Wastewater purification to remove ammonium ions by the oxidation method

Wastewater purification to remove ammonium ions and carbamide by oxidation with hypochlorites of alkali and alkaline-earth metals was studied. The effect of various factors on the degree of purification was examined experimentally.     

Treatment of aqueous solutions with a technogenic carbonate-containing reagent to remove lead(II) ions

Russian Journal of Applied Chemistry - The possibility of using a carbonate-containing technogenic waste as reagent for treatment of aqueous solutions to remove lead(II) ions is demonstrated. The...     

Use of activated carbon materials for wastewater treatment to remove Ni(II), Co(II), and Cu(II) ions

The sorption activity of UVIS-AK activated carbon fiber with respect to the Co(II), Ni(II), and Cu(II) cations was studied. The possibility of using this fiber for industrial wastewater treatment to remove heavy metal ions was examined.     

On purification of wastewater containing complex aluminum and silicon fluorides to remove fluorine

Possibility of sorption-precipitation purification of wastewater to remove admixtures of fluorine with titanium compounds was studied.     

Response of the cation-sensitive glass electrodes to alkyl-substituted ammonium ions

Summary The response of cation-sensitive glass electrodes to alkyl-substituted ammonium ions has been evaluated. Increasing ion size results in decreasing electrode selectivity, progressively greater deviations from the Nernst slope, and increasing equilibration times. Direct potentiometric measurements should be suited to the estimation of smaller alkyl-substituted ammonium ions in the presence of multivalent cations.

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Zusammenfassung In der vorliegenden Untersuchung wurde das Ansprechen von kation-empfindlichen Glaselektroden auf alkylsubstituierte Ammoniumionen geprüft. Mit steigender Größe des Ions konnte eine Abnahme der Selektivität der Elektrode, zunehmende Abweichungen von der Nernstschen Gleichung und eine wachsende Zeitdauer für die Einstellung des Gleichgewichts beobachtet werden. Es ergab sich, daß die kation-empfindliche Glaselektrode zur Bestimmung kleinerer alkylsubstituierter Ammoniumionen in Gegenwart mehrwertiger Kationen verwendet werden kann.

     

Proteomic analysis of Helicobacter pylori cellular proteins fractionated by ammonium sulfate precipitation

Among 1590 ORFs in the Helicobacter pylori genome, >250 have been identified as authentic genes by proteomic analysis. Low-abundance proteins need to be enriched to a minimal amount for MALDI-TOF analysis and salt precipitation has generally been used for protein enrichment. Here, a whole-cell extract of H. pylori strain 26695 was subjected to protein fractionation with stepwise concentrations of ammonium sulfate and the proteins were displayed by 2-DE. The protein spots were quantified using PDQUEST software and identified by peptide fingerprinting. The 2-DE profiles and intensities of individual protein spots differed among the protein fractions. Out of the 98 identified proteins, 61 were found in the stepwise ammonium sulfate fractions but not in the whole-cell extract. Out of these, 37 proteins, including KdsA, were found exclusively in a single fraction. In contrast, GroEL, UreA, UreB, TrxA, NapA, and FldA were ubiquitously present in all fractions. Iron-containing proteins such as NapA, SodB, CeuE, and Pfr were found predominantly in the 100% saturated ammonium sulfate precipitate. Additionally, 29 proteins were newly identified in this study. These data will facilitate the preparation of significant H. pylori proteins, as well as provide information about low-abundance proteins.     

Different approaches to the determination of ammonium ions at low levels by flow injection analysis

Several flow-injection methods are examined critically for their suitability for determing submicromolar levels of ammonium ion on a routine basis. Nesslerization and the Berthelot reaction are not sufficiently sensitive. The gas-diffusion separation is more satisfactory. On the basis of a simple diffusion model, the effects of operating parameters on the ammonium concentration in the acceptor line of the gas-diffusion unit are discussed and experimentally verified. With the optimized gas-diffusion conditions, spectrophotometric detection with an acid-base indicator or the application of a liquid-membrane ammonium-sensitive electrode offers detection limits around 10 ^?8 mol 1^-1. Carbon dioxide interference in the acid-base indicator method causes problems with baseline stability and long-term drift. A severe limitation on futher enhancement of sensitivity by in-valve preconcentration is the contamination levelof ammonium present in water and reagents. Effective preconcentation (20-fold in 1 min) is obtained by using an ion-exchange microcolumn placed in the injection loop of the valve.     

