Superkritična ekstrakcija kao metoda za uklanjanje pesticida iz zemljišta

The aim of this paper is to study the applicability of supercritical extraction with carbon dioxide to the decontamination of soils containing pesticides (in this case with atrazine). The analyzed results indicate that this method can be successfully used for the realization of prominent purpose.Cilj ovog rada je ukazivanje na mogućnost primene superkritične ekstrakcije sa ugljendioksidom na dekontaminaciju zemljišta zagađenih pesticidima (u ovom slučaju atrazinom). Analizirani rezultati ukazuju da se ova metoda veoma uspešno može koristiti za ostvarivanje istaknutog cilja

Influence pressure and size particle to extraction by CO2

Supercritical fluid extraction (SFE) is an efficient extraction technique for the separation of various organic compounds from herbs, or more generally, from plant materials. These proporties of SFE make the products more advantageous in the field of foods, pharmaceuticals, and cosmetics. The aim of this study was to investigate the effect of pressure and particle size on the extraction yield and the quality of the extracts

Proučavanje mogućnosti mikrotalasne polimerizacije monomera na osnovu obnovljivih sirovina

Polylactide belongs to the biodegradable and biocompatible polymers, and degrade to harmless component, lactic acid, which allows their use in various areas. The development of new methods for the synthesis of polylactide can further extend the application of this polymer and makes its use more economical. The use of microwaves in the synthesis of the polymer can reduce the polymerization time of only 10 to 30 minutes and save a large amount of energy. In this paper, polylactide is synthesized in a microwave reactor, using a frequency of 2,45 GHz and a power of 150 W. FITR analysis confirmed the structure of the resulting polylactide and the thermal properties were studied using differential scanning calorimetry.Polilaktid spada u grupu biorazgradivih i biokompatibilnih polimera i može se razložiti na neškodljivu komponentu, mlečnu kiselinu, što omogućava njegovu primenu u najrazličitijim oblastima. Razvoj novih metoda sinteze polilaktida može proširiti područje primene ovog polimera i učiniti njegovu upotrebu ekonomičnijom. Upotreba mikrotalasa u sintezi polimera može skratiti vreme polimerizacije na svega 10 do 30 minuta štedeći veliku količinu energiju. U ovom radu polilaktid je sintetisan u mikrotalasnom reaktoru, koristeći frekvenciju od 2.45 GHz i snagu od 150 W. FTIC analiza je potvrdila strukturu dobijenog polilaktida, a toplotna svojstva su proučavana metodom diferencijalne skenirajuće kalorimetrije.Vrednost temperatura prelaska u staklasto stanje i temperatura kristalizacije dobijenog polimera zavise od molskog odnosa monomera (L-laktida) i katalizatora (kalaj-oktoata)

Metode uklanjanja fenola iz otpadne vode

Phenol is a major pollutant in the wastewater because of its presence in the effluent of major processing and refining plants. It has severe effect on human being, both short term and long term. Various methods are used for removal of the phenol from wastewater such as adsorption, photodecomposition, volatilization and other various biological and non-biological methods. In the present study attempt is done to present the survey of the research on the phenol removal by various methods. The methods such as polymerization, electrocoagulation, extraction, photodecomposition, advanced oxidation and ion exchange were used effectively by various investigators. These methods are reported to be efficient for the phenol removal. Suitable method for phenol removal can be selected based on availability of the material, extent of separation required and properties of phenolic effluent.Fenol je jedan od glavnih polutanata u otpadnoj industrijskoj vodi. Utiče na zdravlje ljidi i taj uticaj se ispoljava kako posle kraćeg tako i posle dužeg prisustva. Za uklanjanje fenola iz otpadne vode koriste se metode kao što su adsorpcija, fotorazgradnja, isparavanje (volatilizacija) kao i biološke i nebiološke metode. U ovom radu daje se prikaz istraživanja o uklanjanju fenola različitim metodama kao što su polimerizacija, elektrokoagulacija, fotorazgradnja, unapređena oksidacija i jonska izmena. Izbor metode za uklanjanje fenola može biti učinjen na osnovu raspoloživog materijala, zahtevanog intenziteta prečišćavanja i osobina fenolnog efluenta

The desorption of ammonia and carbon dioxide from multicomponent solutions: I. Model description and development

A mathematical model of the desorption process based on the synthesised technological topology of the regeneration process gas components NH3 and CO2, was developed. The logical principle methodology of the mathematical modelling of desorption processes was worked out in detail. The mathematical model of the process, including the following: - The synthesized technological scheme of the desorption of components NH3 and CO2, with all the necessary requirements and limitations of the mathematical model; - The relevant multicomponent systems which exist in the process were defined in which the interphase transformation occurs; - The considered units (aparatus) are defined which make up the basic technological topology of the process; - Desorption processes in towers with different types of trays were defined and mathematically described; - The cooling process and condensation of gas phase in a complex multicomponent system was of the gas phase in a complex multicomponent system was defined and mathematically described. Many variants of the process were analyzed by using developed model with the aim of determining the relevant functional dependences between some basic parameters of the process. They will be published in the second part of this study