Investigation of metal ions sorption of brown peat moss powder

For regularities research of sorptive extraction of heavy metal ions by cellulose and its derivates from aquatic solution of electrolytes it is necessary to find possible mechanism of sorption process and to choice a model describing this process. The present article investigates the regularities of aliovalent metals sorption on brown peat moss powder. The results show that sorption isotherm of Al3+ ions is described by Freundlich isotherm and sorption isotherms of Na+ и Ni2+ are described by Langmuir isotherm. To identify the mechanisms of brown peat moss powder sorption the IR-spectra of the initial brown peat moss powder samples and brown peat moss powder samples after Ni (II) sorption were studied. Metal ion binding mechanisms by brown peat moss powder points to ion exchange, physical adsorption, and complex formation with hydroxyl and carboxyl groups

Адсорбционная активность сырья водно-болотных растений Западной Сибири

In order to find effective sorbents of herbal origin, we’ve studied adsorption properties of aerial dry raw materials of 31 marsh-water, medical perspective, plant species. It was found that 8 of those 31 exercises adsorption activity (Shpagnum species).С целью поиска эффективных сорбентов растительного происхождения изучены адсорбционные свойства сухого сырья 31 вида широко распространенных в Западной Сибири водно-болотных растений. Для 8 из них установлены выраженные адсорбционные свойства (мхи рода сфагнум), что позволяет отнести их к числу перспективных видов для получения эффективных сорбентов

Päikesepatareides kasutatavate ZnO nanovarraste läbilaskvusomadused

Bachelor’s thesis Curriculum in EngineeringThe study of the transmittance and absorbance properties of a material in the design of solar cells is of significant importance. The transmittance of a material determines the ability of light to pass through it. Whereas, the absorbance of a material determines its ability to absorb light. ZnO nanostructures are a good choice for such properties as several studies have shown that ZnO nanostructures show high transmittance (~80%). Also, ZnO nanostructures can absorb most of the UV region of light coming from the sun. In this thesis, the transmittance and absorbance properties of four different types of ZnO nanorod samples were investigated, each of which was prepared with different solvents. The solvents used are ethanol, 70% ethanol, methanol, and isopropanol. A UV-1600PC spectrophotometer was used for measuring the transmittance and absorbance of ZnO nanorod samples. Two types of reference materials were used for the measurements. The results obtained based on the transmittance and absorbance measurements are analysed and compared. Finally, the bandgaps for each of the synthesized nanorods were calculated by using the Tauc relation, and the optimal ZnO nanorod sample for solar cell applications was discussed.Materjali läbilaskvuse ja neeldumisvõime omaduste uurimine on päikesepatareide projekteerimisel väga oluline. Materjali läbilaskvus määrab valguse läbilaskvuse läbi materjali. Materjali neelduvus määrab, kui palju valgust materjal suudab neelata. ZnO nanostruktuurid on selliste omaduste poolest hea valik, sest mitmed uuringud on näidanud, et ZnO nanostruktuuridel on kõrge läbilaskvus (~80%). Samuti suudavad ZnO nanostruktuurid absorbeerida enamiku päikesest tuleva valguse UVkiirguse piirkonnast. Käesolevas lõputöös uuriti nelja erineva ZnO nanostruktuuride proovi läbilaskvus ja neeldumisomadusi, millest igaüks valmistati erinevate lahustite abil. Kasutatud lahustid on etanool, 70% etanool, metanool ja isopropanool. ZnO nanovarraste proovide läbilaskvuse ja neelduvuse mõõtmiseks kasutati UV-1600PC spektrofotomeetrit. Mõõtmistes kasutati kahte tüüpi võrdlusmaterjale. Analüüsitakse ja võrreldakse läbilaskvuse ja neelduvuse mõõtmiste põhjal saadud tulemusi. Viimasena arvutati iga sünteesitud nanovarda ribalõhed Tauci suhte abil ja toodi välja ZnO nanovarraste parem valik päikesepatareide kasutamiseks