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The reconstruction of defects of the lateral malleolus involving the exposed fibular bone or tendon is challenging. This study aimed to evaluate the clinical application of the peroneal artery perforator flap with or without split-thickness skin grafting for soft tissue reconstruction of the bony defect of the lateral malleolus of the ankle joints. Reconstruction using a peroneal artery perforator flap with or without split-thickness skin grafting was performed for 15 patients (10 men, 5 women) between January 2007 and December 2018. The mean age was 53.7 years, and the mean size of the flaps was 40 cm2. The flaps were elevated in the form of a perforator flap, and split-thickness skin grafting was performed over the flaps and adjoining raw areas. The flaps survived in all cases; however, partial necrosis was observed in 3 cases. In cases of small-sized defects of the lateral malleolus of the ankle joints where a flap is required for the exposed bone or tendon, reconstruction using the peroneal artery perforator flap is advantageous, since the morbidity rate of the donor site is low and soft tissue is reconstructed.

A bimetallic Fe-Cu catalyst was applied as a catalyst for heterogeneous Fenton reaction. Fluidized-bed crystallization of bimetallic catalyst supported by a silica seed (FeIII0.66CuI0.33 @SiO2) was conducted at specific hydraulic conditions. The deposited state of copper and iron of FeIII0.66CuI0.33@SiO2 were identified as Cu(I) and Fe(III), which could effectively catalyze H2O2 to form hydroxyls radical for the abatement and mineralization of benzoic acid under blue light irradiation (436 nm). The cupric species as an electron donor enabled the reductive dissolution of the deposited iron to drive a Fenton reaction. The blue light irradiation promoted the regeneration of Fe(III) to Fe(II) through the photoreduction mechanism. Operating parameters included Fe to Cu ratio (0.5–4), dose of H2O2 (0–4 mM), initial pH (3–7) and light intensity (0–10 mW/cm2). The photo Fenton process using FeIII0.66CuI0.33@SiO2 catalyst resulted in 86% of benzoic acid mineralization in 3 h.

Given the potential shortage of critical nutrients (e.g., nitrogen, phosphorus, and potassium) predicted in the near future, nutrient recovery technologies have attracted wide attention from the sc...

Acid mine drainage (AMD) released from gold and coal mining contains a large quantity of heavy metals, thus being a threat to the surrounding ecosystem. The recovery of metals from AMD can both address the potential contamination and bring more economic profits. In this study, the sequential selective precipitation and fluidized bed homogeneous crystallization (FBHC) were integrated to recover iron(II) and Al(III) from real AMD wastewater. The selective precipitation of Fe was optimized by adjusting pH. The FBHC recovery of Al performed its best at pH 9.25 ± 0.2, molar ratio of [H2O2]/[Al(III)] = 2.0 and up-flow velocity (U) = 30.5 m/h. Iron(II) and Al(III) were recovered in the form of iron hydroxide (Fe(OH)3) and bayerite (α-Al(OH)3) pellets. Removal efficiencies were as high as 99.7% and 99.3% for Fe(II) and Al(III), respectively. A brief cost-benefit estimation was performed and showed that the estimated profit gained from field-scale recovery of Fe(II) and Al(III) would be $1.31/m3-AMD.

Nanocomposite materials can enhance the capabilities of water treatment processes such as photocatalysis. In this work, novel light-driven nanocatalysts were synthesized by using nickel ferrite (NiFe2O4) to nanoenable graphene oxide (GO) substrates. GO is an emerging 2D nanomaterial with high conductivity and adsorption properties. Moreover, the electric properties of GO improve photocatalytic performance by promoting charge carrier separation. Results of the characterization of the nickel ferrite nanoenabled graphene oxide (NiFe2O4@GO) nanocomposites demonstrate that homogeneous and stable photocatalysts were produced. The as-synthesized nanocatalysts enabled complete decolorization of the colored water matrix in short irradiation times of 150 min using minimal catalyst loading at 0.5 g L−1. The selective hook and destroy mechanism reduced the competitive effect of co-existing ions in solution. Furthermore, the use of specific scavengers helped to elucidate the degradation mechanisms of organic dye methylene blue by NiFe2O4@GO nanocomposites.

