Virus Removal by Activated Sludge Treatment

1985 ◽  
Vol 17 (10) ◽  
pp. 153-158 ◽  
Author(s):  
E. Shimohara ◽  
S. Sugishima ◽  
M. Kaneko
Keyword(s):  
Activated Sludge ◽  
Low Temperatures ◽  
Virus Inactivation ◽  
Batch Experiments ◽  
Anaerobic Conditions ◽  
Sludge Treatment ◽  
Virus Removal ◽  
Virus Survival ◽  
Activated Sludge Processes

Removal of poliovirus 1 by activated sludge treatment in batch experiments was investigated, virus counts were reduced by more than 99% under conditions of 0.2 to 0.4 kg BOD.kg MLSS−1.day−1 and MLSS concentrations of 1,000 to 2,000 mg.l−1. There were no distinct relationships between BOD-SS loadings or TOC of the effluent and virus inactivation rates. MLSS levels of more than 800 mg.l−1 were necessary for more than 99% reduction in viral counts. Although MLSS levels of more than 2,000 mg.l−1 reduced viral counts by 4 log values, factors such as low temperatures and anaerobic conditions which adversely affect the efficiency of activated sludge processes, resulted in prolonged virus survival.

Behaviour of Mechanically Blended Return-Sludge in Absence of Substrate

1970 ◽  
Vol 5 (1) ◽  
pp. 34-54
Author(s):  
Shyam D. Bokil ◽  
Jatinder K. Bewtra
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Aeration Rate ◽  
Batch Experiments ◽  
Sludge Treatment ◽  
Waring Blender ◽  
Settling Characteristics

Abstract Nine sets of batch experiments, each of ten to twelve days duration, were conducted in the laboratory on return-sludge samples collected from activated sludge treatment plant at Windsor. The thickened sludge samples were blended daily in a waring blender and were continuously aerated in twelve-litres capacity jars. Parallel runs were made on control sludge samples which were not blended. Amongst the parameters varied were the speed and frequency of blending and the aeration rate. The effects of these variables on progressive bio-degradation of volatile suspended solids and the settling characteristics of the sludge were determined. Blended sludge showed significant improvement in the rate of bio-degradation and its settling characteristics as compared to the control unblended sludge

Activated Sludge Treatment of Kraft Mill Effluents from Conventional and Oxygen Bleaching

1991 ◽  
Vol 24 (3-4) ◽  
pp. 427-430 ◽  
Author(s):  
J. Nevalainen ◽  
P.-R. Rantala ◽  
J. Junna ◽  
R. Lammi
Keyword(s):  
Activated Sludge ◽  
Kraft Pulp ◽  
Activated Sludge Process ◽  
Chlorinated Phenols ◽  
Pulp Mills ◽  
Main Interest ◽  
Sludge Treatment ◽  
Kraft Pulp Mills ◽  
Activated Sludge Processes ◽  
Oxygen Bleaching

Conventional and oxygen bleaching effluents from hardwood kraft pulp mills were treated in laboratory-scale activated sludge processes. The main interest was the fate of organochlorine compounds in the activated sludge process. In the treatment of conventional bleaching wastewaters the BOD7-reduction was 80-91 % and in oxygen bleaching wastewaters 86-93 %. The respective CODCr removals were about 40 % and about 50 %. The AOX reductions were on average 22 % and 40 % in the treatment of conventional and oxygen bleaching effluents, respectively. The reductions of chlorinated phenols, guajacols and catecols were usually more than 50 % in both reactors. Very little accumulation of AOX into the sludge was observed. The stripping of AOX from aeration unit was insignificant.

scholarly journals Distribution of human fecal marker GB-124 bacteriophages in urban sewage and reclaimed water of São Paulo city, Brazil

2017 ◽  
Vol 16 (2) ◽  
pp. 289-299 ◽  
Author(s):  
Tatiana Prado ◽  
Antônio de Castro Bruni ◽  
Mikaela Renata Funada Barbosa ◽  
Vilma Marques Santos Bonanno ◽  
Suzi Cristina Garcia ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Reclaimed Water ◽  
Sao Paulo ◽  
São Paulo ◽  
Virus Removal ◽  
Urban Sewage ◽  
Viral Marker ◽  
Activated Sludge Processes

