Pyrolysis of sludge to biochar can not only reduce the sludge volume, toxic organic compound, and pathogens, but also be applied as effective adsorbents. However, the immobilization of heavy metals in the sludge and the properties of the biochar greatly rely on the pyrolysis temperature. In this paper, municipal sludge biochar (SBC) was prepared from 400 to 1000 °C. Pyrolysis immobilized heavy metals in sludge and the potential ecological risk of heavy metals significantly decreased to low level at temperature above 500 °C. At 700 °C, the adsorption capacity of Cd(II) reached a maximum (120.24 mg·g). The Cd(II) adsorption fitted the Pseudo-second-order model, indicating the existence of chemical adsorption. The adsorption capacity increased along with the initial pH and slowed down after pH reached 5.5. The existence of coexisting cations (Ca and Na) and anions (SO and NO) displayed different degree of inhibitory action on Cd(II) adsorption. The SEM, XRD, FTIR, and XPS analysis of sludge biochar before and after adsorption revealed that there were CdCO, CdSO, CdSiO, Cd(PO), and Cd(PO) appearing on the surface of sludge biochar, suggesting that the adsorption of Cd(II) by SBC included co-precipitation, ion exchange, coordination with π electrons, and complexation. It was confirmed that different properties formed by pyrolysis temperature made a difference in adsorption mechanism of sludge biochar.
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http://dx.doi.org/10.1007/s11356-022-22827-x | DOI Listing |
Chemosphere
January 2025
Faculty of Agronomy and Veterinary Medicine, University of Brasília, 70910-970, Brasília, Federal District, Brazil.
Phosphorus (P) plays an essential role for plant growth, but conventional P sources used in agriculture are finite and non-renewable. As a result, there is a growing need to explore alternative P sources such as sewage sludge (SS) - a P-rich solid waste and valuable renewable resource that is often mismanaged globally. Pyrolysis is a promising technique for managing SS.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Chemical and Biochemical Engineering Department, University of Western Ontario, London, ON, N6A 5B9, Canada; Civil and Environmental Engineering Department, University of Western Ontario, London, ON, N6A 5B9, Canada. Electronic address:
The convergence of sustainability and climate change has catalyzed the pursuit of inventive strategies for waste management and sustainable energy production. Hereby, we explored the effect of coupling biochar addition and thermal pretreatment in anaerobic mono-digestion and co-digestion of thermally pretreated thickened waste activated sludge (PTWAS) with food waste (FW). Six semi-continuous lab-scale digesters were operated for 161 days at various organic loading rates (OLR of 2, 3, 4 and 8 kgCOD/m/day) with and without biochar (BC) addition.
View Article and Find Full Text PDFWater Res
December 2024
Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, PR China; Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun, 130118, PR China. Electronic address:
As freshwater demand grows globally, using reclaimed water in natural water bodies has become essential. Constructed wetlands (CWs) are widely used for advanced wastewater treatment due to their environmental benefits. However, low carbon/nitrogen (C/N) ratios in wastewater limit nitrogen removal, often leading to eutrophication.
View Article and Find Full Text PDFJ Soil Sci Plant Nutr
November 2024
Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea, Wales SA2 8PP UK.
Unlabelled: Continuous lighting (CL) has the potential to increase crop yield in greenhouse production. Tomato plants, however, when exposed to CL develop inter-vascular chlorosis, a leaf injury which causes a reduction in chlorophyll content and necrosis. The application of biochar can reduce physiological stress in plants, we examine if biochar also reduces necrosis in tomatoes when grown under CL.
View Article and Find Full Text PDFHuan Jing Ke Xue
January 2025
School of Environment and Natural Resources, Zhejiang University of Science and Technology, Hangzhou 310023, China.
Compared to the laboratory preparation of biochar, there is less research on the adsorption of antibiotics by industrial production of biochar in water. In this study, three types of industrial production biochar (peanut shell biochar, sludge biochar, and perishable waste biochar) were selected, and their adsorption performance for tetracycline in composite-polluted water was systematically studied. The results indicated that the Freundlich equation could well fit the adsorption isotherms of the three types of biochar for tetracycline.
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