Affiliations: School of Municipal and Environmental Engineering,
Harbin Institute of Technology, Harbin 150090, China | School of Biological and Environmental Engineering,
Jiangsu University, Zhenjiang 212013, China
Abstract: Sewage sludge was used to develop an effective carbon adsorbent.
This adsorbent was employed for the removal of azo dye such as Direct Dark
Brown M and Acid Mordant Brown RH. The adsorption of dyes on this adsorbent was
studied as a function of contact time, concentration, pH and temperature by
batch method. The equilibrium adsorption capacity of a carbonaceous adsorbent
prepared from city wastewater treatment plant was 502, and 329.7 mg/g of Direct
Dark Brown M and Acid Mordant Brown RH, respectively. The experimental data
were analyzed by the Langmuir and Freundlich models of adsorption. Equilibrium
data fitted well with the Langmuir model. The rates of adsorption were found to
conform to the Lagergren second-order kinetics with good correlation. The
equilibrium adsorption capacity of the carbonaceous adsorbents was determined
with the Langmuir equation as well as the Lagergren second-order rate equation.
The most ideal pH for adsorption of two dyes onto adsorbents was found to be 3
and below. The results indicate that the carbonaceous adsorbents could be
employed as a low cost adsorbent in the removal of dyes from wastewater.