Liquid Mercury Research Articles

Biopolymer-enhanced delivery of reactive sulfide reagents for in-situ mercury remediation of heterogeneous contaminated soils

Mercury pollution from natural and anthropogenic sources demands effective remediation. This study focuses on optimizing a chemical stabilization approach using sulfur-containing compounds to create stable mercury sulfide (HgS) and immobilize elemental mercury in polluted soils. We propose using xanthan gum biopolymer to enhance the in-situ delivery of sulfide microparticles, overcoming soil heterogeneities due to its non-Newtonian behavior. Stability tests indicated that increased biopolymer concentration enhances particle stability due to the viscous and shear-thinning behavior of the polymer solutions. Various combinations (12 solutions) of xanthan polymer, pyrite microparticles, and sulfide-containing reagents were tested in batch experiments. Pyrite microparticles slightly reduced the xanthan solution's viscosity while retaining its non-Newtonian character. All solutions effectively transformed liquid mercury droplets into cinnabar, demonstrating successful mercury stabilization. Notably, solutions containing PIAX and SIPX, xanthate organosulfur compounds, significantly reduced the dissolved concentration of elemental mercury. Column experiments demonstrated xanthan gum's superior performance for in-situ injection of pyrite microparticles and sulfide mixtures into the soil compared to conventional water injection. At a polymer concentration of 4 g/L, a stable displacement front and an 88 % recovery of the initially injected particle-suspension density were achieved. The combined effects of xanthate's floating behavior and xanthan gum's shear-thinning nature substantially enhanced the delivery of pyrite microparticles in porous media for soil mercury remediation. This combination reduced the aqueous elemental mercury concentration in artificially polluted sand by up to 97 %, particularly with the xanthate organosulfur compound, PIAX. Xanthate has a higher potential to react with elemental mercury to form cinnabar compared to sodium thiosulfate. Additionally, the pyrite microparticles, rendered hydrophobic in xanthate solutions, integrated into the mercury droplets, forming a black paste. This study introduces a promising approach for efficient elemental mercury stabilization in contaminated soils by integrating biopolymers, reactive soluble compounds, and pyrite microparticles for sustainable decontamination.

Stabilization of residual mercury from gold mining as metacinnabar and cinnabar in ball mills on a pilot scale

Waste liquid mercury generated as a by-product of the Merrill–Crowe process in gold mining and recovered from mercury-containing waste must be stabilized for secure storage or disposal. This study developed a procedure for mercury stabilization. A ball mill with a 0.5 m3 capacity and a rotational speed of 43 rpm was used to stabilize the residual mercury with sulfur. The treatments were conducted for 30, 60, and 90 min at mercury: sulfur molar ratios of 1.0, 0.8, and 0.67. The ball loading ratio was 7.0 with residual mercury, and the temperature was below 40 °C. The treatment efficiency was evaluated by measuring the concentrations of mercury and other metals using the Toxicity Characteristic Leaching Procedure (TCLP), examining the stabilized residual mercury by X-ray diffraction, and conducting bioassays on Daphnia magna and Lactuca sativa. Principal component analysis (PCA) was performed on the aforementioned variables. The 90-min treatment, with a mercury-to-sulfur molar ratio of 0.67, stabilized mercury mainly as cinnabar compared with the other treatments and presented leachate mercury values below the detection limit <0.003. The leachate from the treatments also showed values of 21.28–38.44 toxic units, classified as very toxic, and generated toxicity, particularly for D. magna, because of the presence of other metals such as Al, Ba, B, Ca, Cu, Cr, Fe, Mn, Ni, and Zn. The variability of the residues in the PCA analysis was explained by the treatment effect and the presence of other metals in the residual mercury. The stabilized residual mercury obtained was classified as non-hazardous and could be stored or disposed of as ordinary waste in a security landfill.

The laser pump X-ray probe system at LISA P08 PETRA III.

