The use of constructed wetlands to upgrade treated sewage effluents before discharge to natural surface water in texel island, The Netherlands – pilot study

1997 ◽  
Vol 35 (5) ◽  
pp. 231-237 ◽  
Author(s):  
M. Schreijer ◽  
R. Kampf ◽  
S. Toet ◽  
J. Verhoeven
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Precipitation ◽  
Pilot Scale ◽  
E Coli ◽  
System A ◽  
Treated Sewage ◽  
Wetland System ◽  
High Degree

Since 1988 experiments have been carried out on a pilot scale on polishing of sewage treatment plant (STP) effluent in a constructed wetland system, a combination of a macrophyte bed and a lagoon. The hydraulic retention time (HRT) has been between one and ten days. At HRTs of 2-3 days a favourable oxygen regime and a high degree of removal of E. coli bacteria could be obtained. The natural alternation of low and high oxygen levels resulted in an extra nitrogen removal from the low levels of nitrogen in the effluent of the STP. Phosphorus removal in the wetland system under these conditions was low, therefore chemical precipitation has to take place in the STP. The favourable results of the study have led to the construction of a full scale 3.5 ha wetland system for the treatment of 3500 m3 effluent day−1 in 1994. The HRT is 2.1 days at dry weather flow. The purpose of this wetland is to further polish the STP effluent in order to match the water quality of the natural local surface waters.

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operation

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Maciej Walczak
Keyword(s):  
Water Quality ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Sewage Treatment Plants ◽  
Plant Operation ◽  
Treated Sewage ◽  
Microbiological Parameters ◽  
Microbial Indices

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operationThis paper reports the results of studies of microbiological changes in the water quality of the Vistula and Brda rivers after the opening of sewage treatment plants in Bydgoszcz. The study involved determining the microbiological parameters of water quality. Based on the results obtained, it was found that the quality of the water in both rivers had improved decidedly after the opening of the plants, although an increased number of individual groups of microorganisms was found at the treated sewage outlet from one of the plants.

Use of lime for the upgrading of existing wastewater treatment systems

1994 ◽  
Vol 29 (12) ◽  
pp. 279-282 ◽  
Author(s):  
C. Güldner ◽  
W. Hegemann ◽  
N. Peschen ◽  
K. Sölter
Keyword(s):  
Large Scale ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Precipitation ◽  
Fatty Acid Production ◽  
German States ◽  
Lime Solution ◽  
First Results ◽  
Pre Treatment

The integration of the chemical precipitation unit which would inject a lime solution into a series of mechanical-biological processes, including nitrification/denitrification, and the sludge treatment are the subject of this project. The essential target is the large-scale reconstruction of a mechanical-biological sewage treatment plant with insufficient cleaning performance in the new German states and the adjustment of the precipitation stage to the unsteady inflow of sewage. First results indicate that the pre-treatment performance could be improved by ≅ 20% and the discharge of concentrations of COD, BOD, N and P could be reduced and homogenized. In addition, experiments on hydrolysis and acidifiability of the pre-treatment sludge have been carried out on a laboratory level with the object of making sources of carbon readily available for denitrification. In the course of the experiment, inhibition of fatty acid production by calcareous primary sludge could not be detected. The characteristics of the sludge, such as draining and thickening were considerably improved by the adding of lime.

Toxicity assays and their evaluation on organic polymer flocculants used for municipal sludge dewatering

1998 ◽  
Vol 38 (7) ◽  
pp. 207-215 ◽  
Author(s):  
H. Takigami ◽  
N. Taniguchi ◽  
Y. Shimizu ◽  
S. Matsui
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Algal Growth ◽  
Pilot Scale ◽  
Organic Polymer ◽  
Municipal Sludge ◽  
Sludge Dewatering ◽  
Algal Toxicity ◽  
Reproduction Tests

The toxicity of organic polymer flocculants used for the dewatering of municipal sludge was evaluated by using two different toxicity assays: the Closterium ehrenbergii algal toxicity test and the Bacillus subtilis rec-assay. The algal toxicity of the effluents from a pilot-scale sewage treatment plant was investigated with and without the addition of a flocculant (0, 0.05, 0.10 and 0.20 mg/L). No clear evidence on the toxicity caused by the flocculant was observed on both asexual and sexual reproduction tests of C. ehrenbergii. It was also found that the algal growth inhibition of various types of flocculants (i.e., cationic, anionic, amphoionic and non-ionic) was in the order of 1 to 20 mg/L, which was mainly due to a molecular weight (MW) fraction of greater than 100,000. The results of the B. subtilis rec-assay for these flocculants indicated that eight out of ten cationic flocculants caused the direct DNA damage with LC50 =0.1 to 10 mg/L. One of the genotoxic flocculants was also fractionated into their components by MW. The experimental results showed that the lethal effects were mainly contributed by the polymer fraction of MW greater than 100,000, although the genotoxicity was not detected in that fraction. Therefore, the detected genotoxicity of the flocculants could be caused by the combined effects of various components, such as polymers, oligomers, monomers and additives.

