Aerobic granular treatment of 2,4-dichlorophenol

2,4-Dichlorophenol (2,4-DCP) fed aerobic granules were cultivated in a sequencing batch reactor (SBR). Stable and compact granules were obtained in 60 days of SBR operation. Formed granules were compact and strong with closed packed channels. After granulation, effluent chemical oxygen demand and 2,4-DCP concentrations were 95 and 2.5 mg L−1 with corresponding removal efficiencies of 96% and 95% were achieved. Degradation profile shows a high initial degradation rate which decreases later. Degradation rate was found to be directly proportional to the substrate concentration. Specific degradation rate of 2,4-DCP was 6.54 mg 2,4-DCP gVSS−1 h−1 at 60 mg L−1 and specific cell growth rate was 0.042 ± 0.02 day−1. High optical density (OD600) the system shows effective retention of biomass which is the main advantage of present technique. Des granules aerobies ont ete cultives avec succes pour la degradation du 2,4-DCP. Des granules stables et compacts ont ete obtenus apres 70 jours d'operations en reacteur a sequencement et par lots. Des efficiences de demande chimique finale en oxygene et d'elimination de 2,4-DCP s'elevant a 96% et 95% ont ete atteintes. Le profil de degradation montre que le taux de degradation etait initialement eleve mais qu'il ralentit plus tard. On a observe une bonne correspondance entre la demande chimique en oxygene et le profil d'elimination de 2,4-DCP. Le taux de degradation est directement proportionnel a la concentration de substrat. Le taux specifique de degradation de 2,4-DCP etait de 6.54 mg de 2,4-DCP gVSS−1 L−1 h−1 a 60 mg L−1 et le taux specifique de croissance cellulaire etait de 0.042 ± 0.02 day−1. Une haute densite optique du reacteur a sequencement et par lots montre une retention de la biomasse effective, ce qui est l'avantage principal de cette technique.