Alkylphenol polyethoxylate removal in a pilot-scale reed bed and phenotypic characterization of the aerobic heterotrophic community.

The removal of the non-ionic surfactant Triton X-100, dosed at 30 and 300 mg/L in a pilot-scale subsurface horizontal flow reed bed, and the aerobic heterotrophic cultivable community associated with the roots and with the substrate gravel in both absence and presence of Triton X-100 were investigated. t-Octylphenol (OP) and its mono-, di- and tri-ethoxyl derivatives, among others, were found in the outlet. A mass balance allowed us to calculate that approximately 40% of the Triton X-100 metabolites OP and octylphenol polyethoxylate derivatives flowed out of the reed bed during the dosage and postdosage experiments. More aerobic heterotrophic microorganisms adhered to the roots than to the gravel. The appearance of new strains (Aeromonas, Flavobacterium, and Aquaspirillum) and the increased presence of others (Pseudomonas) during the dosage of Triton may be linked to the capacity of these bacteria to adapt to the presence of the surfactant or to use it as a nourishment.

[Compulsory and additional parameters in water control]. / Applicazione dei parametri obbligatori ed accessori nel controllo di acque di diversa origine.

The authors have analyzed 22 water samples from the Arno River (both river and drinking samples), as well as 11 effluent samples from an urban plant. Chemical and microbiological features of river samples were in line with the A3 class, needing treatment for drinking use (Executive Order n. 152/99); drinkable water met requirements (Presidents Decree n degrees 236/1988 and Executive Order n degrees 31/2001). As regards chemical parameters, effluents complied with the law (Executive Order n. 152/1999) but their bacteriological figures exceeded the standards set by the Authorities due to a lack in chlorination. Enteric viruses reacted to the RT-PCR test in 5 of the samples, including a Coxsackievirus Type B2 and a Poliovirus. No association was shown between bacteriophage parameters and virus.