Emission Spectrometric Analysis Research Articles

Feasibility of ammonium sulfate recovery from wastewater sludges: Hydrothermal liquefaction pathway vs. anaerobic digestion pathway

This study evaluated two pathways to recover the nitrogen-content of wastewater sludges as ammonium sulfate (AmS) for use as fertilizer. The first pathway entails sludge stabilization by hydrothermal liquefaction (HTL) followed by recovery of AmS from the resulting aqueous product by gas permeable membrane (GPM) separation. The second one entails stabilization of the sludges by anaerobic digestion (AD) followed by recovery of AmS from the resulting centrate by GPM separation. A bench-scale GPM reactor is shown to be capable of recovering >90% of N in the feed. Recoveries of NH3–N in the HTL-pathway ranged 96–100% in 5.5–7.5 h at mass removal rates of 0.2–0.3 g N/day, yielding 3.3–6.0 g AmS/L of feed. Recoveries of 98% were noted in the AD-pathway in 4 h at mass removal rates of 0.06–0.97 g N/day and a yield of 1.7–2.1 g AmS/L of feed. Inductively coupled plasma optical emission spectrometer analysis confirmed that both pathways yielded AmS meeting the US EPA and European region guidelines for land application. The GPM reactor enabled higher nitrogen-recoveries in the HTL-pathway than those reported for current practice of AD followed by ammonia stripping, ion exchange, reverse osmosis, and/or struvite precipitation (96–100% vs. 50–90%). A process model for the GPM reactor is validated using performance data on three different feedstocks.

In-syringe vortex-assisted dispersive liquid–liquid microextraction for determination of copper and vanadium in food samples using a new poly functionalized pyridinone derivative as a complexing agent and soybean oil methyl ester as extraction solvent

Traditional liquid-phase extraction procedures are against the principles of green chemistry. Therefore, it is important to develop eco-friendly procedures. In this study, an in-syringe vortex-assisted dispersive liquid–liquid microextraction (IS-VA-DLLME) approach was developed for the separation of Cu2+ and V5+. Soybean oil methyl ester (SBME) was used as the extraction solvent for the first time, and a newly synthesized poly functionalized pyridinone derivative, that is, 3-acetyl-4-hydroxy-1-(2-hydroxyethyl)-6-methylpyridin-2(1H)-one (AHHP), was employed as the complexing agent. The extraction was performed using a commercial syringe and enhanced by vortex agitation. Under the optimum conditions, a wide linear range was achieved for V5+ (0.3–500.0 μg L−1) and Cu2+ (0.4–800.0 μg L−1) with limits of detection of 0.07 and 0.09 μg L−1, for V5+ and Cu2+, respectively. Reasonable enrichment factors were obtained for V5+ (19.8) and Cu2+ (20.3), for the 10.0 mL sample. The within- and between-run precision (RSD) was in the range of 1.6–2.2% (n = 10). The validity of this procedure was evaluated using certified reference materials. The proposed technique was used to separate V5+ and Cu2+ from different food samples prior to inductively coupled plasma-optical emission spectrometric analysis with relative recoveries ranging from 95.0 to 105.0%.

In situ Raman investigation of dissolved constituent and its evolution in pulp during Zn-S selective flotation with two-step pulp regulation

Redox potential (Eh) of the pulp dominates Zn-S selective flotation, and regulating Eh can maximize Zn grade and recovery of Zn rougher concentrates. However, reasons accounting for the beneficial results of Eh regulation in flotation have not been previously elucidated. This study investigated the inherent causes of macro flotation results by inductively coupled plasma optical emission spectrometer (ICP-OES), Raman spectra and X-ray diffraction (XRD) analyses. The ICP-OES data showed that the levels of calcium and sulfur in the pulp increased considerably after lime regulation. The Raman spectra confirmed that calcium polysulfide (CaSn, n = 2–8) was generated and maintained long-term stability in the pulp regulated by lime without Eh regulation. However, under Eh regulation, CaSn only kept momentary existence in the pulp. Polysulfide reacted quickly with the added copper sulfate and formed brown precipitates, whose main component identified by XRD was CuS, leading to the ineffectiveness of copper-activation for Zn flotation. These findings provide a new insight into the role of Eh in sulfide mineral flotation and partially explain the main reasons to hinder the high-efficiency selective separation of sphalerite from pyrrhotite-containing sulfide ores.

