Application of sludge-based carbonaceous materials in a hybrid water treatment process based on adsorption and catalytic wet air oxidation.
This paper describes a preliminary evaluation of the performance of carbonaceous materials prepared from sewage sludges (SBCMs) in a hybrid water treatment process based on adsorption and catalytic wet air oxidation; phenol was used as the model pollutant. Three different sewage sludges were treated by either carbonisation or steam activation, and the physico-chemical properties of the resultant carbonaceous materials (e.g. hardness, BET surface area, ash and elemental content, surface chemistry) were evaluated and compared with a commercial reference activated carbon (PICA F22). The adsorption capacity for phenol of the SBCMs was greater than suggested by their BET surface area, but less than F22; a steam activated, dewatered raw sludge (SA_DRAW) had the greatest adsorption capacity of the SBCMs in the investigated range of concentrations (<0.05 mol L(-1)). In batch oxidation tests, the SBCMs demonstrated catalytic behaviour arising from their substrate adsorptivity and metal content. Recycling of SA_DRAW in successive oxidations led to significant structural attrition and a hardened SA_DRAW was evaluated, but found to be unsatisfactory during the oxidation step. In a combined adsorption-oxidation sequence, both the PICA carbon and a selected SBCM showed deterioration in phenol adsorption after oxidative regeneration, but a steady state performance was reached after 2 or 3 cycles.
Julcour Lebigue
Carine
C
Université de Toulouse, Laboratoire de Génie Chimique, UMR CNRS 5503, 4, allée Emile Monso, BP 84234, 31432 Toulouse Cedex 4, France. carine.julcour@ensiacet.fr
Andriantsiferana
Caroline
C
N'Guessan Krou
Ayral
Catherine
C
Mohamed
Elham
E
Wilhelm
Anne-Marie
AM
Delmas
Henri
H
Le Coq
Laurence
L
Gerente
Claire
C
Smith
Karl M
KM
Pullket
Suangusa
S
Fowler
Geoffrey D
GD
Graham
Nigel J D
NJ
D000327:Adsorption; D002384:Catalysis; D010084:Oxidation-Reduction; D019800:Phenol / Q000302:isolation & purification*; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D012722:Sewage; D014874:Water Pollutants, Chemical; D019800:Phenol