Scope of this study was to evaluate the effectiveness of a metal salt (Polyaluminium chloride, PACl) dosage into a pilot scale MBR (Membrane BioReactor) in terms of fouling control and permeate quality enhancement, especially with reference to specific textile macro-pollutants (dyes and surfactants). The pilot plant was fed with a mixed domestic-textile wastewater (65% as flow and 70% as COD load) and operated for 7.5 months without flux enhancers (step 1) and 3 months with the addition of PACl (step 2). The optimum dose was defined performing a jar-test campaign between step 1 and step 2 (12.5 mg gMLSS-1 that corresponds to 0.4 g d-1). The addition of PACl resulted in a significant decrease of the filtration resistance due to cake layer formation (Rc, -65.4%) and of the irreversible fouling rate, evaluated as the average variation per unit time of the filtration resistance due to foulants adsorption on membrane pore wall or surface (FR, -45.3%). As for permeate quality, removal rates related to total phosphorus and textile macro-parameters such as colour and anionic surfactants, increased of +64%, +16% and +7%, respectively. No significant effect was observed on COD and nitrogen compounds removal
MBR fouling control and permeate quality enhancement by Polyaluminium Chloride dosage: a case study
TELI, ARONNE;ANTONELLI, MANUELA;BONOMO, LUCA;MALPEI, FRANCESCA
2011-01-01
Abstract
Scope of this study was to evaluate the effectiveness of a metal salt (Polyaluminium chloride, PACl) dosage into a pilot scale MBR (Membrane BioReactor) in terms of fouling control and permeate quality enhancement, especially with reference to specific textile macro-pollutants (dyes and surfactants). The pilot plant was fed with a mixed domestic-textile wastewater (65% as flow and 70% as COD load) and operated for 7.5 months without flux enhancers (step 1) and 3 months with the addition of PACl (step 2). The optimum dose was defined performing a jar-test campaign between step 1 and step 2 (12.5 mg gMLSS-1 that corresponds to 0.4 g d-1). The addition of PACl resulted in a significant decrease of the filtration resistance due to cake layer formation (Rc, -65.4%) and of the irreversible fouling rate, evaluated as the average variation per unit time of the filtration resistance due to foulants adsorption on membrane pore wall or surface (FR, -45.3%). As for permeate quality, removal rates related to total phosphorus and textile macro-parameters such as colour and anionic surfactants, increased of +64%, +16% and +7%, respectively. No significant effect was observed on COD and nitrogen compounds removalI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