Preparation of carbon nanotubes with high filling rate of copper nanoparticles

Performance of carbon nanotubes (CNTs) can be adjusted by filling their cavities with guest materials. In this study, Cu nanoparticles are filled into CNTs via wet chemical method. To improve the filling efficiency, oxygen-containing functional groups (OCFGs) are introduced onto the tube walls of CNTs by acid treatment. The defects and pore size distribution on CNTs are detected and quantified by N2 adsorption-desorption experiment, Raman spectra, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Morphologies of CNTs before and after filling treatment are observed by transmission electron microscope (TEM). The filling rate is characterized by inductively coupled plasma emission spectrometer (ICP) and thermal gravimetric analysis (TGA). The results indicate that the OCFGs can not only improve the hydrophilicity of CNTs, but also greatly affect the filling rate of CNTs. The filling rate of CNTs acid-treated for 24 h (1.99 wt% tested by TGA) is significantly lower than that of acid-treated for 8 h (12.11 wt% tested by TGA), which can be ascribed to the fact that excessive OCFGs could hinder Cu2+ ions from entering the cavity of CNTs. The obtained results can provide a new perspective for the application of CNTs in composite preparation and related fields.

Selecting an Acid Mixture for Microwave Digestion of Diverse Steel Samples in Inductively Coupled Plasma Atomic Emission Spectrometric Analysis of Boron, Aluminum, Silicon, Phosphorous, and Alloyed Elements

Selecting an Acid Mixture for Microwave Digestion of Diverse Steel Samples in Inductively Coupled Plasma Atomic Emission Spectrometric Analysis of Boron, Aluminum, Silicon, Phosphorous, and Alloyed Elements

Ionic Liquid-Modified Porous Organic Polymers as Efficient Metallocene Catalyst Supports

Porous organic polymers (POPs) are widely used in various areas such as adsorption, separation and catalysis. In the present work, ionic liquid-modified porous organic polymers (IL-POPs) synthesized by dispersion polymerization were applied to immobilize metallocene catalysts for olefin polymerization. The prepared IL-POPs were characterized by Fourier transform infrared spectrometer (FT-IR), nitrogen sorption porosimetry, X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), inductively coupled plasma atomic emission spectrometer (ICP) and scanning electron microscope (SEM) analysis. The IL-POPs obtained pores with surface specific area (SSA) ranging from 16.9 m2/g to 561.8 m2/g, and total pore volume (TPV) ranging from 0.08 cm3/g to 0.71 cm3/g. The supported catalysts Zr/MAO@IL-POPs exhibit great activity (3700 kg PE/mol·Zr·bar·h) in ethylene polymerization, and the GPC-IR results show that the polyethylene has narrow molecular weight distribution (2.2 to 2.8). The DSC results show that the melting point of prepared polyethylene was as high as 138 °C, and the TREF analysis results indicate that they have similar chemical composition distribution with elution temperature at 100.5–100.7 °C.

CENTRE OF ISOTOPIC AND GEOCHEMICAL RESEARCH (IGC SB RAS): CURRENT STATE OF MICRO- AND MACROANALYSIS

Centre of Isotopic and Geochemical Research based on the Analytical Department of Vinogradov Institute of Geochemistry SB RAS (Irkutsk) performs a wide range of analytical studies to solve mineralogical and petrological, geochemical, prospecting, ecological, paleoclimatic and applied problems. The studies are supported by the modern equipment for electron microprobe, X-ray diffraction, X-ray fluorescence, atomic emission and mass spectrometric (including isotope) analyses, as well as the necessary international certified reference materials (SRM) and a collection of SRM of the natural and technogenic composition of our production.

