TEMPUS Project Quality Plan (PQP) - An important management tool of project coordinator

Nowadays project management is becoming increasingly important. Project management is responsible for securing and improving the higher education outcomes defined by an approved TEMPUS project proposal. Appropriate design, definition, plan and successful implementaion of the project are supported by an adequate project quality plan (PQP). PQP is a powerful management tool that enables the project coordinator and project team to implement all of the planned activities successfully and with appropriate quality within the agreed deadlines and budget. This paper provides an example of a well-designed PQP. The given example provides the required quality of all activities and results (products) of the TEMPUS project that make the project sustainable in the long-term

Chalcopyrite leaching in acid media: a review

In the modern practice of copper production, more and more attention is paid to the possibility of treating low-percentage sulfide ores that cannot be treated with conventional procedures (crushing, grinding, flotation). In addition to this, the processes of obtaining copper from complex sulfide concentrates, which cannot undergo pyrometallurgical processing, are increasingly being investigated. Extraction of copper from such raw materials is in most cases achieved by applying leaching procedures. Since chalcopyrite (CuFeS2) is by far the most abundant copper sulfide mineral, a large portion of the research is focused on studying the behavior of chalcopyrite in the leaching process, because processes of copper extraction from increasingly poor raw materials may be created using results of these studies. In addition, the main objective of this research is examining the kinetics and mechanism of chalcopyrite oxidation under the influence of various oxidants (O2, Fe3 +, H2O2, chlorate ions, etc.) and at the same time obtaining data necessary for the development of copper production process that could satisfy increasingly stringent technological, economic and environmental criteria. The paper presents the existing knowledge of the chalcopyrite leaching procedure and phenomena that accompany chalcopyrite oxidation in acidic sulfate and chloride solutions

Electrochemical synthesis and characterization of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O: a potential highly efficient sorbent for textile reactive dye removal

A new method of synthesis was developed for the preparation of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O (ECBBN). Electrochemical synthesis of the material was carried out by galvanostatic electrodeposition from an acidic Bi(III) solution on a Ti substrate and further thermal treatment in air at 200 °C. Characterization of ECBBN was conducted by employing SEM–EDX, N2 adsorption, XRD and FTIR, and its pI was also determined. The analyses showed that the material obtained was pure [Bi6O5(OH)3](NO3)5·2H2O. Morphologically, ECBBN aggregates were composed of crystals, some smaller than 50 nm. Electrochemically synthesized sorbent (ECBBN) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solutions of polluted river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. A kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibration of the sorption process was attained in several minutes, i.e. the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Redlich–Peterson and Brouers–Sotolongo isotherm. Using Langmuir isotherm, the maximum sorption capacity of ECBBN was reached at pH 2 and was 1049.19 mg g−1

Synthesis and characterization of new Ti–Bi2O3 anode and its use for reactive dye degradation

This paper reports the synthesis, characterization and application of a Ti–Bi2O3 anode for the electrochemical decolorization of the textile dye Reactive Red 2. The anode was synthesized by electrodeposition on a Ti substrate immersed in an acidic bismuth (III) solution at constant potential, followed by calcination in air at 600 °C. Thermogravimetric Analysis (TGA), Energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis revealed that the electrodeposited material was predominantly metallic bismuth, which was oxidized to pure α-Bi2O3 during the calcination in air. SEM micrographs revealed that the Bi2O3 coat at the anode surface was inhomogeneous and porous. Reactive Red 2 was completely electrochemically decolorized at the synthesized anode in the presence of H2O2. The applied current density, H2O2 and Na2SO4 concentration, medium pH and initial dye concentration affected the dye decolorization rate. The optimal process parameters were found to be as follows: an applied current density of 40 mA cm−2 using a mixture of 10 mmol dm−3 H2O2 and 10 mmol dm−3 Na2SO4 at pH 7. The dye decolorization rate was shown to decrease as its initial concentration increased. The decolorization reactions were found to follow pseudo-first order kinetics

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second order and Chrastil’s model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g-1 for Cr(III) ions and MB, respectively was obtained at 40 °C, pH 5 and sorbent dose 4 g dm-3 for removal of Cr(III) ions and 1 g dm-3 for removal of MB. The prediction of purification process was successfully carried out and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e. after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm-3. Also, removal of MB from the river water was successfully carried out and after 40 min removal efficiency was about 94 %

Oxidation of pyrite: Consequences and significance

This paper presents the most important studies on the oxidation of pyrite particularly in aqueous solutions. The consequences of pyrite oxidation was examined, as well as its importance, from both the technical-technological and environmental points of view. The oxidation of pyrite was considered in two parts. The spontaneous oxidation of pyrite in nature was described in the first part, with this part comprising pyrite oxidation in deposits depots and mines. It is explained how way natural electrochemical processes lead to the decomposition of pyrite and other minerals associated with pyrite. The oxidation of pyrite occurring during technological processes such as grinding, flotation and leaching, was shown in the second part. Particular emphasis was placed on the oxidation of pyrite during leaching. This part includes the leaching of sulphide and oxide ores, the leaching of pyrite coal and the leaching of refractory gold-bearing ores (pressure oxidation, bacterial oxidation, oxidation by means of strong oxidants and the electrolysis of pyrite suspensions). Various mechanisms of pyrite oxidation and of the galvanic interaction of pyrite with other sulphide minerals are shown

