Electrode Chamber Research Articles

Regulating and intervening act of Cr chemical speciation effect on the electrokinetic removal in Cr contaminated soil in arid area

Heavy metals chemical speciation significantly effects the electrokinetic removal of heavy metals contaminated soil, but how to regulate and intervene the chemical speciation for improving the removal efficiency in the electrokinetic remediation of the contaminated soil is still an opened problem. In this study, we used increasing citric acid electrolyte concentration and soil pretreatment as regulating measures and the anolyte circulation and reduction wells as intervening act to explore the detailed transformation and migration of Cr speciation over time during electrokinetic remediation, the effect of the transformation and migration of Cr speciation in arid area contaminated soil on the removal efficiency. Based on the results of sequential extraction, the regulating measures can significantly improve the soil pH and the transformation of Cr speciation in arid areas, but the detailed transformation occurs in the early stage of remediation. The material flows showed that the transformation of other speciation to exchangeable (EXC) was higher than its migration to the electrode chamber and the EXC was not completely removed throughout the experiment. By adding HCl to the soil prior to the electrokinetic remediation, more Cr (III) can migrate to the cathode region. Regulating measure for pretreatment of real contaminated soil in arid area based on high concentration of citric acid and intervening act for the anolyte circulation could significantly reduce the bound to Fe/Mn oxides (FM), but the overall removal efficiency of the real contaminated soil (from 44.86% to 44.90%) was not improved, while the removal efficiency of artificially contaminated soil was higher. Furthermore, the multivariate linear regression analysis of the link between the five fractions and removal efficiency of Cr also shows that their correlation was much higher in artificially contaminated soils than in real contaminated soils. The scale effect would affect the transformation of the speciation, and the smaller the scale of the experiment is, the larger the influence on the migration and transformation of Cr speciation will be. The combination of regulating measures and intervening act provide a valuable reference for the specific transformation and migration of heavy metals speciation and the improvement of removal efficiency during EKR of contaminated soil in arid area.

Cathodic selenium recovery in bioelectrochemical system: Regulatory influence on anodic electrogenic activity

Metal(loid)s are used in various industrial activities and widely spread across the environmental settings in various forms and concentrations. Extended releases of metal(loid)s above the regulatory levels cause environmental and health hazards disturbing the ecological balance. Innovative processes for treating the metal(loid)-contaminated sites and recovery of metal(loid)s from disposed waste streams employing biotechnological routes provide a sustainable way forward. Conventional metal recovery technologies demand high energy and/or resource inputs, which are either uneconomic or unsustainable. Microbial electrochemical systems are promising for removal and recovery of metal(loid)s from metal(loid)-laden wastewaters. In this communication, a bioelectrochemical system (BES) was designed and operated with selenium (Se) oxyanion at varied concentrations as terminal electron acceptor (TEA) for reduction of selenite (Se4+) to elemental selenium (Se0) in the abiotic cathode chamber. The influence of varied concentrations of Se4+ towards Se0 recovery at the cathode was also evaluated for its regulatory role on the electrometabolism of anode-respiring bacteria. This study observed 26.4% Se0 recovery (cathode; selenite removal efficiency: 73.6%) along with organic substrate degradation of 74% (anode). With increase in the initial selenite concentration, there was a proportional increase in the dehydrogenase activity. Bioelectrochemical characterization depicted increased anodic electrogenic performance with the influence of varied Se4+ concentrations as TEA and resulted in a maximum power density of 0.034 W/m2. The selenite reduction (cathode) was evaluated through spectroscopic, compositional and structural analysis. X-ray diffraction and Raman spectroscopy showed the amorphous nature, while Energy Dispersive X-ray spectroscopy confirmed precipitates of the deposited Se0 recovered from the cathode chamber. Scanning electron microscopic images clearly depicted the Se0 depositions (spherical shaped; sized approximately 200 nm in diameter) on the electrode and cathode chamber. This study showed the potential of BES in converting soluble Se4+ to insoluble Se0 at the abiotic cathode for metal recovery.

