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Microplastics in Drinking Water
Čermáková, Lenka ; Novotná, Kateřina ; Peer, Petra ; Janda, V. ; Pivokonský, Martin
The research was focused on microplastics occurring in water sources and in drinking water. Recently, the topic of microplastics in water is very up to date. However, most of the studies are focused on quantification of microplastics in sea water, sediments or surface waters, which are not a source of raw water for drinking water treatment, and at the same time the most of studies deal with the analysis of particles in the size range of 0.3 - 5 mm. The subject of the present study was to quantify microplastics from 0.2 μm in raw and treated water from three unnamed water treatment plants in the Czech Republic and to determine their size distribution, shape and material composition. It has been found that the number of microplastics ranged from 1414-7006 L-1 particles in raw water and 305-921 L-1 particles in treated water. Microplastics smaller than 10 μm were the most plentiful in both raw and treated water samples. Fragments clearly prevailed at two of the water treatment plants and fibres together with fragments predominated at one case.
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Coagulation of different kinds of algal organic matter
Novotná, Kateřina ; Načeradská, Jana ; Barešová, Magdalena ; Janda, V. ; Pivokonský, Martin
This study focused on coagulation of different algal organic matter (AOM) fractions, especially on its non-proteinaceous fraction. It was derived from cellular organic matter of Chlorella vulgaris, a freshwater algae. Two different Al-based coagulants were employed, i.e. alum and pre-hydrolyzed polyaluminim chloride (PACl). The highest coagulation efficiency was obtained at pH around neutral (pH 7.1-7.5 for alum and pH 7.6-8.0 for PACl) at relatively high dosages of coagulant (8 and 10 mg·L-1 as Al for alum and PACl, resp.). However, the maximum removal reached under the optimized conditions was only approximately 20%. The coagulation behaviour and efficiency of non-proteinaceous matter greatly differ from AOM peptide-proteins, which is discussed in the study.
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Are cyanobacteria capable of enhancing drinking water treatment? Sci-fi or reality?
Barešová, Magdalena ; Načeradská, Jana ; Novotná, Kateřina ; Pivokonská, Lenka ; Pivokonský, Martin
Drinking water treatment struggles with cyanobacteria and algae mainly on a seasonal basis especially when they decay and release amounts of cellular organic matter (COM). As COM is not only difficult to be removed but it also impacts the removability of other impurities, this paper aims to evaluate the effect of COM derived from two common cyanobacterial species– Microcystis aeruginosa and Merismopedia tenuissima on coagulation of other naturally occurring particles and molecules present in surface waters: kaolin suspension, humin substances and cells of M. tenuissima. Our findings show that higher COM concentrations do not have to disrupt coagulation. When COM interacts with other impurities, it can even lower coagulant doses and increase both turbidity and humic matter removal efficiencies.
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