A Comparative Experimental Study of Alternative Iron Sulfide Scale Dissolvers in the Presence of Oilfield Conditions and Evaluation of New Synergists to Aminopolycarboxylic Acids

SummaryIssues such as high corrosion rate, hydrogen sulfide (or H2S) generation, and scale reprecipitation have required the use of alternative dissolvers such as tetrakis(hydroxymethyl)phosphonium sulfate (THPS)–ammonium chloride (or NH4Cl) blend and chelating agents to dissolve iron sulfide (or FeS) scales. However, there are many aspects of these dissolvers that need investigation. This paper provides a guideline to select the best dissolver under various oilfield conditions by an extensive laboratory study. Furthermore, the iron sulfide scale removal is enhanced by the use of new synergists to the chelating agents.The application of THPS and diethylenetriaminepentaacetic acid (DTPA) in well tubulars or pipelines requires laboratory testing to determine the optimal conditions such as dissolver concentration, treatment time, and dissolver/scale (D/S) ratio (cm3/g) at 150°F. This evaluation considers oil-wet scales, mixed scales, presence of additives, and presence of salts during the treatment. Synergists such as potassium chloride (or KCl), potassium iodide (or KI), potassium formate (or HCOOK), sodium fluoride (or NaF), and potassium citrate (or K-Citrate) were added to ethylenediaminetetraacetic acid (EDTA), DTPA, and hydroxyethylethylenediaminetriacetic acid (HEDTA), and the scale solubility was evaluated at 150 and 300°F. Inductively coupled plasma–optical emission spectrometer analysis of the supernatant solution at various intervals of time up to 48 hours revealed the kinetics of the dissolution process. H2S generated from the scale dissolution process was measured using Draeger tubes. Corrosion tests helped in measuring the damage to the tubulars as a result of the dissolver’s contact with N-80 coupons.Solubility tests indicated the dissolver’s scale removal capacity at different concentrations. The work also accounted for the consumption of the dissolver for the scale removal. The optimal blend was chosen considering both the dissolution capacity and the dissolver consumption. For THPS–ammonium chloride blend, 0.75 mol/L THPS (30 wt%) and 2 mol/L NH4Cl (10 wt%) proved to be the optimum dissolver concentration at 150°F. Similarly, for DTPA, 0.4 mol/L K2-DTPA was evaluated to be the most effective dissolver concentration. The THPS–ammonium chloride blend was found to dissolve the iron sulfide slowly compared with K2-DTPA and 15% hydrochloric acid (HCl). The presence of crude oil on the scale hindered its solubility with K2-DTPA by 8%. The presence of calcium carbonate influenced higher selectivity of chelating the calcium ions by K2-DTPA. However, the overall fraction of scale removal was not affected. Adding corrosion inhibitors (CIs) did not affect the scale solubility significantly and also helped in maintaining an acceptable corrosion rate of N-80 coupons below 0.05 lb/ft2 at 150°F. The reaction of HCl and the iron sulfide scale generated 1,800 ppm of H2S in comparison with 0- and 10-ppm by THPS–ammonium chloride blend and K2-DTPA, respectively. Adding potassium iodide and potassium citrate to EDTA helped in improving the scale solubility at 150°F. Sodium fluoride improved the scale dissolution by EDTA and DTPA at 300°F.This paper addresses oilfield-like conditions on scale solubility by evaluating the role of mixed scale, scale mass, presence of hydrocarbons on the scale, and presence of monovalent/divalent ions in dissolver solution. A detailed and direct comparison of HCl, THPS–ammonium chloride blend, and DTPA in dissolving iron sulfide at various conditions enables easier selection of the dissolver for a field treatment. New synergists for iron sulfide scale dissolution are introduced in this paper. This work can help oilfield companies understand the nuances of applying different alternative iron sulfide dissolvers.

