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Utilisation of industrial by-products in water treatment:carbon-and silicate-based materials as adsorbents for metals and sulphate removalRuntti, H. (Hanna) 17 June 2016 (has links)
Abstract
Pollutant (such as metals and sulphate) contamination exists in the wastewaters of many industries, including mining operations, metal plating facilities, and tanneries. Adsorption is one of the most commonly used processes for the removal of pollutants from waters and wastewaters due to its high efficiency and simple operation. Activated carbon is the most frequently used adsorbent material, although its high cost inhibits its widespread use in wastewater treatment. Therefore, there is a need to develop other adsorbents from alternative inexpensive raw materials such as locally available industrial and mineral waste and by-products. The aim of this thesis was to study the possibility of using industrial waste materials such as carbon residue, metakaolin, blast-furnace slag and analcime as an inexpensive sorbent for iron, copper, nickel, arsenic, antimony and sulphate removal from aqueous solutions. To enhance their adsorption capacity, different chemical treatments (i.e. activation, modification, geopolymerisation) were performed. As a result, the level of removal of iron, copper and nickel by carbon residue and zinc chloride activated carbon residue was higher than that by the commercial activated carbon. Iron chloride modified carbon residue was the most effective sorbent material for sulphate removal when compared to the other studied chemically modified/activated carbon residues. Blast-furnace slag and metakaolin geopolymers as well as their raw materials, were examined for the simultaneous removal of nickel, arsenic and antimony from the spiked mine effluent. In the case of blast-furnace slag, geopolymerisation clearly increased the efficiency of nickel, arsenic and antimony removal to a beneficial level. The barium chloride modified blast-furnace-slag geopolymer was a very efficient sorbent material for sulphate removal and it could thus be a technically feasible sulphate sorbent for wastewater treatment (e.g. in the mining industry in applications in which very low sulphate levels are desired). Barium chloride modified acid washed analcime could also be a potential sorbent for sulphate removal. / Tiivistelmä
Teollisuuden jätevedet kuten kaivosvedet ja metalliteollisuuden prosessien jätevedet voivat sisältää monenlaisia haitallisia ja jopa myrkyllisiä aineita kuten metalleja ja sulfaattia. Adsorptiota käytetään yleisesti esimerkiksi metallien ja orgaanisten yhdisteiden poistossa vesiliuoksista, koska se on tehokas ja yksinkertainen menetelmä. Aktiivihiili on yleisimmin käytetty adsorbenttimateriaali vedenpuhdituksessa, mutta sen hinta joissain tapauksissa rajoittaa sen käyttöä. Tämän vuoksi on tarvetta kehittää vaihtoehtoisia adsorbenttimateriaaleja edullisista raaka-aineista. Viime vuosien aikana on raportoitu mm. teollisuus- ja mineraalijätteistä, joita voidaan hyödyntää vesien ja jätevesien puhdistuksessa. Tämän työn tavoitteena oli hyödyntää teollisuudesta muodostuvia jätemateriaaleja (hiilijäännös, metakaoliini, masuunikuona ja analsiimi) raudan, kuparin, nikkelin, arseenin, antimonin tai sulfaatin poistossa malli- ja jätevesistä. Materiaaleja käsiteltiin erilaisilla kemikaaleilla (aktivointi, modifiointi tai geopolymerointi), jotta niiden adsorptiotehokkuudet paranisivivat poistettavia aineita kohtaan. Tulokset osoittivat, että raudan, kuparin ja nikkelin poisto oli sekä käsittelemättömällä että sinkkikloridilla aktivoidulla hiilijäännöksellä korkeampi kuin kaupallisella aktiivihiilellä. Arseenin, nikkelin ja antimonin poistoa kaivosvedestä tutkittiin masuunikuona- ja metakaoliinigeopolymeereillä, joista masuunikuonageopolymeeri osoittautui tehokkaimmaksi metallien poistajaksi. Bariumkloridilla modifioitu masuunikuonageopolymeeri puolestaan poisti erittäin tehokkaasti sulfaattia kaivoksen jätevedestä. Rautakloridilla modifioitu hiilijäännös ja happopesty bariumkloridilla modifioitu analsiimi osoittatuivat myös lupaavaksi materiaaliksi sulfaatin poistossa.
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Vývoj kompozitů na bázi anorganických pojiv určených pro extrémní aplikace / The development of composites based on inorganic binders designed for the extreme applicationsJanoušek, Petr January 2013 (has links)
The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
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