Sludge treatment beds (STBs) have been used widely in many countries due to low energy consumption, low operating and maintenance costs, and better environmental compatibility. Penetration, evaporation, and transpiration are the main processes for sludge dewatering in STBs. However, the leachate quality from STBs usually cannot meet discharge limits. Moreover, such leachate has very low COD/N ratio, which makes it difficult to treat. In the present study, two subsurface flow (SSF) constructed wetlands (CWs) were investigated for the treatment of leachate from STBs under three different hydraulic retention time (HRT) (3 days, 4 days, 6 days), aiming for evaluating the effects of plants and HRT on treatment performance, as well as the potential of SSF CWs to treat sludge leachate with low COD/N ration. The results showed that plants play an important role in leachate treatment. The best treatment performance was achieved with HRT of 4 days. In this condition, the mean removal efficiencies of COD (chemical oxygen demand), NH4+-N, TN (total nitrogen), and TP (total phosphorus) in the planted and the unplanted CWs were 61.6% (unplanted - 3.7%), 76.6% (unplanted 43.5%), 70% (unplanted 41%), and 65.6% (unplanted 6%), respectively. Heavy metal concentrations were below the Chinese integrated wastewater discharge standard during the experimental period in the planted CW, and the removal efficiencies in the planted CW system were higher than in the unplanted CW system. In all, planted SSF CWs can be an effective approach in removing leachate from sludge treatment beds. Furthermore, considering to temperature and seasonal variation, the leachate from STBs needs to be further studied in pilot- and full-scale condition.
Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.
- MeSH
- bakteriální toxiny analýza MeSH
- jezera mikrobiologie MeSH
- klimatické změny MeSH
- látky znečišťující vodu analýza MeSH
- mikrocystiny analýza MeSH
- monitorování životního prostředí MeSH
- sinice * MeSH
- teplota MeSH
- tropany analýza MeSH
- uracil analogy a deriváty analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
Cyanobacterial species produce wide range of bioactive compounds. This study characterized production of retinoid-like compounds with embryotoxic and teratogenic potential by commonly occurring cyanobacterial species with tendency to form massive water blooms. The major goal was to simultaneously assess the intracellular and extracellular retinoid-like activity from several independent cultivations of one coccal (Microcystis aeruginosa) and four filamentous cyanobacteria (Aphanizomenon gracile, Cylindrospermopsis raciborskii, Limnothrix redekeii, and Planktothrix agardhii) and characterize the variability in its production among cultivations. The retinoid-like activity was evaluated by in vitro assay along with chemical analyses of nine retinoids: all-trans retinoic acid (ATRA), 9-cis retinoic acid (9cis-RA), 13cis-RA, 13cis-RA methyl ester, 5,6 epoxy-RA, 4keto-ATRA, 4keto-retinal, 4hydoxy-retinoic acid (4OH-ATRA), retinal and retinol. The production of retinoid-like compounds was recalculated per volume, per biomass dry weight and per cell to provide relevant data for risk assessment in relation to occurrence of massive water blooms in the environment. Total produced retinoid-like activity of five selected species ranged from 170 to 25,600ng ATRA-equivalents (REQ)/g dm corresponding to 0.001-0.392ng REQ/106 cyanobacterial cells. Results from chemical analyses showed that all tested extracts contained 4keto-ATRA and retinal. All-trans retinoic acid, 9/13cis-retinoic acid and 5,6 epoxy-retinoic acid were detected in most exudate and extract samples. The reported results of recalculated total retinoid-like activity enable potential predictions of its production by the studied species in water blooms of known cell densities relevant for risk assessment.
