Fate of cerium dioxide (CeO2) nanoparticles in municipal wastewater during activated sludge treatment

2012 ◽  
Vol 108 ◽  
pp. 300-304 ◽  
Author(s):  
Francisco Gómez-Rivera ◽  
James A. Field ◽  
Dustin Brown ◽  
Reyes Sierra-Alvarez
Keyword(s):  
Activated Sludge ◽  
Cerium Dioxide ◽  
Municipal Wastewater ◽  
Ceo2 Nanoparticles ◽  
Sludge Treatment

Occurrence of benzothiazoles in municipal wastewater and their fate in biological treatment

2004 ◽  
Vol 50 (5) ◽  
pp. 203-208 ◽  
Author(s):  
A. Kloepfer ◽  
R. Gnirss ◽  
M. Jekel ◽  
T. Reemtsma
Keyword(s):  
Activated Sludge ◽  
Sulfonic Acid ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Total Concentration ◽  
Sewage Treatment ◽  
Liquid Chromatography Mass Spectrometry ◽  
Sludge Treatment ◽  
Conventional Activated Sludge ◽  
The Individual

A number of 2-substituted benzothiazoles that are known to be used as fungicides, corrosion inhibitors and vulcanization accelerators in industry have been analyzed in municipal wastewater and the effluents of activated sludge and membrane bioreactor (MBR) treatment over a three month period. All six analytes were regularly detected in the municipal wastewater by liquid chromatography-mass spectrometry and amount to a total concentration of 3.4 μg/L. Of these compounds benzothiazole-2-sulfonic acid (1,700 ng/L), benzothiazole (850 ng/L) and 2-hydroxybenzothiazole (500 ng/L) were most prominent. The source of the benzothiazole emission is yet unknown. Activated sludge treatment did not reduce total benzothiazole concentration significantly. Removals of the individual compounds ranged from 90% for 2-mercaptobenzothiazole and 70% for hydroxybenzothiazole to 40% for benzothiazole. The concentration of benzothiazole-2-sulfonic acid increased by 20%, whereas 2-methylthiobenzothiazole increased by 160% during activated sludge treatment, likely due to the methylation of mercaptobenzothiazole. Total benzothiazole removal in two parallely operated MBRs was significantly better (43%) than in the conventional activated sludge treatment. Namely benzothiazole and benzothiazole-2-sulfonic acid were more effectively removed. This first systematic study on the occurrence of benzothiazoles in municipal wastewater has shown that this is a relevant class of trace contaminants in municipal wastewater which is only incompletely removed in biological wastewater treatment. Emission from sewage treatment is dominated by the most polar benzothiazole-2-sulfonic acid. MBR treatment may reduce but cannot avoid this emission.

The Use of Sludge and Sulphide to Remove Heavy Metals from Sewages before Activated Sludge Treatment

1988 ◽  
Vol 20 (4-5) ◽  
pp. 285-292 ◽  
Author(s):  
István Licskó
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Sludge Treatment ◽  
Unit Costs ◽  
Sulphide Ions ◽  
Costs Of Treatment ◽  
Simple Phase ◽  
Plant Trials

The removal of five different heavy metals (Zn2+, Cu2+, Cr 3+,Cd 2+ and Ni 2+) was studied under laboratory conditions using close to neutral mixed municipal wastewater. 90 to 95 % of the Zn2+, Cu2+ and Cr3+ was found to precipitate within 5 min and to become removable by simple phase separation. The Cd2+ and Ni2+, however, refused to precipitate, unless a “reagent” (sulphide ion, primary and activated sludge) was added. In the presence of these, cadmium was normally more readily removed than nickel. Both heavy metals were removed most efficiently, when primary sludge (1.4 g.dm−3) and sulphide ions (5-15 mg.dm−3) were added in combination. As demonstrated by plant trials, this treatment would cause the heavy metals to precipitate and settle out in the primary settling tank, so that traces only would enter the aeration tank.The excess sludge would thus contain trace quantities of heavy metals only, removing an obstacle to land disposal. The introduction of this unit operation has been estimated to increase the overall construction and costs of sewage and sludge treatment by 2.3 %, the unit costs of treatment by 6 %.

Source characterization and removal of N-nitrosamine precursors during activated sludge treatment

2020 ◽  
Vol 6 (9) ◽  
pp. 2432-2443
Author(s):  
Xiaolu Zhang ◽  
Daekyun Kim ◽  
David L. Freedman ◽  
Tanju Karanfil
Keyword(s):  
Water Quality ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Source Water ◽  
Source Characterization ◽  
Sludge Treatment ◽  
Potential Source ◽  
Source Water Quality

Municipal wastewater discharges after secondary biological treatment (e.g., the activated sludge (AS) process) are a major potential source of N-nitrosamine precursors which may impact downstream source water quality.

Pharmaceutical chemicals and endocrine disrupters in municipal wastewater in Tokyo and their removal during activated sludge treatment

2006 ◽  
Vol 40 (17) ◽  
pp. 3297-3303 ◽  
Author(s):  
Norihide Nakada ◽  
Toshikatsu Tanishima ◽  
Hiroyuki Shinohara ◽  
Kentaro Kiri ◽  
Hideshige Takada
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Endocrine Disrupters ◽  
Sludge Treatment

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.

Removal characteristics of retinoic acids and 4-oxo-retinoic acids in wastewater by activated sludge treatment

2013 ◽  
Vol 67 (12) ◽  
pp. 2868-2874 ◽  
Author(s):  
D. Inoue ◽  
K. Sawada ◽  
Y. Wada ◽  
K. Sei ◽  
M. Ike
Keyword(s):  
Activated Sludge ◽  
Laboratory Experiments ◽  
Municipal Wastewater ◽  
Chemical Degradation ◽  
Sludge Treatment ◽  
Retinoic Acids ◽  
Field Investigations ◽  
Agonistic Activity ◽  
Involved Field ◽  
Batch Treatment

Retinoic acid (RA) receptor (RAR) agonists are potential teratogens to various vertebrates. Their contamination has been detected in municipal wastewater in different countries. This study involved field investigations and laboratory batch treatment experiments to elucidate the removal characteristics by activated sludge treatment of RAs (all-trans RA and 13-cis RA) and 4-oxo-RAs (4-oxo-all-trans RA and 4-oxo-13-cis RA), which were identified as major RAR agonists in municipal wastewater. Results obtained in this study show that currently employed activated sludge treatments can remove RAs, 4-oxo-RAs and overall RAR agonist contamination effectively from municipal wastewater in general, although high RAR agonistic activity might sometimes remain in the effluent. Laboratory experiments revealed that RAs were removed rapidly from the aqueous phase by adsorption to the sludge, after which they were removed further by biological and/or chemical degradation. Aside from adsorption to the sludge, 4-oxo-RAs were also apparently removed by biological and chemical degradation. Biodegradation contributed greatly to the removal. Results of additional experiments indicated that novel non-identifiable RAR agonists can occur through the biodegradation of 4-oxo-RAs by activated sludge and that they can persist for a long period.

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