Self-propelled micro/nanomotors are synthetic machines that can convert different sources of energy into motion; at the same time, they are able to serve innovative environmental applications, for example, water purification. The self-propelled micro and nanomachines can rapidly zoom through the solution, carrying catalytic surface or chemical to remove or degrade pollutants in a much faster fashion than that of static systems, which depend on diffusion and fluxes. This review highlights the recent progress of micro/nanomotors in water pollutant detection and pollutant removal applications.

• Klíčová slova
• micromotors, self-propulsion, sustainable chemistry, water chemistry, water purification,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The efficiency of removal of cellular organic matter (COM) of cyanobacteria Microcystis aeruginosa from water with ferric sulfate is influenced primarily by coagulant dosage and reaction pH. Therefore, optimization of the reaction conditions is a prerequisite for efficient purification of surface waters. Because the isoelectric point of COM occurs at a low pH, the purification of waters containing this organic matter should take place in an acidic pH range. It was also found that proteins are removed more efficiently than other organic substances (mainly polysaccharides).

• MeSH
• čištění vody * MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• Microcystis * MeSH
• mikrobiologie vody * MeSH
• organické látky chemie   MeSH
• voda chemie   MeSH
• železité sloučeniny chemie   MeSH
• železo chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ferric sulfate MeSH Prohlížeč
• organické látky MeSH
• voda MeSH
• železité sloučeniny MeSH
• železo MeSH

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 μmol/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 pre-treatment 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 pre-treatment step in water purification processes related to cyanobacterial contamination.

• Klíčová slova
• Advanced oxidation processes, Biotic contamination removal, Continuous treatment technology, High-pressure water jet, Hydrodynamic cavitation, Water treatment,
• MeSH
• čištění vody * MeSH
• hydrodynamika MeSH
• organické látky MeSH
• peroxid vodíku MeSH
• sinice * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• organické látky MeSH
• peroxid vodíku MeSH

Variably thick mesoporous TiO(2) films were prepared by alternately dip- and spray-coating using sol containing titanium(IV) alkoxide, concentrated HCl and suitable block-copolymer as a structure directing agent. The film thickness was controlled by varying the number of deposited layers. Their porosity was homogeneous: surface area and pore volume increased linearly with increasing number of deposited layers. Photoactivity of the films was tested employing photocatalytic degradation of 10(-4) M 4-chlorophenol in a 60 mL photoreactor under UV irradiation at 365 nm. The incident light intensity was 1 mW cm(-2). The degradation rate constants increased with increasing number of layers, proportional to their absorbances. However, the progressive improvement of the photocatalytic performance slightly decreased with the increasing number of layers. The spray-coating layers exhibited lower photocatalytic performance due to their smaller thicknesses.

• MeSH
• chlorfenoly chemie   MeSH
• čištění vody metody   MeSH
• fotochemie MeSH
• katalýza MeSH
• poréznost MeSH
• titan chemie   MeSH
• ultrafialové záření MeSH
• voda analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 4-chlorophenol MeSH Prohlížeč
• chlorfenoly MeSH
• titan MeSH
• titanium dioxide MeSH Prohlížeč
• voda MeSH

There is growing worry that drinking water can be affected by contaminants of emerging concern (CECs), potentially threatening human health. In this study, a wide range of CECs (n = 177), including pharmaceuticals, pesticides, perfluoroalkyl substances (PFASs) and other compounds, were analysed in raw water and in drinking water collected from drinking water treatment plants (DWTPs) in Europe and Asia (n = 13). The impact of human activities was reflected in large numbers of compounds detected (n = 115) and high variation in concentrations in the raw water (range 15-7995 ng L-1 for ∑177CECs). The variation was less pronounced in drinking water, with total concentration ranging from 35 to 919 ng L-1. Treatment efficiency was on average 65 ± 28%, with wide variation between different DWTPs. The DWTP with the highest ∑CEC concentrations in raw water had the most efficient treatment procedure (average treatment efficiency 89%), whereas the DWTP with the lowest ∑177CEC concentration in the raw water had the lowest average treatment efficiency (2.3%). Suspect screening was performed for 500 compounds ranked high as chemicals of concern for drinking water, using a prioritisation tool (SusTool). Overall, 208 features of interest were discovered and three were confirmed with reference standards. There was co-variation between removal efficiency in DWTPs for the target compounds and the suspected features detected using suspect screening, implying that removal of known contaminants can be used to predict overall removal of potential CECs for drinking water production. Our results can be of high value for DWTPs around the globe in their planning for future treatment strategies to meet the increasing concern about human exposure to unknown CECs present in their drinking water.

• Klíčová slova
• Contaminants of emerging concern, Drinking water, High-resolution mass spectrometry, Removal efficiency, Suspect screening, Water treatment,
• MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• čištění vody * MeSH
• lidé MeSH
• monitorování životního prostředí MeSH
• pitná voda * analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Asie MeSH
• Evropa MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• pitná voda * MeSH

This paper presents a critical analysis of the article "Comparison of cooling tower blowdown and enhanced make up water treatment to minimize cooling water footprint" by Müller et al. (2024), which claims to reduce the water footprint (WF) of cooling circuits. The WF concept, introduced in 2002, has evolved with two main approaches: the "volumetric" approach, quantifying water consumption, and the "impact-oriented" approach, assessing impacts associated with water usage. Müller et al.'s method is examined against these established methodologies. The analysis reveals that Müller et al. do not specify their WF approach, but their calculation suggests a "volumetric" WF focus. They claim WF reduction by minimizing cooling tower make-up water and blowdown discharge. However, this does not necessarily reduce the blue WF, as blowdown is typically a return flow that is not included in WF calculations unless it is discharged to another watershed or during a different period. Additionally, the grey WF impact is unclear due to insufficient data on pollutant concentrations in discharged water. The article also does not mention any characterization models or impact categories, making it unlikely that an "impact-oriented" WF approach was used. In conclusion, Müller et al.'s study does not align with established "volumetric" or "impact-oriented" WF methodologies. Instead of reducing water consumption (WF), it focuses on reducing water withdrawals. The use of the term "water footprint" appears to be a misapplication, taking advantage of its popularity. This misuse may mislead readers and underscores the need for rigorous review and critical assessment of published papers.