This study proposed a method for analysis of 10 phthalate esters compounds from wastewater treatment plant sludges. The analytical efficiency of GC-MS for of target compounds was verified by a standard mixture of phthalate esters. The response factors related to the respective internal standards from a five-point calibration curve quantified the phthalate esters in individual compounds. Based on the literature compiled by environmental agencies, new generation phthalate compounds have been developed, such as di-iso-nonyl phthalate (DiNP), di-iso-decyl phthalate (DiDP), as alternative to conventional phthalates. The analytical results showed that the total PAEs concentration was in the range from 7.4 to 138.6 mg kg

The composite electrode of NiCo oxide supported by porous carbon was synthesized for nitrite oxidation and nitrate electro-sorption. The crystal structure and chemical state of the Co and Ni oxyhydroxides which were precipitated on loofah-derived activated carbon (AC) using hypochlorite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and BET surface area. The voltammetry showed that the redox couple of Co(II)/Co(III) and Ni(II)/Ni(III) as the mediator catalytically transferred the electrons of NO

The strong oxidant, persulfate (PS, S

Background and Objectives. Lymph node status is the most important prognostic factor in cutaneous melanoma patients. Recent studies showed that indocyanine green (ICG) fluorescence lymphography helps locating sentinel nodes better. Sometimes, flap reconstruction is needed after wide excision of tumor. Indocyanine green fluorescence also simplifies the intraoperative design of flaps. This study investigates the use of ICG fluorescence in patients with cutaneous melanoma during operation. Methods. We performed a single-center, retrospective study of subjects with cutaneous melanoma using ICG lymphograhy and/or angiography during wide excision of tumor between 2015 and 2019. Patients received a dermal injection of ICG and patent blue (PB) dye. The positive node was excised. Indocyanine green angiography was utilized to visualize better skin paddle during flap reconstruction if needed. Results. A total of 37 sentinel lymph nodes (SLNs) were removed in 12 patients. Indocyanine green successful localization was found in 10 of the 12 patients (83%). Three patients were found with 6 metastatic nodes on final pathology. 100% of these 6 nodes were identified by ICG, while 83% (5/6) were positive PB. Three of the 12 patients received flap reconstruction after operation, and no major complications occurred. Conclusions. ICG dye lymphangiography is a good alternative for locating SLNs in patients with melanoma. It could also visualize well perfusion skin paddle during reconstruction. We reported a reproducible and simple method to utilize ICG fluorescence in cutaneous melanoma patients.

Patients bitten by Naja atra who are treated with bivalent freeze-dried neurotoxic antivenom in Taiwan have an improved survival rate but develop necrotic wound changes. The World Health Organization (WHO) has suggested using the minimum necrotizing dose (MND) of venom as a method of evaluating the neutralization effect of antivenom. The aim of this study was to evaluate the effectiveness of antivenom for the prevention of necrosis based on the MND and clarify which component of the venom of N. atra induces necrosis. The neurotoxins (NTXs) were removed from the crude venom (deNTXs), and different concentrations of deNTXs were injected intradermally into the dorsal skin of mice. After three days, the necrotic lesion diameter was found to be approximately 5 mm, and the MND was calculated. A reduction in the necrotic diameter of 50% was used to identify the MND50. Furthermore, both phospholipase A2 (PLA2) and cytotoxins (CTXs) were separately removed from the deNTXs to identify the major necrosis-inducing factor, and the necrotic lesions were scored. All mice injected with deNTXs survived for three days and developed necrotic wounds. The MND of the deNTXs for mice was 0.494 ± 0.029 µg/g, that of the deNTXs-dePLA2 (major component retained: CTXs) was 0.294 ± 0.05 µg/g, and that of the deNTX-deCTX (major component retained: PLA2) venom was greater than 1.25 µg/g. These values show that CTX is the major factor inducing necrosis. These results suggest that the use of the deNTXs is necessary to enable the mice to survive long enough to develop venom-induced cytolytic effects. CTXs play a major role in N. atra-related necrosis. However, the MND50 could not be identified in this study, which meant that the antivenom did not neutralize venom-induced necrosis.

An electrode made of loofah sponge derived activated carbon supported on nickel foam (AC/Ni) was successfully fabricated and used to remove ammonium ion (NH4+) from aqueous solution. A multilayer adsorption isotherm was used to describe ammonium electro-sorption on AC/Ni electrodes at different temperature, initial NH4+ concentration, and electrical field. The cyclic voltammetry (CV) results suggested that the electrical capacitance of AC/Ni electrodes, with the AC being prepared without preheating (OAC) or with low temperature heating (i.e., 300 AC), were higher than those prepared at high preheating temperature (i.e., 400 AC and 500 AC). Increasing the electro-sorption temperature from 10 to 50 °C decreased the monolayer NH4+ adsorption capacity from 5 to ca. 2–3 mg-N g−1, respectively. Background electrolyte, namely, sodium sulfate, exhibited significant competitive effect on the adsorption of ammonium ion at sodium ion concentration > 10−2 M. The activation energy and heat of adsorption were 9–23.2 kJ mol−1 and −3.7–−10.7 kJ mol−1, respectively, indicating a physisorption and exothermic adsorption characteristics. Based on the kinetics and thermodynamics analysis, there was slight increase in the activation energy with elevating preheating temperature, which increased the quantity of micro-pores and surface heterogeneity of the AC materials. Overall, results clearly demonstrated that carbon pyrolysis played a role on the capacitive charging behaviors of electrodes and the efficiency of NH4+ electro-sorption on the AC/Ni electrodes.

