BIOFILM REACTORS - AN EXPERIMENTAL AND MODELING STUDY OF WASTE-WATER DENITRIFICATION IN FLUIDIZED-BED REACTORS OF ACTIVATED CARBON PARTICLES

• Type: Article in International Scientific Journal
• Date: 1992

Authors

COELHOSO, I (Author) Other; Rui Boaventura (Author) FEUP; Alírio Rodrigues (Author) FEUP

Journal

Title: Biotechnology and Bioengineering

Vol. 40

Pages: 625-633

ISSN: 0006-3592

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 40 Citations

Scopus - 47 Citations

Scientific classification

FOS: Engineering and technology

Other information

Authenticus ID: P-001-P8Q

DOI: 10.1002/bit.260400510

Abstract (EN): A fluidized-bed biofilm reactor using activated carbon particles of 1.69 mm diameter as the support for biomass growth and molasses as the carbon source is used for wastewater denitrification. The start-up of the reactor was successfully achieved in 1 week by using a liquor from garden soil leaching as the inoculum and a superficial velocity u0 = 5u(mf). Typical biofilm thickness is 800-mu-m; therefore covered activated carbon particles have 3.3 mm in diameter. Reactor hydrodynamics was studied by tracer (KCl solution) experiments. The analysis based on residence time distribution theory involved a model with axial dispersion flow and tracer diffusion with linear adsorption inside the biofilm. Peclet numbers higher than 100 were found, allowing the plug flow assumption for the reactor model. Experimental profiles of nitrate and nitrite species were explained by a kinetic model of two consecutive zero-order reactions coupled with substrate diffusion inside the biofilm. Under the operating conditions used thick biofilms were obtained working in a diffusion-controlled regime. Comparison is made with results obtained in the same reactor with sand particles as the support for biomass growth. Activated carbon as the support has the following advantages: good adsorptive characteristics, homogeneous biofilm thickness along the reactor, and easy restart-up of the reactor.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9