Solubility Of Zn Research Articles

Zinc Speciation in Proximity to Phosphate Application Points in a Lead/Zinc Smelter–Contaminated Soil

The use of P to immobilize Pb in contaminated soils has been well documented. However, the influence of P on Zn speciation in soils has not been extensively examined, and these two metals often occur as co-contaminants. We hypothesized that additions of P to a Pb/Zn-contaminated soil would induce Zn phosphate mineral formation and fluid P sources would be more effective than granular P amendments. A combination of different synchrotron-based techniques, namely, spatially resolved micro-X-ray fluorescence (μ-XRF), micro-extended X-ray absorption fine structure spectroscopy (μ-EXAFS), and micro-X-ray diffraction (μ-XRD), were used to speciate Zn at two incubation times in the proximity of application points (0 to 4 mm) for fluid and granular P amendments in a Pb/Zn smelter-contaminated soil. Phosphate rock (PR), triple super phosphate (TSP), monoammonium phosphate (MAP), and fluid ammonium polyphosphate induced Zn phosphate formation. Ammonium polyphosphate was more effective at greater distances (up to 3.7 mm) from the point of P application. Phosphoric acid increased the presence of soluble Zn species because of increased acidity. Soluble Zn has implications with respect to Zn bioavailability, which may negatively impact vegetation and other sensitive organisms. Although additions of P immobilize Pb, this practice needs close monitoring due to potential increases in Zn solubility in a Pb/Zn smelter-contaminated soil.

Effect of indium addition on the microstructural formation and soldered interfaces of Sn-2.5Bi-1Zn-0.3Ag lead-free solder

The microstructural formation and properties of Sn-2.5Bi−xIn-1Zn-0.3Ag (in wt%) alloys and the evolution of soldered interfaces on a Cu substrate were investigated. Apart from the relatively low melting point (about 195°C), which is close to that of conventional eutectic Sn-Pb solder, the investigated solder presents superior wettability, solderability, and ductility. The refined equiaxial grains enhance the mechanical properties, and the embedded bulk intermetallic compounds (IMCs) (Cu6Sn5 and Cu5Zn8) and granular Bi particles improve the joint reliability. The addition of In reduces the solubility of Zn in the β-Sn matrix and strongly influences the separation and growth behaviors of the IMCs. The soldered interface of Sn-2.5Bi-xIn-1Zn-0.3Ag/Cu consists of Cu-Zn and Cu-Sn IMC layers.

A comparison of physiologically based extraction test (PBET) and single-extraction methods for release of Cu, Zn, and Pb from mildly acidic and alkali soils

In vitro digestion test can be applied to evaluate the bioaccessibility of soil metals by measuring the solubility of the metals in synthetic human digestive tract. Physiologically based extraction test (PBET), composed of sequential digestion of gastric and intestinal phase, is one of the frequently used in vitro digestion tests. In this study, the PBET was chosen to determine the bioaccessibility of Cu, Zn, and Pb in 14 mildly acidic and alkali (pH 5.87-8.30) soils. The phytoavailability of Cu, Zn, and Pb in the same soils was also measured using six single-extraction methods (0.1 M HNO₃, 0.4 M HOAc, 0.1 M NaNO₃, 0.01 M CaCl₂, 0.05 M EDTA, and 0.5 M DTPA). The extraction efficiencies of the methods were compared. The PBET had a strong ability to extract metals from soil, which was much greater than neutral salt extraction and close to dilute acid and complex extraction in spite of the last 2 h neutral intestinal digestion. The amounts of bioaccessible Cu, Zn, and Pb in the gastric phase and in the gastrointestinal phase were both largely determined by the total content of soil Cu, Zn, and Pb. But the results of gastrointestinal digestion reflected more differences resulting from element and soil types than those of gastric digestion did. It was noticed that most of variations in the amounts of soil Cu, Zn, and Pb extracted by EDTA were well explained by the total soil Cu, Zn, and Pb, as same as the PBET. Moreover, the solubility of Cu, Zn, and Pb in the gastric phase and gastrointestinal phase were all positively linearly correlated with the results of EDTA. It was suggested that EDTA extraction can be used to predict the bioaccessibility of Cu, Zn, and Pb in mildly acidic and alkali (pH > 5.8) soils, and the PBET and EDTA could be applied to measure, in a certain extent, the bioaccessibility and phytoavailability of Cu, Zn, and Pb in mildly acidic and alkali (pH > 5.8) soils at the same time.

