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Cadmium (Cd) contamination in soils is of great concern, and therefore the development of effective remediation technologies for cadmium contamination is urgent. In our study, nano zero-valent iron (NZVI) supported by metal-organic framework (MOF) materials (MOF-NZVI) were prepared using NaBH

Health risks and hazards caused by the environment have long been one of the most important public issues of concern to the state, society, and the public. At the same time, population aging is becoming a global issue, and residents’ health is the most important component of people’s livelihood, and residents can only pursue other rights and interests if they can protect their own health. Therefore, based on the micro data from the fifth round of the China Family Panel Studies (CFPS), this paper uses binary logistic regression with propensity score matching (PSM) to analyze the effect of environmental perception on the health status (including mental health and physical health) of middle-aged and older adults. It was found that environmental perceptions significantly affect the depressive state and sickness status of middle-aged and older adults. Among them, middle-aged and older adults who were female, of rural households, with low education and relatively low income were more affected by environmental shocks on their health. Therefore, we should pay attention to the mental and physical health of middle-aged and older adults and change the existing design concept of aging policy: the government should formulate effective policies and increase corresponding social support; and society and families should also give corresponding care and encourage middle-aged and older adults to exercise more and provide reasonable psychological guidance.

The ball-milling technology, a highly efficient and cost-effective method, had excellent application prospects for overcoming passivation issues of normal zero-valent iron (ZVI) to enhance the decontamination efficiency. In this work, we investigated the effects and mechanisms of pH, process control agents (PCA), and main process parameters on the removal of V

An effective complex of nanoscale zero-valent iron (NZVI) supported on zirconium 1,4-dicarboxybenzene metals-organic frameworks (UIO-66) with strong oxidation resistance was synthesized (NZVI@UIO-66) for V

African swine fever (ASF) is a fatal and highly infectious haemorrhagic disease that has spread to all provinces in China—the world’s largest producer and consumer of pork. Here we use an input–output model, partial equilibrium theory and a substitution indicator approach for handling missing data to develop a systematic valuation framework for assessing economic losses caused by ASF outbreaks in China between August 2018 and July 2019. We show that the total economic loss accounts for 0.78% of China’s gross domestic product in 2019, with impacts experienced in almost all economic sectors through links to the pork industry and a substantial decrease in consumer surplus. Scenario analyses demonstrate that the worst cases of pig production reduction and price increase would trigger 1.4% and 2.07% declines in gross domestic product, respectively. These findings demonstrate an urgent need for rapid ASF containment and prevention measures to avoid future outbreaks and economic declines. African swine fever has spread to all Chinese provinces, limiting pork production and trade. Outbreaks occurring between 2018 and 2019 led to economic losses in pork and related industries—but projected future outbreaks could cause greater economic impacts.

Being a fundamental issue regarding sewage treatment, heavy metals removal from industrial effluents has been subject to intense scrutiny in both the academic and practical worlds. The removal of pentavalent arsenic (As(V)), one of the most poisonous pollutants, was investigated using a sodium persulfate and iron powder system activated by ferrous ions (Fe2+-ZVI-PS). As(V) could be effectively removed by an Fe2+-ZVI-PS system in a timely fashion (minute scale) with high removal rates (more than 90.0%) over a wide range of pH (1–9) and concentration (20–100 mg/L). The removal of As(V) by the Fe2+-ZVI-PS system integrated favorably with the pseudo-second-order reaction kinetics. Researches on X-ray photoelectron spectroscopy (XPS) demonstrated that the Fe2+-ZVI-PS system enables the removal of As(V) through the process of co-precipitation and adsorption. Our findings thus emphasized that the Fe2+-ZVI-PS system should be an effective trigger to purifying arsenic from the environment. Our results indicated that the Fe2+-ZVI-PS system could be an effective candidate for remediation of arsenic in the environment.

This study evaluates the total economic loss due to the outbreaks of African Swine Fever (ASF) in China between August 2018 and July 2019. We propose a systematic framework to assess both the direct economic loss on the Chinses breeding industry and indirect economic loss on other sectors. Our evaluation system integrates various statistical analysis methods by applying the cost-loss model and substitution indicator method to calculate direct economic losses and using input-output (IO) model to estimate indirect economic losses. The proposed method provides an innovative and commonly applicable way to deal with the missing data that needs to be adjusted and repaired to be used for economic shock evaluation. We find that total economic loss caused by ASF is 224.768 billion yuan consisting of 99.042 billion yuan direct economic loss of the breeding industry and 125.726 billion yuan indirect economic loss of other industries. Our findings suggest that the overall impact of ASF on China's national economy is relatively small, mainly local and short-term impacts on the swine industry.