Treatment of rare-earth concentrate to remove phosphorus and fluorine compounds

It was suggested to purify poor lanthanide concentrate precipitated from the extraction orthophosphoric acid produced by the dihydrate process to remove phosphorus and fluorine compounds by heating a mixture of the concentrate with sulfuric acid in the presence of hydrated silica followed by water leaching of water-soluble sulfates and phosphates. The treatment conditions for the separation of the bulk of phosphorus(V) and the entire fluorine in the form of SiF₄ were determined, ensuring approximately 3.5-fold increase in lanthanide concentration.     

Efficiently removing cetyl trimethyl ammonium bromide from wastewater by graphene oxide

Cetyl trimethyl ammonium bromide (CTAB) containing wastewater from dressing plant may pose a detrimental threaten to mineral beneficiation and environment. The adsorption of CTAB in aqueous solutions by graphene oxide (GO) has been studied in this work. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectrometer, and atomic force spectroscopy were used to characterize GO. The results indicated that the adsorption followed the Freundlich model could be well described by pseudo-second order kinetic model. The adsorption capacity was much bigger than activated carbon and many natural clay minerals. The adsorption process was endothermic, and the adsorption mechanism of CTAB onto GO was proven to be controlled by surface complexation, hydrogen bonding, and electrostatic attraction.     

Use of precipitate electroflotation for increasing the degree of wastewater treatment to remove nonferrous metals

A method is suggested and studied of removing nonferrous metals of from waste waters. The method is, that waste water containing nonferrous metals is treated to adjust pH to 9–10, after which sodium orthophosphate solution is added at metal/phosphate ion weight ratio 1 : (0.5–0.7) resulting in formation of slightly water-soluble metal hydroxyphosphate whose solubility is inferior to that of corresponding metal hydroxide. To isolate resulting compounds, electroflotation method with insoluble anodes is employed. Efficiency of removing nonferrous and heavy metals meets norms established for water discharge into fish-industry reservoirs.     

Treatment of heavy metal ions in wastewater using layered double hydroxides: A review

Heavy metal ions are toxic, and their toxicities change with different valence states, charges, and radii. Among the methods used for heavy metal ion removal, adsorption is widely employed due to its low cost and simple operation. As natural anionic clays, layered double hydroxides (LDHs) have drawn considerable attention for their use in the removal of anionic pollutants (such as heavy metal anions) due to their high removal efficiency and environmental friendliness. This article reviews the effects of the charge, type, and radius of the cations in the laminates of LDHs and the anions in the LDH interlayers, as well as the charge and radius of the heavy metals and the conditions (such as pH, coexisting ions, and temperature) on removing heavy metal ions with LDHs. The removal mechanisms have also been discussed. LDHs are hugely promising as an application for removing heavy metal ions that exist in different ionic forms by controlling the type and condition of LDHs.     

溶剂萃取法处理含六甲基磷酰三胺的废水

六甲基磷酰三胺 (Ｈｅｘａｍｅｔｈｙｌｐｈｏｓｐｈｏｒａｍｉｄｅ ,简称ＨＭＰＡ)是一种无色的极性非质子有机溶剂 ,具有较高的沸点、较高的介电常数、较强的碱性等特性 ,广泛应用于化学反应的介质、离析金属络合物、溶解气体如乙炔、溶解有机和无机盐类以及溶解高聚物 ,也可用作聚合反应的共催化剂 ,是一种十分重要的有机溶剂[1,2 ] 。国内的聚苯硫醚合成研究广泛采用了ＨＭＰＡ作为溶剂 ,目前 ,聚苯硫醚正处于产业化阶段 ,ＨＭＰＡ的用量增加 ,生产产生的废水必须经过处理才能排放 ,否则会对环境造成严重的污染和资源的浪费。但由于ＨＭ…     

A biocompatible method of decorporation: bisphosphonate-modified magnetite nanoparticles to remove uranyl ions from blood

We report on the use of bisphosphonate to functionalize Fe3O4 magnetic nanoparticles via dopamine (DA) linkage. Using tetraethyl-3-aminopropane-1,1-bisphosphonate (BP) as the functional molecule, we created a system with an Fe3O4-DA-BP nanostructure, which possesses high specificity for removing uranyl ions from water or blood. This work demonstrates that magnetic nanoparticles, combined with specific receptor-ligand interactions, promise a sensitive and rapid platform for the detection, recovery, and decorporation of metal toxins from biological environment.     