Understanding and controlling the structure and function of liquid interfaces is a constant challenge in biology, nanoscience and nanotechnology, with applications ranging from molecular electronics to controlled drug release. X-ray reflectivity and grazing incidence diffraction provide invaluable probes for studying the atomic scale structure at liquid-air interfaces. The new time-resolved laser system at the LISA liquid diffractometer situated at beamline P08 at the PETRA III synchrotron radiation source in Hamburg provides a laser pump with X-ray probe. The femtosecond laser combined with the LISA diffractometer allows unique opportunities to investigate photo-induced structural changes at liquid interfaces on the pico- and nanosecond time scales with pump-probe techniques. A time resolution of 38 ps has been achieved and verified with Bi. First experiments include laser-induced effects on salt solutions and liquid mercury surfaces with static and varied time scales measurements showing the proof of concept for investigations at liquid surfaces.

Impact of Pt(hkl) Electrode Surface Structure on the Electrical Double Layer Capacitance.

The classical theory of the electrical double layer (EDL) does not consider the effects of the electrode surface structure on the EDL properties. Moreover, the best agreement between the traditional EDL theory and experiments has been achieved so far only for a very limited number of ideal systems, such as liquid metal mercury electrodes, for which it is challenging to operate with specific surface structures. In the case of solid electrodes, the predictive power of classical theory is often not acceptable for electrochemical energy applications, e.g., in supercapacitors, due to the effects of surface structure, electrode composition, and complex electrolyte contributions. In this work, we combine ab initio molecular dynamics (AIMD) simulations and electrochemical experiments to elucidate the relationship between the structure of Pt(hkl) surfaces and the double-layer capacitance as a key property of the EDL. Flat, stepped, and kinked Pt single crystal facets in contact with acidic HClO4 media are selected as our model systems. We demonstrate that introducing specific defects, such as steps, can substantially reduce the EDL capacitances close to the potential of zero charge (PZC). Our AIMD simulations reveal that different Pt facets are characterized by different net orientations of the water dipole moment at the interface. That allows us to rationalize the experimentally measured (inverse) volcano-shaped capacitance as a function of the surface step density.

Calibration of the 2-Phase Bubble Tracking Model for Liquid Mercury Target Simulation with Machine Learning Surrogate Models

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is one of the most powerful accelerator-driven neutron sources in the world. The intense protons strike on SNS’s mercury target to provide bright neutron beams, which also leads to severe fluid-structure interactions inside the target. Prediction of resultant loading on the target is difficult particularly when helium gas is injected into mercury to reduce the loading and mitigate the pitting damage on vessel walls. A 2-phase material model that incorporates the Rayleigh-Plesset (R-P) model is expected to address this multi-physics problem. However, several uncertain parameters in the R-P model require intensive simulations to determine their optimal values. With the help of machine learning and the measured target strain, we have studied the major uncertain parameters in this R-P model and developed a framework to identify optimal parameters that significantly reduce the discrepancy between simulations and experimental strains. The preliminary results show the possibility of using this mercury/helium mixture and surrogate models to predict a better match of target strain response when the helium gas is injected.

Survey of Variables with the ILMT

Nestled in the mountains of Northern India, is a 4-metre rotating dish of liquid mercury. Over a 10-year period, the International Liquid Mirror Telescope (ILMT) will survey 117 square degrees of sky, to study the astrometric and photometric variability of all detected objects. One of the scientific programs will be a survey of variable stars. The data gathered will be used to construct a comprehensive catalog of light curves. This will be an essential resource for astronomers studying the formation and evolution of stars, the structure and dynamics of our Milky Way galaxy, and the properties of the Universe as a whole. This catalog will be an aid in our advance to understanding the cosmos and provide deeper insights into the fundamental processes that shape our Universe. In this work, we describe the survey and give some examples of variable stars found in the early commissioning data from the ILMT.

Role of Chemisorbing Species in Growth at Liquid Metal-Electrolyte Interfaces Revealed by in Situ X-Ray Scattering

