High-pressure jet-induced hydrodynamic cavitation as a pre-treatment step for avoiding cyanobacterial contamination during water purification

0533657 - BÚ 2021 RIV GB eng J - Journal Article
Zezulka, Štěpán - Maršálková, Eliška - Pochylý, F. - Rudolf, P. - Hudec, M. - Maršálek, Blahoslav
High-pressure jet-induced hydrodynamic cavitation as a pre-treatment step for avoiding cyanobacterial contamination during water purification.
Journal of Environmental Management. Roč. 255, FEB 1 (2020), s. 1-7, č. článku 109862. ISSN 0301-4797. E-ISSN 1095-8630
R&D Projects: GA ČR(CZ) GA16-18316S
Institutional support: RVO:67985939
Keywords : continuous treatment technology * biotic contamination removal * water treatment * advanced oxidation processes
OECD category: Environmental sciences (social aspects to be 5.7)
Impact factor: 6.789, year: 2020
Method of publishing: Limited access
https://doi.org/10.1016/j.jenvman.2019.109862

Due to specific physical properties, hydrodynamic cavitation (HC) is assigned to the powerful technologies for treating the biotic contamination in water including cyanobacteria. Contaminated water stream (CWS) can be cavitated directly by passing through some HC device, or indirectly when high-pressure jet stream (HPJS) is directed against its flow. Relatively small HPJS stream can thus treat a big volume of CWS in a short time or even work in continuous mode. Cyanobacteria floating in the CWS are forced to flow through the mixing cavitation zone. Within 2 h after single HC treatment, cyanobacterial cell suspensions showed disintegration of larger colonies and enhanced biomass sedimentation. Additional pre-treatment of CWS with low amounts of hydrogen peroxide (H2O2, 33, 66 and 99 mu mol/L) enhanced the effect of HC and led to further inhibition of cyanobacterial photosynthesis (maximum quantum yield of photosystem II decreased by up to 60%). The number of cyanobacterial cells in the treated CWS decreased continuously over 48 and 72 h, though some cells remained alive and were able to recover photosynthetic activity. The technique proposed (direction of a HPJS against a CWS and pretreatment with low H2O2 concentrations) provides (i) effective removal of cells from the water column, and (ii) reduced contamination by organic compounds released from the cells (especially cyanotoxins) as the cell membranes are not destroyed and the cells remain alive. This process shows potential as an effective pretreatment step in water purification processes related to cyanobacterial contamination.
Permanent Link: http://hdl.handle.net/11104/0314746