This research contributes to finding sustainable and effective methods for waste treatment for aquaculture, promoting the development of environmentally friendly practices in the industry.

SEDIMENT MICROBIAL FUEL CELL BASED BIOSENSOR FOR REAL TIME DETECTION OF CU2+ IN INDUSTRIAL WASTEWATERS – OPERATION AND EFFECTIVENESS

Sediment microbial fuel cells (SMFCs) are bio-electrochemical systems in which the anode is placed in the anaerobic sediment and the cathode is immersed in the surface layer of water. Natural exoelectrogenic bacteria decompose organic compounds in sediment, producing electrons and protons. The electrons reach the cathode through an external electrical circuit, while the protons pass through the soil layer, which acts as a kind of membrane. Oxygen is in many cases the preferred electron acceptor due to its presence in the cathode region and its high potential. Heavy metal ions and other compounds can also be reduced on the cathode, which will increase the energy generated. Based on the above characteristics, SMFCs would be suitable for application as biosensors for monitoring water pollution with heavy metals. In the present study, the possibility of application of SMFCs as biosensors for water pollution with copper has been studied. A high correlation was found between the concentration of copper ions in the range 0,1 – 100 mg/L and the voltage generated by SMFC. The constructed SMFC based biosensor showed wider detection limits for copper compared to other authors' studies as the coefficient of determination reached 0,9911. Native exoelectrogenic bacteria were represented mainly by Geobacter, Clostridium, Anaeromixobacter and Bacillus.

Effect of Electro-Oil Acclimation of an Indigenous Strain on the Performance of Sediment Microbial Fuel Cells (SMFC)

Sediment microbial fuel cell (SMFC) is a type of MFC without a proton exchange membrane. However, SMFC have had problems with low-power production performance. In this paper, the effects of native bacteria (K1) in oily sludge and their electro-oil-induced domestication on the power generation and oil removal performance of SMFC were studied. The results showed that K1 belonged to Ochrobactrum intermedium. During the domestication process, an upward trend was shown in the OD600 and ORP values in the culture medium, and it grown best at 0.7 V. Ochrobactrum intermedium K1 significantly increased the average output voltage, electromotive force, and maximum power density of SMFC and reduced the apparent internal resistance of the battery. The maximum power density was 169.43 mW/m3, which was 8.59 times higher than that of the control group. Ochrobactrum intermedium K1 improved the degradation of crude oil by SMFC. Ochrobactrum intermedium K1 enhanced the degradation of high-carbon alkanes and even-carbon alkanes in n-alkanes. Cyclic voltammetry and chronoamperometry tests showed that after acclimation, Ochrobactrum intermedium K1 improved the extracellular electron transfer efficiency (EET) mediated by c-Cyts and flavin by increasing the surface protein redox potential.

Self-Driven Electrokinetic Remediation of Cd Contamination Soil by Using Double-Chamber Microbial Fuel Cell

Green and sustainable techniques are in great demand for the remediation of heavy metal-contaminated soil. Cadmium ion (Cd2+) in soil could be extracted under the internal electric field and participating on the surface of the electrode. Here, we proposed a sediment microbial fuel cell (SMFC) for the electrokinetic remediation of cadmium (Cd) contamination soil. Within the 7 weeks of SMFC operation, the removal efficiency for total Cd could be up to 70.04 ± 0.45%, which was significantly higher than that obtained by open circuit SMFC. The maximum output power density was 71.00 ± 0.82 mW m−2 with a current density of 0.60 ± 0.03 A m−2. Results obtained by electrochemical impedance showed that the inter resistance of SMFC was 944 ± 14 Ω. High-throughput sequencing revealed that the Alpha-, Beta- and Gammaproteobacteria increased to 67.85%–80.99% in the SMFC. The relative abundance of Cd2+/Zn2+-exporting ATPase, participating in Cd2+ reduction, in SMFC varied from 25.83% to 30.68%, which were significantly higher than that of control (11.21% to 19.94%). Our findings have presented an effective energy-saving method for the remediation of heavy metal-contaminated soils.