Liquid-liquid interfaces offer intriguing possibilities for nanomaterials growth. Especially, growth at liquid metal surfaces has recently received renewed interest. Here, fundamental interface-related mechanisms that control the growth behavior in these systems are studied for the case of Pb halide compound formation at the interface between liquid mercury electrode and aqueous salt solutions, using in situ X-ray reflectivity and grazing incidence X-ray diffraction, supplemented by electrochemical measurements and optical microscopy. The nucleation and growth of these compounds at potentials in the regime of Pb de-amalgamation was investigated in NaX + PbX2 (X = F, Cl, Br) to systematically explore the role of the halide species. X-ray reflectivity studies reveal the rapid formation of well-defined ultrathin precursor adlayers in Cl- and Br-containing solution. This adlayer formation is followed by subsequent quasi-epitaxial growth of Pb(OH)X bulk crystals, that are oriented with the c-axis along the surface normal. In contrast, growth in F-containing solution proceeds by slow formation of a more disordered deposit, resulting in random bulk crystal orientations on the Hg surface. A detailed structural analysis of the Pb(OH)Br and Pb(OH)Cl precursor adlayers reveals that they determine the orientation of the subsequently formed bulk crystals, with the arrangement in the adlayer providing a template. Together with our previous results on the pseudo-epitaxial growth of PbFBr on Hg (A. Elsen, et al., Proc.Nat.Acad.Sci., 2013, 110, 6663), these data reveal the decisive role of the interface chemistry, especially the strong chemisorption of the anions bromide and chloride, in steering the formation of these textured deposits at the liquid metal surface.

Investigation on coal floatability and pore characteristics using acidification method

This paper investigated the relationship between coal floatability and pore characteristics from the perspective of froth flotation. Three types of coal samples with different ash contents were pretreated with HCl and acetic acid solutions to alter the pore features. The X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) measurements were conducted to specify the reactions that happened in acidification. The batch flotation and contact angle measurements were conducted to evaluate the floatability of the coal samples. The liquid nitrogen adsorption and mercury intrusion porosimetry (MIP) measurements were applied to measure the pore characteristics of the coal. The acidification treatment partially dissolved mineral components and organic functional groups on the coal surface but did not change the types of the major functional groups. The sedimentation of liberated fine minerals on coal pores caused the decrease in pore volume. The BET specific surface area of the three coal samples after acidification was found to have consistent negative relations with the flotation recovery and combustible recovery rate. This indicated the adverse impact of porosity in coal flotation. The floatability of coal is mainly influenced by the pores at the size fraction of 1–20 μm by pore volume. The nano-scale size pore and fine mineral inside the micron pore increased the water-wettability and resulted in the low floatability of coal.

Background and geochemical baseline values of chalcophile and siderophile elements in soils around the former mining area of Abbadia San Salvatore (Mt. Amiata, southern Tuscany, Italy)

Background and geochemical baseline values of Potentially Toxic Elements (PTEs) in soils developed on natural or anthropogenically-affected areas are increasingly important parameters as they represent highly useful tools at local, regional, national and European level. While background values are mostly applied to uncontaminated areas to verify the presence of high to anomalous concentrations of PTEs due to geogenic sources, the geochemical baseline values are better representing those areas where the anthropogenic activities have altered more or less significantly the background values. This is the case of the Municipality of Abbadia San Salvatore, mostly lying above the volcanic products of Mt. Amiata (Tuscany, central Italy) and, subordinately, above sedimentary formations, where >100 years of exploitation of cinnabar (HgS) and production of liquid mercury have affected the environmental matrices, including the pedosphere compartment. Consequently, 51 top-soils and 51 sub-soils, developed on the volcanic and sedimentary domains were collected and analyzed for PTEs (Hg, As, Sb, Cr, Co, Ni, Cu and V). A CoDA (Compositional Data Analysis) approach (robust Principal Component Analysis) combined with geochemical mapping allowed to account for the compositional nature of geochemical data and define the spatial distribution of the investigated chalcophile and siderophile elements. The results obtained by CoDa are useful to understand data variability and relative variations of the elements compared to the barycenter of the total composition. Independently by the substratum (volcanic or sedimentary), the concentrations of Hg, As, Sb, Cr, Co, Ni, Cu and V were highly variable and up to 258, 276, 110, 261, 32, 132, 80 and 173 mg/kg, respectively. Owing to the significant differences between the two geological domains, the two datasets were considered separately in order to define the geochemical baseline values of the analyzed PTEs computed using ProUCL 5.2.0 software. Accordingly, the geochemical baseline values of Hg, As, Cr, Co and V were much higher than the values imposed by the Italian Legislative Decree 152/06, suggesting the importance of exploring the geological features of the investigated territories and their anthropic history, particularly in Italy where poly-metallic sulfide ore deposits have been exploited in many regions since the Etruscan and Roman times.

