0000000000227657
AUTHOR
Artis Robalds
Kūdras un tās modificēšanas produktu izmantošanas iespējas metālisko un nemetālisko elementu sorbcijai
Bakalaura darbs ir veltīts kūdras un tās modifikācijas produktu izmantošanas iespēju izpētei ķīmisko elementu un to savienojumu sorbcijai. Paralēli pētītas kūdras un tās modificēšanas produktu izmantošanas iespējas hroma, vara un arsēna jonu saistīšanai ūdens vidē. Kā cits pētījumu virziens minams kūdras izmantošana t.s. pasīvajās paraugu ievākšanas iekārtās. Ir izveidotas un praktiski pielietotas šādas iekārtas, lai noteiktu ķīmisko elementu, tai skaitā hroma, vara un arsēna, koncentrāciju apkārtējā gaisā. Darba izstrādes gaitā iegūtas atziņas un rezultāti parāda, ka kūdra un tās modifikācijas produkti var tikt izmantoti kā efektīvi sorbenti metālisko un nemetālisko elementu sorbcijai. Dar…
Highlighting inconsistencies regarding metal biosorption.
Thousands of articles have been devoted to examine different types of biosorbents and their use in cleaning polluted waters. An important objective of some studies has been the identification of the biosorption mechanisms. This type of investigation is not always performed, as it can only be done if scientists are aware of all mechanisms that, at least theoretically, control the removal of the target substances. Mistakes are often made, even in highly cited review articles, where biosorption mechanisms are named and/or grouped. The aim of this article is to highlight errors and inaccuracies as well as to discuss different classification systems of the biosorption mechanisms. This article se…
Leaf Biosorbents for the Removal of Heavy Metals
The presence of heavy metals in waters is a global concern. Among various remediation technologies, biosorption is an attractive and promising process since in many cases, it is fast, selective, and highly efficient. Other advantages, such as applicability for various types of pollutants, simplicity, low cost, ease of operation, and the potential reusability of the adsorbents, make it beneficial. Nowadays, more and more green materials, raw or modified, are inclined to be explored instead of conventional adsorbents, within concept of Green Chemistry. This review focuses on the use of leaves-based biosorbents in raw or modified forms to sequestrate heavy metals from waters and wastewaters.
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.
A novel peat-based biosorbent for the removal of phosphate from synthetic and real wastewater and possible utilization of spent sorbent in land application
AbstractRemoval of potentially harmful phosphorus compounds from wastewater by adsorption onto biosorbents is a cost-effective alternative to the conventional treatment methods. Raw peat and peat modified with iron(III) hydroxy ions were used in this study to remove phosphate ions from synthetic solution and household wastewater. Interaction of iron(III) ions with carboxylic groups of peat occurred during peat modification, which was confirmed by the FTIR technique. The effect of the initial phosphate concentration, pH, contact time, temperature, and ionic strength was studied in batch experiments. It was found that the sorption capacity increased with the increasing temperature, i.e. the m…
Sorption of thallium(I) ions by peat.
The increasing industrial use of thallium has raised the need for removal of this highly toxic element from wastewater. Thallium is more toxic than cadmium, copper, zinc, lead and mercury and as it is easily accumulated in humans, animals and plants, it poses a threat to both the environment and human health. Peat has been used as an effective, relatively cheap and easily available sorbent to treat waters containing heavy metals. In this study, peat was characterized and used as sorbent for the removal of Tl(I) ions from aqueous solution. The effect of initial Tl(I) concentration, pH, contact time, temperature and ionic strength was studied in batch mode. The maximum sorption capacity of pe…
Kūdras biosorbentu izmantošana tallija (I), vara (II), hroma (III) un fosfātjonu sorbcijai
Elektroniskā versija nesatur pielikumus
Mikroelementu sorbenti uz kūdras bāzes
Maģistra darba ietvaros ir pētītas kūdras un tās modificēšanas produktu izmantošanas iespējas hroma, vara un arsēna jonu saistīšanai ūdens vidē, kā arī kūdras sorbcijas spējas izmantojot kūdras maisiņu metodi. Darba izstrādes gaitā veiktā literatūras analīze un iegūtie rezultāti parāda, ka kūdra var tikt izmantota kā efektīvs biosorbents vara (II), hroma (III) un arsēna (V) biosorbcijai ūdens vidē. Rezultāti parāda, ka kūdras no dažādiem purviem uzrāda atšķirīgu sorbcijas spēju. Sorbcijas spēju ietekmē arī elementa koncentrācija šķīdumā, pH un saskares laiks starp šķīdumu un kūdru. Veiktais kūdras maisiņu un sūnu maisiņu metodes salīdzinājums parāda, ka kūdra ķīmiskos elementus no atmosfēra…