Anti-Microbial, Anti-Oxidant, and α-Amylase Inhibitory Activity of Traditionally-Used Medicinal Herbs: A Comparative Analyses of Pharmacology, and Phytoconstituents of Regional Halophytic Plants' Diaspora.

Halophytes are the category of plants growing under harsh conditions of super-salinity, and are wide-spread in the coastal Mediterranean climatic conditions and desert oasis. They are adept at surviving through maintaining excessive production of enzymatic, and non-enzymatic secondary metabolites, especially phenolics and flavonoids that primarily work as anti-oxidants and phytoalexins. Five major halophyte species growing in the kingdom’s Qassim’s high-salted desert regions were investigated for confirming their traditionally used biological activity of sugar-control and anti-infectious properties. In this context, the comparative presence of phenolics, and flavonoids together with anti-microbial, anti-oxidants, and the anti-diabetic potentials of the plants’ extracts were investigated through the α-amylase inhibition method. The highest concentrations of phenolics and flavonoids were detected in Salsola imbricata (360 mg/g of the extract as Gallic-Acid-Equivalents/GAE, and 70.5 mg/g of the extract as Rutin-Equivalents/RE). In contrast, the lowest concentrations of phenolics and flavonoids were detected in Salsola cyclophylla (126.6 mg/g GAE, and 20.5 mg/g RE). The halophytes were found rich in trace elements, a factor for water-retention in high-salinity plants, wherein iron and zinc elements were found comparatively in higher concentrations in Aeluropus lagopoides (4113 µg/kg, and 40.1 µg/kg, respectively), while the copper was detected in higher concentration (11.1 µg/kg) in S. imbricata, analyzed through Inductively Coupled Plasma Optical Emission Spectrometric (ICP-OES) analysis. The anti-oxidant potentials and α-amylase enzyme inhibition-based anti-diabetic activity of S. imbricata was significantly higher than the other halophytes under study, wherein S. cyclophylla exhibited the lowest level of α-amylase inhibition. The maximum DPPH radicals’ (52.47 mg/mL), and α-amylase inhibitions (IC50 22.98 µg/mL) were detected in A. lagopoides. The anti-microbial activity against the Methicillin-Resistant Staphylococcus aureus was strongly exhibited by Zygophyllum simplex (33 mm Inhibition Zone-Diameter, 50 µg/mL Minimum-Inhibitory-Concentration), while Escherichia coli, Enterococcus faecalis, and Candida albicans growths were moderately inhibited by Tamarix aphylla. The current findings exhibited significant differences among the locally distributed halophytic plants species with regards to their bioactivity levels, anti-oxidant potentials, and the presence of trace elements. The ongoing data corroborated the plants’ traditional uses in infections and diabetic conditions. The enhanced local distribution of the plants’ diaspora and higher density of occurrence of these plants species in this region, in comparison to their normal climatic condition’s counterparts, seemed to be affected by humans’ use of the species as part of the traditional and alternative medicine over a period of long time.

Preparation of electrospun polyvinylidene fluoride/amidoximized polyacrylonitrile nanofibers for trace metal ions removal from contaminated water

