title: Biodegradation of total petroleum hydrocarbons from acidic sludge produced by re-refinery industries of waste oil using in-vessel composting.
abstract: BACKGROUND
  In Iran, re-refinery industry has been developed many years ago based on the acid-clay treatment. Acidic sludge with high concentration of total petroleum hydrocarbon (TPH) is the final products of some facilities. In this study removal of TPH by aerated in-vessel composting was investigated.
  
  
  METHODS
  In order to microorganisms seeding and nutrient providing, urban immature compost was added as an amendment to acidic sludge. The ratios of acidic sludge (AS) to compost were, 1:0 (as control), 1:5, 1:8, 1:10, 1:15, 1:20, 1:30, 1:40, 1:50, 1:75 and 1:100 (as dry basis) at a C: N: P ratio of 100:5:1 and 45-65% moisture content for 70 days.
  
  
  RESULTS
  The removal efficiency in all reactors was more than 48%. The highest and lowest TPH removal was observed in 1:5 (71.56%) and 1:100 (48.53%) mixing ratios, respectively. The results of the control reactors showed that biological treatment was the main mechanism for TPH removal. Experimental data was fitted second order kinetic model (R2> 0.8006). Degradation of TPH in 1:5 mixing ratio (k2= 0.0038 gmg-1d-1; half-life = 3.08d) was nearly three times faster than 1:100 mixing ratio (k2= 0.0238; half-life = 8.96d). The results of the control reactors showed that biological treatment was the main mechanism for TPH removal.
  
  
  CONCLUSIONS
  The results of this study revealed in-vessel composting with immature urban compost as the amendment maybe recommended as an effective method for TPH remediation.
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Asgari
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
authors.forename: Ramin
authors.initials: R
authors.lastname: Nabizadeh
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.|Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Mahvi
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.|Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
authors.forename: Simin
authors.initials: S
authors.lastname: Nasseri
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
authors.forename: Mohammad Hadi
authors.initials: MH
authors.lastname: Dehghani
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Nazmara
authors.affiliation: Center for Solid Waste Research (CSWR), Institute for Environmental Research (IER), Tehran University of Medical Sciences (TUMS), Tehran, Iran.|Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kamyar
authors.initials: K
authors.lastname: Yaghmaeian
keywords: Acidic sludge; Aerated in-vessel composting; Biodegradation; Kinetic model; Re-refinery industry; Total petroleum hydrocarbons