Two-dimensional electrophoresis method used for determination of plasmid profiles of Escherichia coli isolated from a sewage treatment plant

1993 ◽  
Vol 39 (10) ◽  
pp. 990-993 ◽  
Author(s):  
M. Arturo ◽  
Z. Tamanai-Shacoori ◽  
C. Mamez ◽  
M. Pommepuy ◽  
M. Cormier
Keyword(s):  
Escherichia Coli ◽  
Brackish Water ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Treated Sewage ◽  
Electrophoresis Method ◽  
Dimensional Electrophoresis

The plasmid contents of 306 strains of Escherichia coli isolated from raw and treated sewage from a treatment plant as well as from the water 1 km downstream were determined. The number and molecular weight of plasmids isolated from a representative sample of these strains were also measured. It was observed that biological treatment did not significantly alter these parameters. In contrast, statistically significant differences in plasmid number and size were observed when strains from sewage (raw and treated) were compared with strains isolated from brackish water. In raw and treated sewage, more than 96% of the strains contained plasmids, compared with 85% in brackish water. Nine to 13% of the strains from sewage contained plasmids with more than 56 kilobases, while only 5% of the strains from brackish water reached this size.Key words: Escherichia coli, plasmids, two-dimensional electrophoresis, sewage treatment, brackish water.

The Automatic Control System Based on PROFIBUS for the City Sewage Treatment

2013 ◽  
Vol 385-386 ◽  
pp. 857-861
Author(s):  
Xiao Ping Huang ◽  
Qi Xing Qing
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Automatic Control System ◽  
Fuzzy Controller ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Difficult Problem ◽  
Urban Sewage ◽  
Treated Sewage

On the basis of the computerized technological process control of sewage treatment in a urban sewage treatment plant in the Zone of Nanning, the author had brought forward a plan of PROFIBUS that based on automatic control system for sewage treatment, and designed the automatic control system diagram and the PROFIBUS network diagram for sewage treatment plant. At the same time, the author also made a study of techniques to control the sewage aeration, which was the most difficult problem in sewage treatment process. The fuzzy controller could indicate the changes of the water quality in treated sewage, effectively controlled the volume of aeration and then cut down the operation costs,it had produced good economic and social benefits.

scholarly journals Prevalence of the stx2 Gene in Coliform Populations from Aquatic Environments

2004 ◽  
Vol 70 (6) ◽  
pp. 3535-3540 ◽  
Author(s):  
Cristina Garc�a-Aljaro ◽  
Maite Muniesa ◽  
Juan Jofre ◽  
Anicet R. Blanch
Keyword(s):  
Fecal Coliform ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Coliform Bacteria ◽  
Municipal Sewage ◽  
Aquatic Environments ◽  
Limited Information ◽  
Human Pathogens ◽  
E Coli

ABSTRACT Shiga toxin-producing Escherichia coli strains are human pathogens linked to hemorrhagic colitis and hemolytic uremic syndrome. The major virulence factors of these strains are Shiga toxins Stx1 and Stx2. The majority of the genes coding for these toxins are borne by bacteriophages. Free Stx2-encoding bacteriophages have been found in aquatic environments, but there is limited information about the lysogenic strains and bacteria present in the environment that are susceptible to phage infection. The aim of this work was to study the prevalence and the distribution of the stx 2 gene in coliform bacteria in sewage samples of different origins. The presence of the stx 2 gene was monitored every 2 weeks over a 1-year period in a municipal sewage treatment plant. A mean value of 102 genes/ml was observed without significant variation during the study period. This concentration was of the same order of magnitude in raw municipal sewage of various origins and in animal wastewater from several slaughterhouses. A total of 138 strains carrying the stx 2 gene were isolated by colony hybridization. This procedure detected approximately 1 gene-carrying colony per 1,000 fecal coliform colonies in municipal sewage and around 1 gene-carrying colony per 100 fecal coliform colonies in animal wastewaters. Most of the isolates belonged to E. coli serotypes other than E. coli O157, suggesting a low prevalence of strains of this serotype carrying the stx 2 gene in the wastewater studied.

scholarly journals Clonal Dissemination of a CTX-M-15 β-Lactamase-Producing Escherichia coli Strain in the Paris Area, Tunis, and Bangui

2006 ◽  
Vol 50 (7) ◽  
pp. 2433-2438 ◽  
Author(s):  
M. Lavollay ◽  
K. Mamlouk ◽  
T. Frank ◽  
A. Akpabie ◽  
B. Burghoffer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Geographic Region ◽  
Coli Strain ◽  
E Coli ◽  
Paris Area ◽  
The Common ◽  
Repetitive Extragenic Palindromic Pcr

ABSTRACT One hundred twenty CTX-M-15-producing Escherichia coli strains isolated in 10 different hospitals from Paris (France), in the Hospital Charles Nicolle in Tunis (Tunisia), and in the Pasteur Institute in Bangui, Central African Republic (CAR), between 2000 and 2004 were studied. Eighty isolates, recovered from the three countries, were clonally related by repetitive extragenic palindromic PCR and pulsed-field gel electrophoresis. Various resistance profiles were identified among these clonal strains. After conjugation or electroporation of plasmids from E. coli strains representative of each profile and each geographic region, we observed seven resistance profiles in the recipient strains. Incompatibility typing showed that all the plasmids transferred from the clonal strains studied, except one, belonged to the incompatibility group FII. They all shared a multidrug resistance region (MDR) resembling the MDR region located in pC15-1a, a plasmid associated with an outbreak of a CTX-M-15-producing E. coli strain in Canada. They also shared the common backbone of an apparent mosaic plasmid, including several features present in pC15-1a and in pRSB107, a plasmid isolated from a sewage treatment plant. This study suggests that although the plasmid-borne bla CTX-M-15 gene could be transferred horizontally, its dissemination between France, Tunisia, and CAR was due primarily to its residence in an E. coli clone with a strong propensity for dissemination.

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