Spent lithium ion batteries (LIBs) can be of great environmental concern because of the generation of heavy metal pollution in such wastes in huge quantities, mainly from the fast-growing mobile phone market. In this research, acidic leaching coupled with microwave and ultrasonic heating is integrated with oxidative precipitation and solvent extraction to reclaim and purify the metals in the cathode material of batteries. To optimize the leaching process, the effects of the concentrations of acids and reductant (H2O2), solid loading, and temperature, as well as heating with microwaves and ultrasound, on Co, Li, Mn, Ni, Cu, and Al dissolution are systematically tested. KMnO4 is first applied to remove Mn as MnO2 precipitate from the leachate, and most of the Li can be selectively collected in the aqueous phase by solvent extraction using di-(2-ethylhexyl) phosphoric acid. At the end of the process, the majority of Co and minor amounts of Ni, Cu and Al are reversely extracted using HCl. An effective purification process is proposed to obtain more than 90% of the valuable metals in each of the leaching, precipitation and extraction steps.

Tetrafluoroborate anion (BF4−) is found in the streams of flue-gas desulfurization and borosilicate glasses etching which deteriorates water quality through slow hydrolysis into boric acid and fluoride. Decomposition and electrocoagulation (EC) of BF4− were studied using metallic aluminum as the sacrificial electrode. The dissolved Al(III) from the anode could efficiently decompose BF4− in forms of fluoroaluminate complexes, and the derived boric acid and fluoride ion were removed by sweep flocculation. Major variables were investigated to optimize EC, including the reaction pH, initial concentration of BF4−, current density and electrolyte type. The mechanism of EC process was elucidated with the kinetics of consecutive reactions. Experimental results suggested that the removal of BF4− and total fluoride were less influenced by pH, and that of total boron reached a maximum at pH 8 which favored the surface complexation between borate species and EC precipitates. Under the conditions: [BF4−]0 = 9.3 mM, [NaCl] = 10 mM, pH = 8.0, current density = 5 mA/cm2, 98.3% of BF4− was decomposed and the removal of total fluoride and boron attained 98.2% and 74.1%, respectively within 3 h. EC using the Al electrode outperformed the conventional chemical coagulation and reduced the levels of BF4 , B(OH)3 and F− in aqueous solution synergically.

Harbor sediments normally accumulate the pollutants from municipal and industrial activities in the estuarine zone. This work aimed to characterize the fractionation change of heavy metals in harbor sediments before and after chemical washing. Since the annual dredging around the Kaohsiung Harbor has increased over time, the influence of ex-situ acid washing on sediment quality needs to be evaluated. Experimental parameters of acid washing included the solid loading (4–20%) and types (HCl, HNO3, and citric acid) and concentrations (0.01–1 M) of acids. The fractionation of Cu, Zn, Ni, Cd, Cr, and Pb in the sediments at three estuaries, the Chienchen River, Canon River (Dock No.5), and Yanshui River, before and after washing processes were determined through sequential extraction. The washing efficiencies of HCl, HNO3, and citric acid were similar, being 80.1–83.7%, 27.6–30.9%, 20.7–23.9%, and 97.2–98.8% for Zn, Ni, Cr, and Cd, respectively. After 15 min of washing, HCl was found as a suitable washing agent, and particularly, more effective for Cu (65.3%) and Pb (79.4%) than other acids. The extraction process suggested that the acid washing of carbonate, the Fe-Mn oxide composite, and organic phases were highly correlated to their quantities in the sediments. However, the removal efficiency was inversely related to the metals in the residual phase. Knowing the mobility and bioavailability of heavy metals based on fractionation of metals benefits the assessment of the potential risk of dredged harbor sediment after the washing procedure. This study provided evidence that acid washing, as a remediation method, could be versatile in removing heavy metals from mobile phases without causing mineralogical changes to the contaminated sediments of the harbor area.

In this study, iron is removed from aqueous solution using a fluidized-bed crystallizer. Homogeneous oxyhydroxide pellets (FeOOH) were recovered at various value of pH, surface loading (L), and initial ferrous concentration to assess the treatability of iron-containing water. The optimal conditions for treating initial ferrous concentrations of 100–300 mg/L were L = 0.6 kg/m2/h (with 29 m/h of upflow velocity), a bed expansion of 50% and pH = 6.5 yielding the total iron removal (TR) of more than 99% and a corresponding iron crystallization ratio (CR) of 85%. X-ray diffractometry (XRD) revealed that the pellets consisted of a mixture of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH). Scanning electron microscopy (SEM) yielded images of pellets of up to 1 mm in diameter, which were assembled from FeOOH flakes with thicknessess of 0.2–0.4 µm.