Persulfate could be activated by zero-valent iron (ZVI) leading to the rapid removal of various contaminants. However, quick consumption of Fe

A zirconium 1,4-dicarboxybenzene metal–organic framework (UiO-66 MOF) was successfully used as a template to enhance the distribution and activity of nanoscale zero-valent iron (NZVI). MOF-NZVI showed good anti-interference ability to co-existing ions (Ca2+, Mn2+, Cu2+, H2PO4− and SO42−) and organic acids (oxalic acid and citric acid). SEM and TEM analyses indicated that the MOF as a support efficiently prevent NZVI from aggregation for quick and effective removal of As(III). Through the non-linear least-squares (NLLS) adjustment, As(III) removal by MOF-NZVI could be well fitted by pseudo first and second order reaction kinetics, as well as the Freundlich isotherm. FTIR, XRD and XPS results verified that NZVI and iron oxyhydroxides (Fe3O4, γ-Fe2O3, γ-FeOOH and α-FeOOH) might be responsible for the effective removal of As(III) and its oxidized product As(V) with an adsorption capacity of 360.6 mg As per g NZVI through chemical oxidation and physical adsorption. This work indicates that MOF-NZVI with good reusability and high efficiency is promising for application in As(III)-polluted wastewater treatment.

The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

Nano zero-valent iron (NZVI) with high chemical reactivity and environmental friendliness had recently become one of the most efficient technologies for wastewater restoration. However, the unitary NZVI system had not met practical requirements for wastewater treatments. Expectantly, the development of NZVI would prefer multifunctional NZVI-based composites, which could be prepared and optimized by the combined methods and technologies. Consequently, a systematic and comprehensive summary from the perspective of multifunctional NZVI-composite had been conducted. The results demonstrated that the advantages of various systems were integrated by multifunctional NZVI-composite systems with a more significant performance of pollutant removal than those of the bare NZVI and its composites. Simultaneously, characteristics of the product prepared by the incorporation of numerous methods were superior to those by a simple method, resulting in the increase of the entirety efficiency. By comparison with other preparation methods, the ball milling method with higher production and field application potential was worthy of attention. After combining multiple technologies, the effect of NZVI and its composite systems could be dramatically strengthened. Preparation technology parameters and treatment effect of contaminants could be further optimized using more comprehensive experimental designs and mathematical models. The mechanism of the multifunctional NZVI system for contaminants treatment was primarily focused on adsorption, oxidation, reduction and co-precipitation. Multiple techniques were combined to enhance the dispersion, alleviating passivation, accelerating electron transfer efficiency or mass transfer action for optimizing the effect of NZVI composites.

Being a fundamental issue regarding sewage treatment, heavy metals removal from industrial effluents has been subject to intense scrutiny in both the academic and practical worlds. The removal of pentavalent arsenic (As(V)), one of the most poisonous pollutants, was investigated using a sodium persulfate and iron powder system activated by ferrous ions (Fe

The removal of arsenic(III), one of the most poisonous wastewater pollutants, was investigated using nanoscale zero-valent iron supported onto pumice and modified by chitosan (CS-P-NZVI). Scanning electron microscopy (SEM) analysis revealed that NZVI was distributed dispersedly on CS-P-NZVI without being oxidized. As(III) could be removed by adsorption on CS-P-NZVI in a very short time (minute scale) with high removal rates (more than 99.5%) over a wide range of pH (2.01–12.54) and concentration (20–100 mg/L). The removal of As(III) by CS-P-NZVI agreed well with the pseudo-first-order reaction kinetics and pseudo-second-order reaction kinetics. Reaction rate constants (Kobs) ranged from 0.27 to 0.96 min−1 at varied NZVI dosage. Freundlich isotherm provided a good model of the sorption system, indicating that CS-P-NZVI was heterogeneous in the surface properties. The thermodynamic parameters suggested that As(III) adsorption by CS-P-NZVI was a spontaneous and exothermic process. X-ray photoelectron spectroscopy (XPS) and atomic fluorescence spectrophotometer (AFS) analyses indicated that As(III) was only physically adsorbed on the surface of CS-P-NZVI within 60 min. Our results indicated that CS-P-NZVI might be an effective material for both in situ and ex situ remediation.

