Proper strategies for reducing the sludge production are a key factor for a correct wastewater treatment plant (WWTP) management. This paper describes an experimental study on sludge thermal alkaline hydrolysis under mild conditions (temperatures from 40 to 70 °C and pH up to 11.5), aimed at sludge minimisation. Tested biological sludge derived from two different WWTPs that treat urban and mixed urban/industrial wastewater, respectively. The experimental results showed: 1) an increase of soluble COD in sludge supernatants; 2) very good biodegradability of the supernatants; 3) improved settleability and dewaterability of treated sludge. The best results were obtained under the following conditions, using lime milk: 70°C, pH 10.0–10.5, contact time 3h.
Treatment of waste activated sludge by means of alkaline hydrolysis under 'mild' conditions
COLLIVIGNARELLI, MARIA CRISTINA;SORDI, MARCO;ABBA', ALESSANDRO;CASTAGNOLA, FEDERICO;BERTANZA, GIORGIO
2017-01-01
Abstract
Proper strategies for reducing the sludge production are a key factor for a correct wastewater treatment plant (WWTP) management. This paper describes an experimental study on sludge thermal alkaline hydrolysis under mild conditions (temperatures from 40 to 70 °C and pH up to 11.5), aimed at sludge minimisation. Tested biological sludge derived from two different WWTPs that treat urban and mixed urban/industrial wastewater, respectively. The experimental results showed: 1) an increase of soluble COD in sludge supernatants; 2) very good biodegradability of the supernatants; 3) improved settleability and dewaterability of treated sludge. The best results were obtained under the following conditions, using lime milk: 70°C, pH 10.0–10.5, contact time 3h.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