Effects of Pd nanoclusters in PdxSn100-x/Ni electrodes with preferred diffraction planes of Sn(101) and Sn(200) plated on a nickel foam were studied on electrochemical reduction reaction of nitrate (NO3-). NO3- converted to NO2-, N2 and NH4+ by surface Hads was assessed at different Pd to Sn ratio through the electroanalysis and batch electrolysis at constant current mode. Pd loading obviously enhanced the current density of proton diffusion-controlled Sn0/Sn(II) transition. NO3- reduction was much more efficient on PdSn(200) than on PdSn(101); 53% of N2 yield on Sn(200)/Ni could increase up to 79% on Pd5Sn(200)95/Ni, while further increasing Pd loading would gradually increase NH4+ yield. The steady-state kinetics proposed a scheme of adsorption and deoxygenation of NO3- on Sn(200) and hydrogenation of NO2- to N2 on Pd NPs beside the Sn crystals.

Dyes are hazardous compounds commonly found in industrial wastewaters. Efficient and inexpensive removal of dye molecules from the water matrix has been demonstrated by adsorption processes. Magnetic nano-adsorbents, such as metal ferrites, can be efficiently recovered from the reaction mixture after treating the pollutant. Herein, MFe2O4@GO (M = Cu, Co or Ni) was synthesized via solution combustion method for the removal of dye molecules from aqueous solutions. The characteristics of the MFe2O4@GO, including surface area and pore diameter, surface functional groups, and elemental composition, were examined. Methylene blue was used as representative dye pollutant. Batch adsorption results conformed to the Langmuir isotherm. Maximum adsorption capacities of the MFe2O4@GO (M = Cu, Co or Ni) were 25.81, 50.15 and 76.34 mg g−1, respectively. Kinetics of methylene blue adsorption fitted the pseudo-second-order model. Overall, NiFe2O4@GO exhibited the highest adsorbent performance among the graphene-metal ferrites investigated, primarily because of its high specific surface area and presence of mesopores.

A review of the literature published in 2019 on topics related to hazardous waste management in water, soils, sediments, and air. The review covered treatment technologies applying physical, chemical, and biological principles for the remediation of contaminated water, soils, sediments, and air. PRACTICAL POINTS: This report provides a review of technologies for the management of waters, wastewaters, air, sediments, and soils contaminated by various hazardous chemicals including inorganic (e.g., oxyanions, salts, and heavy metals), organic (e.g., halogenated, pharmaceuticals and personal care products, pesticides, and persistent organic chemicals) in three scientific areas of physical, chemical, and biological methods. Physical methods for the management of hazardous wastes including general adsorption, sand filtration, coagulation/flocculation, electrodialysis, electrokinetics, electro-sorption ( capacitive deionization, CDI), membrane (RO, NF, MF), photocatalysis, photoelectrochemical oxidation, sonochemical, non-thermal plasma, supercritical fluid, electrochemical oxidation, and electrochemical reduction processes were reviewed. Chemical methods including ozone-based, hydrogen peroxide-based, potassium permanganate processes, and Fenton and Fenton-like process were reviewed. Biological methods such as aerobic, anoxic, anaerobic, bioreactors, constructed wetlands, soil bioremediation and biofilter processes for the management of hazardous wastes, in mode of consortium and pure culture were reviewed. Case histories were reviewed in four areas including contaminated sediments, contaminated soils, mixed industrial solid wastes and radioactive wastes.

Nanocomposite materials can enhance the capabilities of water treatment processes such as photocatalysis. In this work, novel light-driven nanocatalysts were synthesized by using nickel ferrite (NiFe

An electrode made of activated carbon that had high-specific-surface area and low pHzpc supported on graphite sheet was fabricated. The electrode, NSA/G, was used to study the effect of reversible surface charge on the adsorption of simple electrolyte, i.e., NaCl, on polarizable electrode. Polarizable surface charge is originated from externally applied potential whereas reversible surface charge is derived from change of activity of potential-determining ions, i.e., H+ or OH– owning to hydrous surface, which undergoes protonation and deprotonation of surface hydroxyl groups. Ion adsorption density was obtained from direct analytical measurement of corresponding ion studied instead of conductivity measurement. Langmuir adsorption isotherm was applied to estimate the monolayer ion adsorption density. Electrosorption/desorption kinetics was fitted well by the first-order rate law. In the applied potential range of −0.3 to −1.0 V (vs. SCE) and pH of 3 to 10, the pH-determining surface, i.e., reversible charge, accounted for Na+ sorption intensity was estimated based on the Gouy-Chapman version of electrical double layer theory. Results revealed that the two major surface charges, i.e., polarizable (σE) and reversible (σpH), contributed equally to the total charge density (σT). At high pH (pH 10) and low applied voltage (-0.3 V vs. SCE), the fraction of pH-determining contribution to total surface charge with respect to Na+ sorption, i.e., σpH/σT, was around 0.50. Results reaffirmed the importance of reversible surface charge together with polarizable surface charge on the design and operation of CDI system for electrosorption of ions from water.

