Search results for "Water pollutant"
showing 10 items of 566 documents
Sorption of uranium(VI) onto ferric oxides in sulfate-rich acid waters.
2003
The mechanisms of the uranium(VI) sorption on schwertmannite and goethite in acid sulfate-rich solutions were studied by Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The samples were prepared under N2 atmosphere and initial uranium(VI) concentrations of 1 x 10(-5) (pH 6.5) to 5 x 10(-5) M (pH 4.2). The ionic strength was adjusted using 0.01 M Na2SO4 or 0.01 M NaClO4, respectively. The EXAFS structural parameters for uranium(VI) sorbed on goethite in sulfate-rich, acid and near-neutral solutions indicate that uranium(VI) forms an inner-sphere, mononuclear, bidentate surface complex. This complex is characterized by a uranium-ferric-iron distance of approximately 3.45 A. Ura…
Screening of halogenated aromatic compounds in some raw material lots for an aluminium recycling plant
2004
Four samples of scrap raw materials for an aluminium recycling plant were screened for the occurrence of persistent halogenated aromatic compounds. The samples contained waste from handling of electric and electronic plastics, filter dust from electronic crusher, cyclone dust from electronic crusher and light fluff from car shredder. In our screening analyses, brominated flame retardants were observed in all samples. Polybrominated diphenyl ethers (PBDE) were identified in all samples in amounts of 245–67450 ng/g. The major PBDE congeners found were decabromo- and pentabromodiphenyl ethers. 1,1-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, ethyl-pentabromobenzene, tetrabromobisphenol-…
Long-term abundance dynamics of coastal zooplankton in the Gulf of Riga
1998
The dynamics of three most abundant mesozooplankton species in the coastal zone of the Gulf of Riga — Bosmina longispina, Synchaeta baltica, Keratella quadrata — is analyzed to detect the regulating environmental factors. The only significant downward trend of species abundance was found for S. baltica in autumn. Statistically significant correlation was estimated only between the summer salinity and the abundance of B. longispina. K. quadrata though showed a negative correlation with summer salinity. The abundance of S. baltica had only nonsignificant correlations with the environmental factors. The abundance of coastal mesozooplankton species is determined by the combination of hydrologic…
Temperature effects explain continental scale distribution of cyanobacterial toxins
2018
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…
Biogenic Fenton process - A possible mechanism for the mineralization of organic carbon in fresh waters.
2020
To explore the mechanisms that mineralize poorly bioavailable natural organic carbon (OC), we measured the mineralization of OC in two lake waters over long-term experiments (up to 623 days) at different pH and iron (Fe) levels. Both the microbial and photochemical mineralization of OC was higher at pH acidified to 4 than at the ambient pH 5 or an elevated pH 6. During 244 days, microbes mineralized up to 60% of OC in the 10-mu m filtrates of lake water and more than 27% in the 1-mu m filtrates indicating that large-sized microbes/grazers enhance the mineralization of OC. A reactivity continuum model indicated that the acidification stimulated the microbial mineralization of OC especially i…
Carbon Budget and Molecular Structure of Natural Organic Matter in Bank Infiltrated Groundwater
2021
Groundwater : : journal of the Association of Ground-Water Scientists and Engineers, a division of the National Ground Water Association (2021). doi:10.1111/gwat.13087
Alterations on AChE Activity of the Fish Anguilla anguilla as Response to Herbicide-Contaminated Water
2000
Abstract The inhibition of both total and specific acetylcholinesterase activities was measured in the whole eyes of the yellow eel Anguilla anguilla after exposure to the carbamate thiobencarb. In vivo assays were conducted under a constant flow-through system of thiobencarb-contaminated water (1/60 LC50 96 h=0.22 ppm for 96 h) followed by a recovery period in clean water (192 h more). The results indicated a measurable level of AChE activity on eyes of control eels, which resulted in a sensitive indicator of the presence of thiobencarb in the water. The pesticide induced significant inhibitory effects on AChE activity ranging from 35% in total AChE activity to 75% in specific AChE activit…
Arsenic Through the Gastrointestinal Tract
2015
Intestinal barrier function regulates (micro-)nutrient absorption and host defense mechanisms at the mucosal interface with the external environment. Maintaining gut homeostasis is essential for human health; however, many factors including food and water pollutants may affect the physiological balance at the intestinal level. One of the contaminants of highest health concern is arsenic, which affects more than 200 million people worldwide, causing cancer and cardiovascular and metabolic diseases. Arsenic affects intestinal health by disrupting barrier function and inducing inflammatory responses. Processes involved in the transiting of arsenic through the gastrointestinal tract can affect …
Liver energy metabolism of Anguilla anguilla after exposure to fenitrothion.
1998
This paper deals with the effect of fenitrothion (0.04 mg/liter) on the energy metabolism of the European eel, Anguilla anguilla, and its recovery from intoxication. Various parameters such as glycogen, lactate, proteins, total lipids, and glucose in eel liver and blood were analyzed after 2, 8, 12, 24, 32, 48, 56, 72, and 96 h of fenitrothion exposure. Subsequently, the fish were allowed recovery periods of 8, 12, 24, 48, 72, 96, 144, and 192 h in clean water, and the same parameters were evaluated. Liver glycogen and lipid contents decreased significantly during the exposure, while blood glucose levels increased markedly. Liver and blood lactate values increased during pesticide exposure,…
Assessing alcohol consumption through wastewater-based epidemiology: Spain as a case study
2020
Background In this study, an alternative and complementary method to those approaches currently used to estimate alcohol consumption by the population is described. This method, known as wastewater-based epidemiology (WBE), allows back-calculating the alcohol consumption rate in a given population from the concentrations of a selected biomarker measured in wastewater. Methods Composite (24-h) wastewater samples were collected at the inlet of 17 wastewater treatment plants located in 13 Spanish cities for seven consecutive days in 2018. The sampled area covered 12.8% of the Spanish population. Wastewater samples were analyzed to determine the concentration of ethyl sulfate, the biomarker use…