Hydrochemistry and Technology

Water treatment is a technological branch aimed at reaching such properties of water to meet the quality requirements with respect to its further use. It uses the knowledge of many scientific disciplines, e.g. hydrochemistry, biochemistry, physical chemistry of surfaces, hydrodynamics, civil and chemical engineering or mathematic modelling. Particularly, the treatment of water for drinking purpose is still a current issue due to the growing population. The drinking water treatment includes the following technological processes: pH adjustment, possibly pre-oxidationformation of suspension (destabilisation/coagulation and aggregation/flocculation of undesirable impurities by the means of iron/aluminium reagents); separation of formed suspension (sedimentationflotationfiltration); and disinfection. The processes of suspension formation and separation can be combined into one technological step with the use of clarification in specially constructed devices – clarifiers. For removal of dissolved substances in lower concentration, adsorption (onto activated carbon, organic resins, ion exchangers) or membrane processes (micro-, ultra-, nanofiltration, reverse osmosis) can be used.

The research at the Institute of Hydrodynamics is aimed at the study of mechanisms of removal of problematic substances from water. Firstly, it is the AOM (Algal Organic Matter) – organic matter originating from the metabolic activity and decay of algae and cyanobacteria, removed by the conventional treatment, i.e coagulation (suspension formation by the means of iron/aluminium coagulants and its subsequent separation), possibly also using pre-oxidation (by potassium permanganate, ozone, chlorine, UV radiation). Secondly, there are micropollutants (pesticides, pharmaceuticals) that are removed by adsorption onto activated carbon. Recently, an occurence and characterization of microplastics in drinking water has become our new research topic. Since microplastics are micropollutants with potential health risks, their presence in drinking water is undesirable. The research in this field is also aimed at the occurence of microplastics in raw water sources and at microplastic removal by individual water treatment pocesses. This is especially important, since no special technology has been designed for microplastics removal so far. Further, the research is aimed at the influence of physical-chemical parameters (type and dose of coagulant, pH, alkalinity, temperature) and hydrodynamic conditions (magnitude and distribution of shear rate) on the properties of flocs (size, structure, porosity and shape) formed during conventional water treatment. Floc (aggregate) properties fundamentally influence the efficiency of their subsequent separation. It is necessary to understand the mechanisms of aggregation and the evolution of aggregate properties in dependence on mentioned conditions to optimize the aggregate formation for particular separation processes.

Novotná, K., Pivokonská, L., Čermáková, L., Prokopová, M., Fialová, K., Pivokonský, M. (2023). Continuous long-term monitoring of leaching from microplastics into ambient water – A multi-endpoint approach. Journal of Hazardous Materials. 444, Part A(February, 15), 130424.

Čermáková, L., Fialová, K., Kopecká, I., Barešová, M., Pivokonský, M. (2020). Investigating adsorption of model low-MW AOM components onto different types of activated carbon – influence of temperat­ure and pH valueEnvironmental Technology. 43(8), 1152-1162.

Pivokonský, M., Vašatová, P., Načeradská, J., Pivokonská, L.: Koagulace při úpravě vody: Teorie a praxe. Praha: Academia, 2020, 323 s.

Barešová, M., Načeradská, J., Novotná, K., Čermáková, L., Pivokonský, M. (2020). The impact of preozonation on the coagulation of cellular organic matter produced by Microcystis aeruginosa and its toxin degradation. Journal of Environmental Sciences. 98(December), 124-133.

Pivokonský, M., Pivokonská, L., Vašatová, P., Načeradská, J.: Sklenicová zkouška pro optimalizaci úpravy vody. Praha: Ústav pro hydrodynamiku AV ČR, v. v. i., 2019, 1. elektronické vydání, 56 s.

Novotná, K., Čermáková, L., Pivokonská, L., Cajthaml, T., Pivokonský, M. (2019). Microplastics in drinking water treatment – Current knowledge and research needs. Science of the Total Environment. 667(June), 730-740.

Gonzales-Torres, A., Pivokonský, M., Henderson, R. (2019). The impact of cell morphology and algal organic matter on algal floc properties. Water Research. 163(October), 114887.

Filipenská, M., Vašatová, P., Pivokonská, L., Čermáková, L., Gonzales-Torres, A., Henderson, R. K., Načeradská, J., Pivokonský, M. (2019). Influence of COM–peptides/proteins on the properties of flocs formed at different shear rates. Journal of Environmental Sciences. 80(June), 116-127.

Brányiková, I., Filipenská, M., Urbanová, K., Růžička, M., Pivokonský, M., Brányik, T. (2018). Physicochemical approach to alkaline flocculation of Chlorella vulgaris induced by calcium phosphate precipitates. Colloids and Surfaces B–Biointerfaces. 166(1), 54–60.

Pivokonský, M., Čermáková, L., Novotná, K., Peer, P., Cajthaml, T., Janda, V. (2018). Occurrence of microplastics in raw and treated drinking water. Science of the Total Environment. 643, 1644–1651.

Barešová, M., Pivokonský, M.; Novotná, K.; Načeradská, J.; Brányik, T. (2017). An application of cellular organic matter to coagulation of cyanobacterial cells (Merismopedia tenuissima)Water Research. 122, 70–77. 

Čermáková, L., Kopecká, I., Pivokonský, M., Pivokonská, L., Janda, V. (2017). Removal of cyanobacterial amino acids in water treatment by activated carbon adsorptionSeparation and Purification Technology. 173(1), 330–338.

Načeradská, J., Pivokonský, M., Pivokonská, L., Barešová, M., Henderson, R.K., Zamyadi, A., Janda, V. (2017). The impact of pre-oxidation with potassium permanganate on cyanobacterial organic matter removal by coagulationWater Research. 114, 42–49. 

Souhrnná výzkumná zpráva z projektu č. TJ01000169 (2018): Vliv podmínek flokulace (intenzita míchání a doba zdržení) na tvar a strukturu tvořených agregátů a účinnost jejich separace sedimentací a filtrací

Souhrnná výzkumná zpráva z projektu č. TJ01000169 (2019): Optimalizace laboratorních postupů pro efektivní řízení technologie úpravy vody.