Use of Ionic Liquids in Solid-Liquid Separation Processes

This chapter reports the possible use of ionic liquids (ILs) in solid-liquid separation processes by their immobilization in suitable solid supports. This method presents some benefits such as economical one—due to the fact that a smaller quantity of ILs is used and the loss of ILs in the aqueous phase is avoided; and second the efficiency benefit—because the advantages of the ILs are combined with the properties of the solid support, and this enhances the removal process of metal ions from aqueous solutions and could be successfully used in the removal processes of metal ions from aqueous solutions containing trace amounts. The type of solid supports used for the immobilization of different ILs, and the methods used for the immobilization were discussed. Also the adsorption efficiency of these ionic liquid immobilized solid supports in the removal process of different metal ions (Cr, Hg, Pt, Au, Pd, Cs, Sr, Tl, etc.) from aqueous solutions were presented. The inorganic materials present a higher efficiency to be used as solid supports for the immobilization of the ILs. It was observed that the physical method of impregnation, especially ultrasonication, has a positive effect on the adsorption capacities of the materials obtained

Studies Regarding Tailings Pond Seepage Water from Mining Activities over Avena sativa L. Germination Influence

Cultivation of oat in the limiting areas of tailings pond might be regarded as one of the possibilities that could lead to the general amelioration of these places. In order to characterize the waste products, to determine and evaluate the components that may be leached from waste products and that can affect the limiting areas of tailings pond, leaching tests were performed. In this paper, we have observed the influence of eluate, obtained from leaching tests, on seed germination, radicle and coleoptyle development as well as on the amount of accumulated dry matter for Avena sativa L., genotypes. According to our researches, we may conclude that the studied genotypes of Avena sativa L. showed tolerance to eluate while values registered for seed germination, radicle and coleoptyle development as well as dry matter content were comparatively higher than those registered for the control variant

Studies on the purification of wastewaters with high nickel ions content

The paper presents studies on the removal of nickel from wastewaters with high nickel ions content resulting from galvanizing process. In the first step of the purification process, nickel ions were precipitated using a 10 M NaOH solution as precipitation agent. By increasing the pH of the Ni2+ solutions up to 11, the residual concentration of nickel ions reached the values required for the discharge in sewerage and in water resources. Taking into account that this pH value does not allow the discharge, the solution resulting from the precipitation process at pH 9 was submitted in the second step to an advanced treatment using as adsorbent material an Amberlite XAD-4 resin impregnated with di-2(ethyl-hexyl) phosphoric acid. To establish the conditions for the adsorption process was studied the influence of contact time and of adsorbent dosage on the efficiency of nickel ions removal from the solution. The maximum efficiency of ~ 94% was reached after 90 min for an adsorbent dosage of 0.3 g:25 mL. The residual concentration of nickel ions was ~0.5 mg/L, value that allows the discharge in the sewerage and even in water resources

Studies regarding the turning to account of the waste resulting from coal exploitation

In this paper was studied the possibility of turning to account of the waste resulting from coal mining. One way was to use the waste in order to stabilize ash dumps. The chemical analysis of the coal waste and ash showed that both have high zinc and nickel content. As remediation method was chosen for this study the cultivation of barley as bio-indicator plant on substrates obtained by mixing the coal waste and ash in various proportions. After bio-remediation, the zinc content of the substrates fell under the maximum permitted value for all coal-ash mixtures. The nickel content decreased very much, but remained somewhat higher than the maximum permitted value. Another way was to use waste material as adsorbent in view of removal of organic dyes from wastewaters resulting from inkjet cartridge remanufacturing. The coal waste was used in various dosages (S:L = 0.1 g:25 mL; 0.2:25; 0.3:25; 0.4:25 and 0.5:25) and the suspensions were shaken for various contact times (15, 30, 45, 60 and 120 min). The highest removal efficiency ( -60%) was reached for a S:L ratio of 0.5:25 after a 60 min contact time

Use of impregnated resins as adsorbents in view of heavy metals removal from aqueous solutions

The presence of heavy metal ions in environment is a major concern because of their toxicity to many life forms. Heavy metal ions can be removal from water by adsorption on solid support. In the present work, we tested the adsorption of metal ions on solvent impregnated resin (SIR). Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) has been chosen as an extractant for the purpose of this study. The interaction between XAD4 resin and D2EHPA was evaluated by physico-chemical methods of analysis (EDX and SEM). The experimental studies on adsorption of metal ions were carried out on Pb2+, Cu2+, Cd2+, Cr3+, Ni , Fe3+, Zn2+ and Ca2+. A separation method was developed for metals ions and was investigated the influence of contact time on the residual concentration of metal ions, on their removal efficiency and on the adsorption capacity of resin towards metal ions

Magnesium silicate functionalized with sodium-β-glycerophosphate used for Sr(II), Cs(I), Tl(I) adsorption

