In activated sludge systems, the sludge settling ability is considered a critical step where filamentous bulking and biomass deflocculation are the most common problems, causing the reduction of the effluent quality. Furthermore, in recent years image processing techniques have been successfully used to elucidate the activated sludge morphology. Keeping that in mind, a program was developed for...

Toxic compounds in sewage or industrial wastewater may inhibit the biological activity of activated sludge impairing the treatment process. This paper evaluates the Inhibition Capacity Index (ICI) for the assessment of activated sludge in the presence of toxicants. In this study, activated sludge was obtained from industrial treatment plants and was also synthetically produced. Continuous respi...

The paper will report about the experiences at an Austrian large wastewater treatment plant of 720,000 population equivalents, where anaerobically digested sewage sludge is further stabilised under aerobic conditions. Enhanced stabilisation of the anaerobically digested sludge was required at the plant in order to get a permit for landfill disposal of the dewatered stabilized sludge. By impleme...

The fate and behavior of estrogenic substances in various biological wastewater treatment processes and several advanced sewage treatment processes were examined. The removal of 17beta-estradiol (E2), estrone (E1) and estriol (E3) was investigated by using a pilot-scale activated sludge plant supplied with domestic sewage. Several sewage treatment plants adopting the activated sludge process we...

the term 'membrane bioreactor' expresses a combination of activated sludge and membrane separation processes. the need to processes like sedimentation and disinfection used in common methods is eliminated through mbr systems in a way that membranes are placed into or out of an aeration tank and the vacuumed wastewater created by the suction pump is pulled up from inside the membranes and leaves...

Wastewater treatment systems employing simultaneous adsorption and biodegradation processes have proven to be effective in treating toxic pollutants present in industrial wastewater. The objective of this study is to evaluate the effect of Cu(II) and the efficacy of the powdered activated carbon (PAC) and activated rice husk (ARH) in reducing the toxic effect of Cu(II) on the activated sludge m...

Background: Wastewater produced by a dairy in Sanandaj is a major source of environmental pollution threatening the city. The dairy uses activated sludge treatment to remove organic pollution from the wastewater. The present study evaluated the performance of this process and its compliance with national requirements for chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total s...

Here, we explore if microbial fuel cell (MFC) technology can replace activated sludge processes for secondary wastewater treatment. We will discuss the present limitations and problems of electric current generation when a complex wastewater is treated with a diverse and undefined community of microbes in large-scale systems. These challenges include low coulombic efficiencies, slow kinetic rat...

In urban centres of industrialising countries, the majority of houses are served by on-site sanitation systems such as septic tanks and unsewered toilets. The faecal sludges (FS) collected from these systems are usually discharged untreated into the urban and peri-urban environment, posing great risks to water resources and to public health. Contrary to wastewater management, the development of...

Although activated sludge communities are considered stable, the presence of toxic substances, such as Cr(VI), in the influent may induce changes in the activity and the performance of a wastewater treatment plant. The main objective of this study was the determination of Cr(VI) effects on the performance and on the protistan community of an activated sludge. Six laboratory scale activated slud...