Abstract Bacteriophages infecting Bacteroides fragilis GB-124 have been described as potential markers of human fecal contamination in water sources. The aim of this study was to evaluate the occurrence of GB-124 phages in raw sewage, secondary effluents and reclaimed water of the São Paulo city using a low-cost microbial source tracking method. Samples were collected monthly from April 2015 to March 2016 in four municipal wastewater treatment plants that operate with activated sludge processes followed by different tertiary treatments (sand-anthracite filtration, membrane bioreactor/reverse osmosis) and final chlorination. GB-124 phages were detected in 100% of the raw sewage samples, with viral loads varying from 7.5 × 103 to 1.32 × 106 PFU/L. Virus removal efficiency in activated sludge processes ranged from 1.89 to 2.31 log10. Frequencies of phage detection were lower in reclaimed water samples (0–22.2%). The results indicated that GB-124 phage could be a complementary low-cost viral marker for the detection of human fecal pollution in waters impacted with urban sewage in this region. However, the datasets of tertiary effluents resulted in several samples with concentrations below the detection limit (DL ≤1 PFU/mL) suggesting the need to obtain analytical methods with lower DL for greater accuracy of negative results.

scholarly journals SIMULATION OF THE OPERATING CONDITIONS OF THE MUNICIPAL WASTEWATER TREATMENT PLANT AT LOW TEMPERATURES USING A MODEL THAT INCLUDES THE IA WPRC ACTIVATED SLUDGE MODEL

1994 ◽  
Vol 30 (4) ◽  
pp. 105-113 ◽  
Author(s):  
Naoyuki Funamizu ◽  
Tetsuo Takakuwa
Keyword(s):  
Activated Sludge ◽  
Low Temperatures ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Nitrifying Bacteria ◽  
Rate Equations ◽  
Sludge Treatment ◽  
Activated Sludge Model ◽  
Temperature Conditions

There are some advantages to using the sewage system to transport and melt snow in snowy regions. Since this would cause a drop in sewage temperature, adequate methods of operating treatment plants at low temperatures should be addressed. First, calibration of the IA WPRC activated sludge model was done using pilot plant data from a 10°C experiment. Then, the temperature coefficients in the reaction rate equations were estimated using the data from operation at 5°C. Comparison of the simulation results with data gathered under other temperature conditions showed that the IA WPRC activated sludge model could be applied to low temperature conditions. A newly developed model of the full-seale plant was able to simulate not only the biological reaction in the aeration basin but also the perfonnance of primary and final clarifiers, and sludge thickening and dewatering processes. The sludge and cake production rates, MLSS, and nitrification perfonnance calculated by this model coincided with plant operation results at I2°C. Operation maps of the plant in Sapporo were drawn at presumed low temperatures, 4 and 8°C. They showed that if nitrifying bacteria were kept in the plant, an overload in the sludge treatment process would be unavoidable without augmenting the capacity of water or of the sludge-treatment system.

scholarly journals Virus removal by activated sludge treatment

1982 ◽  
Vol 18 (1) ◽  
pp. 27-32
Author(s):  
Etsuko SHIMOHARA ◽  
Shinroku SUGISHIMA
Keyword(s):  
Activated Sludge ◽  
Sludge Treatment ◽  
Virus Removal

Virus Inactivation in Water Supplies

1969 ◽  
Vol 4 (1) ◽  
pp. 70-82
Author(s):  
Ann H. Vajdic
Keyword(s):  
Water Treatment ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Virus Inactivation ◽  
Water Supplies ◽  
Sludge Treatment ◽  
Intestinal Origin

Abstract A great deal of evidence has been collected over the last decade or so (Clarke & Kabler (1964) & Lamb et al (1964)), indicating that current methods of sewage and water treatment are largely inadequate to cause inactivation of viruses; these viruses would comprise mainly those of human intestinal origin. For example, Sproul and his co-workers (1967) have calculated that wastewaters can contain seven thousand viruses per litre; if a 90% reduction is assumed to occur during activated sludge treatment and a further 99% reduction upon chlorination, there could still remain as many as seven to seventy viruses per litre in plant effluent, which level is hazardous. Other forms of sewage treatment which may be employed, such as lagooning (Malherbe and Coetzee (1965)), are even less efficient with respect to virus inactivation.

scholarly journals Virus removal by activated sludge treatment

1980 ◽  
Vol 15 (2) ◽  
pp. 21-27
Author(s):  
Etsuko HAYASHI ◽  
Shinroku SUGISHIMA
Keyword(s):  
Activated Sludge ◽  
Sludge Treatment ◽  
Virus Removal
Sign in / Sign up

Export Citation Format

Share Document