Produced water is a type of wastewater generated from hydraulic fracturing, which may pose a risk to the environment and humans due to its high ionic strength and the presence of elevated concentrations of metals/metalloids that exceed maximum contamination levels. The mobilization of As(V) and Se(VI) in produced water and selected soils from Qingshankou Formation in the Songliao Basin in China were investigated using column experiments and synthetic produced water whose quality was representative of waters arising at different times after well creation. Temporal effects of produced water on metal/metalloid transport and sorption/desorption were investigated by using HYDRUS-1D transport modelling. Rapid breakthrough and long tailings of As(V) and Se(VI) transport were observed in Day 1 and Day 14 solutions, but were reduced in Day 90 solution probably due to the elevated ionic strength. The influence of produced water on the hydrogeological conditions (i.e., change between equilibrium and non-equilibrium transport) was evidenced by the change of tracer breakthrough curves before and after the leaching of produced water. This possibly resulted from the sorption of polyacrylamide (PAM (-CHCHCONH-)) onto soil surfaces, through its use as a friction reducer in fracturing solutions. The sorption was found to be reversible in this study. Minimal amounts of sorbed As(V) were desorbed whereas the majority of sorbed Se(VI) was readily leached out, to an extent which varied with the composition of the produced water. These results showed that the mobilization of As(V) and Se(VI) in soil largely depended on the solution pH and ionic strength. Understanding the differences in metal/metalloid transport in produced water is important for proper risk management.
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http://dx.doi.org/10.1016/j.envpol.2017.01.044 | DOI Listing |
Chemistry
December 2024
Osaka University, Graduate School of Pharmaceutical Sciences, 1-6, Yamada-oka, 565-0871, Osaka, JAPAN.
Deuterated molecules are of growing interest because of the specific characteristics of deuterium, such as stronger C-D bonds being stronger than C-H bonds. Polyethylene glycols (PEGs) are widely utilized in scientific fields (e.g.
View Article and Find Full Text PDFAnal Sci
December 2024
School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo, 192-0982, Japan.
A biosensor for biochemical oxygen demand (BOD) was developed based on intracellular 5'-adenosine triphosphate (ATP) measurements in Saccharomyces cerevisiae. Intracellular ATP was measured using an engineered protein named ATeam, comprising a bacterial FF-ATP synthase ε subunit sandwiched between cyan fluorescent protein and mVenus, a modified yellow fluorescent protein. Because the binding of ATP to ATeam induces changes in the fluorescence spectra owing to Fӧrster resonance energy transfer, S.
View Article and Find Full Text PDFEnviron Geochem Health
December 2024
Departamento de Explotación y Prospección Minera, Escuela de Ingeniería de Minas, Energía y Materiales, Universidad de Oviedo, Independencia, 13, 33004, Oviedo, Spain.
The food chain of the Valdezogues River system is at considerable risk due to the presence of mercury in the environment and to intense bioaccumulation and biomagnification processes in some fish species, particularly in piscivorous. Moreover, the presence of mercury in fish is a reliable indicator of the presence of its most toxic form, methylmercury. Of interest is that selenium, when present together with mercury in food, represents a significant decrease in the risks related to the ingestion of methylmercury.
View Article and Find Full Text PDFArch Microbiol
December 2024
Global Leadership School, Handong Global University, Pohang, 37554, South Korea.
Microcystin-LRs (MC-LR) produced by harmful cyanobacterial blooms (HCBs) pose significant hepatotoxic risks to both the environment and public health. Despite the identification and characterization of a limited number of MC-LR degrading bacteria, the challenge of safely removing MC-LRs from freshwater systems without disrupting aquatic ecosystems remains substantial. This study focused on the isolation of lactic acid bacteria from Bapshikhe, a traditional Korean fermented food, and investigated the mechanisms underlying the degradation of MC-LRs by these bacteria.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Université de Mons: Universite de Mons, Sciences, BELGIUM.
This study introduces a novel one-pot strategy for the chemical valorization of poly(lactic acid) (PLA), coupling its base-catalyzed depolymerization with the ring-opening polymerization (ROP) of trimethylene carbonate (TMC). The process exploits an eutectic mixture of lactide (LA) and TMC, which lowers the thermal input required for PLA degradation. Using potassium aryloxide (KOArtBu) as a bifunctional catalyst, the PLA is first quickly hydrolyzed into oligomers or lactic acid, which subsequently initiate the slower polymerization of TMC.
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