In-situ chlorine generation has high disinfection potential for small to medium scale water treatment systems. Electrodes were prepared by coating Pt-, Ni-, Co-oxides on graphite substrate using electrodeless deposition method and characterized with SEM, EDS, XRD, XPS and cyclic voltammetry. Results showed that the molar ratio of Ni- and Co-oxides on graphite surface influenced surface structure and in-situ chlorine generation capacity. Pt0.01Ni0.24Co0.75 electrode exhibited a unique surface structure and the highest in-situ chlorine generation capability. The Pt0.01Ni0.24Co0.75-G electrode exhibited highly porous 3D structure and high oxygen deficit, which significantly promoted the formation of M-Cl− binding on electrode surface and enhanced chlorine generation. The onset of chlorine evolution potential was lower than that of oxygen on Pt0.01Ni0.24Co0.75-G electrode. Moreover, the transfer coefficient of chloride oxidation was smaller than that of water oxidation, which would enhance chloride oxidation current efficiency. The in-situ chlorine generation capability increased with NaCl concentration. The kinetics of chlorine generation was well described by the Langmuir-Hinsheldwood mechanism. The in-situ disinfection rate decreased with the increase in initial E. coli density. A 7.5-log disinfection was achieved in 15 min in the presence of 0.01 M NaCl under 5 mA/cm2 current density at room temperature. The lipid peroxide, morphology changes and destruction of E. coli cell membrane were observed in the in-situ disinfection process, indicating that reactive species such as chlorine radical in addition to free chlorine played the main role of in-situ disinfection.

Mesoporous zirconium pyrophosphate(ZPP) adsorbents were synthesized, with six quaternary ammonium salts (Quats), namely, Octyltrimethylammonium (OTMA, C8), Decyltrimethylammonium (DCTMA, C10), Dodecyltrimethylammonium (DDTMA, C12), Tetradecyltrimethylammonium (TDTMA, C14), Hexadecyltrimethylammoium (HDTMA, C16), and Octadecyltrimethylammonium (ODTMA, C18), as template for studying fluoride adsorption. Quats of long carbon chain length significantly affected the specific surface area of mesoporous ZPP adsorbents. C18-ZPP exhibited the largest specific surface area and fluoride adsorption density. Fluoride adsorption density remained constant at pH 10–11. Langmuir adsorption isotherm described fluoride adsorption characteristics well. Results showed that mesoporous ZPP synthesized with C18 at Zr to C18 molar ratio of 0.57:1 exhibited the best fluoride adsorption capacity (32 mmol/g) among all ZPP adsorbents prepared at various Zr to C18 molar ratios. C18-ZPP exhibited two-fold increase in fluoride removal capacity compared to plain ZPP. The reusability of C18-ZPP was assessed by running fluoride removal at least five cycles. Mesoporous ZPP is a promising adsorbent for fluoride removal from water with much enhanced adsorption capacity, regenerability, and reusability.

Magnetically separable spinel ferrites were created in an electrocoagulation (EC) process for removing boron from aqueous solution. Coprecipitates of NiFe2O4, CoFe2O4 and CuFe2O4 were obtained using sacrificial iron anodes (EC-Fe) in an electrolyte that contained transition metal salts (Ni, Co, Cu). The use of nickel chloride (NiCl2) as the supporting electrolyte yielded the highest boron removal since the maximum adsorption capacity of the resulting sludge was 28.9 mg-B/g. An EC that used iron and nickel as anodes (EC-Fe/Ni) in NaCl electrolyte was then employed to form nickel ferrite by electrochemical dissolution of ferrous (Fe(II)) and nickel (Ni(II)) ions, providing comparable removal efficiency but minimizing the residual level of Ni(II) in the treated water. The saturation magnetization of the precipitate that was produced in the EC-Fe/Ni system was 50.3 emu/g which exceeded that in the EC-Fe system with nickel chloride – 21.8 emu/g, indicating its outstanding magnetic separability. EC-Fe/Ni was optimized to remove 95% of boron from solution in 60 min with an initial boron concentration of 10 ppm at pH 8 and a current density of 3.75 mA/cm2.

A nickel foam-supported Ni(OH)2/NiOOH electrode, synthesized in-situ at a specific electrode overpotential, was used to study the oxidation of ammonia in aqueous solution. Results of voltammetric analysis showed the formal potential of Ni(OH)2/NiOOH transition at +0.6 V (vs. Hg/HgO, pH 11) at which the current profile was improved by electron transfers of NH3 in the electrolyte. Selectivity of NH3 conversion to NO3− and N2 was evaluated by batch constant current experiments. Electrochemical parameters, including solution pH (6–12), temperature (20–40 °C), current density (0.2–3 mA cm−2), and initial NH3-N concentration (20–450 mg-L−1), that may affect ammonia oxidation toward nitrogen selectivity were studied. At constant current density of 1.5 mA cm−2A, ammonia removal reached 98.5% and NO3− was the major product at initial NH3-N concentration of 50 mg-L−1 in 7 h. By contrast, N2 evolution dominated at low current density ( 100 mg-L−1). A surface steady-state approach, with NH3 deprotonation as the rate-limiting step, provided the reaction pathways of NH3 conversion to molecular nitrogen byproduct.

