Removal efficiency
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Despite the importance of phosphorus as a nutrient for humans and its role in ecological sustainability, its high abundance, resulting in large part from human activities, causes eutrophication that negatively affects the environment and public health. Here, we present the use of ferrate(VI) as an alternative agent for removing phosphorus from aqueous media. We address the mechanism of phosphate removal as a function of the Fe/P mass ratio and the pH value of the solution. The isoelectric point of γ-Fe2O3 nanoparticles, formed as dominant Fe(VI) decomposition products, was identified to play a crucial role in predicting their efficiency in removing of phosphates. Importantly, it was found that the removal efficiency dramatically changes if Fe(VI) is added before (ex-situ conditions) or after (in-situ conditions) the introduction of phosphates into water. Removal under in-situ conditions showed remarkable sorption capacity of 143.4 mg P per gram of ferric precipitates due to better accessibility of active surface sites on in-situ formed ferric oxides/oxyhydroxides. At pH = 6.0-7.0, complete removal of phosphates was observed at a relatively low Fe/P mass ratio (5:1). The results show that phosphates are removed from water solely by sorption on the surface of γ-Fe2O3/γ-FeOOH core/shell nanoparticles. The advantages of Fe(VI) utilization include its environmentally friendly nature, the possibility of easy separation of the final product from water by a magnetic field or by natural settling, and the capacity for successful phosphate elimination at pH values near the neutral range and at low Fe/P mass ratios.
OBJECTIVE: Antineoplastic drugs (ADs) pose risks to healthcare staff. Surface disinfectants are used in hospitals to prevent microbial contamination but the efficiency of disinfectants to degrade ADs is not known. We studied nine disinfectants on ten ADs in the standardized laboratory and realistic in situ hospital conditions. METHODS: A survey in 43 hospitals prioritized nine most commonly used disinfections based on different ingredients. These were tested on inert stainless steel and in situ on contaminated hospital flooring. The effects against ten ADs were studied by LC-MS/MS (Cyclophosphamide CP; Ifosfamide IF; Capecitabine CAP; Sunitinib SUN; Methotrexate MET; Doxorubicin DOX; Irinotecan IRI; Paclitaxel PX; 5-Fluorouracil FU) and ICP-MS (Pt as a marker of platinum-based ADs). RESULTS: Monitoring of the floor contamination in 26 hospitals showed that the most contaminated are the outpatient clinics that suffer from a large turnover of staff and patients and have limited preventive measures. The most frequent ADs were Pt, PX, FU and CP with maxima exceeding the recommended 1 ng/cm2 limit by up to 140 times. IRI, FU, MET, DOX and SUN were efficiently removed by hydrolysis in clean water and present thus lower occupational risk. Disinfectants based on hydrogen peroxide were efficient against PX and FU (> 70% degradation) but less against other ADs, such as carcinogenic CP or IF, IRI and CAP. The most efficient were the active chlorine and peracetic acid-based products, which however release irritating toxic vapors. The innovative in situ testing of ADs previously accumulated in hospital flooring showed highly problematic removal of carcinogenic CP and showed that alcohol-based disinfectants may mobilize persistent ADs contamination from deeper floor layers. CONCLUSION: Agents based on hydrogen peroxide, peracetic acid, quaternary ammonium salts, glutaraldehyde, glucoprotamine or detergents can be recommended for daily use for both disinfection and AD decontamination. However, they have variable efficiencies and should be supplemented by periodic use of strong chlorine-based disinfectants efficient also against the carcinogenic and persistent CP.
- MeSH
- dekontaminace metody MeSH
- detergenty MeSH
- dezinficiencia * MeSH
- diaminy MeSH
- glutaraldehyd MeSH
- kontaminace zdravotnického vybavení MeSH
- kvartérní amoniové sloučeniny MeSH
- kyselina peroctová MeSH
- laboratoře MeSH
- nemocnice MeSH
- nerezavějící ocel MeSH
- peroxid vodíku MeSH
- podlahy a podlahové krytiny MeSH
- protinádorové látky * MeSH
- pyrrolidinony MeSH
- Publikační typ
- časopisecké články MeSH
Eutrophication of water by nutrient pollution remains an important environmental issue. The aim of this study was to evaluate the nutrient uptake capacity of an algal biofilm as a means to treat polluted water. In addition, the study investigated the nutrient removal process. The algal biofilm was able to remove 99% of phosphorus within 24 hours of P addition, with the PO4-P concentration in inflowing water ranging from 3 to 10 mg L-1. Different patterns of phosphorus and nitrogen removal were observed. Daily quantity of removed NO3-N ranged from 2 to 25% and was highly dependent on solar irradiance. Precipitation of phosphorus during the removal process was studied using X-ray diffraction analyses and was not confirmed in the biofilm. The biofilm system we constructed has a high efficiency for phosphorus removal and, therefore, has great potential for integration into wastewater treatment processes.