Corrosion Behavior of the Cu24Zn5Al Alloy in Sodium Sulfate Solution in the Presence of 1-Phenyl-5-mercaptotetrazole

The results of this research on the electrochemical behavior of Cu24Zn5Al alloy in a 0.1 mol/dm3 sodium sulfate (Na2SO4) solution containing 1-phenyl-5-mercaptotetrazole (PMT) are presented in this paper. The influence of PMT concentration, chloride ion concentration, and pre-treatment were examined. The influence of pre-treatment was studied in terms of the effect of the immersion time of the electrode in the appropriate inhibitor solution. After selecting the optimal immersion time, its effect on the behavior of the Cu24Zn5Al alloy was tested in a 0.1 mol/dm3 solution of sodium sulfate in the presence of different concentrations of chloride ions. Research shown that with the increase of PMT concentration, the anodic current density around the corrosion potential decreases, indicating that PMT behaves as a corrosion inhibitor for Cu24Zn5Al alloy

Electrochemical Analysis of the Influence of Purines on Copper, Steel and Some Other Metals Corrosion

Metals stability and corrosion resistance are very important factors that influence the possibility of their applications. In order to study and foresee the behavior of metals during various applications in all kinds of conditions and media, numerous approaches and techniques are developed and applied. Among those techniques, electrochemical measurements nowadays have a dominant role since they are proved to be highly efficient, reliable, fast, relatively low-cost, and easy regarding the preparation and execution of measurements. Besides that, they also provide quite a good amount of data regarding the effect and the mechanism of the reactions that metals interact in. Metals corrosion is reduced by various methods, one of the most frequently used ones is the application of corrosion inhibitors. Usually, organic compounds are studied as potential corrosion inhibitors, and at the moment the focus is on the effect on the environment. Hence, environmentally friendly and non-toxic inhibitors are important research topics. Purines, since they are the group of bioorganic compounds found in numerous biochemical structures such as DNA and RNA, present a very interesting possible solution and are studied as inhibitors of corrosion for copper, steel, aluminum, etc., as well as for some metal alloys. Data obtained and available up until the present are presented and discussed in this review

Recent Advances in Electrochemical Sensors for Caffeine Determination

The determination of target analytes at very low concentrations is important for various fields such as the pharmaceutical industry, environmental protection, and the food industry. Caffeine, as a natural alkaloid, is widely consumed in various beverages and medicines. Apart from the beneficial effects for which it is used, caffeine also has negative effects, and for these reasons it is very important to determine its concentration in different mediums. Among numerous analytical techniques, electrochemical methods with appropriate sensors occupy a special place since they are efficient, fast, and entail relatively easy preparation and measurements. Electrochemical sensors based on carbon materials are very common in this type of research because they are cost-effective, have a wide potential range, and possess relative electrochemical inertness and electrocatalytic activity in various redox reactions. Additionally, these types of sensors could be modified to improve their analytical performances. The data available in the literature on the development and modification of electrochemical sensors for the determination of caffeine are summarized and discussed in this review

The Extraction of Copper from Chalcopyrite Concentrate with Hydrogen Peroxide in Sulfuric Acid Solution

Research on chalcopyrite leaching represents a great challenge, given its importance as one of the most abundant copper minerals and its significant role in global copper extraction. This study aimed to evaluate the effects of different parameters on chalcopyrite leaching by hydrogen peroxide as a strong oxidizing reagent in sulfuric acid solution. A series of leaching tests were carried out to investigate the effect of the solid/liquid ratio, stirring speed, temperature, oxidant and acid concentrations, and lixiviant dosing method on copper extraction from chalcopyrite concentrate. The catalytic decomposition of hydrogen peroxide occurred in the investigated leaching system, as reflected in the obtained metal extraction values. Copper extraction was increased in the first 60 min of the reaction, after which it essentially ceased. The maximum final copper extraction of 64.5% was attained with 3.0 mol/L H2O2 in 3.0 mol/L H2SO4 at a temperature of 40 °C after 120 min of reaction. Due to the catalytic decomposition of hydrogen peroxide in the examined leaching system, the leaching experiment was performed with the periodic addition of lixiviant at specific time intervals as well. The dissolution process was described by the first-order kinetics equation with an apparent activation energy of ~39 kJ/mol. Finally, XRD and SEM-EDS analyses were used to characterize the leached residue, and the results showed that the formation of elemental sulfur on the chalcopyrite surface affected the dissolution process