The distribution and characteristics of heavy metals around an electric arc furnace (EAF) plant in Taichung City, Taiwan, were investigated. The aim of this research was to predict the main steelmaking processes causing contamination of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the environment. Food crop, surface water, sediments, and soils were collected from a total of 65 and 53 sampling sites during November 2011 and June 2012, thus establishing the basic environmental information. The heavy metals in samples were assessed by potential ecological risk indices. The correlation between the source and receptors of contamination was evaluated through the statistical significance of isotope approach and hierarchical cluster analysis. The heavy metal contamination was mainly from the storage facility of waste iron and the discharging device of fly ash in the EAF plant. Surface runoff and rainwash were the two potential routes distributing the metallurgical Cd and Pb to the surrounding environment. Based on the mathematical simulation of dispersion modeling, the impact of heavy metals through the two specific flue gases on the farmland was insignificant; the particulate matter (PM), SO2, and NOx were concentrated southward in the atmosphere, and they were 1.71 μg—PM/Nm3, 2.80 ppb—SO2, and 1.87 ppb—NOx, respectively. Because of topographical features, the contaminated sediment produced by steelmaking activities is washed into downstream via surface runoff, which is supposed to be the major source of long-term accumulation of heavy metals in the environments, although the contamination with heavy metals was graded as low.

Chemical oxo-precipitation (COP) is a modified precipitation process in which hydrogen peroxide is used to transform boric acid to perborate anions, which are precipitated with calcium salt under ambient conditions. To minimize the production of sludge, chemical oxo-precipitation was performed in a fluidized-bed reactor to reclaim boron as unseeded calcium perborate pellets. Several major experimental parameters, including effluent pH, calcium dosage, and surface loading that affected the degree of supersaturation and the efficiency of boron removal, were tested. A crystallization ratio of around 60% was attained under the following conditions: initial boron concentration = 1000 ppm, molar ratios of [Ca]/[B] = 0.6 and [H2O2]/[B] = 2, effluent pH = 10.6, bed height = 80 cm, and hydraulic retention time = 18 min. On the basis of the characterization of XRD, SEM, and Raman spectroscopy, the granules recovered were amorphous calcium perborates Ca(B(OH)3OOH)2 and CaB(OH)3OOB(OH)3.

Direct electrocatalytic oxidation of ammonia was carried out using an open-pore structured nickel foam electrode via electrochemical formation of Ni(OH)2/NiOOH nano-flowers (theophrastite phase) on the nickel substrate at specific overpotentials. The electrode surface was analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectrometer (RS), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammograms gave information on the nature of electron transfer between nitrogen species and nickel foam electrode and revealed the potential dependence nature of ammonia oxidation over the potential window of +0.7 V to +0.85 V (vs. Hg/HgO). Batch controlled potential experiments using nickel foam as the working anode in a three-electrode system were conducted to study the oxidation of ammonia in solution containing 0.1 M of Na2SO4 electrolyte, at pH 11 and temperature of 25 °C. Based on the current efficiency and reaction kinetics, it was possible to establish the mechanism of selective ammonia conversion to gaseous nitrogen and nitrate.

The capability of manganese dioxide (MnO2) supported on loofah-derived activated carbon (AC) in the electrosorptive removal of common inert ions was studied in constant potential mode. Four MnO2 polymorphs were prepared by redox chemical precipitation and characterized by XRD, SEM, BET and XPS. The pseudocapacitance property of the MnO2/AC electrode, significantly affected by the surface- and diffusion-controlled charge storage mechanism, was assessed via voltammetry and modified Langmuir adsorption isotherm. Batch electrosorption experiments were then performed at constant potential in the range of −1.5 V to + 1.5 V (vs. Ag/AgCl) using AC and α-MnO2/AC electrodes in the presence of common simple electrolytes, including NaNO3, Li2SO4, and Ca(ClO4)2. Consequently, the applied working potential (Eapp) positively affected the ion electrosorption rate and capacity. Faradaic processes occurred on MnO2, i.e., Mn(III)/Mn(IV) transition, increased the diffusion capacitance of AC, thus enhancing the first-order rate and monolayer capacity, mainly for the electrosorption of cations. Results showed that ion solvation, controlled by the ionic radius and valence of an ion, which impacted ion intercalation in MnO2 and affected ion adsorption characteristics. The cation sorption capacity of α-MnO2/AC followed the order of Na+ (2.8 × 10-4 mol g−1) > Ca2+ (2.1 × 10-4 mol g−1) > Li+ (0.76 × 10-4 mol g−1) at Eapp = -1.5 V. The differential capacitance as affected by polarized potential and the shift of zero net charge or IEP toward more positively charging potential further highlighted the contribution of pseudocapacitance to ion adsorption on α-MnO2/AC electrode.