In this study, a mixture of polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), and dimethylformamide (DMF) as solvent were reacted with hydroxylamine hydrochloride to produce polyvinylidene fluoride (PVDF)/amidoximized polyacrylonitrile (AOPAN) spinning solution, and then a novel composite PVDF/AOPAN was fabricated by electrospinning technique. Later the electrospun PVDF/AOPAN nanofibers (NFs) were treated with KOH and pitched in (plunged in) mini-column to be used as an adsorbent material under continuous flow. The structural and morphological characterization of nanofibers membrane was determined using scanning electron microscope equipped with an energy dispersive spectrometer(SEM/EDS), Fourier transform infrared spectrometer (FTIR), and goniometer, the inductively coupled plasma optical emission spectrometer (ICP-OES) analysis was used to evaluate the adsorption capability. The effects of pH and metal ions concentration on the transport properties of PVDF/AOPAN nanofibers were also studied. The Langmuir model fits well with isotherm data for lead and copper and the Redlich–Peterson model for nickel, whereas pseudo-second order was the best to clearly delineate the investigated kinetics. The modified PVDF/AOPAN NFs showed excellent adsorption capability with very fast kinetics reaching the equilibrium in 90 min for lead, copper, and 60 min for nickel. EDS analysis of PVDF/AOPAN after metal adsorption confirmed the attachment of the metals. Obtained results illustrate that converting PAN to AOPAN enhanced the hydrophilicity drastically. The removal rate for lead, copper, and nickel reached 99.5% 99.5% 99.6% under 10 mg L−1 respectively, more interestingly for lead, even the concentration was 100 mg L−1, the removal rate still reached 98.1%. Moreover, the adsorbent displayed an excellent regeneration ability by using 0.5 M HCl. This study showed that PVDF/AOPAN is an effective adsorbent for Pb(II), Cu(II), and Ni(II) removal in trace amount.

Heavy metal contamination in recorded and unrecorded spirits. Should we worry?

Heavy metals can be released into all alcoholic beverages during production and storage. However, there is at least a theoretical risk that they could be present in higher, and potentially toxic, concentrations in those produced in the household and small-scale stills common in Central and Eastern Europe, which lack quality control and whose products are unrecorded by authorities. Yet, so far, few studies comparing concentrations of heavy metals in recorded and unrecorded spirits have been published. In this study we ask whether there is any difference between heavy metal concentrations in recorded and unrecorded spirits and, thus, the related health risk. The levels of heavy metals were determined in recorded (n = 97) and unrecorded (n = 100) spirits using inductively coupled plasma optical emission spectrometric analysis and applied to population-based risk assessments, considering average, regular and chronic heavy drinkers. Concentrations of Cu, Zn, and Sn were significantly higher in unrecorded spirits than those in their recorded counterparts and recorded spirits contained significantly higher levels of Fe, Mn, and Ni than unrecorded spirits. Combined exposure to heavy metals posed a potential health risk in chronic heavy drinkers consuming recorded spirits. However, when compared to the health risk arising from drinking large volumes of ethanol, the risk is negligible. Consequently, there are no grounds to worry about the adverse effects of heavy metals from spirits.

Investigation of metalloporphyrin compound in maltenes of duri crude oil

Metalloporphyrin is one of the compounds that could potentially cause deactivation of catalysts in the process of catalytic cracking and hydrotreating. Knowledge of the structure of metalloporphyrin can be used as the basic information in overcoming the problem of catalyst poisoning. This work is performed to identify metalloporphyrins in the maltenes fraction of Duri crude oil. The low content of asphaltenes in Duri crude oil with a fractional weight of 0.79 %, allows a high level of metalloporphyrin in the fraction of maltenes which has a fractional weight of 82.73 %. Metalloporphyrin in the maltenes derivate fraction, saturates, aromatics, and resin were separated using column chromatography. Saturates, aromatics and resins have fractional weight of 49.75; 34.92; and 15.33 %, respectively. Only resin contained metalloporphyrin based on the analysis of UV-Vis spectrophotometer and Fourier-transform infrared spectroscopy (FT-IR), thus metalloporphyrins in resin was further separated into fractions by column chromatography. The result of UV-Vis spectrophotometer analysis for resin separation showed an absorbance peak of metalloporphyrin at 480–700 nm, while FT-IR analysis showed the presence of pyrrole group as porphyrin base framework with vibrational region at 400–1100 cm−1 The results of micro plasma-atomic emission spectrometer (MP-AES) analysis showed the presence of Fe, Ni, and V metals content. The liquid chromatography-mass spectrometer (LC-MS) analysis showed the molecular structure of the obtained compound was C33H34N4VO2. According to the results, metalloporphyrins presented in the maltenes fraction of Duri crude oil was vanadyl porphyrin.