Oreate - Oxide Reduction by Electrochemical Amalgamation and Thermal Extraction

Establishing a capability for generating consistent, small-scale, and high-purity metals (i.e., transition metals, lanthanides and actinides) would have significant impact in many levels from fundamental science to national security related applications. Among the many procedures to purify transition and f-block metals (direct oxide reduction, electrolysis in molten salts, etc), there does not exist a U.S. process that can respond to the diverse needs of small- and large-scale science campaigns. Hence, there is widespread need to develop a capability that can supply a broad range of customers with “craft” metals of interest. The main goal is to consistently convert metal oxides to chemically pure metals in near quantitative yield.Traditional separation methods of actinides and lanthanides from aqueous media has been based on structure and bonding differences between these metals with various ligands. Although liquid-liquid extractions have proven to be quite efficient, they are expensive and require complex engineering. On the other hand, separation by pyro-chemistry based on the difference of their reductive extraction to metallic phase provides a good separation performance but requires the use of high temperatures, which adds technological difficulties to the process. An alternative method that has grown interest in the last few years is the utilization of the difference in the reduction potentials from ionic state to metallic state. However, this electrochemical approach has been believed difficult because of the highly negative reduction potentials of these metals (more negative than hydrogen evolution) and the challenging control of their electrolytic deposition onto solid cathodes.In this work we present a process comprising the oxide reduction by electrochemical amalgamation and thermal extraction (OREATE) that intends to be an optimized version of the traditional electrochemical amalgamation process in aqueous medium for trivalent f-elements. A mercury pool is used as cathode material to overcome most of the difficulties related to the use of solid cathodes: (i) Once reduced to the metallic state, the metal quickly dissolves into the liquid mercury to form amalgam, which ensures more stable surface condition of the cathode. (ii) Higher hydrogen over-voltage on mercury enables more effective reduction of the metals in a slightly acidic solution. (iii) Mercury's high vapor pressure allows an easy thermal extraction process to obtain a highly pure metal.As part of our study, we have maximized the yield of the Ce electrochemical amalgamation (yield > 99%) by monitoring dissolved Ce3+ concentration in solution by UV-vis, optimized the mercury recycling process during the thermal extraction (Hg recycling > 99%), as well as improved the purity of the Ce content in the product (Ce purity > 99%). The proposed OREATE method appears easier and simpler than traditional separation and purification methods and is suitable for laboratory scale preparation of high purity metals.

Experimental study of high performance mercury-based triboelectric nanogenerator for low-frequency wave energy harvesting

Wave energy is acknowledged as one of the most promising renewable energy sources, effectively developing wave energy conversion technologies might contribute to solving the power shortage dilemma. However, the optimum performance frequency range of current wave energy capture devices does not match the low-frequency ocean kinetic energy. Here, a triboelectric nanogenerator based on liquid mercury (M-TENG) is presented for low-cost and high-power harvesting. The start-up performance of the M-TENG unit is analyzed at low operating frequencies, and discuss the effect of kinematic inputs, structural parameters and materials aspects on output performance. Meanwhile, the sloshing characteristics of mercury in a rectangular unit were calculated by the SST k-ω model, deriving the matching law between mercury volume and electrical output. Furthermore, 18-unit integrated M-TENG produce a peak power output of 4.57 mW, the mercury with its unique physical properties generates higher transferred charge density up to 35.84 mC/m3, sufficient to light 270 commercial LEDs at 1.00 Hz. The relatively high volumetric power density provides a realistic self-supply technological solution for renewable energy harvesting and guarantees the widespread use of milliwatt power equipment in the marine industry.

Simulating vibro-acoustic damping of bubbles in fluids

Bubbles in fluids are common occurrence due to impurities, thermal or flow variations. They are sometimes considered detrimental to the flow and more importantly surrounding structural integrity. On the other hand, bubbles were used positively towards damping vibrations in fluid filled structures [1] and as barriers or curtains in the removal of plastic waste from water ways [2] and also in noise attenuation from offshore windfarms [3]. In the latter two cases, engineers hypothesized these curtains help marine life from sound pollution from surrounding machinery and ships. In this paper the authors discuss two cases to study the effect of bubble size and bubble density. In the first experiment a curtain of air bubbles was introduced in a water body and sound transmission loss (STL) through this curtain was studied. In a second experiment, a stainless-steel tank filled with liquid mercury is infused with helium bubbles and the vibration levels were monitored.

