Not all phosphorus removed in activated sludge systems can be accounted for by polyphosphate accumulating organisms (PAO). A method for the qualitative and quantitative in situ characterization of PAO cell clusters and closely associated extracellular polysaccharides (EPS) is described. X-ray microanalysis was performed on samples from four activated sludge plants situated in Pretoria, South Af...

Sludge fermentation between pH 4 and 11 was investigated to generate volatile fatty acids (VFA). Despite the highest sludge solubilization of 25.9% at pH 11, VFA accumulation was optimized at pH 8 (12.5% out of 13.1% sludge solubilization). 454 pyrosequencing identified wide diversity of acidogens in bioreactors operated at the various pHs, with Tissierella, Petrimonas, Proteiniphilum, Leviline...

Maximizing recovery and characterization of extractable proteins from secondary paper sludge is essential to explore the potential value from utilization of readily available waste products from pulp and paper mills. A multistep physicochemical recovery process was used, involving optimum alkaline solubilization of protein into an aqueous phase followed by augmented physical disruption of cell ...

Two respirometric principles are combined in an experimental setup based on a laboratory scale batch reactor and applied to the characterization of activated sludge and wastewater. In the first respirometric principle the temporary disturbance of the dissolved oxygen concentration in the reactor is used to estimate the respiration rate. To this end, the oxygen mass-transfer must be calculated a...

The challenging problems faced by the tannery based countries are the safe disposal of the sludge generated by the effluent treatment plants. In this work, the disposal of the sludge at various generation points such as beam house (BHS) and after tertiary treatment process (TS) is studied. The FT-IR of the beam house sludge confirmed the presence of organic matter at 2880.31cm -1 and calcined p...

This paper presents a brief characterization of the method of electrochemical conditioning of sludge, using the effect of low-temperature plasma. Primary sludge from the municipal wastewater treatment plant in Gorzów was analysed. The sludge was conditioned electrochemically, chemically with calcium hydroxide and dihydrogen dioxide, and using a combined method – electrochemical and chemical. Fo...

background: domestic and industrial wastewaters are mostly treated by biological process such as activated sludge, aerobic pond, and anaerobic treatment. this study focuses on characterizing the quality of sewage sludge in the sultanate of oman chosen from three industrial sewage treatment plants (stps): rusayl industrial estate (rsl.ie); sohar industrial estate (sie); and raysut industrial est...

In order to better understand land application of sewage sludge, the characterization of heavy metals, PCDD/F and PAHs in sewage sludge was investigated from six different wastewater treatment plants (WWTP) in Beijing City, China. It was found that the total concentrations of Zn in Wujiacun (WJC) sewage sludge, and Cd and Hg in sewage sludge generated from all of the six different places are hi...

AIMS To study the diversity and virulence of Listeria monocytogenes isolated from sludge. METHODS AND RESULTS A total of 60 isolates of L. monocytogenes from sludge were characterized by serotyping, PFGE typing and using in vitro and in vivo virulence assays. The PFGE patterns were compared with those of food and human isolates to determine whether specific group clones are associated with en...

Biological phosphorus removal in activated sludge systems is thought to be a result of the action of polyphosphate accumulating organisms (PAO). However, not all phosphorus removed can be accounted for by PAO. A method for the qualitative in situ characterization of PAO cell clusters and closely associated extracellular exopolymers (EPS) is described. X-ray microanalysis was performed on sample...