The production of a Ca-alginate/Pseudomonas fluorescens biocatalyst, for the removal of phenol, chlorophenol, dichlorophenol, and trichlorophenol from wastewaters was studied. Rheological characterization (before and after heat treatment) of the Na-alginate solution was carried out. The effect of some operational parameters of production including air pressure, alginate solution concentration, feed rate, and alginate/cells ratio, on the size and quality of the spheres wa!; evaluated. In addition, a study of the biocatalyst including the quantity of cells entrapped into the alginate spheres, the apparent and real catalyst densities, the humidity and the epsilon void fraction was carried out together with a kinetic characterization of the Ca-alginate spheres through a first order expression. Finally, an assessment of the catalyst in the biodegradation of phenol, mono, di-, and trichlorophenol at medium-high concentrations (1000, 500, 400 and 100 mg l(-1)) is presented and discussed.