Pilot-scale anaerobic digestion of screenings from wastewater treatment plants.

The anaerobic digestion of screenings from a municipal wastewater treatment plant was studied in a 90 L pilot-scale digester operated at 35 degrees C under semi-continuous conditions. In the first 4 weeks, a dry solids residence time of 28 days was applied, but the installation of inhibitory conditions was observed. Feeding was therefore suspended for 4 weeks to allow the digester to recover from inhibition, and then progressively increased up to a constant load of 6 kg of raw waste per week, corresponding to an average residence time of about 35 days of dry solids.

Characterization of screenings from three municipal wastewater treatment plants in the Region Rhône-Alpes.

The objective of this study was to analyze the composition of the screenings sampled from three municipal wastewater treatment plants (wwtp) located in the Region Rhône-Alpes, France. The plants were equipped with multi screening stages with gap sizes ranging from 60 to 3 mm. Waste production flows from each plant were monitored over at least 48 hours in each sampling campaign in order to calculate average production rates.