From Coin to Medal: A Metallurgical Study of the Brazing Drop on a 19th Century Scudo

In the past, it was customary to use out-of-circulation coins as pendants by brazing a peg or ring on the edge of the coin in order to transform it into a devotional or decorative object; this practice was very common for specimens of the Papal States, especially for silver coins. This metallurgical investigation of a 19th century Scudo aimed to relate the internal structure of the coin to the minting technology with a special focus on the brazing drop, in order to provide information on the solidification microstructure arising from a strongly nonequilibrium process such as brazing. The results show that the Ag content in the coin ranges from 92% in the bulk up to 97% on the surface, due to enrichment, while analysis of the brazing revealed that it consists of an Ag-Cu-Zn-Pb alloy, for which the melting temperature has been estimated. Considering the distribution of minor elements, Zn segregates in the secondary (Cu-rich) β-dendrites and inside the whole eutectic structure, while Pb is only present in the Ag-based phases and seems to reduce the solubility of Zn inside the primary (Ag-rich) α-dendrites.

Experimental investigation on phase equilibria of Ce-Sn-Zn system at 400 °C

The Ce-Sn-Zn alloys were prepared by furnace melting. The isothermal section of the Ce-Sn-Zn system at 400 °C over the whole composition range was established by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). A new ternary compound, CeSn2Zn2, was discovered in the present work. This compound adopted CaBe2Ge2 structure type (space group P4/nmm) with the lattice parameters of a=0.4455 (9) nm and c=1.0348 (1) nm. The existence of previously known ternary compounds, CeSnZn and Ce2SnZn3, were confirmed, too. The maximum solubility of Zn in CeSn3 was determined to be 12.7 at.%.

Near surface layer evolution in Zn+ ions implanted Si upon annealing treatments

The damaged layer in Zn implanted n-type CZ-Si(100) substrates was investigated by a secondary ion mass-spectrometry (SIMS), an X-ray diffraction (XRD) and an atomic force microscopy (AFM). The substrates were implanted with 64Zn+ ions at an energy of 100keV and an ion dose of 2×1016cm−2 with subsequent annealing at 400, 600, 700, 800, 900 and 1000°C for 60min in neutral/inert and oxygen atmosphere. A significant redistribution of Zn atoms in the damaged layer caused by the thermal annealing was found by SIMS. Zn concentration maximum exceeds a Zn solubility limit in Si; therefore, a decomposition of Zn solid solution in Si resulting in formation of zinc-containing phases in the surface layer should be expected. In an as-implanted state, the amorphous layer with thickness about 100nm, which located inside of a substrate on the depth more than value Rp, is formed. After thermal annealing at 800°C nanoparticles on the sample surface were revealed. After 1000°C annealing the radiation-induced defects completely disappeared, and Zn implanted atoms are revealed in the near surface layer.

Phase relations and crystal structures in the system Ce–Ni–Zn at 800 °C

Phase relations have been established for the system Ce–Ni–Zn in the isothermal section at 800°C using electron microprobe analysis and X-ray powder diffraction. Phase equilibria at 800°C are characterized by a large region for the liquid phase covering most of the Ce-rich part of the diagram, whereas a Zn-rich liquid is confined to a small region near the Zn-corner of the Gibbs triangle. Whereas solubility of Ce in the binary Ni-Zn phases is negligible, mutual solubilities of Ni and Zn at a constant Ce content are large at 800°C for most Ce–Zn and Ce–Ni compounds. The solid solution Ce(Ni1−xZnx)5 with the CaCu5-type is continuous throughout the entire section and for the full temperature region from 400 to 800°C. Substitution of Zn by Ni is found to stabilize the structure of CeZn11 to higher temperatures. At 800°C Ce(NixZn1−x)11 (0.03≤x≤0.22) appears as a ternary solution phase. Similarly, a rather extended solution forms for Ce2(NixZn1−x)17 (0≤x≤0.53). Detailed data on atom site occupation and atom parameters were derived from X-ray structure analyses for single crystals of Ce2+y(NixZn1−x)17, y=0.02, x=0.49 (a=0.87541(3), c=1.25410(4)nm; Th2Zn17 type with space group R3¯m,RF2=0.018) and Ce(Ni0.18Zn0.82)11 (a=1.04302(2), c=0.67624(3)nm, BaCd11 type with space group I41/amd, RF2=0.049).

