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A magnetic nitrogen-doped sludge-based biochar (NAlSB-Fe-Si) was prepared based on waterworks sludge for raw material and dicyandiamide for nitrogen source to adsorb methylene blue (MB) from water. And the magnetic particles loaded on the adsorbent were obtained through functionalizing iron and silicon ions which were extracted from the biochar by acid and alkali impregnation. Physicochemical properties of sludge-based biochar (SB) were analyzed by SEM, BET, FTIR, XRD, XPS and VSM. Compared with the original biochar, NAlSB-Fe-Si had richer pore structure and higher pore volume, and the SiO and FeO loading made the specific surface area increased by 200%. Possible adsorption mechanism was proposed by exploring the initial pH, MB concentration and reaction time. Results revealed that alkaline environment was more conducive to the rapid removal of cationic dyes such as MB. Pseudo-second-order kinetic model and intra-particle diffusion model could describe the adsorption behavior of MB on NAlSB-Fe-Si. The fitting results of Langmuir model showed that adsorption temperature is positively correlated with adsorption capacity, and the maximum adsorption capacity of MB on nitrogen-doped sludge-based biochar (NSB) and NAlSB-Fe-Si at 25 °C was 26.47 and 300.36 mg/g, respectively. Finally, the MB removal rate of NAlSB-Fe-Si could still reach 70% after four cycles, indicating that the composite was an efficient cationic dye adsorbent, and its preparation could be regarded as a way of resource utilization of waterworks sludge.
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http://dx.doi.org/10.1016/j.jenvman.2021.114297 | DOI Listing |
Sci Rep
August 2025
Advanced Materials/Solar Energy and Environmental Sustainability (AMSEES) Laboratory, Faculty of Engineering, Menoufia University, Shebin El-Kom, Egypt.
One of the guiding sustainability principles is centered on mitigating the waste streams through the industrial ecology manner. On this regard, this research examines the conversion of dewatered alum sludge (AS) waste derived from water-works plants to be and innovative, magnetic and inexpensive nanoadsorbent. Alum sludge (AS) is calcined at 400 °C and mixed with zinc ferrite (F-Zn) that is prepared by simple co-precipitation route and signified with its high chemical stability, harmfulness as well as good magnetic properties that makes them a candidate as reusable adsorbent.
View Article and Find Full Text PDFEnviron Monit Assess
July 2025
College of Resources and Environment, Chengdu University of Information Technology, No.24 Block 1, Xuefu Road, Chengdu, 610225, China.
Water supplies have come under serious environmental stress in suburban communities in China due to developmental activities. A comprehensive study was carried out to investigate the occurrence of pharmaceutical compounds in county-level drinking water sources within Chengdu City. The solid-phase extraction combined with ultra-high performance liquid chromatography/tandem mass spectrometry was employed to analyze the residues of pharmaceuticals in the water sources for water supply in Chengdu.
View Article and Find Full Text PDFJ Environ Manage
August 2025
GeoBioTec, Civil Engineering and Architecture Department, University Beira Interior, Calçada Fonte do Lameiro 6, 6200-358, Covilhã, Portugal.
Clays and geosynthetics are the main materials for hydraulic barriers due to low conductivity for environmental protection. However, high costs and lack of disponibility generate the need for alternatives. Therefore, linked to immediate action regarding reducing the amount of waste generated and developing strategies for preventing contamination, industrial waste has emerged as alternative liner materials.
View Article and Find Full Text PDFVirusdisease
September 2024
Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunin-Cho, Shinjuku-Ku, Tokyo, 169-0073 Japan.
RSC Adv
September 2024
School of Environmental Science and Engineering, Tianjin University Tianjin 300350 China
Heavy metals have been considered an evolving environmental concern due to their harmful and long-lasting impacts. We synthesized a composite of FeS/CS@MIBWS for aqueous Cr(vi) adsorption and reduction utilizing the iron-based waterworks sludge modified by chitosan and FeS. After determining the optimal conditions for the FeS/CS@MIBWS preparation, its Cr(vi) removal capability was evaluated using material characterisation and static Cr(vi) adsorption assays.
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