title: Biodrying of pulp and paper secondary sludge: kinetics of volatile solids biodegradation.
abstract: This study focuses on the kinetics of volatile solids (VS) biodegradation of the biodrying process using pulp and paper secondary sludge. The experiments were carried out with air-flow rates of 0.51, 1.61, 3.25 and 5.26L/minkgVS) and initial moisture content of 64-66% w.b. Using five kinetic models and a nonlinear regression method, kinetic parameters were estimated and the models were analyzed with two statistical indicators. Higher air-flow rates cause greater moisture content reduction, lower temperature in the matrix, and lower VS reduction. At an air-flow rate as high as 5.26L/minkgVS there is no biodrying but only convective drying. The kinetic models used successfully simulate the VS biodegradation under biodrying conditions, with a root mean square error (RMSE) between 0.007929 and 0.02744. In conclusion, we show for the first time that VS biodegradation in the biodrying process can be successfully modeled with a kinetic model.
authors.affiliation: Departamento de Ingeniería Química, Universidad de Santiago de Chile, Casilla 442, Correo 2, Santiago, Chile. Electronic address: cesar.huilinir@usach.cl.
authors.forename: Cesar
authors.initials: C
authors.lastname: Huiliñir
authors.affiliation: Departamento de Ingeniería Química, Universidad de Santiago de Chile, Casilla 442, Correo 2, Santiago, Chile.
authors.forename: Manuel
authors.initials: M
authors.lastname: Villegas
mesh_terms: D000388:Air; D001673:Biodegradation, Environmental; D001709:Biotechnology / Q000379:methods*; D003890:Desiccation; D006813:Humidity; D007700:Kinetics; D008962:Models, Theoretical; D010209:Paper; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014835:Volatilization
chemical_list: D012722:Sewage
keywords: Biodegradation; Biodrying; Kinetics; Pulp and paper industry; Secondary sludge