- MeSH
- biodegradace MeSH
- biofilmy * MeSH
- čištění vody * MeSH
- dusík * MeSH
- fosfor * MeSH
- odpad tekutý - odstraňování MeSH
- Publikační typ
- časopisecké články MeSH
The removal efficiency of heavy metal ions (cadmium(II), Cd(II); cobalt(II), Co(II); nickel(II), Ni(II); copper(II), Cu(II)) by potassium ferrate(VI) (K2FeO4, Fe(VI)) was studied as a function of added amount of Fe(VI) (or Fe) and varying pH. At pH = 6.6, the effective removal of Co(II), Ni(II), and Cu(II) from water was observed at a low Fe-to-heavy metal ion ratio (Fe/M(II) = 2:1) while a removal efficiency of 70% was seen for Cd(II) ions at a high Fe/Cd(II) weight ratio of 15:1. The role of ionic radius and metal valence state was explored by conducting similar removal experiments using Al(III) ions. The unique combination of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), in-field Mössbauer spectroscopy, and magnetization measurements enabled the delineation of several distinct mechanisms for the Fe(VI)-prompted removal of metal ions. Under a Fe/M weight ratio of 5:1, Co(II), Ni(II), and Cu(II) were removed by the formation of MFe2O4 spinel phase and partially through their structural incorporation into octahedral positions of γ-Fe2O3 (maghemite) nanoparticles. In comparison, smaller sized Al(III) ions got incorporated easily into the tetrahedral positions of γ-Fe2O3 nanoparticles. In contrast, Cd(II) ions either did not form the spinel ferrite structure or were not incorporated into the lattic of iron(III) oxide phase due to the distinct electronic structure and ionic radius. Environmentally friendly removal of heavy metal ions at a much smaller dosage of Fe than those of commonly applied iron-containing coagulants and the formation of ferrimagnetic species preventing metal ions leaching back into the environment and allowing their magnetic separation are highlighted.
- MeSH
- chemické látky znečišťující vodu chemie izolace a purifikace MeSH
- čištění vody metody MeSH
- difrakce rentgenového záření MeSH
- fotoelektronová spektroskopie MeSH
- kationty chemie MeSH
- koncentrace vodíkových iontů MeSH
- magnetické nanočástice chemie MeSH
- sloučeniny draslíku chemie MeSH
- sloučeniny železa chemie MeSH
- spektroskopie Mossbauerova MeSH
- těžké kovy chemie izolace a purifikace MeSH
- voda MeSH
- železité sloučeniny chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Arsenates, when present in water resources, constitute a risk to human health. In order to remove them, various technologies have been developed; out of them, sorption approach is widely adopted employing a wide spectrum of suitable sorbent materials. Nanoparticles of iron oxide are frequently used due to a high surface area and ability to control them by external magnetic field. In this work, we report on a simple and cheap synthesis of ultrafine iron(III) oxide nanoparticles with a narrow size distribution and their exploitation in the field of arsenate removal from aqueous environment. It is shown that the adsorption capacity is enhanced by a mesoporous nature of nanoparticle arrangement in their system due to strong magnetic interactions they evolve between nanoparticles. A complete arsenate removal is achieved at Fe/As ratio equal to ∼20/1 and at pH in the range from 5 to 7.6. Under these conditions, the arsenates are completely removed within several minutes of treatment. Among iron-oxide-based nanosystems synthesized and employed in arsenate remediation issues so far, our assembly of iron(III) oxide nanoparticles shows the highest Freundlich adsorption coefficient and equilibrium sorption capacity under conditions maintained. Taking into account simple and low-cost preparation procedure, product high yields, almost monodispersed character, room-temperature superparamagnetic behavior, and strong magnetic response under small applied magnetic fields, the synthesized iron(III) oxide nanoparticles can be regarded as a promising candidate for exploitation in the field of removing undesired toxic pollutants from various real water systems.