Zinc nutrition in rice production systems: a review

Zinc (Zn) deficiency is one of the important abiotic factors limiting rice productivity worldwide and also a widespread nutritional disorder affecting human health. Given that rice is a staple for populations in many countries, studies of Zn dynamics and management in rice soils is of great importance. Changing climate is forcing the growers to switch from conventional rice transplanting in flooded soils to water-saving cultivation, including aerobic rice culture and alternate wetting and drying system. As soil properties are changed with altered soil and water management, which is likely to affect Zn solubility and plant availability and should be considered before Zn management in rice. In this review, we critically appraise the role of Zn in plant biology and its dynamics in soil and rice production systems. Strategies and options to improve Zn uptake and partitioning efficiency in rice by using agronomic, breeding and biotechnological tools are also discussed. Although soil application of inorganic Zn fertilizers is widely used, organic and chelated sources are better from economic and environmental perspectives. Use of other methods of Zn application (such as seed treatment, foliar application etc., in association with mycorrhizal fungi) may improve Zn-use efficiency in rice. Conventional breeding together with modern genomic and biotechnological tools may result in development of Zn-efficient rice genotypes that should be used in conjunction with judicious fertilization to optimize rice yield and grain Zn content.

Research on High Pressure Solidification Microstructure and the Microhardness of Al-Mg-Zn Alloy

The solidification microstructure and the microhardness of Al-11Mg-4.5Zn alloy under high pressure were researched by optical microscope, scanning electron microscope (SEM), X-ray diffraction(XRD) and microhardness tester. The results revealed that high pressure solidification refined the dendrite structure, and made the primary dendrite arms grow long. The alloy all consisted of α-Al phase and Mg32(Al, Zn)49 phase whether under normal pressure or high pressure solidification conditions. However, the morphology of the Mg32(Al, Zn)49 phases changed from fork-like of normal pressure to the graininess of high pressure, the size of them reduced, and that of the amount decreased. Furthermore, the solid solubility of Mg and Zn in α-Al phase increased comparing with those of normal pressure, and they were the largest at 4GPa high pressure, reaching 11.37% and 4.15%, respectively. The microhardness of Al-Mg-Zn alloy had an increment with the pressure increasing.

Experimental study of the phase relations in the Co–Si–Zn ternary system at 723 and 873 K

The 723 and 873K isothermal sections of the Co–Si–Zn system have been determined using equilibrated alloys with the aid of a diffusion couple approach. The specimens were investigated by means of scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, electron probe microanalysis and X-ray diffraction. There are nine three-phase regions exist in the isothermal section at 723K and eight three-phase regions at 873K. The CoSi phase can coexist with all compounds in Co–Zn binary system except β1 phase. The solubility of Si in Co–Zn binary compounds is limited. The maximum solubility of Zn in CoSi2, CoSi and Co2Si is 2.0, 6.2, and 5.4at.%, respectively.

Dissolution Kinetics of Macronutrient Fertilizers Coated with Manufactured Zinc Oxide Nanoparticles

The solubility of Zn in Zn fertilizers plays an important role in the agronomic effectiveness of the fertilizer. On the basis of thermodynamics, zinc oxide (ZnO) nanoparticles (NPs) should dissolve faster and to a greater extent than bulk ZnO particles (equivalent spherical diameter >100 nm). These novel solubility features of ZnO NPs might be exploited to improve the efficiency of Zn fertilizers. In this study, we compared the Zn solubility and dissolution kinetics of ZnO nanoparticles and bulk ZnO particles coated onto two selected granular macronutrient fertilizers, urea and monoammonium phosphate (MAP). The main Zn species on coated MAP and urea granules were zinc ammonium phosphate and ZnO, respectively. Coated MAP granules showed greater Zn solubility and faster dissolution rates in sand columns compared to coated urea granules, which may be related to pH differences in the solution surrounding the fertilizer granules. The kinetics of Zn dissolution was not affected by the size of the ZnO particles applied for coating of either fertilizer type, possibly because solubility was controlled by formation of the same compounds irrespective of the size of the original ZnO particles used for coating.

