Open AccessA comparative study between dried anaerobic digested sludge and dried activated sludge for the removal of 4-chlorophenol from aqueous solutions
Author(s) -
Vahid Reza Fanaie,
Mohsen Karrabi,
Mohammad Mehdi Amin,
Bahar Shahnavaz,
Ali Fatehizadeh
Publication year - 2016
Publication title -
international journal of environmental health engineering
Language(s) - English
Resource type - Journals
ISSN - 2277-9183
DOI - 10.4103/2277-9183.184220
Subject(s) - biosorption , chemistry , adsorption , aqueous solution , activated sludge , freundlich equation , anaerobic exercise , chromatography , wastewater , sewage treatment , nuclear chemistry , pulp and paper industry , environmental engineering , organic chemistry , environmental science , physiology , sorption , engineering , biology
Aims: In this study, the adsorption capacity of dried anaerobic digested sludge (DADS) and dried activated sludge (DAS) for the removal of 4-chlorophenol (4-CP) from aqueous solutions was evaluated. Materials and Methods: Both anaerobic digested sludge and activated sludge were collected from a south municipal wastewater treatment plant in Isfahan. Batch biosorption experiments were carried out to investigate the effects of solution pH, contact time, biosorbent dosage and initial concentration of 4-CP. The residual concentration of 4-CP was analyzed by colorimetry method. Isotherms and kinetic equations were applied to study kinetic and equilibrium of adsorption. Results: Results indicated that, DAS have higher removal potential in comparison with DADS. The optimum pH was detected to be 3 for DADS and 4 for DAS. By increasing contact time and biosorbent dosage, removal efficiency of 4-CP increased for both biosorbents. Furthermore, a decreasing trend was observed when initial concentrations were increased. The equilibrium time for DAS was 2.5 h and for DADS was 4 h. The maximum adsorption capacity were found 1.67 mg/g for DAS and 0.93 mg/g for DADS. The 4-CP removal equilibrium isotherm was modeled by Freundlich equation. Kinetic studies suggested that pseudo-first-order model for DADS and second order for DAS were the best choices to describe biosorption behavior.Conclusion: According to the present study, DAS, have better efficiency for the removal of 4-CP in comparisons with DADS