A Sodium Polysulfide Battery with Liquid/Solid Electrolyte: Improving Sulfur Utilization Using P2S5 as Additive and Tetramethylurea as Catholyte Solvent

Herein, the proof of concept of a sodium polysulfide battery consisting of two electrode chambers being separated by a solid electrolyte is described. The concept is suited for dissolved polysulfide cathodes and has the advantage that both half reactions can be optimized separately. The formation of solid sulfide discharge products is identified as the major limiting factor for cell cycling. This issue can be alleviated by adding solid P2S5. Further improvement can be achieved by replacing diglyme (2G) as the cathode compartment solvent with tetramethylurea (TMU). Using TMU, the cell cycles with Coulombic efficiencies >99% and capacities of 800 mAh g−1 are maintained for at least 30 cycles. Viscosity, density, conductivity, and the electrochemical stability window values of the 2G‐ and TMU‐based electrolytes are compared. The latter shows higher viscosity (2.806 vs 1.603 mPa s), higher density (1.016 vs 0.996 g cc−1), and higher conductivity (4.27 vs 1.45 mS cm−1). The oxidative stability limit of the TMU electrolyte is 3.2 V versus Na+/Na, which is sufficient for polysulfide redox reactions. Vis spectroscopy is used to follow the electrode reaction. In case of TMU, the reaction is based on the redox activity of S3−• radicals (blue coloration of the catholyte solution).

Inference of X-Ray Emission From a Plasma Focus Discharge: Comparison Between Characteristic Parameters and Neural Network Analyses

Pulsed plasma discharges, such as the plasma focus, are a source of pulsed X rays, therefore it is desirable to understand the relationship between this fast transient phenomena and the electrical variables of the discharge. Parameters from the electrical diagnostic signals are typically used to characterize the plasma focus discharge and for the correlations with X rays measurements via scatter plots. To further evaluate relevant information in the electrical signals, besides the characteristic parameters, an implementation of different types of machine learning algorithms, that included deep learning, was performed. A classification of pulses associated with an X rays measurement, in terms of the electrical signals data as input, was carried out. Two approaches were compared: the selection of the characteristic parameters and the use of the entire signals so the algorithms could find additional information for the classification task. The electrical diagnostic signals corresponded to: the voltage at the electrodes of the discharge chamber measured with a resistive voltage divider; time variation of the circuit current measured with a Rogowski coil and an inductive loop sensor; and the electromagnetic burst from the circuit measured with a Vivaldi antenna. The X rays measurement corresponded to the signal obtained from a scintillator-photomultiplier. In terms of the performance of the algorithms models in this classification problem, the results indicated that there is no significative improvements when using the entire signal or the selection of characteristic parameters. The best results were obtained when the following parameters were used: voltage at time of gas breakdown, voltage at time of pinch, current at time of pinch, time derivative of current at time of pinch, time from breakdown to pinch, and the Fast Fourier Transform of the part of the Vivaldi antenna signal related to the pinch event.

Mathematical modeling of heating of coal particle within the space between electrodes of arc-heating reactor

A mathematical model of heating of coal particles that move in the initial section of a submerged gas jet within the space between electrodes of reaction chamber of arc-heating reactor is created. The model takes into account convective heat transfer and heat transfer by radiation from a sphere (particle) – circle (anode) system. The temperatures of particles on mechanical trajectory are obtained depending on particle diameters and the initial coordinate of nozzle leaving.

An on-chip microfluidic-based electrochemical magneto-immunoassay for the determination of procalcitonin in plasma obtained from sepsis diagnosed preterm neonates.

A novel on-chip electrochemical magneto-immunoassay for the determination of procalcitonin (PCT) has been proposed. The strategy involved the on-line performing of the biorecognition event and detection on the thin-film microfluidic gold electrode chamber operating at E = -0.20 V (vs. Au). The complete assay was performed in less than 15 minutes using only 25 μL of the sample, covering the entire range of clinically relevant PCT concentrations in sepsis diagnosis with a limit of detection and quantification of 0.02 ng mL-1 and 0.05 ng mL-1, respectively (the sepsis diagnosis threshold: 0.5 ng mL-1). The on-chip electrochemical magneto-immunoassay provided excellent results in the analysis of very unique samples obtained from preterm neonates admitted with suspected sepsis, in which the sample volume is hardly available. These characteristics fulfill the POCT requirements for PCT determination in the whole clinically relevant concentration range. Because of the high clinical relevance and the important role of PCT in sepsis, this approach opens new perspectives for sepsis diagnosis and therapy guidance using low volume samples.

