title: Phosphorus and cadmium availability in soil fertilized with biosolids and ashes.
abstract: The recycling of hygienized municipal sewage sludge (biosolids) to soil as the source of phosphorus (P) is generally encouraged. The use of biosolids, however, has some concerns, such as the presence of elevated concentrations of potentially toxic trace elements, and the possible presence of pathogens, hormones and antibiotics. Organic substances are destroyed during combustion whereas trace elements could partly be separated from P in different ash fractions. Biomass combustion waste (ash) can instead be considered as an alternative P source. This study evaluates and compares the impact of biosolids and their combustion residues (ashes), when used as fertilizers, on P and Cd solubility in soil, plant growth and plant uptake of these elements. Biosolids were also amended with K and Ca to improve the composition and properties of P in ashes, and incinerated at either 800 °C or 950 °C. Combustion of biosolids improved the Cd/P ratio in ashes by 2-5 times, compared with the initial biosolids. The low Cd content in ashes (4-9 mg Cd (kg P)(-1)) makes this material a particularly attractive alternative to mineral fertilizers. Significantly higher pore water P (as well as total N) was measured in soils containing biosolids, but plants produced a higher biomass in soil fertilized with ashes. The K and Ca amendments prior to biosolids combustion generally decreased the total Cd in ash, but had little effect on P and Cd uptake and biomass growth. Similarly, the combustion temperature had negligible effect on these factors as well.
authors.affiliation: Waste Science and Technology, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden. Electronic address: jurate.kumpiene@ltu.se.
authors.forename: Jurate
authors.initials: J
authors.lastname: Kumpiene
authors.affiliation: Waste Science and Technology, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden. Electronic address: evelina.brannvall@ltu.se.
authors.forename: Evelina
authors.initials: E
authors.lastname: Brännvall
authors.affiliation: Waste Science and Technology, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-97187 Luleå, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Wolters
authors.affiliation: Energy Engineering, Department of Engineering Sciences & Mathematics, Luleå University of Technology, SE-97187 Luleå, Sweden. Electronic address: nils.skoglund@ltu.se.
authors.forename: Nils
authors.initials: N
authors.lastname: Skoglund
authors.affiliation: Department of Mathematical Modelling, Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania. Electronic address: stasys.cirba@vgtu.lt.
authors.forename: Stasys
authors.initials: S
authors.lastname: Čirba
authors.affiliation: Department of Geodesy and Cadastre, Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania. Electronic address: ceslovas.aksamitauskas@vgtu.lt.
authors.forename: Vladislovas Česlovas
authors.initials: VČ
authors.lastname: Aksamitauskas
mesh_terms: D018533:Biomass; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism; D005308:Fertilizers / Q000032:analysis; D017745:Incineration; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism; D063245:Plant Development; D010944:Plants / Q000378:metabolism; D012722:Sewage / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism
chemical_list: D005308:Fertilizers; D012722:Sewage; D012989:Soil Pollutants; D002104:Cadmium; D010758:Phosphorus
keywords: Combustion; Grass; Phytoavailability; Sewage sludge; Soil pore water