Implementing bubbly mercury material model (R-P model) in the pulse simulation to predict strain on the Spallation Neutron Source target vessel with gas injection

The Spallation Neutron Source (SNS) creates neutrons by striking a liquid mercury target with short pulses of high-energy protons. SNS targets have been operated with helium microbubble gas injection into portions of the flowing mercury since 2017. The measurements during in situ testing showed that the strain response of the stainless steel target vessel significantly decreased with gas injection. Strain reductions ranged from 40% to 75% for targets operating with gas-injection rates between 2 and 3 standard liters per minute. These strain reductions have allowed SNS to operate reliably at 1.4 MW over the last few years and are expected to significantly improve the fatigue life of the target vessel. The achieved mitigation of the pulse response and the associated cavitation damage with gas injection is a cornerstone of the upgrade basis to the redesigned mercury vessel for planned higher power operation.Existing methods can simulate the structural response of the target operated without gas injection. Developing simulation techniques that account for the benefits of gas injection adds a considerable challenge. A combined mercury/bubble material model based on the Rayleigh–Plesset equation was developed to improve simulation of the response of a structure containing liquid and gas by incorporating bubble growth volume feedback. This paper details the implementation of the mercury/bubble material model in the pulse simulation of an existing target design. The newly developed simulation technique combines the current no-gas mercury material model for no-gas regions and the bubbly mercury material model for the regions with gas bubbles. The results of the strain response simulation using the new techniques are promising. The challenges of the technique development are also discussed. For example, the bubble size distributions are crucial for the simulations but remain an area of active research.

Nanometals and Metal Ion Pollution from Dental Materials in Dental Environment

The dental environment is being polluted with metals from dental materials in many ways, mainly due to aerosol-generating procedures; this could affect the long-term well-being of dentists, dental students, and dental personnel. The current dental pollution incorporates metallic nanoparticles, which are highly reactive and quickly become airborne, especially those particles that become unbound in the bulk composition. In addition, liquid mercury or mercury vapors may be released from dental amalgam, causing concerns in the dental community. In our study, we reviewed the behavior of metallic elements present in dental materials, their routes of exposure, and their potentially toxic effects on the dental team. This review found that skin and lung disorders are the most harmful effects of metallic exposure for dentists, dental students, and dental personnel. Therefore, chronic exposure to low concentrations of metals in the dental environment, especially in nanosized forms, should be further investigated to improve the environmental matrix, material choice, and safety protocols.

Oh, My Darling Clementine: A Detailed History and Data Repository of the Los Alamos Plutonium Fast Reactor

The Los Alamos Plutonium Fast Reactor, Clementine, provided the first fast neutron spectrum using a metallic plutonium fuel system and liquid mercury coolant. Clementine is often mentioned in the history of fast, metal-fueled, or metal-cooled designs, with little public information regarding the specifications or timeline. This paper contains a synopsis of each report regarding the development, operation, experimental results, failures, and subsequent disassembly of Clementine to explore this unique reactor within the context of modern advanced reactor development.

Spin hydrodynamic generation in unsteady flows

We theoretically investigate a spin-mediated conversion from fluid dynamics to voltage, known as spin hydrodynamic generation (SHDG), in oscillatory and transient unsteady flows. We consider unsteady flows of liquid metal between two parallel infinite planes and then calculate its vorticity fields based on the Navier–Stokes equation for an incompressible viscous fluid. The spin accumulation and spin current generated by unsteady flows are derived using a spin-diffusion equation, including spin-vorticity coupling, which is a couple of angular momentum between electron spin and vorticity field in unsteady flows. The estimation of SHDG in liquid mercury flow suggests that an observable magnitude of voltage can be induced in unsteady flows. Our results are expected to enable the realization of high-speed spin devices with unsteady flows and broaden the range of fluid spintronics applicability.

