Comparison of different technologies for textile wastewater treatment.

Textile wastewaters are usually subjected to secondary activated sludge treatment before being discharged in the environment or re-used. In order to improve the efficiency of this treatment, four reactors possessing different configurations and fluid dynamic characteristics (i.e. a Bioflotation® system; a fixed bed biofilm reactor (FBBR) filled with polypropylene balls; a flow-jet aeration system and a conventional activated sludge reactor) were developed and fed with a textile industry wastewater. COD, TC and non ionic surfactant concentrations were monitored in the reactor effluents and the cultivable heterotrophic biomass was isolated from the effluents. The results evidenced that the fluid dynamic characteristics and the air supply system can greatly influence the degradation efficiency of the secondary treatment. In particular, Bioflotation® and FBBR technologies appear to be the most efficient in term of pollutant removal. An highly specialized biomass, rich in strains belonging to the Pseudomonas and Stenotrophomonas genera, was evidenced in these reactors, thus allowing to conclude that there is a direct correlation among reactor configuration, biomass specialization and reactor performances.