Structure Characterization and Adsorption Properties of Pyrolyzed Sewage Sludge

• Published in: Environmental science & technology Vol. 39; no. 11; pp. 4249 - 4257
• Main Authors: Rio, S, Faur-Brasquet, C, Le Coq, L, Le Cloirec, P
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.06.2005
• Subjects: Adsorbents; Adsorption; Applied sciences; Calcium - chemistry; Carbon - chemistry; Chemistry; Copper - chemistry; Copper - isolation & purification; Engineering Sciences; Exact sciences and technology; General and physical chemistry; Hydrogen-Ion Concentration; Incineration; Kinetics; Other industrial wastes. Sewage sludge; Pollution; Porous materials; Sewage - chemistry; Sewage - microbiology; Sewage disposal; Sludge; Surface chemistry; Surface physical chemistry; Temperature; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Wastes; Water Purification - instrumentation; Water Purification - methods; Water treatment plants; Pyrolysis; Carbonaceous materials; Heat treatment; Waste treatment; Reaction product; Adsorption capacity; Inorganic adsorbent; Fabrication property relation; Sewage sludge; Porous material; Surface structure; Carbonization; Pore size; Upgrading; Waste reuse; Fabrication structure relation; Surface area
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es0497532

Sewage sludges produced from wastewater treatment plants continue to set environmental problems in terms of volume and way of reuse. Thermal treatment of sewage sludge is considered as an attractive method in reducing sludge volume, and at the same time, it produces reusable byproducts. This paper deals with porous carbonaceous materials production from sewage sludge by pyrolysis (or carbonization) process with a goal of different industrial applications. Carbonization experiments were carried out on two kinds of sludge, namely viscous liquid sludge and limed sludge by varying carbonization temperature between 400 °C to 1000 °C. The porous structure and surface chemistry of the materials obtained were characterized using nitrogen adsorption, scanning electron microscopy, elemental analysis, Boehm titration, and pH of zero point of charge determination. The results show that basic character of the carbonized residues increases with increasing carbonization temperature. Then, carbonization allows specific surface area and pore volumes to be developed. Carbonized viscous liquid sludge and carbonized limed sludge are mainly mesoporous in nature, with specific surface areas reaching about 100 m2 g-1 and 60 m2 g-1, respectively. Finally, adsorption experiments, in aqueous solution, were carried out and show that carbonized viscous liquid sludges and limed sludge remove effectively the metallic ion Cu2+, acid and basic dyes, and phenol. Pyrolyzed sludges properties seem to be encouraging for the preparation of activated carbon by physical activation process.