АППАРАТУРА ДЛЯ ИССЛЕДОВАНИЯ ПРОЦЕССОВ ДЕЛЕНИЯ

This article is devoted to the study of the principles of operation of a pulsed ionization chamber, in which particles emitted from a target create a sequence of well-isolated current pulses (the distance between pulses is several times greater than their width). Firstly, using the Ramo-Shockley theorem, the mechanisms of forming signals on the electrodes of an ionization chamber with Frisch nets are considered, then it is shown how information on energy and spatial orientation of particles can be extracted from such signals using modern electronic pulse digitizers.

Elucidating effects of component materials and flow fields on Sn–Fe hybrid flow battery performance

Component materials and flow fields are key design parameters that influence the advection-diffusion-reaction process and thereby the performance of a Sn–Fe hybrid flow battery. In this work, various electrode configurations (empty chamber and porous carbon-based electrodes), membranes (cation and anion conducting) and flow fields (serpentine and interdigitated) are systematically investigated to elucidate their effects on the unique charge/discharge behaviors of the Sn–Fe flow battery with tin metal plating/striping. It is found that the battery capacity roughly increases linearly with the porosity of the porous electrode especially at low current densities, and a highly porous electrode (graphite felt) is more desirable than an empty chamber configuration in terms of capacity and power density. In addition, as compared to cation exchange membrane (Nafion 212), the anion exchange membrane (Fumasep FAP-450) exhibits improved capacities and columbic efficiencies in sulfuric acid-based electrolytes at low current densities due to the reduction of cation crossover. Interestingly, it is showed that although a serpentine flow field and a low flow rate generally lead to poor battery performance, they tend to ameliorate the maldistribution of plated tin at the negative electrode owing to the restricted mass transfer of reactants.

Energy capture from thermolytic solutions and simulated sunlight coupled with hydrogen peroxide production and wastewater remediation

A novel solar salinity energy nexus was developed by combining a photocatalytic fuel cell (PFC) and a reverse electrodialysis (RED). The hybrid cell (called a PRC) can effectively transfer the solar energy and salinity gradient energy (which is regenerated by low grade industrial waste heat) to electrical energy coupled with enhanced pollutant (Rhodamine B, RhB) degradation and H2O2 production. Energy-Environment win-win will be realized. The open circuit voltage of the PRC was the sum of those of the PFC and the RED, and the RED stack made the larger contribution to the electricity production of PRC. The bias voltage generated from the RED stack accelerated the separation of photo-induced holes and electrons on the three-dimensional TiO2 array photoanode, which enhanced RhB degradation and H2O2 production. The flow rate and concentration of the working fluids (ammonium bicarbonate) and the reaction conditions in the electrode chambers had substantial effects on the PRC performance. Under the optimal condition, the peak power density and energy efficiency of PRC reached 1500 mW m−2 and 4.21% respectively. The performance of PRC on electricity production is better than photocatalytic electrolytic cell driven by desalination(PFCD), but not good as microbial reverse electrodialysis electrolysis cell (MREC).

Hydrogen Production from Water Electrolysis Driven by High Membrane Voltage of Reverse Electrodialysis

The voltage produced from the salinity gradient in reverse electrodialysis (RED) increases proportionally with the number of cell pairs of alternating cation and anion exchange membranes. Large-scale RED systems consisting of hundreds of cell pairs exhibit high voltage of more than 10 V, which is sufficient to utilize water electrolysis as the electrode reaction even though there is no specific strategy for minimizing the overpotential of water electrolysis. Moreover, hydrogen gas can be simultaneously obtained as surplus energy from the electrochemical reduction of water at the cathode if the RED system is equipped with proper venting and collecting facilities. Therefore, RED-driven water electrolysis system can be a promising solution not only for sustainable electric power but also for eco-friendly hydrogen production with high purity without CO2 emission. The RED system in this study includes a high membrane voltage from more than 50 cells, neutral-pH water as the electrolyte, and an artificial NaCl solution as the feed water, which are more universal, economical, and eco-friendly conditions than previous studies on RED with hydrogen production. We measure the amount of hydrogen produced at maximum power of the RED system using a batch-type electrode chamber with a gas bag and evaluate the interrelation between the electric power and hydrogen energy with varied cell pairs. A hydrogen production rate of 1.1 × 10<sup>−4</sup> mol cm<sup>−2</sup> h<sup>−1</sup> is obtained, which is larger than previously reported values for RED system with simultaneous hydrogen production.

