title: Properties of biochars from conventional and alternative feedstocks and their suitability for metal immobilization in industrial soil.
abstract: In contaminated soils, excessive concentrations of metals and their high mobility pose a serious environmental risk. A suitable soil amendment can minimize the negative effect of metals in soil. This study investigated the effect of different biochars on metal (Cu, Pb, Zn) immobilization in industrial soil. Biochars produced at 300 and 600 °C from conventional (MS, maize silage; WP, wooden pellets) and alternative (SC, sewage sludge compost; DR, digestate residue) feedstocks were used as soil amendments at a dosage of 10 % (w/w). The type of feedstock and pyrolysis temperature affected the properties of the biochars and their ability to immobilize metal in soil. Compared to production at 300 °C, all biochars produced at 600 °C had higher pH (6.2-10.7), content of ash (7.2-69.0 %) and fixed carbon (21.1-56.7 %), but lower content of volatile matter (9.7-37.2 %). All biochars except DR biochar had lower dissolved organic carbon (DOC) content (1.4-2.3 g C/L) when made at 600 °C. Only MS and SC biochars had higher cation exchange capacity (25.2 and 44.7 cmol/kg, respectively) after charring at 600 °C. All biochars contained low concentrations of Cd, Cu, Ni, Pb and Zn; Cd was volatilized to the greatest extent during pyrolysis. Based on FTIR analysis and molar ratios of H/C and O/C, biochars had a greater degree of carbonization and aromaticity after charring at 600 °C. The efficiency of the biochars in metal immobilization depended mainly on their pH, ash content, and concentration of DOC. SC and DR biochars were more effective for Cu and Zn immobilization than MS and WP biochars, which makes them attractive options for large-scale soil amendment.
authors: Faculty of Environmental Sciences, Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Sloneczna St. 45G, 10-719, Olsztyn, Poland. mariusz.gusiatin@uwm.edu.pl.
authors: Zygmunt Mariusz
authors: ZM
authors: Gusiatin
authors: Faculty of Environmental Sciences, Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Sloneczna St. 45G, 10-719, Olsztyn, Poland.
authors: Radosław
authors: R
authors: Kurkowski
authors: Faculty of Mathematics and Computer Science, Department of Relativistic Physics, University of Warmia and Mazury in Olsztyn, Sloneczna St. 54, 10-710, Olsztyn, Poland.
authors: Szczepan
authors: S
authors: Brym
authors: Faculty of Technical Sciences, Department of Electric and Power Engineering, University of Warmia and Mazury in Olsztyn, Oczapowskiego St. 11, 10-736, Olsztyn, Poland.
authors: Dariusz
authors: D
authors: Wiśniewski
mesh_terms: D002606:Charcoal / Q000737:chemistry*; D007221:Industry; D019216:Metals, Heavy / Q000032:analysis*; D012722:Sewage / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013696:Temperature
chemical_list: D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal
keywords: Compost; Digestate; FTIR; Maize; Metal mobility; Pellets; Pyrolysis