- MeSH
- biodegradace MeSH
- čištění vody metody MeSH
- environmentální zdraví statistika a číselné údaje MeSH
- látky znečišťující vodu analýza toxicita MeSH
- mikrobiologie vody MeSH
- testy toxicity metody MeSH
- vodní organismy účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- úvodní články MeSH
- úvodníky MeSH
The occurrence of POPs in remote areas, such as Antarctica, is the result of their ability to udergo Long Range Transport (LRT) in the atmosphere, precipitation and cold condensation. In this study, both recent levels of various POPs in Trematomus bernacchii and their changes in roughly three decades were determined in order to evaluate trends of POPs in Antarctic benthic seawaters. In fact, Trematomus bernacchii is considered a good sentinel bio-indicator for monitoring not only the extent of contamination by POPs in the Antarctic aquatic ecosystem, but also changes in Antarctic ecosystem quality and trends. A slight decreasing PCB trend was detected during 30-years time span (from early 1980's to 2010) in the circumantarctic seawaters. Two higher peaks of concentrations were reported in 2001 and 2005 in the Ross Sea and they may reflect the ice melting of icebergs. Because fire risk is very high in Antarctica due to the very dry air, a large use of flame retardants in buildings and furniture of stations is highly probable; moreover, many stations were built when there were no restrictions on flame retardants use. The PBDE levels in the T. bernacchii from 2001 to 2011 ranged 0.05-0.35 pg/g and were of the same order of magnitude in 2001/2011 and in 2002/2005, with a maximum value in 2005 (0.35 pg/g). Comparable concentrations of HCB, HCHs PCDDs and PCDFs are available only for few seasons: all these compounds showed a decreasing temporal trends and their concentrations were one or more order of magnitude lower in 2000s-2010s.
- MeSH
- časové faktory MeSH
- ekosystém MeSH
- halogenované uhlovodíky analýza MeSH
- látky znečišťující vodu analýza MeSH
- mořská voda chemie MeSH
- Perciformes metabolismus MeSH
- retardanty hoření analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Antarktida MeSH
This work presents the development of a fully automated flow-batch analysis (FBA) system as a new approach for on-line preconcentration, photodegradation and fluorescence detection in a lab-constructed mixing chamber that was designed to perform these processes without sample dispersion. The system positions the mixing chamber into the detection system and varies the instrumental parameters according to the required photodegradation conditions. The developed FBA system is simple and easily coupled with any sample pretreatment without altering the configuration. This FBA system was implemented to photodegrade and determine the fluorescence of the degradation products of metsulfuron methyl (MSM), a naturally non-fluorescent herbicide of the sulfonylurea׳s family. An on-line solid phase extraction (SPE) and clean up procedure using a C18 minicolumn was coupled to the photodegradation-detection mixing chamber (PDMC) that was located in the spectrofluorometer. An enrichment factor of 27 was achieved. Photodegradation conditions have been optimized by considering the influence of the elution solvent on both the formation of the photoproduct and on the fluorescence signal. Under optimal conditions, the calibration for the MSM determination was linear over the range of 1.00-7.20 µg L(-1). The limit of detection (LOD) was 0.28 µg L(-1); the relative standard deviation was 2.0% and the sample throughput for the entire process was 3h(-1). The proposed method was applied to real water samples from the Bahía Blanca׳s agricultural region (Bahía Blanca, Buenos Aires, Argentina). This method obtained satisfactory recoveries with a range of 94.7-109.8%.
- MeSH
- arylsulfonany analýza MeSH
- extrakce na pevné fázi MeSH
- fluorescenční spektrometrie MeSH
- fotochemie metody MeSH
- fotolýza MeSH
- herbicidy analýza MeSH
- kalibrace MeSH
- koncentrace vodíkových iontů MeSH
- látky znečišťující vodu analýza MeSH
- limita detekce MeSH
- reprodukovatelnost výsledků MeSH
- sulfonylmočovinové sloučeniny analýza MeSH
- světlo MeSH
- technologie zelené chemie MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aims: Impact of potentially toxic elements (PTE) on the health status of population of the Slovak Republic has been studied in two historical mining areas with ore extraction from Middle Ages (the Middle Slovak Neovolcanics, the Slovak Ore Mts.) and one historical mining area with more than hundred years brown coal mining (Upper Nitra region). Methods: The contents of PTE were analysed in groundwater/ drinking water and soils. The health status of resident population was evaluated based on 43 health indicators classified according to the international classi- fication of diseases (ICD, 10th revision), including mainly those indicators characterizing mortality on cardiovascular and oncological diseases. In these areas the health status of population living in municipalities with increased PTE contents (As, Pb, Zn, Cu, Cd, Hg and Sb) was compared with that in adjacent municipalities showing low PTE contents.
