Biological treatment of highly foaming pharmaceutical wastewater by modified bubble-column under mechanical foam control

2000 ◽  
Vol 42 (3-4) ◽  
pp. 331-337 ◽  
Author(s):  
K. Yamagiwa ◽  
M. Yoshida ◽  
A. Ohkawa ◽  
S. Takesono
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Bubble Column ◽  
Bubble Columns ◽  
Pharmaceutical Wastewater ◽  
Sludge Treatment ◽  
Mechanical Foam ◽  
Breaking Mechanism ◽  
Foam Control ◽  
Sludge Settling

Activated sludge treatment of highly foaming pharmaceutical wastewater was carried out with modified bubble columns equipped with a mechanical foam-breaker (MFRD). The geometry of the bubble column was modified based on the foam breaking mechanism of the MRFD in order to improve the foam breaking capacity and hence to enhance the treatment capacity. Four types of modifications were examined. The activated sludge treatment of the wastewater with the modified columns was successfully carried out with COD removal efficiency about 90% at BOD loading of 4 g/Ld. Little effect of the mechanical foam control on the sludge settling characteristics was observed. The column modification significantly reduced the power required for foam control. The maximum power decrement of 75% was attained. Furthermore, oxygen transfer was found to be facilitated in the modified bubble columns. The results are expected to be helpful for economic and effective treatment of highly foaming organic wastewater.

scholarly journals Cost Effective Method for Toxicity Screening of Pharmaceutical Wastewater Containing Inorganic Salts and Harmful Organic Compounds

2019 ◽  
Vol 23 (1) ◽  
pp. 52-63 ◽  
Author(s):  
Elina Strade ◽  
Daina Kalnina
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Practical Implementation ◽  
Toxicity Screening ◽  
Pharmaceutical Wastewater ◽  
Cost Effective Method ◽  
Wide Range ◽  
Wastewater Biological Treatment

Abstract Pharmaceutical wastewater biological treatment plants are stressed with multi-component wastewater and unexpected variations in wastewater flow, composition and toxicity. To avoid operational problems and reduced wastewater treatment efficiency, accurate monitoring of influent toxicity on activated sludge microorganisms is essential. This paper outlines how to predict highly toxic streams, which should be avoided, using measurements of biochemical oxygen demand (BOD), if they are made in a wide range of initial concentration. The results indicated that wastewater containing multivalent Al3+ cations showed a strong toxic effect on activated sludge biocenosis irrespectively of dilutions, while toxicity of phenol and formaldehyde containing wastewater decreased considerably with increasing dilution. Activated sludge microorganisms were not sensitive to wastewater containing halogenated sodium salts (NaCl, NaF) and showed high treatment capacity of saline wastewater. Our findings confirm that combined indicators of contamination, such as chemical oxygen demand (COD), alone do not allow evaluating potential toxic influence of wastewater. Obtained results allow identifying key inhibitory substances in pharmaceutical wastewater and evaluating potential impact of new wastewater streams or increased loading on biological treatment system. Proposed method is sensitive and cost effective and has potential for practical implementation in multiproduct pharmaceutical wastewater biological treatment plants.

scholarly journals Groundwater Remediation Using Biological And Photocatalytic Methods

2015 ◽  
Vol 43 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Sándor Guba ◽  
Viola Somogyi ◽  
Erzsébet Szabóné Bárdos
Keyword(s):  
Activated Sludge ◽  
Active Ingredient ◽  
Biological Treatment ◽  
Groundwater Remediation ◽  
Uv Light ◽  
Transport Modelling ◽  
Sludge Treatment ◽  
Treatment Methods ◽  
Laboratory Conditions ◽  
Preliminary Information

Abstract The degradability of two commercially available pesticides was studied using heterogeneous photocatalytic and activated sludge treatment methods. The first pesticide contained 5% quizalofop-P-ethyl as an active ingredient and petroleum naphtha as a solvent, the latter causing difficulties both in photocatalytic and biological treatment methods. The active ingredient of the second compound was acetamiprid. The photocatalysis proved to be effective both under laboratory conditions (using UV light) and when exposed to sunlight, but the pesticides remained stable during the employed biological treatment. Preliminary information on its behaviour in soil was obtained from transport modelling.

