0000000000083073

AUTHOR

Juris Kostjukovs

Enrichment and activation of smectite-poor clay

A new method of smectite clay enrichment has been developed. The method is based on dispersing clay in a phosphate solution and sequential coagulation. The product of enrichment is characterized with X-ray powder diffraction, wavelength dispersive X-ray fluorescence spectrometry, differential thermal analysis and thermogravimetry. Sorption of methylene blue and hexadecylpyridinium bromide on raw and purified clays was studied.

research product

Determination and Toxicology Studies of Quaternary Ammonium Salts in Solution after Organoclay Processing

Organoclays have potential to be used as additives in various facade paints and other finishing materials. Such new innovative materials must be rigorously tested for them to have no impact on environment. Focus of this study was to develop HPLC – TOF/MS method for determining quaternary ammonium salts in various material washing solutions and to determine organoclay toxicity by performing acute toxicity test on Daphnia magna. From the obtained results, it was possible to conclude that organoclays can be safely used as additives in various materials with low or no impact on environment. We determined that organoclays are significantly less toxic then some quaternary ammonium salts on its ow…

research product

Rapid Catalytic Water Disinfection from Earth Abundant Ca 2 Fe 2 O 5 Brownmillerite

Water disinfection is a crucial challenge for humanity. Approaches that are effective, cheap, environmentally friendly, and do not promote gene exchange between bacteria are urgently required. Strongly oxidizing radicals are highly promising to achieve this as they lead to bacterial activation at high efficiencies. However, sources to consistently generate these radicals are limited to high energy UV/H2O2 treatments requiring a large energy input. Here the use of abundant, cheap, brownmillerite (Ca2Fe2O5) is demonstrated as an efficient radical generation material under dark conditions, showing a seven order of magnitude decrease in bacterial concentration over 10 min. This decrease is attr…

research product

Natural iron oxide (earth colour) deposits in Latvia: an assessment of the possibilities for their use in inorganic pigment manufacturing

research product

Membrane-less amphoteric decoupled water electrolysis using WO 3 and Ni(OH) 2 auxiliary electrodes

This work has been supported by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 “To increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure” of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/3/19/466). Institute of Solid-State Physics, the University of Latvia as the Centre of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART. 2

research product