The effect of arsenate,and of transitioń-metal ions,on the precipitation of phosphate as ammonium 12-molybdophosphate

The radionuclides phosphorus-32, arsenic-74, iron-59 and molybdenum-99 were used to determine the effect-of arsenate and some transition-metal ions on the precipitation of phosphorus as ammonium 12-molybdophosphate. Under the conditions necessary for the quantitative precipitation of phosphorus, arsenic is also precipitated by ammonium molybdate. The presence of iron(III) nitrate inhibits the precipitation of phosphorus and, particularly, arsenic, although the precipitates contain more molybdenum, and are heavier, than when iron is absent. Chromium (111) nitrate, nickel(II) nitrate and manganese(II) nitrate do not inhibit the precipitation of phosphorus and arsenic to the same extent as iron (III) nitrate.     

Interaction of heavy metal ions with ammonium humates

Sorption properties of ammonium humates with respect to Fe(III), Cu(II), Al(III), Ni(II), Pb(II), and Zn(II) are studied. The effect of the metal ion concentration on the ammonium humate consumption is examined and the corresponding dependences are analyzed using regression equations. The IR spectra of brown coal humic acids, ammonium humates, as well as Fe, Cu, Ni, Zn, Pb, and Al humates are presented.     

Novel ions of quaternary ammonium halides in FDMS

Field desorption mass spectrometry exhibited novel ions [ Y-n H+n R ]+and [ Y-nH+nX]+as well as cluster ions [nY+(n-1)X-mH+mR]+and [nY+( n-1)X-mH+mX]+(n,m=0-3; X and Y represent the cation and anion moieties of quaternary ammonium halides),whose formation mechanism was discussed.     

Determination of sodium and ammonium ions in disproportionate concentration ratios by ion chromatography

In ion chromatography, samples of very different ammonium-to-sodium concentration ratios are difficult to quantify since these two cations have similar selectivities for stationary phases containing commonly used sulfonate or carboxylate cation-exchange functional groups. The IonPac CS15 cation-exchange column, with carboxylate and phosphonate functional groups as well as a crown ether group, was developed to address this limitation. Selectivity for the common inorganic cations on this column is different from that of conventional cation-exchange columns in that the separation between sodium and ammonium ions has been greatly increased, allowing for determinations of low levels of one in the presence of high levels of the other with an isocratic eluent. For larger than 4000:1 sodium-to-ammonium concentration ratios, an eluent step change or gradient elution is needed. For moderate ratios, combinations of this column with a carboxylate column, containing no crown ether group, can be used at room temperature with an isocratic eluent containing no organic solvent.     

Recovery of ammonia from wastewater through chemical precipitation

Journal of Thermal Analysis and Calorimetry - Chemical precipitation is a consolidated technique applied in wastewater treatment to remove and recover phosphorous and ammonium that remain in the...     

Raising the efficiency of electroflotation purification of wastewater formed in production of printed-circuit boards to remove copper ions in the presence of complexing agents,surfactants, and flocculants

It was found that the solution composition, pH value, concentration, and nature of surfactants and flocculant affect the process of electroflotation extraction of copper hydroxide in the presence of an excess amount of ammonia. A relationship between the ζ-potential of the dispersed phase and the degree of copper extraction was found. It is shown that a cationic surfactant and flocculants positively affect the efficiency of the electroflotation extraction of copper. Under the optimal conditions, the degree of the electroflotation extraction reaches values of 95–96%, and that with additional filtration, 97–99%. A technological scheme for implementing the electroflotation process is suggested.