Chemical characterization and source identification of particulate matter at Ballari (15.15°N, 76.93°E), Karnataka over Southern Indian region

The present study reports the chemical composition and source identification of the total suspended particulate matter in the sub-urban environment, Ballari. There were 28 particulate matter aerosol sampled between February 2017–July 2018. The surface mass concentration ranged from 103 μg m−3 to 367 μg m−3 with an average value of ~225 ± 65 μg m−3 during the study period. The morphology and elemental composition of aerosol particles were analyzed by using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray system (EDX). From the EDX results aluminosilicate group (Al, Si, K, Fe, Na, Mg, Ti and Ca) contains about ~31% of the total particles, which mainly due to mineral particulate aerosol originate from crustal origin through windblown dust. Further, we also investigated the morphology and chemical composition of total mass concentration during haze (27-03-2018) and clear days (23-02-2018). The SEM pictures show the most notable deposition of spherical particles with smooth surfaces on a hazy day suggesting that the carbon aerosols on haze day were favourable to coagulation of Aitken mode particles, which is consistent with their respective aerosol subtypes captured from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO) satellite over the study region. Inductively coupled plasma optical emission spectrometer (ICP-OES) analysis showed the relative contribution of inorganic ions (SO42−, NO3−, Na+, Ca2+, Cl−, NH4+, K+) is higher than others on 1-05-2017 and 01-01-2018 days over the observational site. The relative contribution of non-sea salt SO42− was abundance (~35%) on both days, indicating the significant anthropogenic influence at this location. The concentration weighted trajectory (CWTs) analysis showed the major sources of particulate matter were soil particles, vehicular emissions, and mining activities surroundings the vicinity of the sampling site.

Metals Composition in Low Cost Apartment in Kuala Lumpur

House dust was found to be a great indicator of metal pollutants for indoor air quality. This study aims to assess the level of metals in house dusts and identify the relationship between the composition of metals concentration in low cost apartment, Kuala Lumpur. Eight houses were selected randomly from four levels of low cost apartment buildings. The samples were collected using a brush and plastic pan and then the samples were digested. The compositions of metals were determined using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) and statistical analysis was used to analyze the data by using Statistical Packages for the Social Sciences (SPSS). The results show that the highest concentration of metals obtained was Fe with the mean value of 1483.64 mg/kg followed by Zn with the mean value of 1197.07 mg/kg, while Cd recorded as the lowest mean value of 0.131 mg/kg. The trend distribution of metals in the investigated areas followed the order Fe > Zn > Cu > Pb > Cd. Statistical analysis indicates significant correlation between all the possible pairs of metals.

Volatile and semi-volatile compounds of Tephrosia purpurea and its medicinal activities: Experimental and computational studies

Abstract The volatile and semi volatile compounds of Tephrosia purpurea L. PERS (TP) were analyzed by using the high-resolution gas chromatography (GC-HRMS). The aqueous extract of TP (whole plant) was tested for medicinal activities including antioxidant, ant-diabetic and anti-inflammatory assays. The GC-HRMS analysis have confirmed the presence of 2-methoxy-4-vinylphenol, sucrose, 2,3,4,5,6,7-hexahydroxyheptanal, 4-(3-hydroxyprop-1-enyl)-2-methoxyphenol, n-hexadecanoic acid, 9,12-octadecadienoic acid, (E)-1,3-diacetoxypropan-2-yl octadec-9-enoate, 1,3-dihydroxypropan-2-yl pentadecanoate, (E)-1,3-dihydroxypropan-2-yl octadec-9-enoate and oleic acid. Based on the Inductively coupled plasma - optical emission spectrometric (ICP-OES) analysis the observed amount of essential metal ions for Ca, Mg, Fe, Co, Cu, Zn and Se was 869.16 ± 7.52, 285.21 ± 5.44, 25.12 ± 1.88, 7.58 ± 0.92, 1.04 ± 0.14, 28.85 ± 1.04 and 11.87 ± 0.78 mg/kg respectively. The aqueous extract of TP (whole plant) exhibited the antioxidant potential (>65%), anti-diabetic (68.45 ± 4.23%), anti-inflammatory (value of binding constants (k) was 5.23 ± 0.04 × 10−5 μM−1) and antimicrobial (MIC values 23–52 mg/ml) qualities. The antioxidant and reactivity indices of the major phenolic compounds observed through the GC-HRMS analysis were validated by applying the density functional theory (DFT) studies. The DFT studies were performed at the B3LYP/6-31G(d) level of theory. The theoretical studies have revealed the antioxidant applications of 4-(3-hydroxyprop-1-enyl)-2-methoxyphenol and 2-methoxy-4-vinylphenol.

