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Contamination of Peruvian drinking water by arsenic and boron - origin, properties and treatment
Sadloň, Matúš ; Stejskal, Vojtěch (advisor) ; Cencarová, Vendula (referee)
Excessive arsenic and boron concentrations determined in natural waters within the Department of Tacna in southern Peru are associated with active Andean volcanism, being further exacerbated by the ongoing mining activity in the area. Both arsenic and boron concentrations at five investigated sites significantly exceed the maximum permissible limits determined by the World Health Organisation and the Peruvian legislation for drinking water, thus affecting the health and wellbeing of the local population. Due to the remoteness of the area of interest, which lacks infrastructure, skilled human resources as well as capital, Photon Water Technology s.r.o. has come up with a solution based on the use of small water treatment plants operating on the principle of reverse osmosis in combination with a commercial remediation product Katalox Light® . This product enables the formation of alkaline conditions needed for proper complexation of boron into B(OH)4 - (aq), which is better remediated by the proposed technology. Reverse osmosis can remediate arsenic, although the efficiency of As removal depends on the chemical composition of natural waters at the investigated sites. Laboratory experiments have been focused to prove the viability of Katalox Light® for enhancing the rate of boron removal within the designed...
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Importance and occurrence of chromium in hydrogeology
Sadloň, Matúš ; Nedvěd, Jakub (advisor) ; Šantrůček, Jaromír (referee)
in English Chromium, particularly its two most stable oxidation states - hexavalent and trivalent chromium - plays a very significant role in the environment. While trivalent chromium is an essential nutrient both for humans and plants, hexavalent chromium proved to be one of the most dangerous contaminants negatively affecting people and the environment on a wide- ranging scale. This thesis aims to provide a complex overview of chromium occurrence in various natural systems, its physical and chemical properties as well as its mobility in the environment. Furthermore, the thesis will describe two case studies (from Greece and India), which illustrate both the natural and anthropogenic sources of hexavalent chromium contamination. Due to its mutagenic and carcinogenic properties, a complex set of remediation methods was suggested for hexavalent chromium removal, including both in-situ and ex-situ ones. Given their proven record in successful elimination of hexavalent chromium contamination from groundwater, in-situ methods are being utilised far more frequently nowadays; these will be explained more comprehensively. The most notable categories of in- situ remediation methods include biological and chemical reduction, chemical precipitation and chemical sorption. Besides these, other promising...
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