Actinomycete Scum Problems in Australian Activated Sludge Plants

Abstract

The formation of extensive, biological foams or scums on the liquid surfaces of domestic activated sludge plants in Australia was investigated. A survey of the problem in Queensland and Australia was carried out; the dominant organisms in the foam were isolated and identified; their physiology was investigated and the intrinsic reasons for foam formation were explored in the laboratory. Foaming in activated sludge plants was found to be a significant problem in Australia. Greater than 90% of plants in Queensland have experienced biological foaming episodes, whilst in 38% of the plants the problem was continuously present. Nocardia amarae and a newly described actinomycete Nocardia pinensis were the dominant organisms isolated from the foam. Plants that contained N. pinensis in the scum were found to be operated at long sludge ages. Although technical problems were experienced with chemostat methodology when applied to N. amarae, a limited amount of information about their physiology was obtained. The cells of N. amarae were found to be hydrophobic and a surfactant(s) was produced in culture. These are properties which suggest an explanation for the mechanism of foam formation based upon adsorptive bubble separation theory.

Streptomyces griseusEnhances Denitrification byRalstonia pickettiiK50, Which Is Possibly Mediated by Histidine Produced during Co-Culture

“…This was a somewhat unexpected effect, since actinomycetes are known to be problematic microorganisms in biological wastewater treatment, causing viscous foam or scum on the surfaces of activated sludge aeration tanks. [14][15][16] In this study, we analyzed the mechanism of enhancement of denitrification activity and the possible interactions between these two bacteria.…”

Design and preparation of quantum dots fluorescent probes for in situ identification of Microthrix parvicella in bulking sludge

“…The sludge bulking is a frequently occurring phenomenon in wastewater treatment plants (WWTPs), which mainly associates with the excessive growth of filamentous bacteria (Blackall et al 1988;de los Reyes et al 2002;Lienen et al 2014;Martins et al 2004;Rossetti et al 2005), and results in sludge separation problems like Bbulking^and Bfoaming^ (Araújo et al 2015;Jenkins et al 1993;Rossetti et al 2005;Wanner and Nielsen 2010). And it is reported that Microthrix parvicella (M. parvicella) is one of the dominant microorganism responsible for these problems (Kumari et al 2009).…”

A Novel Separation Method of Microthrix parvicella Filaments from Activated Sludge by a Hydrophobic Plate

“…The sludge bulking is mainly associated with the excess growth of filamentous bacteria [2][3][4], and excess growth of filamentous bacteria results in the formation of a viscous thick stable foam, causing solid separation problems in WWTPs [5]. The Microthrix parvicella (M. parvicella) is one of the most famous microorganism reported to be responsible for these problems in activated sludge systems [6][7][8][9][10]. The excessive growth of M. parvicella in WWTPs can cause severe problems, like bulking and floating of sludge [5,11].…”