title: Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars.
abstract: Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.|Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
authors.forename: Qiming
authors.initials: Q
authors.lastname: Xian
authors.affiliation: Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Shen
authors.affiliation: Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Institute of Ecological and Environmental Sciences, Sichuan Agricultural University, Chengdu, China.
authors.forename: Yanzong
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D000818:Animals; D018533:Biomass; D002244:Carbon; D002606:Charcoal / Q000737:chemistry; D003224:Congo Red / Q000302:isolation & purification*; D004785:Environmental Pollutants / Q000302:isolation & purification; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000302:isolation & purification*; D009835:Oligochaeta; D012987:Soil / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water
chemical_list: D004785:Environmental Pollutants; D012987:Soil; D012996:Solutions; C540010:biochar; D014867:Water; D002606:Charcoal; D003224:Congo Red; D002244:Carbon; D008751:Methylene Blue