In this research Sr(II), Cs(I), Tl(I) were removed through adsorption using a functionalized solid support, magnesium silicate with sodium-β-glycerophosphate. The influence of the initial concentration of metal in the solution and of the contact time were investigated. The adsorption process runs quickly obtaining the highest adsorption capacity for Sr(I) 7 mg/g

As(V) adsorption using MFe2O4 (M=Cd2+, Ni2+) ferrite nanoparticles

The paper present the possibilities of arsenic removal from aqueous solutions using as adsorbent MFe2O4 (M=Cd2+, Ni2+) ferrite nanoparticles due to the affinity of arsenic towards iron ions. The ferrites were obtained after a heating treatment of the cadmium respectively nickel ferrioxalate coordination compounds, as precursors, at 500oC. From the two studied adsorbent material the nickel ferrite developed a higher maximum adsorption capacity (132 µg As(V)/g of ferrite) than the cadmium ferrite (109 µg As(V)/g of ferrite) in the removal process of As(V) from aqueous solutions. In both cases the equilibrium between the adsorbent and adsorbate was achieved in 60 minutes

Studies regarding strontium adsorption onto styrene-1% divinylbenzene grafted with phosphonium groups and impregnated with ionic liquid

The paper present the studies regarding the strontium ions removal from aqueous solution through adsorption onto a functionalyzed polymer impregnated with a ionic liquid. As a a solid support styrene-1%divinylbenzene grafted with phosphonium groups was used and this was impregnated with 1-ethyl-3-methylimidazolium chloride ionic liquid. The impregnation of the studied ionic liquid onto the studied polymer solid support was realised through ultrasonication. The SEM, and energy dispersive EDX applied to the obtained adsorbents proved the fact that the polymer solid support was impregnated with the studied ionic liquids and also put in evidence the morphology changes of the solid support produced by its impregnation with these ionic liquids. The styrene-1% divinylbenzene functionalised with phosphonium gropus and impregnated with 1-ethyl-3-methylimidazolium chloride developed a maximum adsorption capacity in the removal process of Sr2+ ions from aqueous solution of 1.28 mg Sr2+/g of adsorbent. The equilibrium between the adsorbent and adsorbate is achieved in 60 minutes

Synthesis and characterization TIO2 powders and thin film obtained by solvothermal method for applications in environment friendly building material technologies

The ability to fast obtain materials around specific application like design various new concept devices, such as gas sensors, catalysts, applications in environment friendly building material technologies with unique parameters of light absorption, solid state fuel cell, energy harvest, charge generation, and charge transport is thus vital to improving sciences and creating novel functionalities necessary for increasing implementation of photoactive materials [1]. Our research focus has been mainly on fast obtaining anatase TiO2 in two forms: powder and film using solvothermal method. Characterization of the obtained compounds was achieved by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectrophotometry (UV-VIS), Raman Spectroscopy and Photoluminescence. Visible Raman spectra was recorded at room temperature on a Scanning Probe Microscopy (SPM) System with MultiView 1000 platform using 532 nm single-frequency laser as excitation source. The SE was carried out by Woollam VASE ellipsometer at (1.25 – 5) eV photon energy range at 55º- 75º angles of light incidence. The data analysis was performed with commercial Woollam CompleateEase software. Rietveld profile fitting of X-ray diffraction (XRD) pattern of the TiO2 nanoparticles revealed highly crystalline anatase with P42/mnm structure. The anatase phases of TiO2 could be sensitively identified by Raman spectroscopy based on their Raman spectra. Variable angle spectroscopic ellipsometry (VASE) has been used to determine the optical properties of the TiO2 film. The energy dependent ellipsometric angles Ψ and ∆ were recorded for 3 angles. Measurement of ellipsometry was performed in the spectral range 1.24– 5 eV at incident angles of 65-70-75°. The TiO2 layer is approximated by a Kramers-Kronig consistent B-spline

Quantitative determination by atomic absorption spectrometry for macro elements of mineral waters from Romania

The aim of this paper is to present the results of studies for some microelements from mineral water. Mineral water was collected from three different regions of Romania (West Region, Centre Region and North Region). The microelements: lead (Pb), nickel (Ni), manganium (Mn), iron (Fe), cooper (Cu), chromium (Cr), and cadmium (Cd) were analyzed by atomic adsorption spectrometry determination, using the graphite tubular electrothermic owen method VARIAN GTA 110. As a conclusion, the lead (Pb) maximum value recorded for the west region waters was in sample A1 (18.6 µg/L), the nickel (Ni) exhibits maximum value in center region, in sample C2 (54.15 µg/L), the manganium (Mn) reaches the maximum in the west region in sample A1 (360 µg/L), the iron (Fe) exhibits maximum value in sample B3 (6.25 µg/L) from north region, and for the cadmium (Cd), the maximum value was reached in sample A1 (8.18 µg/L) from the west region. When comparing the allowable limits for heavy metals, (ORDER NO. 975 OF 16 DECEMBER 1998 ON THE APPROVAL RULES OF THE SANITARY HYGIENIC FOOD) were not observed exceedances of microelements concentrations studied