Removal of congo red from wastewater by adsorption onto waste red mud

Chemosphere, Vol. 34. No. 2, pp. 401417, 1997

Copyright 0 1997 Elsevier Science Ltd

Printed in Great Britain. All rights reserved

PII: SOO45-6535(96)00385-Z 0045.6535/97 $17.00+0.00

REMOVAL OF CONGO RED FROM WASTEWATER BY ADSORPTION

ONTO WASTE RED MUD

C. NAMASIVAYAM* and D. J. S. E. ARASI

Environmental Chemistry Division

Department of Environmental Sciences

Bharathiar University

Coimbatore - 641 046

Tamil Nadu - INDIA.

(Received in USA 23 June 1996; accepted 23 August 1996)

ABSTRACT

Waste red mud, an industrial byproduct,

generated during the processing of bauxite ore, is recycled

for the adsorption of congo red from aqueous solution.

Adsorption kinetics were studied using the parameters such

as dye concentration, adsorbent dose, agitation time and pH.

Adsorption followed first rate expression. The equilibrium

adsorption data obeyed both Langmuir and Freundlich

isotherms. The adsorption capacity of the red mud for the

dye was 4.05 mg/g. Adsorption was found to be nearly

quantitative at pH 2.0. Effect of pH and desorption studies

suggest that the mechanism of adsorption is mostly ion

exchange.0 1997 Elsevier Science Ltd. All rights reserved

Key words : Waste red mud, congo red, adsorption isotherms

pH effect.

* Author to whom correspondence should be addressed.

E-mail: sandflas250.bharathi.ernet.in

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