The following sludge reduction alternatives were tested in wastewater biological reactors: oxic-settling-anaerobic (OSA-process); ultrasonic disintegration (UD); chlorination (CH); 3,3',4',5tetrachlorosalicylanilide (TCS); and folic acid (FA). Compared to the control system, UD reduced 55% of the sludge production, and greater substrate and nutrient removal efficiency was achieved. CH worsened ...

Sludge minimization by thermal treatment within activated sludge process was investigated at pilot scale. A 90°C treatment was set up in the return activated sludge loop. When keeping apparent sludge age at 15 days, 90°C treatment decreased sludge production by 30.4%. However, effluent quality was altered. A sludge minimization ASM1 based model was set up and calibrated against experimental dat...

Extracellular polymeric substances (EPS) play important roles in regulating the dewaterability of sludge. This study sought to elucidate the influence of EPS on the dewaterability of sludge during bioleaching process. Results showed that, in bioleaching system with the co-inoculation of Acidithiobacillus thiooxidans TS6 and Acidithiobacillus ferrooxidans LX5 (A. t+A. f system), the capillary su...

BACKGROUND Biliary sludge is associated with gallbladder (GB) dysmotility and mucus hypersecretion suggesting a link between biliary sludge and the formation of GB mucoceles (GBM). If biliary sludge progresses to GBM, treatment to reduce the production and progression of sludge is warranted. HYPOTHESIS/OBJECTIVES The objective of this study was to determine the course of biliary sludge in dog...

The principal aim of the study is to identify nature and causes changes surface a landfill body waste from nickel production located in industrial zone town Sereď (Slovak Republic). This change related natural anthropogenic geomorphological processes characteristic temperate northern hemisphere. an accumulative form relief, its composed artefact-metallurgical sludge, which has specific properti...

This study evaluates the application of an anoxic side-stream reactor in the sludge return line of a conventional activated sludge system for the reduction of biomass production. The oxidation-reduction potential was maintained at -150 mV while the applied sludge loading rate was modified by changing the percentage of return sludge treated in this reactor. The observed yield from the convention...

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...

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...