|چکیده انگلیسی||Bioremediation of storage tank bottom sludge by using a two-stage composting system: Effect of mixing ratio and nutrients addition.
Koolivand A1, Rajaei MS2, Ghanadzadeh MJ2, Saeedi R3, Abtahi H4, Godini K5.
Department of Environmental Health Engineering, Faculty of Health, Arak University of Medical Sciences, Arak, Iran. Electronic address: email@example.com.
Department of Environmental Health Engineering, Faculty of Health, Arak University of Medical Sciences, Arak, Iran.
Department of Health Sciences, School of Health, Safety and Environment, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, Iran.
Department of Environmental Health Engineering, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
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-1 and 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.
Bioremediation; C/N/P ratio; Petroleum hydrocarbons; Storage tank bottom sludge; Two-stage composting|