Atrazine removal from water by two polycations pre-adsorbed on montmorillonite was studied. Batch experiments demonstrated that the most suitable composite poly (4-vinylpyridine-co-styrene)-montmorillonite (PVP-co-S90%-mont.) removed 90-99% of atrazine (0.5-28 ppm) within 20-40 min at 0.367% w/w. Calculations employing Langmuir's equation could simulate and predict the kinetics and final extents of atrazine adsorption. Column filter experiments (columns 20x1.6 cm) which included 2g of the PVP-co-S90%-mont. composite mixed with excess sand removed 93-96% of atrazine (800 ppb) for the first 800 pore volumes, whereas the same amount of granular activated carbon (GAC) removed 83-75%. In the presence of dissolved organic matter (DOM; 3.7 ppm) the efficiency of the GAC filter to remove atrazine decreased significantly (68-52% removal), whereas the corresponding efficiency of the PVP-co-S90%-mont. filter was only slightly influenced by DOM. At lower atrazine concentration (7 ppb) the PVP-co-S90%-mont. filter reduced even after 3000 pore volumes the emerging atrazine concentration below 3 ppb (USEPA standard). In the case of the GAC filter the emerging atrazine concentration was between 2.4 and 5.3 microg/L even for the first 100 pore volumes. Thus, the PVP-co-S90%-mont. composite is a new efficient material for the removal of atrazine from water.
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http://dx.doi.org/10.1016/j.watres.2008.10.050 | DOI Listing |
Int J Biol Macromol
January 2025
Department of Physical Sciences, Chemistry Division, College of Science, Jazan University, P.O. Box. 114, Jazan 45142, Kingdom of Saudi Arabia. Electronic address:
In this work, graphitic carbon nitride (g-CN) prepared by thermal treatment, graphitic carbon nitride/chitosan (GCS), and graphitic carbon nitride/chitosan embedded thiosemicarbazide (TGCS) were developed as an effective solid adsorbent. The fabricated adsorbents were characterized by nitrogen adsorption, ATR-FTIR, TGA, XRD, ζ potential, SEM, and TEM, where TGCS composite had a higher surface area (536.79 m/g), total pore volume (0.
View Article and Find Full Text PDFPLoS One
January 2025
Grupo de Investigación Materiales con Impacto (Mat&mpac) Universidad de Medellín, Medellín, Colombia.
In this study, we utilized drinking water treatment sludge (WTS) to produce adsorbents through the drying and calcination process. These adsorbents were then evaluated for their ability to remove azithromycin (AZT) from aqueous solutions. The L-500 adsorbent, derived from the calcination (at 500°C) of WTS generated under conditions of low turbidity in the drinking water treatment plant, presented an increase in the specific surface area from 70.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Institute of Inorganic Chemistry (IAC), Karlsruhe Institute of Technology (KIT) Engesserstraße 15 D-76131 Karlsruhe Germany
Pt-CeO nanosponges (1 wt% Pt) with high surface area (113 m g), high pore volume (0.08 cm g) and small-sized Pt nanoparticles (1.8 ± 0.
View Article and Find Full Text PDFAWWA Water Sci
March 2024
Department of Civil, Construction, and Environmental Engineering, North, Carolina State University, Raleigh, North, Carolina, USA.
Per- and polyfluoroalkyl substances (PFAS) occur widely in drinking water, and consumption of contaminated drinking water is an important human exposure route. Granular activated carbon (GAC) adsorption can effectively remove PFAS from water. To support the design of GAC treatment systems, a rapid bench-scale testing procedure and scale-up approach are needed to assess the effects of GAC type, background water matrix, and empty bed contact time (EBCT) on GAC use rates.
View Article and Find Full Text PDFPharm Res
January 2025
Synthetic Molecule Pharmaceutical Sciences, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, USA.
Purpose: The purpose of this study is to present a correlative microscopy-tomography approach in conjunction with machine learning-based image segmentation techniques, with the goal of enabling quantitative structural and compositional elucidation of real-world pharmaceutical tablets.
Methods: Specifically, the approach involves three sequential steps: 1) user-oriented tablet constituent identification and characterization using correlative mosaic field-of-view SEM and energy dispersive X-ray spectroscopy techniques, 2) phase contrast synchrotron X-ray micro-computed tomography (SyncCT) characterization of a large, representative volume of the tablet, and 3) constituent segmentation and quantification of the imaging data through user-guided, iterative supervised machine learning and deep learning.
Results: This approach was implemented on a real-world tablet containing 15% API and multiple common excipients.
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