The pyrolysis of excess sludge derived from wastewater treatment plants to prepare biochar can achieve the mass-reduction and harmlessness of solid waste, but it is also necessary to further explore the application prospect of these biochars as a resource for wastewater treatment. In this study, Fe-modified biochar (BC-Fe) was prepared by pyrolysis of excess sludge modified by FeCl solution. The molecular structure, elemental valence state, and composition of biochars were comprehensively investigated. The results showed that, compared with the biochar prepared from sludge without modification (BC-blank), the O/C ratio of BC-Fe increased from 0.07 to 0.12, and the (N + O)/C ratio increased from 0.21 to 0.27, indicating increased polarity and weakened aromaticity. The ratio of integrated intensity of the D band and G band in the Raman spectrum increased from 1.34 to 2.40, showing the increased defect structure of the biochar obtained by Fe modification. In the reaction between BC-Fe and dicamba, the removal rate of dicamba reached 92.1% within 180 min, which was far higher than the 17.8% of BC-blank. It was confirmed the adsorption removal dominated and accounted for 70.6% of the dicamba removal by BC-Fe, and the adsorption capacity of biochar could be significantly enhanced by Fe-modification by 5.3 times. Moreover, the persistent free radicals (PFRs) on the surface of biochar was detected by an electron paramagnetic resonance analyzer, and the decline of PFRs signals after the reaction revealed that PFRs participated in the degradation process of dicamba. Through Q-TOF analysis, it could be concluded that dicamba was first converted to 3,6-dichlorosalicylic acid (DCSA) by PFRs reduction and then further transformed to 3,6-dichlorogentisic acid (DCGA). This study provided a reference for the understanding of the removal mechanism of dicamba by Fe-modified biochar and offered an application potential of biochar derived from Fe-containing sludge for the pollution control of dicamba pesticide pollutants.
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http://dx.doi.org/10.1016/j.jenvman.2021.113602 | DOI Listing |
Chem Commun (Camb)
January 2025
Department of Chemistry, Memorial University of Newfoundland, St. John's Newfoundland and Labrador, A1B 3X7, Canada.
The challenge with synthetically modified biochars is that they are notoriously difficult to characterize, and a new characterization approach that circumvents the challenges posed by overlapping bands in IR spectra is needed. We report multinuclear NMR approaches successful in the easy identification and quantification of covalently-bound functional groups on the biochar surface using P{H} CPMAS NMR spectroscopy.
View Article and Find Full Text PDFBioresour Technol
January 2025
College of Resources and Environment, Northeast Agricultural University, Harbin 150030 Heilongjiang, China. Electronic address:
Enhancing the passivation of heavy metals and increasing organic matter content during the composting of sewage sludge poses significant challenges for maximizing its utilization value. Results indicated that in the control, biochar, microbial agents and microbial agents-loaded biochar (BCLMA) groups, BCLMA addition led to a higher composting temperature, with increases of 17-62% in humic acid, 25-73% in germination index, and 30-35% in organic matter consumption. And the residual fraction of Cu, Zn, Cr and Cd were increased by 30%, 12%, 22%, and 17%, respectively.
View Article and Find Full Text PDFBioresour Technol
January 2025
Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, 229 Taibai North Road, Xi'an, Shaanxi 710069, China. Electronic address:
Enhanced microbial remediation represents a promising technique for the removal of polycyclic aromatic hydrocarbons (PAHs). However, high-efficiency remediation agents remain limited, including microbial resources and remediation materials. In this study, a novel strain of Pseudomonas xizangensis S4 was isolated from plateau lake sediment, exhibiting a fluoranthene degradation rate of 41.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, PR China. Electronic address:
Hydroxyl radical (OH) plays a critical role in accelerating organic contaminant attenuation during water-table decline in paddy soil, but the impacts of widely applied agricultural amendments (e.g., organic manure, rice straw, and biochar) on these processes have been rarely explored.
View Article and Find Full Text PDFHeliyon
January 2025
Transmission Electronic Microscopy Laboratory, Electronic Microscopy Unit, Department of Biology, University of Cauca, Popayán, 190002, Colombia.
A green methodology for the synthesis of carbon quantum dots (CQDs) from coffee husk without the use of any toxic solvents is proposed in this work. Sonochemical exfoliation of biochar, obtained from the thermal carbonization of coffee husk (from a certified coffee seeds) at low temperature in an air-restricted atmosphere, is described as an alternative procedure for the sustainable production of CQDs. The synthesized CQDs exhibited blue fluorescence with a strong maximum emission band at 410 nm when excited at a maximum absorption wavelength of 330 nm.
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