A 2-year sampling campaign was conducted in three wastewater treatment plants of various sizes in the Rome area to assess the occurrence of nutrients and micropollutants among primary, secondary and digested sludge. The primary purpose was to evaluate the quality of different sludge types and their suitability for agricultural use. Primary sludge was consistently more polluted than secondary in...

Although dental foci can be sources of bacteremia and bacterial endocarditis, hematogenous spread of infection presented with septic pulmonary embolism apparently is rare. The occurrence of septic pulmonary embolism in patients with periodontal disease without suppurative thrombophlebitis of the great vessels of the neck is well documented but to our knowledge, there is no report on septic pulm...

The effect of raw and anaerobically digested sludge on heat inactivation of poliovirus was investigated. Raw sludge was found to be very protective of poliovirus plaque-forming ability at all temperatures studied, but digested sludge had variable effects that were highly dependent upon the experimental conditions. In low concentrations and at relatively low inactivation temperatures, digested s...

Oxic-settling-anaerobic process (OSA) was known as a cost-effective way to reduce the excess sludge production with simple upgrade of conventional activated sludge process (CAS). A low oxidation-reduction potential (ORP) level was the key factor to sludge decay and lysis in the sludge holding tank of the OSA process. However, the ORP control with nitrogen purge or chemical dosing in the OSA pro...

In view of the well recognized need of reject water treatment in MWWTP (municipal wastewater treatment plant), this paper outlines two strategies for P removal from reject water using alum sludge, which is produced as by-product in drinking water treatment plant when aluminium sulphate is used for flocculating raw waters. One strategy is the use of the alum sludge in liquid form for co-conditio...

The purpose of this work was to examine the settling properties of activated sludge from a sequencing batch reactor (SBR). The experiments were carried out in a bench-scale reactor, fed with wastewater from the University of Olsztyn treatment plant. Concentrations of the examined activated sludge varied between 2.5 and 6.0 kg SS m. Laboratory analyses of the sludge comprised: sludge concentrati...

The organic composition of the feed sludge to six laboratory-scale anaerobic digesters was adjusted by substituting a proportion of the primary sludge for glucose or propionic acid solution. Substitution with glucose caused an increase in the microbial extracellular polymer (ECP) content of the digested sludge, which altered the particle size distribution of the sludge and made the sludge more ...

An understanding of sludge rheology during anaerobic digestion can improve digester performance, particularly with regards to mixing. However, the “black box” nature of digesters limits the knowledge on sludge flow behaviour, once it enters the digester. A study on the flow properties (i.e. apparent viscosity and yield stress) as well as the yielding and restructuring behaviour of primary, seco...