450 °C Isothermal Section of the Al-V-Zn System

The 450 °C isothermal section of Al-V-Zn ternary system has been determined experimentally by means of optical microscopy, scanning electron microscopy coupled with energy-dispersive spectrometric, and x-ray diffraction. A new ternary compound named T, containing 8.2-9.9 at.% V, 12.1-27.4 at.% Zn, is positively identified for the first time in this study. The T phase only equilibrates with Al3V, α-Al, and L-Zn. Experimental results indicates that the maximal solubility of Al in VZn3 is 25.2 at.%. The maximum solubility of Zn in α-V is 5.7 at.%. The Zn solubility in Al-V compounds (Al8V5, Al3V, Al23V4, Al45V7, and Al21V2) is 10.6, 9.2, 1.2, 0.6, and 0.4 at.%, respectively. The maximum solubility of Al in V is 41.0 at.%. Nine three-phase regions have been confirmed experimentally in this ternary system.

Effects of Common Ions on Zn Sorption in Some Calcareous Soils of Western Iran

AbstractZinc (Zn) is essential to plant growth and relatively mobile in soils. This study was conducted to assess the effect of common ions (Ca2+, K+, Na+, NH4+, Cl−, NO3−, and H2PO4−) on sorption of Zn in surface samples of ten calcareous soils from western Iran using 10 mmol L−1 KCl, KNO3, KH2PO4, Ca(NO3)2, NaNO3, and NH4NO3 solutions as background electrolytes. The results indicated that both NH4+, K+, and Ca2+ equally decreased Zn sorption as compared to Na+. Zinc sorption was decreased by H2PO4− as compared to NO3− and Cl−. The Langmuir and Freundlich equations fitted closely to the sorption data of all ions. The Langmuir maximum, bonding energy constant, and Freundlich distribution coefficient for Zn sorption differed among the various ionic background electrolytes. Langmuir sorption parameters showed that the presence of H2PO4− decreased the maximum Zn adsorbed, but increased the bonding energy. Although K+ and NH+ equally influenced maximum Zn adsorbed, they differed in their effect on the distribution coefficient of Zn in soils. Values of saturation index calculated using Visual MINTEQ indicated that at the low Zn concentration, Zn solubility was controlled by sorption reactions and at the high Zn concentration, it was mainly controlled by sorption and mineral precipitation reactions, such as precipitation of Zn3(PO4)24H2O, Zn5 (OH)6 (CO3)2, and ZnCO3. For most ionic background electrolytes, soil pH, CaCO3, and cation exchange capacity (CEC) were significantly correlated with sorption parameters.

Speciation and Release Kinetics of Zinc in Contaminated Paddy Soils

Zinc is an important nutrient for plants, but it can be toxic at high concentrations. The solubility and speciation of Zn is controlled by many factors, especially soil pH and Eh, which can vary in lowland rice culture. This study determined Zn speciation and release kinetics in Cd-Zn cocontaminated alkaline and acidified paddy soils, under various flooding periods and draining conditions, by employing synchrotron-based techniques and a stirred-flow kinetic method. Results showed almost no change in Zn speciation and release kinetics in the two soils, although the soils were subjected to different flooding periods and draining conditions. The mineral phases in which Zn is immobilized in the soil samples were constrained by linear least squares fitting (LLSF) analyses of bulk X-ray absorption fine structure (XAFS) spectra. Only two main phases were identified by LLSF, i.e., Zn-layered double hydroxides (Zn/Mg-hydrotalcite-like, and ZnAl-LDH) and Zn-phyllosilicates (Zn-kerolite). Under all soil pHs, flooding, and draining conditions, less than 22% of Zn was desorbed from the soil after a two-hour desorption experiment. The information on Zn chemistry obtained in this study will be useful in finding the best strategy to control Cd and Zn bioavailability in the Cd-Zn cocontaminated paddy soils.

