0000000000230976

AUTHOR

Linda Ansone

Arsenic Sorption onto Peat and Iron Humates

Environmental pollution with arsenic is a global problem; therefore, new remediation methods are needed. Peat modified with iron compounds and iron humates were prepared and tested for sorption of arsenic compounds. The highest sorption capacity was observed when iron-modified peat was used. Sorption of different arsenic speciation forms onto iron-modified peat sorbents was investigated as a function of pH, reaction time and temperature. Sorption capacity increases with temperature and was spontaneous and endothermic.

research product

Behaviour of Nanomaterials in the Environment: A Study of Interaction between Humic Acids and Fullerene C60

Interaction between buckminsterfullerene and humic substances of different origin was investigated using fluorescence spectrometry as function of concentration of humic substances, pH and ionic strength. Binding constants of humic substances and buckminsterfullerene were calculated. It can be suggested that the complexation was driven by hydrophobic interaction depending on properties of the interacting compounds. Hydrophobic interaction model was indicated by linear Stern–Volmer plot, and high Kd values characterized interaction between buckminsterfullerene and humic acids. The results of this study support the development of understanding of fate of nanomaterials in environment as well as…

research product

Kūdras resursi un to izmantošanas iespējas

Latvijā un pasaulē kūdra tiek izmantota un iegūta daudz mazākā apjomā nekā tas būtu ekonomiski pamatoti, neapdraudot dabas vērtības un to aizsardzībai paredzētās teritorijas. Rakstā novērtēti Latvijas purvi un kūdras resursi, kā arī to izmantosanas jomas. Tiek sniegts ieskats purvu un kūdras klasifikācijā, kūdras veidosanās procesā un to ietekmējosajos faktoros.

research product

Mirušo kults un kapu kultūra Latvijā kā kulturoloģijas tēma vidusskolā

Kultūras izpausmes ir ļoti daudzveidīgas, arī mirušo apbedīšanas tradīcijas un kapu kultūra ir nozīmīga kultūrvēsturiska liecība. Šī darba mērķis ir pierādīt, ka arī Latvijā pastāvējis un pastāv mirušo kults kā svarīgs kultūras elements, un tāpēc par to jārunā vidusskolas kulturoloģijas kursā. Darbā iezīmēts ieskats pasaules mirušo kultu izpausmēs, lai veiktu salīdzinājumu ar Latvijas kultūru, iztirzāta mitoloģiskā nāves uztvere, veļu laika nozīmīgums gada ritējumā, atspoguļotas bedības kā viens no galvenajiem latviešu godiem, kā arī analizētas apbedīšanas tradīcijas no senatnes līdz mūsdienām. Lai pierādītu mirušo kulta esamību, tika izvirzīts uzdevums iepazīties ar dažādu laiku un dažādu …

research product

Characterization of interaction between tricyclic structures containing pharmaceuticals, their models and humic substances.

Their persistence and wide consumption identify pharmaceuticals as “emerging pollutants”. The complexation of pharmaceuticals containing adamantine ring structures and their model substances with humic acids (HA) of different origins was compared using fluorescence spectroscopy as a function of pH, humic acid concentration, ionic strength, and molecular mass of HA. Binding constants between the studied pharmaceuticals and humic acids were calculated. A combination of dynamic and static quenching processes as indicated by nonlinear Stern-Volmer plots and high Kd values were positively correlated with the concentration of carboxyl groups in the studied humic acids. For basic functional group-…

research product

Spectrofluorimetric study of dissolved organic matter in River Salaca (Latvia) basin waters

Dissolved organic matter (DOM) in surface waters influences mineral weathering, nutrient cycling, aggregation of particulate matter and photochemical reactions in waters and aquatic communities. In this study, the effectiveness of UV and fluorescence measurements in distinguishing the origin of DOM and processes within the river basin were analyzed using the River Salaca basin as an example. The basin of River Salaca is characterized by low anthropogenic pressure, however, the water color during the last few decades has increased (an effect known as brownification). As tools to study the composition of dissolved organic substances in waters of the River Salaca and its tributaries the use of…

research product

Characterization of Interaction Between Humic Acids and Buckminsterfullerene Using Flourescene Spectroscopy

The interaction between buckminsterfullerene C60 and humic acids (HA) of different origins was compared using fluorescence spectroscopy as a function of pH, humic acid concentration, ionic strength. Binding constants between fullerene and humic acids were calculated. It can be suggested that the complexation was driven by hydrophobic interactions depending on the properties of the interacting compounds. Hydrophobic interaction model as indicated by linear Stern-Volmer plots and high Kd values is characterizing the interaction between buckminsterfullerene C60 and humic acids The results of this study support the development of an understanding of the fate of nanomaterials in the environment …

research product

Use of peat-based sorbents for removal of arsenic compounds

Abstract It is important to apply sorbent materials for purification of water from arsenic contamination due to serious arsenic pollution worldwide. We have developed new sorbents based on natural materials that provide a cheap and environmentally friendly alternative. For the first time, peat modified with iron compounds and iron humates were tested for sorption of arsenic compounds. The highest sorption capacity was found in peat modified with iron compounds. We have found that sorption of different arsenic speciation forms was strongly dependent on solution pH, reaction time and temperature. Calculations of the sorption process using thermodynamic parameters indicate the spontaneity of s…

research product

Antimona(V) sorbcijas izpēte uz modificētiem biomateriālu sorbentiem

Antimona(V) savienojumu sorbcijai veikta bioloģiskas izcelsmes sorbentu modificēsana ar dzelzs savienojumiem. Izmantojot dažādas fizikālķīmiskās metodes, noteikti sorbentus raksturojosie parametri. Veikti antimona sorbcijas eksperimenti, izmantojot modificētus – kūdras, skaidu, sūnu, salmu, niedru un smilsu sorbentus, noteikta iegūto rezultātu atbilstība gan Lengmīra, gan Freindliha teorētiskajiem sorbcijas modeļiem. Pētīta sorbcijas atkarība no temperatūras un veikti termodinamisko parametru aprēķini. Konstatēts, ka labākais antimona(V) savienojumu sorbents ir modificēta kūdra, sorbcijas process ir spontāns un endotermisks.

research product