As-cast microstructural features of a U-5.4Nb alloy, including average grain size, dendrite structure, inclusion evolution behavior, solute (Nb) distribution and micromechanical properties were investigated with respect to a diverse number of calculated cooling rates in this paper. Various solidification techniques, including suction casting, arc remelting and induction melting followed by argon cooling, were employed to obtain wide ranges of cooling rates between 90 K/s and 9.9 × 105 K/s. Average grain sizes of suction cast samples decreased from 16.8 μm to 4.35 μm with increasing cooling rates. Similarly, inclusion evolution behavior was shown to refine in size with the increase of cooling rates. Fully developed dendrites inside the argon-cooled sample at a low cooling rate consisted of primary dendrite arms, secondary dendrite arms and tertiary dendrite arms that exhibited a fascinating dendrite structure with hexagonal symmetry. In addition, the segregation ratios of niobium decreased with decreasing cooling rates. Furthermore, the nanoindentation test indicated that the segregation of niobium had a significant influence on the mechanical properties of the dendrite arms and interdendritic regions. The elastic modulus and hardness for the primary dendrite arm, the secondary dendrite arm, and the interdendritic region were 61 GPa and 3.6 GPa, 62 GPa and 3.3 GPa, and 113 GPa and 6.5 GPa, respectively.

Persulfate could be activated by zero-valent iron (ZVI) leading to the rapid removal of various contaminants. However, quick consumption of Fe2+ largely constrained the removal (%) of target pollutants. Here it was reported that Na2S2O8 (SP) combined with ZVI, as an external source of Fe2+, was activated by Fe2+ to quickly (minutes scale) and efficiently (more than 90%) remove As (III) from aqueous solution at an initial pH value from 1.0 to 9.0. As (III) removal was obviously improved by an increase of Fe2+ rather than Na2S2O8 dosage. The removal of As (III) using Fe2+-SP-ZVI system followed the pseudo-second-order kinetic and pseudo-first-order kinetic expression. Fe2+ from ZVI oxidization could improve the efficient generation of , which obviously boosted ZVI corrosion. The production of could be manipulated by oxalic acid, ethylenediaminetetraacetic acid (EDTA), citric acid and phosphates through controlling the concentration of dissociative Fe2+, leading to an obvious repression on As (III) removal. The fitting of X-ray absorption fine structure (XAFS) spectra illustrated that the interatomic distance of As–O shell was located between As(III)–O and As(V)–O shell and external Fe2+ could promote the oxidation of As (III) to As (V) from 35.6% in 1.0 min–44.5% in 10.0 min. Goethite as the main component of iron oxyhydroxides might play a significant role of As (III) adsorption in Fe2+-SP-ZVI system. These findings are crucial for knowing the fate and transport of arsenic under permeable reactive barriers.

Sediment contamination by heavy metals has become a widespread problem that can affect the normal behaviors of rivers and lakes. After chitosan/Fe0-nanoparticles (CS-NZVI) beads were cross-linked with glutaraldehyde (GLA), their mechanical strength, stability and separation efficiency from the sediment were obviously improved. Moreover, the average aperture size of GLA-CS-NZVI beads was 20.6 μm and NZVI particles were nearly spherical in shape with a mean diameter of 40.2 nm. In addition, the pH showed an insignificant effect on the removal rates from the sediment. Due to the dissolution of metals species into aqueous solutions as an introduction of the salt, the removal rates of all heavy metals from the sediment were increased with an increase of the salinity. The competitive adsorption of heavy metals between the sediment particles and GLA-CS-NZVI beads became stronger as the sediment particles became smaller, leading to decreased removal rates. Therefore, the removal efficiency could be enhanced by optimizing experimental conditions and choosing appropriate materials for the target contaminants.

The removal of heavy metals from wastewater is one of the most important issues for the world, especially from industrial effluents. Pumice-nanoscale zero-valent iron (P-NZVI) was successfully prepared in different experimental conditions. Meanwhile, the shape, size and distribution of NZVI on P-NZVI were evaluated using a scanning electron microscope (SEM). At the optimum condition, NZVI with a mean diameter of 20.2 nm was distributed uniformly and consistently on the surface of pumice. Freundlich isotherm analysis suggested that the surface property of P-NZVI were heterogeneous. The removal of Hg (II) and Cr (VI) by P-NZVI could be well described by pseudo-first-order kinetic model. At equilibrium qmax of Hg (II) and Cr (VI) was 107.1 and 106.9 mg/g, respectively. Thermodynamic investigation suggested that the removal of Hg (II) and Cr (VI) by P-NZVI was an endothermic and spontaneous process. The less values of ΔH0 for Hg (II) than those for Cr (VI) demonstrated that more thermal energy was needed to remove Cr (VI) than Hg (II) at the same reaction rate.