- MeSH
- chemické znečištění vody analýza statistika a číselné údaje MeSH
- geologické jevy MeSH
- geologické sedimenty MeSH
- hornictví * MeSH
- kardiovaskulární nemoci mortalita MeSH
- látky znečišťující půdu analýza MeSH
- látky znečišťující vodu analýza MeSH
- lidé MeSH
- nádory mortalita MeSH
- pitná voda chemie MeSH
- podzemní voda chemie MeSH
- průmyslový odpad MeSH
- těžba uhlí MeSH
- ukazatele zdravotního stavu MeSH
- vystavení vlivu životního prostředí * MeSH
- znečištění životního prostředí * analýza statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Slovenská republika MeSH
The aim of the study is to assess the evolving mine water quality of closed uranium mines (abandoned between 1958 and 1992) in the Czech Republic. This paper focuses on the changes in mine water quality over time and spatial variability. In 2010, systematic monitoring of mine water quality was performed at all available locations of previous uranium exploitation. Gravity flow discharges (mine adits, uncontrolled discharges) or shafts (in dynamic state or stagnating) were sampled. Since the quality of mine water results from multiple conditions-geology, type of sample, sampling depth, time since mine flooding, an assessment of mine water quality evolution was done taking into account all these conditions. Multivariate analyses were applied in order to identify the groups of samples based on their similarity. Evaluation of hydrogeochemical equilibrium and evolution of mine waters was done using the Geochemist's Workbench and PHREEQC software. The sampling proved that uranium concentrations in mine waters did not predominantly exceed 0.45 mg/L. In case of discharges from old adits abandoned more than 40 years ago, uranium concentrations were below the MCL of US Environmental Protection Agency for uranium in drinking water (0.03 mg/L). Higher concentrations, up to 1.23 mg/L of U, were found only at active dewatered mines. Activity concentration of 226Ra varied from 0.03 up to 1.85 Bq/L except for two sites with increased background values due to rock formation (granites). Radium has a typically increasing trend after mine abandonment with a large variability. Concerning metals in mine water, Al, Co and Ni exceeded legislative limits on two sites with low pH waters. The mine water quality changes with a focus on uranium mobility were described from recently dewatered mines to shafts with water level maintained in order to prevent outflows to surface water and finally to stagnating shafts and discharges of mine water from old adits. The results were in good agreement with published experience on mine water stratification, its disturbance by pumping or natural water decant and the "first flush" phenomenon after mine flooding.
- MeSH
- hornictví * MeSH
- kovy analýza MeSH
- kvalita vody MeSH
- látky znečišťující vodu analýza MeSH
- podzemní voda chemie MeSH
- radium analýza MeSH
- uran analýza MeSH
- životní prostředí MeSH
- znečištění vody statistika a číselné údaje MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Cyanobacteria pose a serious threat to water resources around the world. This is compounded by the fact that they are extremely resilient, having evolved numerous protective mechanisms to ensure their dominant position in their ecosystem. We show that treatment with nanoparticles of zerovalent iron (nZVI) is an effective and environmentally benign method for destroying and preventing the formation of cyanobacterial water blooms. The nanoparticles have multiple modes of action, including the removal of bioavailable phosphorus, the destruction of cyanobacterial cells, and the immobilization of microcystins, preventing their release into the water column. Ecotoxicological experiments showed that nZVI is a highly selective agent, having an EC(50) of 50 mg/L against cyanobacteria; this is 20-100 times lower than its EC(50) for algae, daphnids, water plants, and fishes. The primary product of nZVI treatment is nontoxic and highly aggregated Fe(OH)(3), which promotes flocculation and gradual settling of the decomposed cyanobacterial biomass.
- MeSH
- Araceae účinky léků růst a vývoj MeSH
- čištění vody metody MeSH
- Daphnia účinky léků fyziologie MeSH
- hořčice rodu Sinapis účinky léků růst a vývoj MeSH
- kořeny rostlin účinky léků růst a vývoj MeSH
- kovové nanočástice toxicita MeSH
- látky znečišťující vodu analýza MeSH
- listy rostlin účinky léků růst a vývoj MeSH
- Microcystis účinky léků růst a vývoj MeSH
- mikrobiologie vody MeSH
- mikrocystiny analýza MeSH
- Scenedesmus účinky léků růst a vývoj MeSH
- železo toxicita MeSH
- živorodka MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- epidemiologie MeSH
- hygiena MeSH
- kvalita vody MeSH
- laboratoře MeSH
- látky znečišťující vodu analýza MeSH
- lidé MeSH
- monitorování životního prostředí metody přístrojové vybavení MeSH
- motorová vozidla MeSH
- preventivní lékařství metody přístrojové vybavení MeSH
- vojenské lékařství metody přístrojové vybavení MeSH
- znečištění ovzduší analýza prevence a kontrola MeSH
- znečištění vody analýza prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- Geografické názvy
- Afghánistán MeSH