Intermetallics and phase relations of Mg-Zn-Ce alloys at 400 °C

The crystal structures, compositions and phase relations of the intermetallics of Mg-Zn-Ce system in the Mg-rich corner at 400 °C were identified through equilibrium alloy method. For Mg-Zn-Ce system, there is a linear ternary compound (T phase), whose chemical formula is (Mg1-xZnx)11Ce. The range of Zn content in T phase is from 9.6% to 43.6% (molar fraction). The crystal structure of T phase is C-centered orthorhombic lattice with lattice parameters of a=0.96-1.029 nm, b=1.115-1.204 nm, c=0.940-1.015 nm. And the lattice parameters of T phase are decreasing a little with increasing Zn content. According to the results of composition and crystal structure, the maximal solubility of Zn in Mg12Ce is about 7.8% (molar fraction), and the chemical formula of the solid solution can be identified as (Mg1-xZnx)12Ce. The isothermal section of Mg-Zn-Ce system in Mg-rich corner at 400 °C was constructed.

Syntheses and Magnetic-Properties of Zn-Diluted Sr-Based Perovskite Cobalt Oxides, Sr1−x Zn x CoO3; 0.05≤x≤0.3

In order to check the solubility of Zn in the (Sr1−x Zn x )CoO3 perovskite structure and their research findings, several polycrystalline samples have been prepared under wide extreme synthesis conditions at 6 GPa/1300–1650 °C. While 0.05≤x≤0.3 compositions revealed single phased cubic structure materials, x>0.3 showed multi-phased materials for (Sr1−x Zn x )CoO3 system. Like other substituted perovskite cobalt oxide systems (Ca, Y, Ho and Ce), the transport properties of the present materials show rather sizable changes with respect to ‘x’, although there are insignificant variations in lattice parameter and in Curie temperature, T c . All the present samples show soft ferromagnetism with T c in the range of 272–285 K for 0.05≤x≤0.3. The effective paramagnetic moment, P eff determined from the paramagnetic region decreases upon the substitution of Zn for Sr-site. These P eff (3.3–2.8 μB/Co) values for 0.05≤x≤0.3 compositions seem to suggest that the Co4+ lie in intermediate spin (IS) state for the present (Sr1−x Zn x )CoO3 series, although they are slightly smaller than those expected for IS-Co4+; P eff=3.87 μB/Co. The electrical resistivity is found to increase with increase of ‘x’ for the investigated samples. The temperature and field dependence of both positive and negative magnetoresistance (MR) are noted for the Zn substituted samples. About 5% of –MR is observed for x=0.05 sample around the transition temperature (280 K) under the field strength difference, ΔH=90 kOe. The present research findings are compared with our previous results on different perovskite cobalt oxides.

Effects of FeEDDS and EDDS on Peat-based Substrate pH and Cu, Fe, Mn, and Zn Solubility

Common chelating agents used in horticultural fertilizers like ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and ethylenediaminedi(o-hydroxyphenylacetic) acid (EDDHA) are not readily biodegradable and may persist in the environment, maintaining the capacity to solubilize heavy metals. For this reason, biodegradable chelating agents like ethylenediaminedisuccinic acid (EDDS) are being evaluated for use in horticultural crop production. Therefore, the objectives of the study were to determine the effects of FeEDDS and EDDS on substrate pH and copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) solubility in peat-based substrate compared with various Fe and chelate-ligand sources. Extractions were performed using the 1:2 by volume substrate analysis method with an incubation period of 24 hours. The control was distilled deionized water extractions. Iron-source (FS) extractants consisted of 1 mg·L−1 Fe solutions derived from FeEDDS, FeEDTA, FeDTPA, FeEDDHA, and FeSO4. Iron-source extractant solution pH ranged from 7.1 (FeEDDS) to 5.4 (FeSO4). The extract pH for all Fe-source treatments was similar at pH 6.7, demonstrating the buffering capacity of the peat-based substrate. Iron recovery rates for FS treatments were determined after subtracting Fe that was freely extracted with distilled-deionized water: FeSO4 (13%), FeEDDHA (68%), FeEDDS (73%), FeEDTA (102%), and FeDTPA (121%). Iron-source treatments were not different for Mn, averaging 0.03 mg·L−1, and Cu (0.04 mg·L−1) and Zn (0.24 mg·L−1) were greatest in the FeEDDS treatment. Chelate-ligand (CL) extractants consisted of 5 mm solutions of EDDS, EDTA, and DTPA. Chelate-ligand extractant solution pH ranged from 9.7 (EDDS) to 2.3 (DTPA), and extract solution pH ranged from 7.2 (EDDS) to 4.7 (DTPA). Extractant solutions of EDDS and DTPA resulted in the lowest and highest levels of Cu (0.06 and 0.14 mg·L−1, respectively) and Fe (4.3 and 13.1 mg·L−1, respectively) in extract solutions. Overall, these results suggest that there are no negative implications for the use of FeEDDS with peat-based substrate in terms of horticultural crop production based on substrate Fe solubility, which was not different from FeEDTA.

