An In Situ Incorporation of Acrylic Acid and ZnO Nanoparticles into Polyamide Thin Film Composite Membranes for Their Effect on Membrane pH Responsive Behavior.

This paper focuses on an in situ interfacial polymerization modification of polyamide thin film composite membranes with acrylic acid (AA) and zinc oxide (ZnO) nanoparticles. Consequent to this modification, the modified polyamide thin film composite (PA-TFC) membranes exhibited enhanced water permeability and Pb (II) heavy metal rejection. For example, the 0.

Hyperbranched polyethylenimine-modified polyethersulfone (HPEI/PES) and nAg@HPEI/PES membranes with enhanced ultrafiltration, antibacterial, and antifouling properties.

This study reports a simple fabrication of polyethersulfone (PES)-based membranes, their characterisation, and application. These membranes are modified with hyperbranched polyethyleneimine (HPEI) and -silver (nAg)-decorated HPEI. These were then compared for filtration, organic fouling, antifouling, and antibacterial properties against the neat PES membrane.

Degradation of methyl orange on Fe/Ag nanoparticles immobilized on polyacrylonitrile nanofibers using EDTA chelating agents.

Bimetallic nanoparticles are effective for the removal of organic pollutants from environmental water samples through catalytic degradation reactions. Hence, this work reports on the preparation of Fe/Ag bimetallic nanoparticles immobilized on electrospun polyacrylonitrile nanofibers (PAN NFs) pre-functionalized with EDTA and ethylenediamine (EDA) chelating agents. Characterization techniques included attenuated total reflectance coupled to Fourier transform infrared spectrometer (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA).

Environmentally friendly microwave-assisted sequential extraction method followed by ICP-OES and ion-chromatographic analysis for rapid determination of sulphur forms in coal samples.

A rapid three-step sequential extraction method was developed under microwave radiation followed by inductively coupled plasma-optical emission spectroscopic (ICP-OES) and ion-chromatographic (IC) analysis for the determination of sulphur forms in coal samples. The experimental conditions of the proposed microwave-assisted sequential extraction (MW-ASE) procedure were optimized by using multivariate mathematical tools. Pareto charts generated from 2 full factorial design showed that, extraction time has insignificant effect on the extraction of sulphur species, therefore, all the sequential extraction steps were performed for 5 min.

Removal of phenolics from aqueous media using quaternised maize tassels.

This paper reports on the preparation and modification of powdered maize tassels with polydiallyldimethylammonium chloride (polyDADMAC). The modified tassel were applied for the removal of phenolic compounds from water, through adsorption. The effect of contact time, sorbent dose, pH of the sample and the adsorption capacity were investigated at fixed temperature (25 °C).

Method Development for the Determination of Diallyldimethylammonium Chloride at Trace Levels by Epoxidation Process.

Domestic water is abstracted from its sources in raw form with a high content of dissolved and suspended material. Polydiallyldimethylammonium chloride (polyDADMAC) is a cationic polyelectrolyte used in the initial water clarification process. However, its residues in treated water pose a health risk as they react with chlorine to produce a carcinogenic compound.

Preconcentration of molybdenum, antimony and vanadium in gasolsine samples using Dowex 1-x8 resin and their determination with inductively coupled plasma-optical emission spectrometry.

Strong ion exchangers (Dowex 50W-x8 and Dowex 1-x8) were used for the separation and preconcentration of trace amounts of Mo, Sb and V in gasoline samples. Dowex 1-x8 resin was found to be suitable for the quantitative retention of these metal ions from organic matrices. The elution of the metal ions from Dowex 1-x8 resin was achieved by using 2.

Immobilized Fe (III)-doped titanium dioxide for photodegradation of dissolved organic compounds in water.

Photocatalytic degradation of dissolved organic carbon (DOC) by utilizing Fe(III)-doped TiO2 at the visible radiation range is hereby reported. The photocatalyst was immobilized on sintered glass frits with the coating done by wet method, calcinated at 500 °C and then applied in a photodegradation reactor. The addition of a transition metal dopant, Fe(III), initiated the red shift which was confirmed by UV-Vis spectroscopy, and the photocatalyst was activated by visible radiation.

Oxolane-2,5-dione modified electrospun cellulose nanofibers for heavy metals adsorption.

Functionalized cellulose nanofibers have been obtained through electrospinning and modification with oxolane-2,5-dione. The application of the nanofibers for adsorption of cadmium and lead ions from model wastewater samples is presented for the first time. Physical and chemical properties of the nanofibers were characterized.

Evaluation of copper speciation in model solutions of humic acid by mini-columns packed with Chelex-100 and new chelating agents: application to speciation of selected heavy metals in environmental water samples.

A solid-phase extraction procedure using mini-columns packed with Chelex-100 and two new chelating agents based on poly(vinyl chloride) functionalized with 3-ferrocenyl-3-hydroxydithioacrylic acid and N,N'-[1,1'-dithiobis(ethylene)]-bis(salicylideneimine) (H(2)sales) loaded on microcrystalline naphthalene, is reported. The columns were used to separate labile copper fractions in model solutions and in real samples with subsequent determination using electrothermal atomic absorption spectrometry (ETAAS). Various model solutions containing 20 microg L(-1) of Cu(2+) and 0.

Speciation studies of nickel and chromium in wastewater from an electroplating plant.

A speciation scheme involving the use of flame atomic absorption spectrometry (FAAS) and differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV) techniques was applied to studies of nickel and chromium in wastewater from a nickel-chrome electroplating plant. Dimethylglyoxime (DMG) and diethylenetriaminepentaacetic acid (DTPA) were employed as complexing agents for adsorptive voltammetric determination of Ni and Cr, respectively. Cr(III) and Cr(VI) were determined by exploiting differences in their reactivity towards DTPA at HMDE.

Voltammetric detection of sulfonamides at a poly(3-methylthiophene) electrode.

Detection of sulfonamide compounds in a mixture of standards at a poly(3-methylthiophene) coated on glassy carbon (GC) electrode is reported. The polymer, poly(3-methylthiophene), was electrochemically synthesized at a GC rotating disk-working electrode versus Ag/AgCl using cyclic voltammetry (+0.5 to +2.

Studies of chromium removal from tannery wastewaters by algae biosorbents, Spirogyra condensata and Rhizoclonium hieroglyphicum.

Chromium in the effluent is a major concern for tanning industry. Chemical precipitation methods are commonly employed for the removal of chromium but this leads to formation of chrome-bearing solid waste, plus it is uneconomical when the concentration of chromium in the effluent is low. Ion exchange and membrane separation methods are relatively expensive.