A system of zerovalent iron combined with potassium permanganate and ferrous irons (Fe(II)-KMnO4-ZVI) was used to remove As(III), one of the most poisonous wastewater pollutants. The Fe(II)-KMnO4-ZVI system was characterized by using X-ray photoelectron spectroscopy and scanning electron microscopy. The As(III) removal efficiency by the Fe(II)-KMnO4-ZVI system under different conditions was investigated and the experimental data were fitted to adsorption kinetics and isotherm models. As(III) could be removed by both physisorption and chemisorption through mixing adsorbents in a very short time (minute scale) with high removal ratios (more than 99.5%) over a wide range of pH (1–9) and concentration (20–100 mg/L). The removal of As(III) by the Fe(II)-KMnO4-ZVI system agreed well with pseudo-first-order reaction kinetics and pseudo-second-order reaction kinetics. The Freundlich isotherm provided a good model of the adsorption system, indicating that the Fe(II)-KMnO4-ZVI system has heterogeneous structure. The results show that the Fe(II)-KMnO4-ZVI system exhibited a high removal efficiency for As(III), which suggested that it might be an effective material for As(III) remediation.

Nanoscale zero-valent iron successfully supported on pumice (P-NZVI) was used to remove heavy metals from wastewater with a higher removal capacity and efficiency. NZVI particles with a mean diameter of 30.6 nm are distributed uniformly on the surface of P-NZVI. The thermal stability and mechanical strength of P-NZVI were also obviously enhanced. P-NZVI with a 7.7% NZVI mass fraction had a specific surface area (SBET) of 32.2 m2/g. The removal capacity of Hg (II) and Cr (VI) by P-NZVI was 332.4 mg Hg/g Fe and 306.6 mg Cr/g Fe, respectively. As an increase of pH, the removal rates of Hg (II) increased but those of Cr (VI) decreased gradually. P-NZVI is a regenerated material. The X-ray photoelectron spectroscope analysis (XPS) results indicated that Hg (II) and Cr (VI) were removed by a rapid physical adsorption in the first 0.5 min and predominantly by reduction. In terms of the efficiency and speed, P-NZVI was a promising candidate for applications to in situ environmental remediation, especially to the heavy metals pollution incidents with an extremely high concentration of heavy metals.

Surface water and groundwater are the main water resources used for drinking and production. Assess- ments of the relationship between surface water and groundwater provide information for water resource man- agement in Sanjiang plain, Northeast China. The surface water (river, lake, and wetland) and groundwater were sampled and analyzed for stable isotopic (dD, d 18 O) composition, tritium, and chlorofluorocarbons concentra- tions. The local meteoric water line is dD = 7.3d 18 O-6.7. The tritium (T) and chlorofluorocarbon (CFC) contents in groundwater were analyzed to determine the groundwater ages. Most groundwater were modern water with the ages \50 years. The groundwaters in mountain area and near rivers were younger than in the central plain. The oxygen isotope (d 18 O) was used to quantify the relationship between surface water and groundwater. The Songhua, Heilongjiang, and Wusuli rivers were gaining rivers, but the shallow groundwater recharged from rivers at the confluence area of rivers. At the confluence of Songhua and Heilongjiang rivers, 88 % of the shallow groundwater recharged from Songhua river. The combination of stable isotopes, tritium, and CFCs was an effectively method to study the groundwater ages and interrelation between sur- face water and groundwater. Practically, the farmlands near the river and under foot of the mountain could be culti- vated, but the farmlands in the central plain should be controlled.

We present an electrostatically actuated rotary stage featuring liquid rings, which serve as both mechanical bearings and electric connections between the rotor and the substrate. The liquid rings are formed by confining a liquid inside hydrophilic grooves and repelling it from the superhydrophobic surfaces outside the grooves. Made of a fluid, the liquid-ring bearing avoids the dry friction of the solid bearings, significantly improving the reliability. Formed as rings, it avoids the resistance of contactangle hysteresis sliding over droplets, and hence dramatically reducing the static friction. Furthermore, surface tension facilitates the self-alignment of the rotor to the substrate and stator during the assembly and provides the stability against drift and shock during operation. Electrically, each liquid ring passes an independent electric signal, allowing a direct electrical path between the substrate and potential components on the rotor. A three-phase electrostatic rotary stage has been design, fabricated, and tested. The minimum torque to initiate the rotation is ∼2.5nṄm - hundreds of times smaller than droplet-based counterparts. The device has operated successfully by applying sequential voltages of 50V DC between the rotor and the stators. The electric transmission has been verified by powering an LED on a rotating rotor. This is the first report of an electrostatically actuated rotating microdevice with a liquid bearing and a direct power transmission. © 2013 IEEE.