Balancing ion parameters and fluorocarbon chemical reactants for SiO2 pattern transfer control using fluorocarbon-based atomic layer etching

In manufacturing, etch profiles play a significant role in device patterning. Here, the authors present a study of the evolution of etch profiles of nanopatterned silicon oxide using a chromium hard mask and a CHF3/Ar atomic layer etching in a conventional inductively coupled plasma tool. The authors show the effect of substrate electrode temperature, chamber pressure, and electrode forward power on the etch profile evolution of nanopatterned silicon oxide. Chamber pressure has an especially significant role, with lower pressure leading to lower etch rates and higher pattern fidelity. The authors also find that at higher electrode forward power, the physical component of etching increases and more anisotropic etching is achieved. By carefully tuning the process parameters, the authors are able to find the best conditions to achieve aspect-ratio independent etching and high fidelity patterning, with an average sidewall angle of 87° ± 1.5° and undercut values as low as 3.7 ± 0.5% for five trench sizes ranging from 150 to 30 nm. Furthermore, they provide some guidelines to understand the impact of plasma parameters on plasma ion distribution and thus on the atomic layer etching process.

Enhancement of gasworks groundwater remediation by coupling a bio-electrochemical and activated carbon system

Here, we show the electrical response, bacterial community, and remediation of hydrocarbon-contaminated groundwater from a gasworks site using a graphite-chambered bio-electrochemical system (BES) that utilizes granular activated carbon (GAC) as both sorption agent and high surface area anode. Our innovative concept is the design of a graphite electrode chamber system rather than a classic non-conductive BES chamber coupled with GAC as part of the BES. The GAC BES is a good candidate as a sustainable remediation technology that provides improved degradation over GAC, and near real-time observation of associated electrical output. The BES chambers were effectively colonized by the bacterial communities from the contaminated groundwater. Principal coordinate analysis (PCoA) of UniFrac Observed Taxonomic Units shows distinct grouping of microbial types that are associated with the presence of GAC, and grouping of microbial types associated with electroactivity. Bacterial community analysis showed that β-proteobacteria (particularly the PAH-degrading Pseudomonadaceae) dominate all the samples. Rhodocyclaceae- and Comamonadaceae-related OTU were observed to increase in BES cells. The GAC BES (99% removal) outperformed the control graphite GAC chamber, as well as a graphite BES and a control chamber both filled with glass beads.

An energy-saving “nanofiltration/electrodialysis with polarity reversal (NF/EDR)” integrated membrane process for seawater desalination. Part III. Optimization of the energy consumption in a demonstration operation

For the proposed energy-saving “nanofiltration/electrodialysis with polarity reversal (NF/EDR)” integrated membrane process for seawater desalination, studies on the NF process and the optimization of the ED process have been previously conducted. Based on the obtained results, a multi-stage, multi-passage ED process is presented in this manuscript to realize the optimization of energy consumption. In addition, the integration between NF and EDR processes at a pilot scale was accomplished, in which actual seawater was the feed water and >1200 h of demonstrative operation was implemented. During the NF process, 15 NF90-4040 elements with high desalination capacity were applied. During the EDR process, the membrane stack consisted of three stages with six passages were utilized, in which 250 cell pairs were included with unequal pairs of membranes for each stage. From the first to the third stage, there were 100, 80, and 70 membrane pairs, respectively. In addition, the energy-saving process was achieved by thinning the thickness of the electrode chamber to 2 mm and filling the electrode chambers with mixed ion exchange resin at an appropriate volume ratio. Furthermore, the voltage and the current for each stage can be independently controlled. The results show that the total desalination rate of the integrated process can be 99.26%, the system energy consumption is <2.15 kWh/(m3 produced water), which is significantly lower than that of SWRO, suggesting that the proposed integrated membrane process is an efficient and economically feasible seawater desalination system.

A New Method for Modulation, Control and Power Boosting in Microbial Fuel Cells.

