Symbiotic algal bacterial wastewater treatment

Interesting study of use of Alage in Wastewater Treatment.
http://www.iwaponline.com/wst/05511/wst055110165.htm
Water Science & Technology Vol 55 No 11 pp 165–171 © IWA Publishing 2007 doi:10.2166/wst.2007.351

Symbiotic algal bacterial wastewater treatment: effect of food to microorganism ratio and hydraulic retention time on the process performance
M. Medina and U. NeisInstitute of Wastewater Management and Water Protection, University of Technology Hamburg Harburg, FSP 1-02, D-21071 , Hamburg, Germany (E-mail: marcela.medina@tuhh.de)
ABSTRACT
Algal incorporation into the biomass is important in an innovative wastewater treatment that exploits the symbiosis between bacterial activated sludge and microalgae (Chlorella vulgaris sp. Hamburg). It allows a good and easy algae separation by means of clarification. The effect of process parameters food to microorganisms ratio (F/M) and hydraulic retention time (HRT) on the process performance, evaluated by settleability, microalgae incorporation to biomass and nutrient removal, was studied. HRT hinted at a significant influence in the growth rate of algae, while F/M turned out to be important for stability when algae are incorporated into the biomass. This parameter also affects the total nitrogen removal of the treatment. Stable flocs with incorporated algae and supernatants with low free swimming algae concentrations were obtained at high HRT and low F/M values.
Keywords: Chlorella vulgaris; F/M (food to microorganism) ratio; hydraulic retention time; symbiotic algal bacterial wastewater treatment; symbiotic biomass