In the activated sludge process, the share of filamentous bacteria is crucial for proper settlement and high sewage treatment efficiency. Disequilibrium of the microbial community may be a reason for the appearance of bulking episodes. During 19 months (August 2007-February 2009) activated sludge samples were collected and analyzed by physicochemical, microscopic, and molecular methods. Amplifi...

In Saudi Arabia, the Riyadh Sewage Treatment Plant (RSTP) uses the activated sludge technology as the secondary treatment process for sewage. Due to the complex nature of the process, a rather simplified, yet practical, steady state model that captures the most important features of the RSTP was developed. Actual operating and design conditions were obtained from RSTP data bank. The monthly ave...

This work focuses on the use of chemometric techniques for identifying activated sludge process abnormalities. Chemometric methods combined with image analysis can improve activated sludge systems monitoring and minimize the need of analytical measurements. For that purpose data was collected from aggregated and filamentous biomass, biomass composition on Gram-positive/Gram-negative bacteria an...

In the present time study,dried activated sludge(DAS) and dried activated nano sludge(DANS) was used for the removal of Cu(II) from aqueous solution in a fixed-bed reactor. The effect of important parameters including the flow rate and bed height were examined. Dried activated nano sludge column regeneration using 1 M concentration of HNO3 has been studied.The Thomas model was used for the math...

The treatment of paper mill effluent for COD, TOC, total phenols and color removal was investigated using combined activated sludge-ozonation processes and single processes. The combined activated sludge-O3/pH 10 treatment was able to remove around 80% of COD, TOC and color from Kraft E(1) effluent. For the total phenols, the efficiency removal was around 70%. The ozonation post treatment carri...

The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxo...

Bulking of activated sludge is a world-wide problem which negatively affects wastewater treatment efficiency. The most common reasons of bulking are bacterial community changes, especially excessive growth of filamentous bacteria (filamentous bulking) or excess of biopolymers on the surface of non-filamentous microbes (non-filamentous or Zoogleal bulking). Because of the complex nature of the b...

activated sludge or extended aeration treatment involves a continous system where aerobic biological growths are mixed with waste water and then separated in a gravity clarifier. therefore, waste treatment system such as the activated sludge system depend on the activities of communities of living organism. in this study, an attempt was made on the indentification of the bacterial population in...

UNITANK is a biological wastewater treatment process that combines the advantages of traditional activated sludge process and sequencing batch reactor, which is divided into Tank A, B and C. In this study, the sludge distribution and its impact on performance of UNITANK were carried out in Liede Wastewater Plant (WWTP) of Guangzhou, China. Results showed that there was a strong affiliation betw...

The purpose of the experiments described in this article was the comparison of integrated fixed film activated sludge (IFAS) and activated sludge (AS) system. The IFAS applied system consists of the cigarette filter rods (wasted filter in tobacco factories) as a biofilm carrier. The comparison with activated sludge was performed by two parallel treatment lines. Organic substance, ammonia and TP...