Microbial fuel cells (MFCs) are energy transducers, which through the metabolic reactions of facultative anaerobic microorganisms, transform the energy in organic matter directly into electricity. Extrinsic parameters such as hydraulic retention time, fuel quality (type and concentration) and physicochemical environment of electrodes and biofilms (e.g., temperature, pH, salinity, and redox), can all influence system efficiency. This work proposes that MFCs can be “fine‐tuned” by adjustment of any of the physicochemical conditions including redox potential; in this context, an entirely novel method was investigated as a practical means of tuning, modulating and monitoring the redox potential within the electrode chambers. The method uses additional electrodes – known as 3rd and 4th‐pins for anode and cathode chambers, respectively – which can be used in individual units, modules, cascades or stacks, for optimising the production of a large variety of chemicals, as well as biomass, water and power. The results have shown that the power output modulation resulted in an up to 79% and 33% increase, when connected via 3rd and 4th pins, respectively. Apart from power improvement, this study also demonstrated a method of open circuit potential (OCP) sensing, by using the same additional electrodes to both monitor and control the MFC signal in real time.

A novel All-in-One electrolysis electrode and bioreactor enable better study of electrochemical effects and electricity-aided bioprocesses.

An autoclavable All-in-One electrolysis electrode in a rod shape assembly is developed as a new tool for bioelectrochemical systems and electricity-aided bioprocesses. It can replace the classic two-chamber bioelectrochemical system for electrolysis reactions, be inserted into conventional bioreactors and is easily adaptable as electrocatalytic surface or generator of super-fine bubbles (H2 and O2) for bioconversion processes. Whereas the bioreactor itself functions as the working electrode chamber, a well-integrated inner counter electrode chamber enables water electrolysis without the normally encountered undesired ion-transfer effect. The efficiencies of the electrode are characterized and its advantages and usefulness compared to the classic H-Cell bioelectrochemical system (BES) are demonstrated with glycerol fermentations by Clostridium pasteurianum DSM 525.

A temperature-controlled photoelectrochemical cell for quantitative product analysis.

In this study, we describe the design and operation of a temperature-controlled photoelectrochemical cell for analysis of gaseous and liquid products formed at an illuminated working electrode. This cell is specifically designed to quantitatively analyze photoelectrochemical processes that yield multiple gas and liquid products at low current densities and exhibit limiting reactant concentrations that prevent these processes from being studied in traditional single chamber electrolytic cells. The geometry of the cell presented in this paper enables front-illumination of the photoelectrode and maximizes the electrode surface area to electrolyte volume ratio to increase liquid product concentration and hence enhances ex situ spectroscopic sensitivity toward them. Gas is bubbled through the electrolyte in the working electrode chamber during operation to maintain a saturated reactant concentration and to continuously mix the electrolyte. Gaseous products are detected by an in-line gas chromatograph, and liquid products are analyzed ex situ by nuclear magnetic resonance. Cell performance was validated by examining carbon dioxide reduction on a silver foil electrode, showing comparable results both to those reported in the literature and identical experiments performed in a standard parallel-electrode electrochemical cell. To demonstrate a photoelectrochemical application of the cell, CO2 reduction experiments were carried out on a plasmonic nanostructured silver photocathode and showed different product distributions under dark and illuminated conditions.

Iron (III) oxide hydroxide based novel electrode for the electrochemical detection of trace level fluoride present in water

Present article describes the development of novel electrode for the electrochemical detection of fluoride ion (F−) present in water. The electrode is prepared by growing thin iron (III) oxide hydroxide film on conducting glass substrate through simple and cost effective dip coating technique. Electrochemical sensing performances of the developed electrode through cyclic voltammetric and amperometric technique are studied within a three electrode chamber. Ag/AgCl and Pt are used as reference and counter electrodes respectively to carry out the sensing experiments. The developed working electrode shows distinguishable cyclic voltammetric and amperometric response in presence of different concentration (0.27–2.48 mM) of aqueous fluoride solution. The interference of the sensor is verified in presence of nitrate (NO3−) and chloride (Cl−) ions. In order to understand the behaviour of electrochemical interaction, the phase and morphology of the electrode material is studied prior and after sensing. A plausible mechanism is proposed for the electrochemical sensing of fluoride by iron (III) oxide hydroxide film.