Removal of selected metals from municipal wastewater using a constructed wetland with a horizontal subsurface flow was studied. The objective of the work was to determine the efficiency of Cu, Zn, Ni, Co, Sr, Li, and Rb removal, and to describe the main removal mechanisms. The highest removal efficiencies were attained for zinc and copper (89.8 and 81.5%, respectively). It is apparently due to the precipitation of insoluble sulfides (ZnS, CuS) in the vegetation bed where the sulfate reduction takes place. Significantly lower removal efficiencies (43.9, 27.7, and 21.5%) were observed for Li, Sr, and Rb, respectively. Rather, low removal efficiencies were also attained for Ni and Co (39.8 and 20.9%). However, the concentrations of these metals in treated water were significantly lower compared to Cu and Zn (e.g., 2.8 ± 0.5 and 1.7 ± 0.3 μg/l for Ni at the inflow and outflow from the wetland compared to 27.6 ± 12.0 and 5.1 ± 4.7 μg/l obtained for Cu, respectively). The main perspective of the constructed wetland is the removal of toxic heavy metals forming insoluble compounds depositing in the wetland bed. Metal uptake occurs preferentially in wetland sediments and is closely associated with the chemism of sulfur and iron.
- MeSH
- chemické látky znečišťující vodu chemie izolace a purifikace MeSH
- kobalt chemie izolace a purifikace MeSH
- lithium chemie izolace a purifikace MeSH
- měď chemie izolace a purifikace MeSH
- mokřady * MeSH
- nikl chemie izolace a purifikace MeSH
- odpadní voda chemie MeSH
- rubidium chemie izolace a purifikace MeSH
- stroncium chemie izolace a purifikace MeSH
- zinek chemie izolace a purifikace MeSH
- Publikační typ
- časopisecké články MeSH
Portable household air purifiers are widely used devices designed to maintain a high-quality level of indoor air. Portable air purifiers equipped with the high-efficiency air (HEPA) filter served 100 h in a household space occupied by two adults without any symptoms of respiratory tract infection. The main objective of the study was to determine microbial contamination on the HEPA filter and to investigate if the selected nanotextile monolayer made of polyamide 6 (PA6) nanofibers can capture potential microorganisms when installed downstream of the HEPA filter as the final filtration medium. Samples were taken from the inlet and outlet surfaces. Samples from the nanotextile were collected in the same manner as from the HEPA filter. QIAStat DX® 1.0 Analyzer using the Respiratory SARS CoV-2 Panel multiplex PCR detection system was selected for microorganism detection. Adenovirus was detected on the inlet surface of the HEPA filter. The outlet surface of the filter contained no viruses included in the Respiratory SARS CoV-2 Panel portfolio. The nanotextile monolayer was replaced twice during the 100 h of operation, so three pieces were used and all contained coronavirus 229 E. Coronavirus 229 E was then detected in the nasopharynx of one of the members of the household as well. It may be assumed that the selected nanotextile is capable of capturing a virus of a small size.
- MeSH
- filtrace MeSH
- lidé MeSH
- pilotní projekty MeSH
- SARS-CoV-2 MeSH
- syndrom akutního respiračního selhání * MeSH
- vzduchové filtry * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Východiska: Aferéza kmenových buněk je v procesu autologní transplantace kmenových buněk klíčovým krokem. Dostupné separátory krevních buněk (blood cell separators – BCS) mají díky svým technickým vlastnostem a vlivem obsluhy různou účinnost. Materiál a metody: Retrospektivě byla shromažďována data z aferéz periferních kmenových buněk provedených pomocí dostupných BCS od výrobce Fresenius (ComTec a Amicus) v Ukrajinském národním onkologickém institutu (National Cancer Institute Ukraine) v letech 2017–2020. Byl vypočítán koeficient účinnosti odběru (collection efficiency coefficient – CEC) a pro každý separátor byl upraven vzorec pro predikci celkového objemu zpracované krve (total volume of processed blood – TVPB). Výsledky: Analýza dat 60 pacientů (celkem 92 provedených aferéz). Průměrné hodnoty CEC byly (53,8 ± 36,6) % pro přístroj Amicus a (44,2 ± 37,3) % pro přístroj ComTec; p = 0,22. Při použití přístroje Amicus byl získán nižší objem produktu v porovnání s přístrojem ComTec; p = 2×10–7. Množství odebraných kmenových buněk bylo v obou skupinách srovnatelné: (5,8 ± 5,7) ×106/kg pro Amicus a (4,1 ± 3,1) ×106/kg pro ComTech; p = 0,064. Aby bylo dosaženo optimálního množství kmenových buněk, byla provedena úprava vzorce pro odhad TVPB. Závěr: Hodnoty CEC pro oba přístroje byly v obecně akceptovaném rozmezí 30–50 % a výrazně se nelišily. Nicméně při použití přístroje Amicus bylo dosaženo nižších objemů produktu, přičemž ostatní charakteristiky byly srovnatelné.
