Wastewater reclamation and reuse is becoming a widespread practice for irrigation purposes, owing to new devices and techniques that have been decreasing the overall cost of water recycling in the agro-industry. Recently, the introduction of an ultrafiltration stage improved significantly the effectiveness of wastewater treatment schemes, thus contributing to reach higher sustainable productivities. In this study, we aimed at monitoring the performances of advanced treatment processes, recently introduced within a traditional activated-sludge wastewater treatment plant of a vegetable processing industry. The added tertiary treatments included sand filtration, membrane ultrafiltration (nominal pore size 0.05 µm) and UV disinfection (6x 300W mercury-vapor lamps). The company produced on average 5*104 m3/y of wastewater. At the different treatment stages, water samples were characterized by high electrical conductivity (2.5±0.9 mS/cm), high organic content (1.0±0.3 gCOD/L), low pH (5.6±0.4), and a variable fecal contamination (106-107 CFU/100mL of E. coli). Flow cytometry (FCM) was applied as a diagnostic tool to evaluate the removal of potential microbial contaminants. By quantifying the total and living microorganisms before and after each treatment, we found a moderate effectiveness of disinfection treatments, with a four-time increase of dead cells after UV exposure. Instead, the ultrafiltration stage was highly efficient, with the removal of >99% of the inlet microbial biomass. Whereas microbiological water quality assessment is traditionally based on cultivation methods with substantial manual handling and results only available after 2-5 days, FCM was suited uniquely for this application, due to its speed and potential for automation . Our cytometric outcomes provided a solid information basis for operational decisions concerning the treatment regime and operation, hence contributing to the safety of water reuse.
Assessing the performances of advanced treatment processes for water reuse: a flow cytometric approach.
Vergine P;Amalfitano S;Salerno C;Pollice A
2015
Abstract
Wastewater reclamation and reuse is becoming a widespread practice for irrigation purposes, owing to new devices and techniques that have been decreasing the overall cost of water recycling in the agro-industry. Recently, the introduction of an ultrafiltration stage improved significantly the effectiveness of wastewater treatment schemes, thus contributing to reach higher sustainable productivities. In this study, we aimed at monitoring the performances of advanced treatment processes, recently introduced within a traditional activated-sludge wastewater treatment plant of a vegetable processing industry. The added tertiary treatments included sand filtration, membrane ultrafiltration (nominal pore size 0.05 µm) and UV disinfection (6x 300W mercury-vapor lamps). The company produced on average 5*104 m3/y of wastewater. At the different treatment stages, water samples were characterized by high electrical conductivity (2.5±0.9 mS/cm), high organic content (1.0±0.3 gCOD/L), low pH (5.6±0.4), and a variable fecal contamination (106-107 CFU/100mL of E. coli). Flow cytometry (FCM) was applied as a diagnostic tool to evaluate the removal of potential microbial contaminants. By quantifying the total and living microorganisms before and after each treatment, we found a moderate effectiveness of disinfection treatments, with a four-time increase of dead cells after UV exposure. Instead, the ultrafiltration stage was highly efficient, with the removal of >99% of the inlet microbial biomass. Whereas microbiological water quality assessment is traditionally based on cultivation methods with substantial manual handling and results only available after 2-5 days, FCM was suited uniquely for this application, due to its speed and potential for automation . Our cytometric outcomes provided a solid information basis for operational decisions concerning the treatment regime and operation, hence contributing to the safety of water reuse.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
