Olive mill wastewater (OMW) is a liquid waste achieved from the extraction process of olive oil; this wastewater type is one of the main pollutant products in the Mediterranean area. Since the annual production of OMW worldwide is estimated to be more than 30 million m3 year-1 [1], a process for OMW biodegradation is mostly required. At the beginning, light dependent microorganisms like microalgae were used for biomass production using OMW as nutrient medium [2]. In the first decade of this third millennium, a different approach was proposed using a photofermentative process by purple non-sulfur bacteria (PNS) [3]. Later, using Rhodopseudomonas palustris 6A, we produced biogas rich in hydrogen using pretreated OMW diluted with distilled water (25 % v:v) [4]. In the present study the exploitation of fresh olive mill waste (OMWF) processed with an eco-technological pre-treatment was investigated to produce bioH2. The culture broth containing OMWF (30%) and distilled water (70%) was tested for hydrogen photoproduction using a non-sulfur photosynthetic bacteria Rhodopseudomonas palustris 42OL. The photofermentative process was studied in batch growth conditions, at three different irradiances (18.5, 37 and 74 W/m2). The lowest cumulative hydrogen (439 ml/l) was attained at 18.5 W/m2, the highest one (1030 ml l) was achieved at 74 W/m2. The average hydrogen evolution rate, based on the culture volume (HPRavg), achieved at the three different irradiances (18.5, 37 and 74 W/m2) were 1.40, 3.17 and 5.28 ml/l/ h respectively. The culture age, at which hydrogen photoevolution stopped, showed an inverse proportionality with respect to the irradiance: the higher the irradiance the lower the culture age. The light conversion efficiency (?) was maximal (1.07 %) at 37 W/m2 and got down (< 1.0 %) at lower and higher irradiances.
Exploitation of pretreated olive mill wastewater for hydrogen photoproduction by Rhodopseudomonas palustris 42OL
Pintucci C;Padovani G;Giovannelli A;Traversi ML;Ena A;Carlozzi P
2012
Abstract
Olive mill wastewater (OMW) is a liquid waste achieved from the extraction process of olive oil; this wastewater type is one of the main pollutant products in the Mediterranean area. Since the annual production of OMW worldwide is estimated to be more than 30 million m3 year-1 [1], a process for OMW biodegradation is mostly required. At the beginning, light dependent microorganisms like microalgae were used for biomass production using OMW as nutrient medium [2]. In the first decade of this third millennium, a different approach was proposed using a photofermentative process by purple non-sulfur bacteria (PNS) [3]. Later, using Rhodopseudomonas palustris 6A, we produced biogas rich in hydrogen using pretreated OMW diluted with distilled water (25 % v:v) [4]. In the present study the exploitation of fresh olive mill waste (OMWF) processed with an eco-technological pre-treatment was investigated to produce bioH2. The culture broth containing OMWF (30%) and distilled water (70%) was tested for hydrogen photoproduction using a non-sulfur photosynthetic bacteria Rhodopseudomonas palustris 42OL. The photofermentative process was studied in batch growth conditions, at three different irradiances (18.5, 37 and 74 W/m2). The lowest cumulative hydrogen (439 ml/l) was attained at 18.5 W/m2, the highest one (1030 ml l) was achieved at 74 W/m2. The average hydrogen evolution rate, based on the culture volume (HPRavg), achieved at the three different irradiances (18.5, 37 and 74 W/m2) were 1.40, 3.17 and 5.28 ml/l/ h respectively. The culture age, at which hydrogen photoevolution stopped, showed an inverse proportionality with respect to the irradiance: the higher the irradiance the lower the culture age. The light conversion efficiency (?) was maximal (1.07 %) at 37 W/m2 and got down (< 1.0 %) at lower and higher irradiances.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