Graphite-supported α- and β-PbO2 electrodes (PbO2@G) were prepared by electrochemical deposition at appropriate potentials with regard to Pb(II)/PbO2 redox couple under alkaline and acidic conditions, respectively, for studying the direct electro-oxidation of ammonia in aqueous solutions. Results of surface characterization including scanning electron microscopy (SEM), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) indicated the presence of polymorphs of PbO2@G. Cyclic voltammetry (CV) of the electrolyte containing NH3 indicated mediation of electron transfer by PbO2. At the onset potential of ca. +1.0 to +1.45 V (vs. Hg/HgO), a pathway of NH3 oxidation to nitrogen byproducts, namely, N2, NO2−, and NO3− was proposed. The removal efficiency and selective conversion of ammonia (0.1 M Na2SO4, pH 11, 25 °C) on PbO2@G was determined based on controlled potential experiments.

This work demonstrates the recovery of phosphorus from a solution (150 mg-P/L) using ferrous salts (FeSO 4 ) and hydrogen peroxide (H 2 O 2 ) as precipitants through the fluidized bed crystallization (FBC) process. Jar-test experiments were conducted to investigate effective pH and molar ratios of H 2 O 2 /Fe(II) and Fe(II)/P in the removal of phosphate. The pure ferric phosphate crystal was then recovered using the FBC process and the effluent pH e and surface loading (L, kg-P/m 2 h) were tested. The results of XRD revealed that the FBC pellets were composed of the mixtures of rodolicoite and giniite, with a Fe/P molar ratio of approximately 1.1, based on elemental analysis. Under conditions pH e = 2.6, an H 2 O 2 /Fe(II) molar ratio of 0.6, an Fe(II)/P molar ration of 1.2, and L = 0.3–0.89 kg/m 2 h, a crystallization ratio of 86% and a removal efficiency of 95% were achieved.

Chemical oxo-precipitation (COP) has become a promising method for treating boron wastewater at room temperature; it uses hydrogen peroxide to convert boric acid to perborate species, which are precipitated using alkaline earth metals. In this work, solubility models of barium perborates were established to predict residual boron levels from COP. The solubility product constants (pKsp) of two major barium perborates - amorphous Ba(B(OH)3OOH)2 (A-BaPB) and crystalline BaB(OH)2(OO)2B(OH)2 (C-BaPB) - were experimentally estimated (8.335±0.109 and 9.190±0.057, respectively) to define the solubility curves of BaPBs at given pH, ionic strength and concentrations of barium and peroxide species. The characterization of precipitates that were formed by COP confirmed that the boron levels in aqueous solution were governed by the phase transformation of A-BaPB to C-BaPB. The predictive solubility models of barium perborates can perfectly predict the residual concentration of boron after COP treatment and can be used to optimize the process for reducing boron concentrations in wastewater.

Alginate is a natural rich anionic polysaccharide (APS), commonly available as calcium alginate (CAPS). It can maintain a physiologically moist microenvironment, which minimises bacterial infection and facilitates wound healing at a wound site. Patients with burn injuries suffer from pain and an inflammatory response. In this study, we evaluated the CAPS dressing and traditional dressing containing carboxymethyl cellulose (CMC) for wound healing and scar tissue formation in a burn model of rat and swine. In our pilot study of a burn rat model to evaluate inflammatory response and wound healing, we found that the monocyte chemoattractant protein (MCP)-1 and transforming growth factor (TGF)-β were up-regulated in the CAPS treatment group. Next, the burn swine models tested positive for MCP-1 in a Gram-positive bacterial infection, and there was overproduction of TGF-β during the burn wound healing process. Rats were monitored daily for 1 week for cytokine assay and sacrificed on day 28 post-burn injury. The swine were monitored over 6 weeks. We further examined the pain and related factors and inflammatory cytokine expression in a rodent burns model monitored everyday for 7 days post-burn. Our results revealed that the efficacy of the dressing containing CAPS for wound repair post-burn was better than the CMC dressing with respect to natural wound healing and scar formation. The polysaccharide-enriched dressing exerted an antimicrobial effect on burn wounds, regulated the inflammatory response and stimulated anti-inflammatory cytokine release. However, one pain assessment method showed no significant difference in the reduction in levels of adenosine triphosphate in serum of rats after wound dressing in either the CAPS or CMC group. In conclusion, a polysaccharide-enriched dressing outperformed a traditional dressing in reducing wound size, minimising hypertrophic scar formation, regulating cytokines and maximising antimicrobial effects.

