Activated sludges are an inoculum source commonly used in biodegradation studies, as wastewater treatment facilities constitute an entry point to the environment for many chemicals. In this paper, the main issues relating to the use of activated sludge in biodegradability tests are presented. Special attention is also devoted to discussing the factors affecting both the activity of the microbia...

The present disposal routes of sewage sludge represent a critical environmental issue in Egypt. Recently, there has been an increasing concern about sewage sludge management due to the environmental risks, which resulted from the fast expansion of wastewater treatment plants without equal attention in dealing with the produced sludge. This paper discusses the current situation of sewage sludge ...

Conventional water treatment plant generates two types of process wastes, filter back wash water and sludge. Characteristic studies of these wastes reveals that it contains high solids content, metals and bacteriological concentration, which are generally more than permissible disposable standards. Direct disposal of these wastes in to natural stream pollutes the receiving streams, affects huma...

How do you feel when you hear the words " wastewater, " " sludge, " " sewer, " and " sewage " ? These words may make you feel uncomfortable. However, as Victor Hugo wrote in " Les Misérables, " these words are inevitably related to human society (16): " ... The history of men is reflected in the history of sewers. The Germoniae narrated Rome. The sewer of Paris has been an ancient and formidabl...

Studies that focus on the microbiological composition of water treatment plants (WTP) sludge, as well its pathogenicity, are extremely necessary, especially with regard to environmental regulations, where characterization WTP waste can encourage new policies related management. In Brazil, few studies address which, in general, is classified non-hazardous and non-inert waste, this material being...

As a result of uncontrolled discharge of wastewaters containing high levels of phosphorus to the receiving bodies could create adverse effects on water quality. Therefore phosphorus should be eliminated prior to discharging into aquatic environment together with carbon and nitrogen to reduce eutrophication risk. Control of effluent phosphorus level by enhanced biological methods became a standa...

This paper presents three new approaches to reduce excess sludge production in activated sludge systems: 1) modification of conventional activated sludge process with insertion of a sludge holding tank in the sludge return line; 2) chlorination of excess sludge so as to minimize excess sludge production; and 3) utilization of a metabolic uncoupler, 3, 3', 4', 5-Tetrachlorosalicylanilide (TCS) t...

AIMS Fourier transform infrared (FT-IR) was used to analyse a selection of Acinetobacter isolates in order to determine if this approach could discriminate readily between the known genomic species of this genus and environmental isolates from activated sludge. METHODS AND RESULTS FT-IR spectroscopy is a rapid whole-organism fingerprinting method, typically taking only 10 s per sample, and ge...

“Biosensors” are defined as sensors that allow the measurement and interpretation of the biological response of activated sludge to a known disturbance. The purpose of “biosensing” the activated sludge, on-line at the full-scale plant or off-line in lab-scale tests, is to obtain specific information about one or several activated sludge processes. This information can serve as plant performance...

Extracellular polymeric substances (EPS) were quantified in flocculent and aerobic granular sludge developed in two sequencing batch reactors with the same shear force but different settling times. Several EPS extraction methods were compared to investigate how different methods affect EPS chemical characterization, and fluorescent stains were used to visualize EPS in intact samples and 20-mum ...