Chitosan Hydrogel Beads Supported with Ceria for Boron Removal.

In this study, a chitosan hydrogel supported with ceria (labelled Ce-CTS) was prepared by an encapsulation technique and used for the efficient removal of excess B(III) from aqueous solutions. The functionalisation of chitosan with Ce(IV) and the improvement in the adsorptive behaviour of the hydrogel were determined by SEM-EDS, FTIR, XRD, and inductively coupled plasma optical emission spectrometer (ICP-OES) analyses and discussed. The results demonstrate that Ce-CTS removes boric acid from aqueous solutions more efficiently than either cerium dioxide hydrate or raw chitosan beads, the precursors of the Ce-CTS biosorbent. The maximum adsorption capacity of 13.5 ± 0.9 mg/g was achieved at pH 7 after 24 h. The equilibrium data of boron adsorption on Ce-CTS fitted the Freundlich isotherm model, while the kinetic data followed the Elovich pseudo-second-order model, which indicated that the process was non-homogeneous. The dominant mechanism of removal was the reaction between boric acid molecules and hydroxyl groups bound to the ceria chelated by chitosan active centres. Due to its high efficiency in removing boron, good regeneration capacity and convenient form, Ce-CTS may be considered a promising biosorbent in water purification.

Heavy metals in seafood purchased from a fishery market in Hungary

ABSTRACTHeavy-metal content (arsenic, cadmium, lead and mercury) was investigated and evaluated in shellfish, oysters and squids. The samples were collected weekly for 20 weeks from a fishery product market in Hungary. The concentration of heavy metals was measured by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) analysis after sample preparation. The results were analysed statistically by one-way ANOVA method. The average concentration of arsenic (3.01 ± 1.46 mg kg−1) in shellfish was significantly higher (p < 0.001) compared to oysters (2.88 ± 1.12 mg kg−1) and squids (1.28 ± 0.52 mg kg−1). The level of mercury was below the limit of detection (0.5 mg kg−1) in each sample and there was no statistical significance in the concentrations of cadmium (p = 0.351) and lead (p = 0.412) in the species investigated. The provisional tolerable intake values were also calculated. Based on the obtained results of the heavy-metal content of the investigated samples, the seafood is considered to be safe for human consumption. However, prolonged ingestion of oysters and squids at these levels may contribute to the consumers’ cadmium burden.

Cicer arietinum extract ameliorate γ-irradiation disorders via modulation of oxidative/antioxidative pathway

