Environmental friendly electrochemical determination of aspirin from alkaline aqueous solution

The electrochemical determination of acetylsalicylic acid (ASA) on multi-walled carbon nanotube- epoxy composite electrode (MWCNTs-EP) in aqueous solution was investigated using electrochemical techniques, e.g. cyclic voltammetry (CV), differentialpulsed voltammetry (DPV) and square-wave voltammetry (SWV). SWV applying allowed to reach the best performance in relation with the sensitivity for ASA determination in alkaline medium

Photocatalytic degradation of methylene blue from water using UV irradiation

The aim of this study was to investigate the influence of various parameters on the photocatalytic activity of a copper doped zeolite in the degradation of cationic dye Methylene Blue (MB) from aqueous solution under UV irradiation. The experimental studies revealed that the removal efficiency expressed in terms of discoloration and aromatic ring- opening depended strongly of the initial pH, initial concentrations of the dye solution and catalyst doses. Some mechanistic aspects have been investigated in relation with Zeta potential measurements correlated with adsorption and heterogeneous photocatalysis principles at various pH values

Simultaneous fluoride and arsenic removal from groundwater by using aluminium sacrificial anode

The simultaneous removal of fluoride and arsenic in groundwater collected from three deep wells situated in Western part of Romania was carried out by electrocoagulation (EC) with aluminium sacrificial anode. The current density was of 156, 480 and 780 A/m2 , respectively and the electrolysis time 60 min. The removal efficiency of fluoride and arsenic was determined based on their residual concentration. Also, the specific energy consumption was calculated and it was in the range of 0.14 - 1.40 kWh/m3

Electrochemical degradation of drug residues from water

The aim of this work was to investigate the performance of the boron doped diamond (BDD) for the degradation and mineralization of acetylsalicylic acid (ASA), chosen as a model of the pharmaceuticals pollutants from wastewater effluents proceeded from the pharmaceutical industry

Synthesis and characterization of ammonium phosphate fertilizers with boron

The concentration of boron, an essential micronutrient for plants, presents a narrow range between deficiency and toxicity. In order to provide the boron requirement for plants, and to avoid toxicity problems, boron compounds are mixed with basic fertilizers. Sodium borate pentahydrate was used as a boron source. Ammonium orthophosphates fertilizers with boron were prepared by neutralizing phosphoric acid with ammonia and addition of variable amounts of sodium tetraborate pentahydrate to the reaction mixture at a NH3:H3PO4 molar ratio of 1.5. The fertilizers obtained with boron contents ranging from 0.05 to 1 % (w/w) were fully characterized by chemical analysis, thermal analysis, X-ray diffraction and infrared spectrophotometry. The studies showed that up to 500 °C, regardless of the boron content, no significant changes concerning thermal stability and nutritional properties occurred. Above 500 °C, an increase of thermal stability with an increase of the boron content was observed. X-Ray diffraction of a heat-treated sample containing 5 % (w/w) boron indicated the appearance of boron orthophosphate, BPO4, as a new crystalline phase, and the disappearance of the previous structures above 500 °C, which explains the increase in thermal stability

Synthesis, characterization and photocatalytic application of copper-modified zeolite

The copper-modified zeolite (Z-Cu) prepared by an ion-exchange process was characterized by X-ray diffraction, DRS spectroscopy, SEM microscopy and EDX analysis. The XRD analysis indicated the reduction of the peak intensity corresponding to Na+ presence as a consequence of ion exchange process between Na+ and Cu2+. The presence of copper into Z-Cu was confirmed by EDX analysis. The DRS spectra showed that Z-Cu exhibited an intense absorption maximum at ~280 nm, which can be associated with the presence of Cu 2+ ions within the zeolite. The photocatalytic activity of Z-Cu was proved through comparative studies of photolysis, photocatalysis on Z-Na and photocatalysis on Z-Cu

Equilibrium of phenol and chromate adsorption on ionic liquid functionalized Zn-al layered double hydroxide

A Zn3Al-type layered double hydroxide (LDH) was impregnated with methyltri-nbutylammonium chloride (IL) in order to obtain a functionalized material (IL-LDH). Both materials were utilized as adsorbents for phenol and chromate from water. The results show that the functionalized material has better adsorption capacities than the starting material. Four equations (Langmuir, Freundlich, Langmuir-Freundlich and Redlich-Peterson) were taken into consideration in order to describe the adsorption equilibrium

Electrochemical detection of paraquat from water using platinum modified BDD electrode

Voltammetric and amperometric detection of paraquat (PQ) herbicide from aqueous solutions has been successfully achieved using a boron-doped diamond (BDD) electrode modified with platinum particles. Electrochemical deposition of platinum was performed by chronoamperometry technique operated at two potential levels, i.e., -0.15 V for 1 s and 0.1 V for 6s. Operational parameters of electrochemical techniques tested in detection application were determined in order to achieve superior electroanalytical performances for quantitative assessment of paraquat concentration at trace level. Both cyclic voltammetry and multiple-pulsed amperometry exhibited best electroanalytical performances in terms of sensitivity and lowest detection limit, in comparison with the other applied voltammetric pulsed techniques

Reactive Yellow 125 degradation using titanium dioxide doped with N

The aim of this paper was the syntheses of titanium dioxide undoped and doped with nitrogen ion through sol-gel method in order to degrade Reactive Yellow 125 dye from water. The obtained nanomaterials were characterized by XRD, DRUV-VIS and SEM/EDX. Ndoped Ti02 catalyst exhibited good electrocatalytic activity for RY125 discoloration and degradation under both UV and VIS irradiation, which gives a practical utility of this catalyst

Voltammetric detection of drugs considered as emerging pollutant in water at carbon nanofiber composite electrode

In this study, carbon nanofiber-epoxy (CNF) composite electrode was tested using cyclic voltammetry (CV), differential-pulsed voltammetry (DPV) and square-wave voltammetry (SWV) techniques for the quantitative determination of naproxen (NPX), which was chosen the model for the anti-inflammatory drugs as emerging pollutants from water. The best performance in relation with the sensitivity and the detection potential value was obtained by employing DPV, and in relation with the lowest limit of detection and quantification was achieved by SWV under operating conditions of modulation amplitude of 0.2V, step potential of 0.05V and a scan rate of 0.025V