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.

Chemical Neutralization of Alkaline Wastewater During Activated Sludge Treatment

1970 ◽  
Vol 5 (1) ◽  
pp. 80-101 ◽  
Author(s):  
Jerzy Ganczarczyk
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Kraft Pulp ◽  
Pulp Mill ◽  
Total Alkalinity ◽  
Sludge Treatment ◽  
Mixed Liquor ◽  
Kraft Pulp Mill ◽  
Ph Values ◽  
Practical Limit

Abstract The chemical neutralization of alkaline wastewater during the activated sludge treatment is due mostly to the development of CO2 during such biological treatment. The full-scale activated sludge treatment of alkaline wastewater without preliminary separate chemical neutralization was studied for the case of an unbleached Kraft pulp mill effluent. The treatment was carried out in limited-mixing aeration tanks at conventional loadings. Maximum pH values of the mixed liquor were 10.2, and the corresponding total alkalinity values reached 23.8 me/l. It was observed that considerable parts of the waste-water alkalinity were removed during the initial periods of mixed liquor aeration. The practical limit of this type of neutralization seems to be close to pH of 8.

Effect of chemical treatment on the acute toxicity of two commercial textile dye carriers

2007 ◽  
Vol 55 (10) ◽  
pp. 253-260 ◽  
Author(s):  
I. Arslan-Alaton ◽  
G. Iskender ◽  
B. Ozerkan ◽  
F. Germirli Babuna ◽  
O. Okay
Keyword(s):  
Acute Toxicity ◽  
Activated Sludge ◽  
Chemical Treatment ◽  
Textile Industry ◽  
Ferrous Sulphate ◽  
Textile Dye ◽  
Sludge Treatment ◽  
Treatment Conditions ◽  
Test Organisms ◽  
Sludge Settling

In the present experimental study, the effect of chemical treatment (coagulation–flocculation) on the acute toxicity exerted by two commercial dye carriers (called Carrier A and B herein) often used in the textile industry was investigated. Two different test organisms were selected to elucidate the situations in activated sludge treatment systems (activated sludge microorganisms) as well as in receiving water bodies (ultimate marine discharge). According to the results of a comprehensive analysis covering COD removal efficiencies, sludge settling characteristics and operating costs involved in coagulation-flocculation, the optimum treatment conditions were defined as follows; application of 750 mg/L ferrous sulphate at a pH of 9.0 for Carrier A; and application of 550 mg/L ferrous sulphate at a pH of 9.0 for Carrier B. The acute toxicities of both dye carriers towards marine microalgea Phaeodactylum tricornutum could be reduced significantly after being subjected to coagulation–flocculation. Fair toxicity removals (towards heterotrophic mixed bacterial culture accommodated in activated sludge treatment) were obtained with coagulation–flocculation for both of the carriers under investigation.

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.

Experimental basis of activated sludge treatment for industrial wastewaters - the state of the art

1999 ◽  
Vol 40 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Derin Orhon ◽  
Rüya Taşlı ◽  
Seval Sözen
Keyword(s):  
Experimental Data ◽  
Organic Carbon ◽  
Activated Sludge ◽  
Biological Treatment ◽  
State Of The Art ◽  
Experimental Information ◽  
Experimental Basis ◽  
Sludge Treatment ◽  
Industrial Wastewaters ◽  
Wide Range

The paper provides a comprehensive coverage of the experimental information required for the activated sludge treatment of industrial wastewaters. Emphasis is placed upon the choice of parameters for organic carbon removal, the value of basic relationships between major parameters, the merit of size distribution for the evaluation of pretreatment, COD fractionation and its implication in system design, major kinetic and stoichiometric coefficients for process modelling. Relevant experimental data related to a wide range of industrial wastewaters compatible with biological treatment are provided.

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