Influence of applied zinc and organic matter on zinc desorption kinetics in calcareous soils

Zinc (Zn) desorption from an exchange complex to solution, the release of Zn from organic matter (OM), crystalline minerals and other precipitates into the solution phase, is the process that controls Zn mobility in soils. An experiment was conducted to determine the pattern of Zn desorption and the soil characteristics affecting it. Desorption of Zn in 15 calcareous soils from southern Iran, treated with 10 mg Zn kg soil−1 as zinc sulfate (ZnSO4•7H2O) and 10 g organic matter (OM) kg−1 as feedlot cattle manure, equilibrated and extracted with diethylenetriamine pentaacetic acid (DTPA), was studied. Eight kinetic models were evaluated to describe the rate of Zn desorption of soil extracted with DTPA. There was a rapid rate of desorption during the first 4 h followed by a slower rate during the next 12 h. Two-constant rate and simple Elovich models were determined as the best models describing Zn desorption kinetics. Zinc desorption increased as Zn was applied, whereas it decreased with applied OM. The constants of the simple Elovich (βs) and two-constant rate equations (a and b) were closely correlated with cation-exchange capacity (CEC), OM and pH, which affect Zn solubility, sorption–desorption and diffusion in soils.

Enhanced thermoelectric performance in zinc substituted p-type filled skutterudites CeFe4−xZnxSb12

In this study, Zn-substituted polycrystalline skutterudites CeFe4−xZnxSb12 (x=0, 0.05, 0.1, 0.2, 0.3) were successfully prepared by a traditional melting–annealing method. The solubility of Zn in Fe site is ∼1.2%, exceeding which trace amount of ZnSb phase can be detected in the XRD. This ZnSb impurity phase, with size of several hundred nanometers for the sample with x=0.2 but showing surprisingly small size of ∼10nm for the sample with x=0.3, selectively distributes on the grain boundaries. In particular, the introduction of Zn in Fe site effectively improves the Seebeck coefficient in a manner of enhancement in hole effective mass, but it has negligible influence on both electrical and thermal conductivities though the hole concentration is increased. Consequently the corresponding improvement in power factor leads to an improved thermoelectric figure of merit (ZT) of 0.9 at 800K for the sample with x=0.1, which is ∼15% higher than that of Zn-free sample. This study demonstrates a favorable effect of Zn iso-substitution and opens a new strategy to improve the thermoelectric properties of p-type Fe-based skutterudites beyond the sole phonon engineering.

Comparative Use of Soil Organic and Inorganic Amendments in Heavy Metals Stabilization

Remediation strategies are capable to mitigate negative effects of heavy metals (HMs) on soils. The distribution of cooper (Cu), zinc (Zn), and chromium (Cr) was evaluated in a contaminated soil after adding biosolid compost (BC) and phosphate fertilizer (PF). A greenhouse assay and sequential extraction procedure were performed to determine the fractionation of HM in contaminated and remediated soil. In BC treatment, among 4 to 6% of Cu was associated with soil humic substances. Without amendments and with fertilizer application, Zn solubility increased by 15.4 and 8.4%, respectively, with experiment time. Although Cr was significantly adsorbed to the inorganic fraction, with compost application there was a transfer to organic fraction. A single amendment application is not suitable for immobilizing all metals of concern, because there are diverse union’s behaviors between HM and soil matrix. As the organic matter and phosphate fertilizer were effective in reducing mobility of Cu, the organic matter was more effective in the immobilization of Cr, and inorganic amendment induced the Zn precipitation, results from this pilot study suggest a combined use of these two amendments for soil remediation strategies. However, liming may be further needed to prevent soil acidification on longer time scales. Also, we propose the use of chemical and biological remediation strategies for potential improvement of effectiveness.