title: Bioremediation of storage tank bottom sludge by using a two-stage composting system: Effect of mixing ratio and nutrients addition.
abstract: The effect of mixing ratio and nutrients addition on the efficiency of a two-stage composting system in removal of total petroleum hydrocarbons (TPH) from storage tank bottom sludge (STBS) was investigated. The system consisted of ten windrow piles as primary composting (PC) followed by four in-vessel reactors as secondary composting (SC). Various initial C/N/P and mixing ratios of STBS to immature compost (IC) were examined in the PC and SC for 12 and 6weeks, respectively. The removal rates of TPH in the two-stage system (93.72-95.24%) were higher than those in the single-stage one. Depending on the experiments, TPH biodegradation fitted to the first- and second-order kinetics with the rate constants of 0.051-0.334d-1and 0.002-0.165gkg-1d-1, respectively. The bacteria identified were Pseudomonas sp., Bacillus sp., Klebsiella sp., Staphylococcus sp., and Proteus sp. The study verified that a two-stage composting system is effective in treating the STBS.
authors.affiliation: Department of Environmental Health Engineering, Faculty of Health, Arak University of Medical Sciences, Arak, Iran. Electronic address: alikoulivand@arakmu.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Koolivand
authors.affiliation: Department of Environmental Health Engineering, Faculty of Health, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Mohammad Sadegh
authors.initials: MS
authors.lastname: Rajaei
authors.affiliation: Department of Environmental Health Engineering, Faculty of Health, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Mohammad Javad
authors.initials: MJ
authors.lastname: Ghanadzadeh
authors.affiliation: Department of Health Sciences, School of Health, Safety and Environment, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Saeedi
authors.affiliation: Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Abtahi
authors.affiliation: Department of Environmental Health Engineering, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Godini
mesh_terms: D001673:Biodegradation, Environmental; D006838:Hydrocarbons / Q000378:metabolism; D010578:Petroleum / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D012987:Soil
chemical_list: D006838:Hydrocarbons; D010578:Petroleum; D012722:Sewage; D012987:Soil
keywords: Bioremediation; C/N/P ratio; Petroleum hydrocarbons; Storage tank bottom sludge; Two-stage composting