title: Effect of Pine Waste and Pine Biochar on Nitrogen Mobility in Biosolids.
abstract: Humanity produces ∼27 kg of dry matter in biosolids per person per year. Land application of biosolids can improve crop production and remediate soils but may result in excessive nitrate N (NO-N) leaching. Carbonaceous materials can reduce the environmental impact of biosolids application. We aimed to ascertain and compare the potentials for Monterey pine ( D. Don)-sawdust-derived biochars and raw sawdust to reduce NO-N leaching from biosolids. We used batch sorption experiments 1:10 ratio of material to solution (100 mg kg of NH or NO) and column leaching experiments with columns containing biosolids (2.7% total N, 130 mg kg NH and 1350 mg kg NO) mixed with soil, biochar, or sawdust. One type of low-temperature (350°C) biochar sorbed 335 mg kg NH, while the other biochars and sawdust sorbed <200 mg kg NH. None of the materials sorbed NO. Biochar added at rates of 20 to 50% reduced NH-N (<1% of total N) leaching from columns by 40 to 80%. Nitrate leaching (<7% of total N) varied little with biochar form or rate but was reduced by sawdust. Incorporating dried sawdust with biosolids showed promise for mitigating NO-N leaching. This effect likely is due to sorption into the pores of the biochar combined with denitrification and immobilization of N rather than chemical sorption onto surfaces.
authors.forename: Dharini
authors.initials: D
authors.lastname: Paramashivam
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Clough
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Dickinson
authors.forename: Jacqui
authors.initials: J
authors.lastname: Horswell
authors.forename: Obed
authors.initials: O
authors.lastname: Lense
authors.forename: Lynne
authors.initials: L
authors.lastname: Clucas
authors.forename: Brett H
authors.initials: BH
authors.lastname: Robinson
mesh_terms: D002606:Charcoal; D009584:Nitrogen / Q000737:chemistry*; D028223:Pinus; D012987:Soil
chemical_list: D012987:Soil; C540010:biochar; D002606:Charcoal; D009584:Nitrogen