title: Removal of Cr3+ from aqueous solution by biosorption with aerobic granules.
abstract: Aerobic granules were utilized as an effective biosorbent to remove Cr(3+) from aqueous solution. The results showed that the initial pH, contact time, and Cr(3+) concentration affected the biosorption process significantly. Both Freundlich and Langmuir isotherms were able to describe the equilibrium data reasonably with high correlation coefficients (R(2)>0.95) and pseudo-second-order model best fitted the biosorption process at experimental conditions. Moreover, Environmental Scanning Electronic microscope (ESEM), X-ray energy dispersion (EDX), and Fourier transform infrared (FTIR) analyses revealed that metal complexation, chemical precipitation, and ion exchange were involved in the removal of Cr(3+) with aerobic granules. Further analysis by a metal ion fraction test demonstrated that metal complexation could be the dominant mechanism of biosorption, whereas chemical precipitation and ion exchange appeared only to have minor role in the overall Cr(3+) biosorption process.
authors.affiliation: Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yao
authors.forename: Zheng-fang
authors.initials: ZF
authors.lastname: Ye
authors.forename: Mei-ping
authors.initials: MP
authors.lastname: Tong
authors.forename: Peng
authors.initials: P
authors.lastname: Lai
authors.forename: Jin-ren
authors.initials: JR
authors.lastname: Ni
mesh_terms: D000327:Adsorption; D001420:Bacteria, Aerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D011232:Chemical Precipitation; D002857:Chromium / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D002857:Chromium