The synergistic effect of two different advanced oxidation technologies, heterogeneous sulfate radical based Fenton and TiO2 photocatalysis, was observed through a drastic enhancement of Rhodamine B removal in Co–TiO2/Oxone/Photo process. Our catalysts were obtained by a citric acid-assisted sol–gel method and Rhodmine B was used as model organic pollutant. The cobalt species in Co–TiO2 play a crucial role of integration Fenton with TiO2 photocatalysis in one heterogeneous hybrid system that not only active Oxone to produce SO4-, but also enhance the photocatalytic activity of TiO2 as well as extend its absorption spectrum to visible region, thus it can be defined as a type of bifunctional catalyst. The influence of the pH, [Oxone]/[RhB] molar ratio and catalyst concentration of the catalytic performance were investigated. The Rhodamine B can be eliminated 100% and TOC removal of solution can reach 68% at the optimum conditions by Photo/Co–TiO2/Oxone process. Moreover, the catalyst was demonstrated to have good stability and reusability.

We demonstrate a 3-in-1 hybrid silicon-PDMS neural probe with electrochemical sensing, directional optical stimulation, and drug delivery capabilities to manipulate and record neural cell activities. Blue light with a wavelength of 450nm is coupled onto the probe by a grating coupler and delivered to the probe tip through a silicon nitride waveguide. Another grating coupler at the tip couples the light out and provides directional illumination near the center of a sensing electrode. A liquid channel is bonded on top of the silicon probe using a novel PDMS thin-film transfer process.

Fe0 nanoparticles (NZVI) were successfully immobilized on epichlorohydrin/chitosan beads (ECH–CS–NZVI beads) for reduction of Cr(VI) from wastewater. Characterization with scanning electron microscope (SEM) showed that ECH–CS–NZVI beads with an average aperture size of 23.2 μm mainly consisted of Fe, O, C and N. Fourier transform infrared (FTIR) spectrum suggested that ECH could be grafted to CS–NZVI beads. A marked decrease in crumpling ratios indicated that the mechanical strength of Fe0-nanoparticles–chitosan (CS–NZVI) beads was obviously enhanced by cross-linking of epichlorohydrin (ECH). The thermal stability of ECH–CS–NZVI beads was also enhanced. Cr(VI) concentration, NZVI dosage, pH values and reaction temperature played an important role in the lifetime and using efficiency of ECH–CS–NZVI beads. Under all experimental conditions, the removal of Cr(VI) using ECH–CS–NZVI beads was consistent with pseudo first-order reaction kinetics. A removal rate could be maintained as high as 76.6% and 48.2% on the second and third runs, respectively, which hinted that ECH–CS–NZVI beads could be regenerated. The study demonstrates that ECH–CS–NZVI beads could become an effective and promising technology for in situ remediation of Cr(VI).

We report a micro- and nano-machined surface cavity on which boiling nucleation resumes after ceasing in perfluorohexane (i.e., FC-72, a Fluorinert™ from 3M™) for a short time. To the best of our knowledge, this is the first such success with FC-72, which has the lowest surface tension of all available liquids and completely wets any existing material including Teflon® so that all surface cavities get flooded once nucleation stops. Despite the wide usage in electronics cooling, FC-72 was never considered for boiling heat transfer because once cooled boiling would not restart without an excessive heating. Our result experimentally supports the half-century-old idea of doubly re-entrant cavities envisioned to facilitate more stable nucleation, encouraging further development.

We report that superhydrophobic (SHPo) surfaces based purely on surface structuring shows a robust super-repellency under a prolonged contact with serum droplet as an example of protein-rich biological fluids. In contrast, normal SHPo surfaces, which are based on surface chemistry and surface structuring, lose repellency and eventually get wetted in the same tests. This is the first report of a SHPo surface maintaining super-repellency to a biological fluid.

