Legionella prevalence in wastewater treatment plants of Taiwan

2009 ◽  
Vol 60 (5) ◽  
pp. 1303-1310 ◽  
Author(s):  
S. W. Huang ◽  
B. M. Hsu ◽  
P. H. Ma ◽  
K. T. Chien
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Domestic Wastewater ◽  
Aquatic Environments ◽  
Human Pathogens ◽  
Wastewater Systems

Legionella is a bacterium that is ubiquitous in natural and artificial aquatic environments. Some species of Legionella are recognized as opportunistic potential human pathogens. We investigated the distribution of Legionella at seventeen WWTPs throughout Taiwan. Legionella were detected in 10 of the 17 WWTPs (58.8%) and 25 of 41 samples (61.0%). In the integrated, hospital, industrial and domestic wastewater systems were 13/18 (72.2%), 7/12 (58.3%), 2/7 (28.6%) and 3/4 (75.0%) of the samples were positive for Legionella, respectively. The most frequently encountered species were L. donaldsonii and uncultured L. spp., which were both found in 10 samples (24.4% of all samples), then followed by L. lytica (4.9%) and L. pneumophila (4.9%). L. anisa was detected in one sample (2.4%). The results of this survey confirm that Legionella are ubiquitous in WWTPs in Taiwan. Therefore, long-term investigations should be conducted to evaluate the overall occurrence of Legionella in WWTPs in Taiwan.

Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands

1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Housing Stock ◽  
Research Work ◽  
Field Research ◽  
Domestic Wastewater ◽  
Research Programme ◽  
Definition Of

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.

scholarly journals Broad diversity of bacteria degrading 17ß-estradiol-3-sulfate isolated from river sediment and biofilm at a wastewater treatment plant discharge

2021 ◽  
Author(s):  
Tamara Mainetti ◽  
Marilena Palmisano ◽  
Fabio Rezzonico ◽  
Blaž Stres ◽  
Susanne Kern ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
River Sediment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Aquatic Environments ◽  
Bacterial Isolates ◽  
Degrading Bacteria ◽  
17Β Estradiol ◽  
Aquatic Wildlife ◽  
Harmful Effects

AbstractConjugated estrogens, such as 17β-estradiol-3-sulfate (E2-3S), can be released into aquatic environments through wastewater treatment plants (WWTP). There, they are microbiologically degraded into free estrogens, which can have harmful effects on aquatic wildlife. Here, the degradation of E2-3S in environmental samples taken upstream, downstream and at the effluent of a WWTP was assessed. Sediment and biofilm samples were enriched for E2-3S-degrading microorganisms, yielding a broad diversity of bacterial isolates, including known and novel degraders of estrogens. Since E2-3S-degrading bacteria were also isolated in the sample upstream of the WWTP, the WWTP does not influence the ability of the microbial community to degrade E2-3S.

scholarly journals Long-term investigation of phosphorus removal by iron electrocoagulation in small-scale wastewater treatment plants

2018 ◽  
Vol 78 (6) ◽  
pp. 1304-1311 ◽  
Author(s):  
I. Mishima ◽  
M. Hama ◽  
Y. Tabata ◽  
J. Nakajima
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Phosphorus Release ◽  
Small Scale ◽  
Operational Conditions ◽  
Long Time ◽  
Negative Effect ◽  
Iron Electrolysis

Abstract Small-scale wastewater treatment plants (SWTPs), called Johkasou, are widely used as decentralized and individual wastewater treatment systems in sparsely populated areas in Japan. Even in SWTPs, nutrients should be removed to control eutrophication. An iron electrolysis method is effective to remove phosphorus chemically in SWTPs. However, it is necessary to determine the precise conditions under which phosphorus can be effectively and stably removed in full scale SWTPs for a long period. Therefore, long-term phosphorus removal from SWTPs was investigated and optimum operational conditions for phosphorus removal by iron electrolysis were analyzed in this study. Efficient phosphorus removal can be achieved for a long time by adjusting the amount of iron against the actual population equivalent. The change of the recirculation ratio had no negative effect on overall phosphorus removal. Phosphorus release to the bulk phase was prevented by the accumulated iron, which was supplied by iron electrolysis, resulting in stable phosphorus removal. The effect of environmental load reduction due to phosphorus removal by iron electrolysis was greater than the cost of power consumption for iron electrolysis.

Model-based evaluation of nitrogen removal in a tannery wastewater treatment plant

2004 ◽  
Vol 50 (6) ◽  
pp. 251-260 ◽  
Author(s):  
M.S. Moussa ◽  
A.R. Rojas ◽  
C.M. Hooijmans ◽  
H.J. Gijzen ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Computer Modelling ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Plant Performance ◽  
Accurate Estimation ◽  
Model Parameters ◽  
Biological Tests

Computer modelling has been used in the last 15 years as a powerful tool for understanding the behaviour of activated sludge wastewater treatment systems. However, computer models are mainly applied for domestic wastewater treatment plants (WWTPs). Application of these types of models to industrial wastewater treatment plants requires a different model structure and an accurate estimation of the kinetics and stoichiometry of the model parameters, which may be different from the ones used for domestic wastewater. Most of these parameters are strongly dependent on the wastewater composition. In this study a modified version of the activated sludge model No. 1 (ASM 1) was used to describe a tannery WWTP. Several biological tests and complementary physical-chemical analyses were performed to characterise the wastewater and sludge composition in the context of activated sludge modelling. The proposed model was calibrated under steady-state conditions and validated under dynamic flow conditions. The model was successfully used to obtain insight into the existing plant performance, possible extension and options for process optimisation. The model illustrated the potential capacity of the plant to achieve full denitrification and to handle a higher hydraulic load. Moreover, the use of a mathematical model as an effective tool in decision making was demonstrated.