• Klíčová slova
• Cooling circuit, Water consumption, Water footprint, Water use,
• MeSH
• čištění vody metody   MeSH
• voda * MeSH
• zásobování vodou MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• voda * MeSH

Nanocellulose (NC), a one-dimensional nanomaterial, is considered a sustainable material for water and wastewater purification because of its promising hydrophilic surface and mechanical characteristics. In this regard, nanostructured membranes comprising NC and two-dimensional (2D) nanomaterials emerged as advanced membranes for efficient and sustainable water purification. This article critically reviews the recent progress on NC-2D nanostructured membranes for water and wastewater treatment. The review highlights the main techniques employed to fabricate NC-2D nanostructured membranes. The physicochemical properties, including hydrophilicity, percent porosity, surface roughness, structure, and mechanical and thermal stability, are summarized. The key performance indicators such as permeability, rejection, long operation stability, antifouling, and interaction mechanisms are thoroughly discussed to evaluate the role of NC and 2D nanomaterials. Finally, summary points and future development work are highlighted to overcome the challenges for potential practical applications. This review contributes to the design and development of advanced membranes to solve growing water pollution concerns in a sustainable manner.

• Klíčová slova
• 2D nanomaterials, Advanced membrane, Nanocellulose, Sustainability, Water purification,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Sludge drying reed beds (SDRBs), as a natural biological technology, have positive effects on surplus sludge treatment. However, few studies focus on the sludge leachate purification in the SDRBs regarding the wetland plant species and sludge loading rates. In this study, four SDRBs planted with two wetland plant species (Phragmites australis, Typha angustifolia) were investigated for leachate purification under six sludge loading volumes and feeding frequencies (9L/3d, 6L/3d, 4L/d, 3L/d, 2.5L/d, and 2L/d). Results showed that the lowest Escherichia coli content of 630 number/mL was determined in the P. australis SDRBs, with 86.2-92.8% lower than those in the T. angustifolia controls. However, similar removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN), ammonium (NH4+), total phosphorus (TP), and heavy metals were obtained in the SDRBs with both plant species. Moreover, the optimum sludge loading volume and feeding frequency of 3L/d was determined in the P. australis system, with pollutants (COD, TN, NH4+, and TP) mass removal efficiencies in the leachate being over 94.9%. In addition, the principal component analysis indicated that water loss and oxidation-reduction potential had positive influences on pollutant removal in the planted SDRBs. Overall, the best leachate removal efficiency was obtained in the P. australis SDRBs under the sludge loading volume and feeding frequency of 3L/d.

• Klíčová slova
• Leachate purification, Plant species, Sludge drying reed beds, Sludge loading frequencies,
• MeSH
• chemické látky znečišťující vodu * MeSH
• čištění vody * MeSH
• dusík analýza   MeSH
• fosfor analýza   MeSH
• měření biologické spotřeby kyslíku MeSH
• mokřady MeSH
• odpad tekutý - odstraňování MeSH
• odpadní vody MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• dusík MeSH
• fosfor MeSH
• odpadní vody MeSH

This paper describes the commissioning of the new water line (NWL) of the Central wastewater treatment plant in Prague and also the gradual reduction of the existing water line (EWL) loading. Concerning the NWL, the gradual start-up of the process without inoculation will be described. As to the EWL, the presentation describes the adaptation of the EWL operation to the relatively quick reduction of loading to approximately 35%.

• MeSH
• čištění vody * MeSH
• odpad tekutý - odstraňování * MeSH
• odpadní voda MeSH
• odpadní vody MeSH
• voda MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• odpadní voda MeSH
• odpadní vody MeSH
• voda MeSH

Microplastics (MPs) have recently been detected in oceans, seas and freshwater bodies worldwide, yet few studies have revealed the occurrence of MPs in potable water. Although the potential toxicological effects of MPs are still largely unknown, their presence in water intended for human consumption deserves attention. Drinking water treatment plants (DWTPs) pose a barrier for MPs to enter drinking water; thus, the fate of MPs at DWTPs is of great interest. This review includes a summary of the available information on MPs in drinking water sources and in potable water, discusses the current knowledge on MP removal by different water treatment processes, and identifies the research needs regarding MP removal by DWTP technologies. A comparison of MPs with other common pollution agents is also provided. We concluded that special attention should be given to small-size MPs (in the range of several micrometres) and that the relationship between MP character and behaviour during distinct treatment processes should be explored.

• Klíčová slova
• Coagulation, Drinking water treatment, Microplastics, Potable water, Wastewater,
• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• čištění vody * MeSH
• monitorování životního prostředí MeSH
• pitná voda chemie   MeSH
• plastické hmoty analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• pitná voda MeSH
• plastické hmoty MeSH