Enhanced electrokinetic remediation of lead- and cadmium-contaminated paddy soil by composite electrolyte of sodium chloride and citric acid

The aim of this study was to inquire about the removal efficiencies of lead and cadmium in paddy soil by a composite electrolyte of sodium chloride and citric acid under electrokinetic remediation. The experiment was operated in a plexiglass tank, which was divided into one soil column (length × width × height = 20 cm × 5 cm × 5 cm) and two electrode chambers (length × width × height = 6 cm × 5 cm × 5 cm). In this paper, the composite electrolyte (sodium chloride + citric acid) which combined the merits of two different chemicals was investigated for electrokinetic remediation of lead- and cadmium-contaminated paddy soil under a voltage gradient of 1.5 V/cm during a 20-day treatment. The total concentrations of lead and cadmium in the initial soil were 940.83 and 4.51 mg/kg, respectively. As sodium chloride was solubilized in solution, a number of Na+, Cl−, OH−, and H+ ions were generated that could dissolve some of Pb and Cd in soil to form Cd–Cl and Pb–Cl. When the lead- and cadmium-contaminated paddy soil was implemented with 0.1 M sodium chloride, the total removal efficiencies of lead and cadmium were 23.10 and 27.94%, respectively, which were little higher than those implemented with deionized water. Citric acid was not only used to control pH, but it can also combine with metals to form soluble M-citrate. When sodium chloride was mixed with citric acid in electrokinetic (EK) remediation, high redox potential was obtained that forced most of the metals to migrate out from soil. The overall removal efficiencies of lead and cadmium were increased from 56.85 and 62.26% with single citric acid electrolyte to 80.37 and 90.86% with composite electrolyte of sodium chloride and citric acid, respectively. Eventually, the residual concentrations of lead and cadmium in the soil were only 184.70 and 0.41mg/kg, respectively, which met the demand of agricultural production and human health requirements. Citric acid + sodium chloride treatment poses less environmental risk than inorganic acid (HCl, HNO3, and H2SO4). There is good synergistic effect of sodium chloride and citric acid during the EK remediation process. Thus, citric acid + sodium chloride is considered as an effective electrolyte to remove lead and cadmium from paddy soil.

Energy from Salinity Gradients

Osmotic power or salinity gradient power (SGP) is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarded osmosis (PRO). SGP can be generated from reversible mixing of two kinds of water with different salt contents. A process for generating potential from salinity concentration gradient produced in single cell (25 cm2) and multi-cell assembly is presented. The salinity gradient is created using a fuel cell type cell with a micro-porous ion exchange membrane, both anionic (AEM) and cationic (CEM). The study was performed for various gradients. Salt : Fresh, from 100 : 0 to 16000 : 0 was established using NaCl solution, in the electrode chambers. A potential of 25 mV/cm was realized at ambient temperatures and pressures for a bipolar AEM/CEM cell. The achievable potential is still below theoretical value. The performance was optimized for various static and dynamic flow rates of the saline and fresh water. For this purpose the cell flow field was simulated using ANSYS and the flow field design was optimized for maximum coverage of the cell area. The cell performance can further be optimized for various Membrane Electrode System (MES) structure. Cyclic Voltammetry (CV) studies were made to understand the redox process. The electrochemical and electrical efficiency was discussed for various gradients and flow rates. The higher the salinity gradient the larger is the potential generated. This is limited by the membrane characteristics. The membrane characteristics have been studied for optimal ion crossover for various gradients and flow.

A novel electrochemical reactor for nitrogen and phosphorus recovery from domestic wastewater

To separate and concentrate NH4+ and PO4 3– from the synthetic wastewater to the concentrated solution through a novel electrochemical reactor with circulated anode and cathode using the difference of the concentration between electrode chamber and middle chamber.In recent years, the research on electrochemical processes have been focused on phosphate and ammonium removal and recovery. Among the wide range of possibilities with regards to electrochemical processes, capacitive deionization (CDI) saves the most energy while at the same time does not have continuity and selectivity. In this study, a new electrochemical reactor with electrolyte cyclic flowing in the electrode chambers was constructed to separate and concentrate phosphate and ammonium continuously and selectively from wastewater, based on the principle of CDI. At the concentration ratio of NaCl solution between the electrode chambers and the middle chamber (r) of 25 to 1, phosphate and ammonium in concentration level of domestic wastewater can be removed and recovered continuously and selectively as struvite. Long-term operation also indicated the ability to continuously repeat the reaction and verified sustained stability. Further, the selective recovery at the certain r could also be available to similar technologies for recovering other kinds of substances.