Nitrate pollution of water emerging from various anthropogenic activities has become a major environmental concern because of its deleterious effects on natural water resources. The present work deals with the synthesis of the ternary nanocomposite based on chitosan, iron oxide (FeO), and titanium dioxide (TiO) and its application for the removal of nitrates from model-contaminated water. FeO derived through a coprecipitation method was incorporated into the chitosan matrix which was fabricated in the form of beads. The wet gel beads were then successfully coated with sol-gel-derived silver-doped titanium dioxide sol followed by drying under suitable conditions to get the functional nanocomposite beads. The synthesized functional materials were further characterized for their structural, morphological, and textural features using X-ray diffraction analysis, physical property measurement (PPMS), Fourier transform infrared (FTIR) analysis, UV visible spectroscopy analysis (UV-vis), BET surface area analysis (BET), field emission scanning electron microscopic (FESEM), and transmission electron microscopy (TEM) analysis. The ternary nanocomposites were further used for the removal of nitrates via adsorption cum photocatalytic reduction technique from the model contaminated water when subjected to an adsorption study under dark conditions and photocatalytic study under UV/visible/sunlight for a definite time. FeO in the nanocomposite provides enhanced adsorption features whereas the functional coating of titanium dioxide aids in the removal of nitrates through the photocatalytic reduction technique. The functional beads containing 3% FeO in the wet gel form (CTA-F3) have excellent nitrate removal efficiency of ~ 97% via adsorption cum solar photocatalysis towards the removal of nitrate ions from 50 ppm nitrate solution, whereas the dried nanocomposite beads have got a nitrate removal efficiency of ~ 68% in 1 h from 100 ppm nitrate solution. Continuous flow adsorption cum photocatalytic study was performed further using the oven-dried functional beads in which flow rate and bed height were varied while maintaining the concentration of feed solution as constant. A nitrate removal efficiency of 65% and an adsorption capacity of 4.1 mgg were obtained for the CTA-F3 beads in the continuous flow adsorption cum photocatalysis experiment for up to 5 h when using an inlet concentration of 100 ppm, bed height 12 cm, and flow rate 5.0 ml min. A representative fixed-bed column adsorption experiment conducted using CTA-F3 beads for the treatment of a real groundwater sample shows reasonable results for nitrate removal (71.7% efficiency) along with a significant removal rate for the other anions as well. Thus, the novel adsorbent/photocatalyst developed is suitable for the removal of nitrates from water due to the synergistic effect between FeO, chitosan, and titanium dioxide.
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http://dx.doi.org/10.1007/s11356-024-34553-7 | DOI Listing |
Bioresour Technol
December 2024
Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China; Engineering Research Centre of Chemical Pollution Control, Ministry of Education, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China. Electronic address:
Anammox coupled partial S-driven autotrophic denitrification (PSAD) technology represents an innovative approach for removing nitrogen from wastewater. The research highlighted the crucial role of biofilm on sulfur particles in the nitrogen removal process. Further analysis revealed that sulfur-oxidizing bacteria (SOB) are primarily distributed in the inner layer of the biofilm, while anammox bacteria (AnAOB) are relatively evenly distributed in inner and outer layers, with Thiobacillus and Candidatus Brocadia being the dominant species, respectively.
View Article and Find Full Text PDFWater Res
December 2024
Department of Sanitation and Environmental Engineering, School of Engineering, Federal University of Minas Gerais, Avenue Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, Brazil. Electronic address:
Arsenic (As) enrichment in groundwater stems from natural and hydrogeochemical factors, leading to geological contamination. Groundwater and surface water are interconnected, allowing As migration and surface water contamination. The As contamination poses health risks through contaminated water consumption.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
School of Environment and Ecology, Jiangnan University, Wuxi, 214122, China.
Invasive alien plants pose a great threat to local plants and ecosystems. How to effectively alleviate this hazard is an unresolved issue. This study explored the carbon release characteristics of an invasive plant Spartina alterniflora and evaluated the ability of nitrogen removal from shrimp culture wastewater through constructing seawater wetland.
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December 2024
Gerald May Department of Civil, Construction, and Environmental Engineering, The University of New Mexico, Albuquerque, New Mexico, 87131, United States. Electronic address:
Enhanced biological phosphorus removal (EBPR) water resource recovery facilities (WRRFs) often fail to meet phosphorus discharge permit limits, indicating a need to improve EBPR to reduce environmental phosphorus discharges. EBPR designs are largely based on the Accumulibacter polyphosphate accumulating organism (PAO) metabolism, while understudied Tetrasphaera PAOs are equally important to EBPR in many facilities worldwide. Anaerobic organic carbon competition is believed to be a key driver of EBPR reliability.
View Article and Find Full Text PDFBioelectrochemistry
December 2024
School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353 Shandong, PR China; State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, Shandong, PR China. Electronic address:
Sediment microbial fuel cell (SMFC) is a device for biological denitrification, in which electrons produced by sediment microorganisms can be transferred to the upper layer of the water column lacking electron donors. However, the low efficiency of denitrifying bacteria in acquiring electrons and enriching at the cathode greatly hinders the application of SMFC for nitrogen removal. In this study, we report a novel method of constructing a high-performance biocathode by modifying electrodes with zero-valent iron to enhance the enrichment and electron transfer of electroactive bacteria.
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