Measurement of a radial flow profile with eddy current flow meters and deep neural networks *

Eddy current flow meters (ECFMs) measure flows of conductive fluids. Recent interest in ECFMs has increased due to applications in advanced nuclear reactors. ECFMs are well suited for such applications, as they can provide non-invasive measurements of flow in fluids that are often difficult to measure. Traditionally, ECFMs are operated using an alternating current at a single frequency, limiting ECFMs to measure average fluid velocities, blockages, or voids. We expand the capabilities of ECFMs by measuring the fluid radial velocity profile of liquid mercury. To accomplish this, we made several ECFM sensitivity measurements at a range of frequencies. Different frequencies vary the electromagnetic skin depth of the device. By adjusting frequencies, we probed the fluid velocity at various radial locations and constructed a flow-velocity profile. The relationship between the ECFM measurements and velocity profile is nonlinear and requires solving an inverse problem. Using electromagnetic finite-element simulations to train a deep neural network (DNN), we created a model that provides a stable general relationship between the sensitivity measurements of an ECFM and the fluid velocity profile. Using ECFM measurements of liquid mercury, our DNN model calculates a flow profile that agrees well with computational fluid dynamics (CFD) simulations. This technique has potential to improve flow monitoring for optimization, safe operation of conductive fluid loops, and/or validating complex CFD models.

Test of Mercury (Hg) Content in Mozambique Tilapia Fish (Oreochromis Mossambicus) from Lake Rawa Taliwang Nature Tourism Park, West Sumbawa Regency

Rawa Taliwang Lake Natural Tourism Park is a freshwater waters located in West Sumbawa Regency with an area of ​​819.20 ha. Rawa Taliwang Lake Natural Tourism Park is dominated by various types of fish, so that local people catch fish in this lake to meet their consumption needs and for sale. In addition, the lake's catchment area also holds mining potential, especially gold. Small-scale gold mining, mostly found in the mountains and hills around catchment area Lake Rawa Taliwang. This mining uses liquid mercury as a gold binder from the ore. Some waste that has an impact on the end of lake water so that it can affect the lake ecosystem. Therefore, research is needed to determine the amount of mercury (Hg) in tilapia mozambique fish (Oreochromis mossambicus) from Rawa Taliwang Lake Natural Tourism Park. This study uses a quantitative descriptive method. In this study, sampling was carried out by purposive sampling at 3 location points with 3 repetitions. The research sample used 9 tilapia Mozambique fish. The data obtained were analyzed using the Atomic Absorption Spectrophotometry (AAS) method. The results showed that the mercury content in tilapia mozambique fish was &lt; 0.001 ppm. So it can be said that in the flesh of tilapia fish no heavy metal mercury (Hg) was detected.

History of Amalgam

Dental amalgam fillings are often called "silver fillings" because of their silver-like appearance. This material was used to fill cavities caused by tooth decay. The dental amalgam is a mixture of metals consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper.

Sonochemical oxidation and stabilization of liquid elemental mercury in water and soil

Over 3000 mercury (Hg)-contaminated sites worldwide contain liquid metallic Hg [Hg(0)l] representing a continuous source of elemental Hg(0) in the environment through volatilization and solubilization in water. Currently, there are few effective treatment technologies available to remove or sequester Hg(0)l in situ. We investigated sonochemical treatments coupled with complexing agents, polysulfide and sulfide, in oxidizing Hg(0)l and stabilizing Hg in water, soil and quartz sand. Results indicate that sonication is highly effective in breaking up and oxidizing liquid Hg(0)l beads via acoustic cavitation, particularly in the presence of polysulfide. Without complexing agents, sonication caused only minor oxidation of Hg(0)l but increased headspace gaseous Hg(0)g and dissolved Hg(0)aq in water. However, the presence of polysulfide essentially stopped Hg(0) volatilization and solubilization. As a charged polymer, polysulfide was more effective than sulfide in oxidizing Hg(0)l and subsequently stabilizing the precipitated metacinnabar (β-HgS) nanocrystals. Sonochemical treatments with sulfide yielded incomplete oxidation of Hg(0)l, likely resulting from the formation of HgS coatings on the dispersed µm-size Hg(0)l bead surfaces. Sonication with polysulfide also resulted in rapid oxidation of Hg(0)l and precipitation of HgS in quartz sand and in the Hg(0)l-contaminated soil. This research indicates that sonochemical treatment with polysulfide could be an effective means in rapidly converting Hg(0)l to insoluble HgS precipitates in water and sediments, thereby preventing its further emission and release to the environment. We suggest that future studies are performed to confirm its technical feasibility and treatment efficacy for remediation applications.