Calcium is one of the divalent ions contributing to the hardness level of the water. This work describes the removal of calcium ions from aqueous solution using carbonate salts as precipitants and the recovery of homogeneous calcium carbonate crystals via a fluidized-bed homogeneous crystallization (FBHC) process without a heterogeneous seed material. The considered parameters were effluent pH, initial molar ratio of carbonate salt to Ca, up-flow velocity, and cross-section loading. The removal efficiency of Ca hardness reached 95% at the optimal pH of 10–11 and the corresponding crystallization ratio was 88% for initial concentrations of Ca of 50–330 ppm. The FBHC process was effective with a cross-section loading of calcium in the water of up to 4.5 kg/m 2 /h. The efficiency of Ca immobilization as the crystal grew on the fluidized pellets was greatly improved by adjusting the degree of supersaturation in the range 2–3, resulting in the crystallization ratio (CR) and total removal of Ca (TR) of 88% and 92%, respectively. XRD analysis revealed that the formed crystals comprised two calcium carbonate (CaCO 3 ) phases—calcite and aragonite. SEM images of the surface morphology revealed that calcium carbonate particles (around 1–2 mm) were formed by the aggregation of fine crystals (around 5 µm).

The electrocoagulation (EC) using metallic Ni foam as electrodes was studied for the removal of boron from solution. The electrolytic parameters were pH (4-12), current density (0.6-2.5 mA cm-2), and initial concentration of boron (10-100 mg L-1). Experimental results revealed that removal efficiency was maximized at pH 8-9, and decreased as the pH increased beyond that range. At particular onset potentials (0.5-0.8 V vs. Hg/HgO), the micro-granular nickel oxide that was created on the surface of the nickel metal substrate depended on pH, as determined by cyclic voltammetry. Most of the crystallites of the precipitates comprised a mixed phase of β-Ni(OH)2, a theophrastite phase, and NiOOH, as revealed by XRD and SEM analyses. A current density of 1.25 mA cm-2 was effective in the EC of boron, and increasing the concentration of boric acid from 10 to 100 mg L-1 did not greatly impair removal efficiency. A kinetic investigation revealed that the reaction followed a pseudo-second order rate model. The optimal conditions under which 99.2% of boron was removed from treated wastewater with 10 mg L-1-B, leaving less than 0.1 mg L-1-B in the electrolyte, were pH 8 and 1.25 mA cm-2 for 120 min.

Spent ion exchange resins have become a crucial radioactive solid waste from the nuclear industry. Developing effective and safe disposal methods as alternatives to the present cementation method remains challenging. This investigation demonstrates the treatment of a mixed resin (sulfonated and quaternary ammonium polystyrene beads with a weight ratio of 40%:60%) by the electro-Fenton process. Mesh-type titanium metal that was coated with IrO 2 /RuO 2 (Ti-DSA) was used as the anode and a stainless steel net was used as the cathode. The conversion of resins to soluble fragments and the removal of total organic carbon reached 92% and 99.4%, respectively, under conditions of solid loading = 40g L −1 , pH 2, applied current = 2 A, H 2 O 2 flow rate = 1.2 mL min −1 , FeSO 4 = 20 mM at 85 °C. A pseudo first-order kinetic model of consecutive reactions specified that the efficacy of the electro-Fenton depended strongly on the slowly generated styrene in the aqueous phase by H 2 O 2 and strong acid, which was rapidly mineralized by the hydroxyl radicals. The electro-Fenton process with reused iron catalyst was effective for treating ion exchange resin for at least for three runs, greatly reducing the volume of waste resin liquid.

In this investigation, fluidized bed crystallization (FBC) is utilized to treat phosphorus wastewater that is produced by the manufacture of thin film transistor-liquid crystal displays (TFT-LCD). TFT-LCD wastewater contains 500 ± 10 ppm phosphorus. The pH and molar ratio of Fe/P for removing phosphorus was initially examined by performing a jar-test. The parameters of the FBC – effluent pHe, Fe/P ratio and the upflow velocity (m h−1) – were tested to recover phosphorus from wastewater as ferrous phosphate pellets, characterized using an X-ray diffractometer (XRD) and scanning electron microscopy (SEM), and silica sand was used as the seed material. The experimental results revealed that the control of effluent pHe was an essential parameter in maximizing the phosphorous removal (PR%) and crystallization ratio (CR%). At pHe 5–6, the supersaturation of phosphate precipitation by conditioning the molar ratio of Fe/P to 1.5 and the upflow rate was adjusted within the range of 30.56–68.76 m h−1 in the metastable zone at a cross-section loading of 0.72 kg per P per h per m2, leading to a phosphorus removal (PR) of 95% and a crystallization ratio (CR) of 63%. Under optimal hydraulic conditions, the treatment of real wastewater in a FBC process was viable by converting the pollutant into crystals with a high-purity phase of vivianite (Fe3(PO4)2·8H2O).