Using metazoa to reduce sludge production

1997 ◽  
Vol 36 (11) ◽  
pp. 171-179 ◽  
Author(s):  
J. H. Rensink ◽  
W. H. Rulkens
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Brewery Wastewater ◽  
Trickling Filters ◽  
Starting Point ◽  
Nitrification Process ◽  
Sludge Production

Pilot plant experiments have been carried out to study the mineralization of sludge from biological wastewater treatment plants by worms such as Tubificidae. Trickling filters filled with lava slags were continuously fed with a certain quantity of excess activated sludge of a Dutch brewery wastewater treatment plant (Bavaria) by recirculation during 10 to 14 days. At the starting point of each experiment the trickling filters were inoculated with Tubificidae. Recirculation of sludge showed that use of Tubificidae resulted in a COD reduction of the sludge (mixed liquor) of 18–67–. Without worms this reduction was substantially lower. The sludge production in a pilot activated sludge system for treating settled domestic wastewater reduced from 0.40 to 0.15 g MLSS/g COD removed when Tubificidae were added to the system. The lower amounts of sludge were always accompanied by an increase of nitrate and phosphate concentration in the wastewater. There was no disturbance of the nitrification process. Application of Tubificidae or other worms may have interesting potential for practical application.

Lessons learnt from evaluating full-scale ammonium feedback control in three large wastewater treatment plants

2014 ◽  
Vol 69 (7) ◽  
pp. 1573-1580 ◽  
Author(s):  
L. Åmand ◽  
C. Laurell ◽  
K. Stark-Fujii ◽  
A. Thunberg ◽  
B. Carlsson
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Full Scale ◽  
Feedback Controllers ◽  
Energy Assessment ◽  
Different Types ◽  
Term Evaluation ◽  
Save Energy

Three large wastewater treatment plants in Sweden participate in a project evaluating different types of ammonium feedback controllers in full-scale operation. The goal is to improve process monitoring, maintain effluent water quality and save energy. The paper presents the outcome of the long-term evaluation of controllers. Based on the experiences gained from the full-scale implementations, a discussion is provided about energy assessment for the purpose of comparing control strategies. The most important conclusions are the importance of long-term experiments and the difficulty of comparing energy consumption based on air flow rate measurements.

Experimental study on sequencing batch biofilm reactor with biological filtration (SBBR-BF) for wastewater treatment

2004 ◽  
Vol 48 (11-12) ◽  
pp. 299-307 ◽  
Author(s):  
T.W. Li ◽  
Y.Z. Peng ◽  
Y.Y. Wang ◽  
G.B. Zhu ◽  
W.Q. Chi ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Laboratory Experiment ◽  
Wastewater Treatment Plants ◽  
Domestic Wastewater ◽  
Biofilm Reactor ◽  
Treatment Technology ◽  
Biological Filtration ◽  
Efficient System ◽  
Filtration Cycle ◽  
Sequencing Batch Biofilm Reactor

A novel wastewater treatment technology combining a sequencing batch biofilm reactor and biological filtration in an SBBR-BF system was presented. Elastic plastic filaments were fixed as biofilms carrying media. Particle materials (sand or anthracite) and the settled sludge constituted the filtration layer. In the laboratory studies, operating results of SBR, SBBR and SBBR-BF were compared. Better quality and stable water quality of effluent could be achieved in SBBR-BF because the fixed film and filtration layer were added in the reactor. Other laboratory experiment results indicated that slow filtration, cycle water stirring and backwashing making use of the settled supernatant are successful methods for preventing clogging and saving energy. The velocity and headloss of filtration were significantly impacted by different MLSS concentration. The MLSS concentration in the reactor must be less than 1,400 mg/L for optimal results. The average velocity of filtration ranging from 0.6 to 1.0 m/h, the backwash velocity of 10–15 m/h and the backwash time of 20 seconds are recommended according to the laboratory experiment. On-site experiment and study showed that SBBR-BF is a stable and efficient system for domestic wastewater treatment, and is particularly suited for small wastewater treatment plants, because of the simple operation and compact installation.

scholarly journals Quality control of wastewater treatment operational data by continuous mass balancing: dealing with missing measurements and delayed outputs

2015 ◽  
Vol 50 (3) ◽  
pp. 228-239
Author(s):  
A. Spindler ◽  
J. Krampe
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Mass Conservation ◽  
Missing Measurements ◽  
Daily Data ◽  
Continuous Mass ◽  
Mass Balancing ◽  
Operational Data

Continuous mass balancing defines a new standard in data quality validation. Likewise relying on the principles of mass conservation it outperforms long-term static mass balancing approaches because faults in data can be assigned to their time of occurrence. This research was carried out with practical application to routine operational data in mind and two major aspects are investigated to make this application feasible. Sludge concentrations of typically balanced components (chemical oxygen demand, total nitrogen, total phosphate) are not routinely measured in wastewater treatment plants. Therefore they need to be determined from alternative, more frequent measurements such as total suspended solids. To provide the necessary statistical basis for such determination, monthly sludge sampling was found sufficient. Further, contrary to long-term static mass balancing, the effects of delay between input and output loads must not be neglected in continuous mass balancing based on daily data. While a storage/release approach did not give the desired results, the consideration of hydraulic retention (first-order flow dynamics) fundamentally improved the performance of the proposed method.

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