TITLE:
Effect of Alkali Treatment on Heavy Metals Adsorption Capacity of Sewage Sludge
AUTHORS:
Jianlong Hu, Xiaosong Yang, Linan Shao, Xuwen He, Kunkuo Men
KEYWORDS:
Sewage Sludge, Alkali Treatment, Heavy Metals, Adsorption
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.3 No.2,
April
1,
2015
ABSTRACT: Sewage sludge is the promising
raw material for biosorbent preparation. In this work, we evaluated the heavy
metals adsorption characteristics of alkali treated sewage sludge (ATSS) by equilibrium
studies. The adsorption isotherms were fitted with Langmuir and Freundlich
models. Comparing with untreated sewage sludge, the total adsorption capacity (qm)
of ATSS (prepared with 0.125 mol/L NaOH) for Cd, Pb, Ni, increased by 0.51,
0.70 and 0.32 mmol/g, respectively. When the NaOH concentration for ATSS
preparation increased from 0.125 mol/L to 0.25 mol/L, the qm of ATSS for Pb decreased
from 1.05 mmol/g to 0.84 mmol/g. However, when the NaOH concentration increased
from 0.25 mol/L to 7.5 mol/L, it showed increasing trend. According to the IR
spectra data, the adsorption effect of biosorbent for heavy metals was mainly
due to the complexation of -N-H groups and -COOH groups.