Ionized radiations trigger thoughtful adverse hazards through multiple organ dysfunctions. Recently, antioxidant-based biodrugs are used to prevent and treat ionizing radiation hazards. The present study aimed to investigate the prospective ameliorative effect of Cicer arietinum extract (CAE) against γ-irradiation and the pathway of this amelioration in male albino rats. Twenty four rats were allocated into four groups; (i) control group, (ii) CAE group in which rats treated with a dosage of 500 mg CAE/kg b.wt, (iii) γ-irradiated group in which rats exposed to 6Gy γ-irradiation, (iv) γ-irradiated+CAE group; rats of this group treated with CAE 1 h post exposure. All rats treated for 21 days. Liver, kidney and femoral bone were rapidly excised and homogenized for the biochemical analysis. Energy dispersive X-ray (EDX) and inductively coupled plasma emission spectrometer (ICP) analyses exhibit that γ-irradiation elicits significant change in the essential trace elements content in liver, kidney, and bone. Further, significant increases in TBARS and H2O2 contents accompanied by significant decreases in GSH, SOD, CAT, and GPx activities in liver, kidney and bone tissues were recorded in the γ-irradiated rats compared to control group. Additionally, marked reduction in the thickness of cortical bone was recorded in rats exposed to γ-irradiation. Conversely, CAE (500 mg/kg b.wt, p.o) administration for 21 days to γ-irradiated rats effectively reverses most of the altered parameters of the γ-irradiated rats. In conclusion, the present findings suggested that CAE is a potential agent that can be used against radiation hazards. This effect may be owing to its antioxidant mechanism, as CAE has an inhibitory effect against hydrogen peroxide (H2O2) and superoxide radical (O2·−) beside its ferric reducing antioxidant power (FRAP). This finding recommended that CAE can be utilized clinically to mitigate ionized radiation-induced hazard effects.

Preparation and Application of Phosphorylated Xylan as a Flocculant for Cationic Ethyl Violet Dye.

In this study, phosphorylated birchwood xylan was produced under alkali conditions using trisodium trimetaphosphate. Three single-factor experiments were used to explore the influences of time, temperature, and the molar ratio of trisodium trimetaphosphate to xylan on the degree of substitution (DS) and charge density of xylan. The response surface methodology was used to explore the interaction of these three factors. Phosphorylated xylan with a maximum DS of 0.79 and a charge density of −3.40 mmol/g was produced under the optimal conditions of 80 °C, 4 h, and a molar ratio of xylan/sodium trimetaphosphate (STMP) of 1/3. Fourier transform infrared (FTIR), ascorbic acid method analyses, and inductively coupled plasma–atomic emission spectrometer (ICP-AES) analyses confirmed that the phosphate groups were successfully attached to xylan. Thermogravimetric analysis confirmed that phosphorylated xylan was less stable than birchwood xylan. Furthermore, the phosphorylated xylan was applied as a flocculant for removing ethyl violet dye from a simulated dye solution. The results indicated that more than 95% of the dye was removed from the solution. The theoretical and experimental values of charge neutralization for the dye removal were close to one another, confirming that charge neutralization was the main mechanism for the interaction of dye and phosphorylated xylan. The impacts of salts on the flocculation efficiency of phosphorylated xylan were also analyzed.

Rh-Pd-alloy catalyzed electrochemical hydrodefluorination of 4-fluorophenol in aqueous solutions

Hydrodefluorination (HDF) is the key step in fluoroaromatic pollutant (FAP) degradation, making the search for efficient HDF catalysts and the determination of the corresponding mechanism a matter of great importance. In this study, we developed an efficient HDF catalyst (a Rh-Pd alloy) and investigated the underlying catalytic reaction mechanism, using 4-fluorophenol (4-FP) as a model FAP. Specifically, the rapid aqueous-phase HDF of 4-FP at pH 3 was achieved on a Rh-Pd alloy-modified Ni foam electrode, which was followed by ring hydrogenation (RH) of the HDF product (phenol) to afford cyclohexanone and cyclohexanol. Inductively coupled plasma optical emission spectrometer (ICP-OES) and thermodynamic analyses showed that, in addition to those supplied by the applied current, the electrons involved in the HDF of 4-FP and the RH of phenol were largely provided by the oxidative dissolution of the Ni foam support. Hydrogenation and cyclic voltammetry experiments indicated that the HDF of 4-FP probably follows an indirect mechanism (featuring adsorbed H atoms as the direct reductant) and that the strength of 4-FP adsorption onto the surface of the catalyst significantly influences its HDF activity.