Background: Stem cells apheresis is a key step in the process of the autologous stem cell transplantation. Available blood cell separators (BCS) have different efficiency due to the technical characteristics and influence of the operator. Materials and methods: Retrospectively, data were collected of the peripheral blood stem cells apheresis performed using available BCS manufactured by Fresenius (ComTec and Amicus) in the National Cancer Institute Ukraine from 2017 to 2020. The collection efficiency coefficient (CEC) was calculated, the formula for predicting the total volume of processed blood (TVPB) was adapted for each separator. Results: The analysis included data from 60 patients (total of 92 apheresis procedures). The mean CEC was established at the level of (53.8 ± 36.6) % for the Amicus device and (44.2 ± 37.3) % for the ComTec device; P = 0.22. The lower product volume was obtained using the Amicus device compared to the ComTec device; P = 2×10–7. The amount of collected stem cells was comparable in both groups (5.8 ± 5.7) ×106/kg and (4.1 ± 3.1) ×106/kg, respectively; P = 0.064. The adaptation of the formula for predicting the TVPB to achieve the optimum amount of stem cells was performed. Conclusion: The CEC for each device was within the generally accepted limits of 30–50%, and did not differ significantly. Nevertheless, using of the Amicus BCS allowed to collect lower volumes of the product, maintaining other characteristics of the product competitive.
Removal of nonionic surfactants from municipal wastewater using a constructed wetland with a horizontal subsurface flow was studied in 2009 and 2010. Extraction spectrophotometry with 3',3″,5',5″-tetrabromophenolphthalein ethyl ester and KCl served to determine the analyte concentrations. Triton(®) X-100 was used as a standard to express the nonionic-surfactant concentrations. Anionic and cationic surfactants were shown not to interfere during the determination. Nonionic surfactants were degraded (to products undeterminable by the method) with a high average efficiency that reached 98.1% in 2009 and 99.1% in 2010, respectively. The average concentration of nonionic surfactants at the inflow was 0.978 mg/l, while it was close to the limit of quantification at the outflow (0.014 mg/l). A significant fraction of nonionic surfactants (38.7%) was already degraded during the pretreatment, and only 14.0% of the nonionic surfactants remained in the interstitial H(2) O taken in the vegetation bed at a distance of 1 m from the inflow zone at a 50-cm depth. Nonionic surfactants were degraded both under aerobic and anaerobic conditions.
The aim of this study was to evaluate the treatment of organic-carbon-deficient wastewater containing benzotriazole (BTA) in lab-scale aerated biofilters filled with natural manganese oxide ore, sand coated with synthetic manganese oxides and sand (as a control material) in terms of BTA removal efficiency, its transformation products and ecotoxicological impact of the treated wastewater. Additionally, the effect of Mn(II) feeding was tested. The removal of BTA in all the biofilters was ≥97%. The contribution of the biotic removal of this compound was 15%, 50%, and 75% in the systems filled with sand, synthetic and natural manganese oxides, respectively. Only the columns filled with natural manganese oxides provided significant removal of DOC and decrease of UV254 and SUVA254, with even more pronounced effect with Mn(II) feeding. The presence of Mn(II) was also found to enhance the removal of NNH4 in the systems filled with either form of manganese oxides, otherwise the removal of NNH4 was negligible or negative. The transformation reactions of BTA were methylation, hydroxylation, and triazole ring cleavage. Based on the number of compounds and their relative abundance, the methylated transformation products were predominant in the effluent. The reduction of the ecotoxicity (Microtox bioassay) of the effluents was positively correlated with the decrease of UV254, SUVA and DOC and only moderately with the removal of BTA. This study has shown that the natural manganese oxide ore provides the broadest set of services as a filtering material for aerated biofilters treating carbon-deficient wastewater containing BTA.
- MeSH
- čištění vody metody MeSH
- mangan chemie MeSH
- odpadní voda chemie MeSH
- oxidy MeSH
- sloučeniny manganu MeSH
- triazoly izolace a purifikace MeSH
- uhlík MeSH
- Publikační typ
- časopisecké články MeSH