We report the first superhydrophobic surface made of a material that is highly wetting (Young's angle below 10 degrees) to the liquid in service. The concept is proposed and experimentally confirmed by microstructuring silicon dioxide (SiO2), which is highly wetting to aqueous liquids (e.g. water). In pushing the surface geometry to a doubly re-entrant topology, the key is in the geometric details of the microstructures and how to fabricate them. Tested on micrograting surfaces, the measured apparent contact angle agreed with the theory, and the pressure the microstructures can resist against wetting transition was found consistent with the claimed design.

We have obtained interfacial properties of Galinstan, a nontoxic liquid-metal alloy, to help replace mercury in miniature devices. To prevent formation of an oxide skin that severely hinders the fluidic behavior of small Galinstan droplets and leads to inaccurate property data, we performed our experiments in a nitrogen-filled glove box. It was found that only if never exposed to oxygen levels above 1 part per million (ppm) would Galinstan droplets behave like a liquid. Two key properties were then investigated: contact angles and surface tension. Advancing and receding contact angles of Galinstan were measured from sessile droplets on various materials: for example, 146.8 ° and 121.5 °, respectively, on glass. Surface tension was measured by the pendant-drop method to be 534.6 ± 10.7 mN/m. All the measurements were done in nitrogen at 28 ° C with oxygen and moisture levels below 0.5 ppm. To help design droplet-based microfluidic devices, we tested the response of Galinstan to electrowetting-on-dielectric actuation. © 2012 IEEE.

Nanoscale zero-valent iron (NZVI) was successfully entrapped in chitosan (CS) beads for reduction of Cr (VI) from wastewater. The removal mechanism may include both physical adsorption of Cr (VI) on the surface or inside of CS-NZVI beads and subsequent reduction of Cr (VI) to Cr (III). The free amino groups and hydroxyl groups on CS may contribute little to hinder the formation of Fe(III)–Cr(III) precipitate. Entrapment of NZVI in CS beads prevents the particles from aggregation and oxidation. The results indicate that there is no significant difference between the reaction rates of bare NZVI and entrapped NZVI. Cr (VI) reduction kinetics follows a pseudo-first-order rate expression. The reduction capacity for Cr (VI) increases with increasing temperature and NZVI dosage but decreases with the increase in initial concentration of Cr (VI) and pH values. This study demonstrates that entrapment of NZVI in CS beads has the potential to become a promising technique for in situ groundwater remediation.

The effects of nanoparticle dosage, initial hexavalent chromium concentration, pH value, reaction temperature, and initial concentration of humic acid (HA) on chromate (CrO(4)(2-)) removal from landfill leachate by nanoscale zero-valent iron (NZVI) and hematite (alpha-Fe(2)O(3)) nanoparticles were examined in the present investigations. The Cr(VI) removal rate decreased as the initial Cr(VI) concentration and the reaction temperature increased, whereas corresponding removal rate by NZVI was higher than that of alpha-Fe(2)O(3). The optimum pH for the removal of Cr(VI) by NZVI was found to be 5.0 and more than 99.0% of Cr(VI) was removed within 5 h. However, the removal rate by alpha-Fe(2)O(3) decreased as pH increased. Presence of HA resulted in substantial reduction in the rate and extent of Cr(VI) removal by NZVI, whereas Cr(VI) removal rate by alpha-Fe(2)O(3) did not significantly decrease as HA concentration increased from 0.5 g/L to 3.0 g/L. Increasing the dosage of nanoparticles enhanced the rate constant and the removal of Cr(VI) by NZVI and alpha-Fe(2)O(3) followed pseudo-first-order reaction kinetics. The information should be very useful for the successful application of NZVI and alpha-Fe(2)O(3) for the treatment of groundwater or raw wastewater.

We report our characterization of nontoxic liquid-metal alloy Galinstan® on its potential for substituting mercury droplets in miniature devices. To combat the super fast oxidation, which has been hindering the studies of Galinstan® our entire experiments are performed in a nitrogen-filled glove box. Galinstan® droplets are found to behave like a true liquid, indicating a good liquid-air interface, only if the oxygen traces stay below 1 ppm. Surface tension of Galinstan® is measured to be 534.6±±10.7 mN/m in nitrogen at 28°C using a pendant drop method. Advancing/receding contact angles on glass and Teflon surfaces are found to be 146.8°/121.5° and 161.2°/144.4°, respectively. The electrowetting on dielectric (EWOD) mechanism of Galinstan® is also demonstrated.