scholarly journals Impacts of onsite greywater reuse on wastewater systems

2017 ◽  
Vol 75 (8) ◽  
pp. 1862-1872 ◽  
Author(s):  
Roni Penn ◽  
Manfred Schütze ◽  
Jens Alex ◽  
Eran Friedler
Keyword(s):  
Urban Areas ◽  
Process Model ◽  
Field Experiments ◽  
Wastewater Treatment Plants ◽  
Domestic Wastewater ◽  
Sewer Systems ◽  
Case Study Site ◽  
Wastewater Systems ◽  
Greywater Reuse

Together with significant water savings that onsite greywater reuse (GWR) may provide, it may also affect the performance of urban sewer systems and wastewater treatment plants (WWTPs). In order to examine these effects, an integrated stochastic simulation system for GWR in urban areas was developed. The model includes stochastic generators of domestic wastewater streams and gross solids (GSs), a sewer network model which includes hydrodynamic simulation and a GS transport module, and a dynamic process model of the WWTP. The developed model was applied to a case study site in Israel. For the validation of the sewer simulator, field experiments in a real sewer segment were conducted. The paper presents the integration and implementation of these modules and depicts the results of the effects of various GWR scenarios on GS movement in sewers and on the performance of the WWTP.

Design and Operation of Small Wastewater Treatment Plants by the Microbial Film Process

1990 ◽  
Vol 22 (3-4) ◽  
pp. 139-144 ◽  
Author(s):  
S. Iwai ◽  
Y. Oshino ◽  
T. Tsukada
Keyword(s):  
Urban Areas ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
Small Scale ◽  
Small Communities ◽  
Fishing Villages ◽  
Sewer Systems ◽  
Water Treatment Plants ◽  
History Of ◽  
Microbial Film

Although the ratio of sewer systems to population in Japan has been improving in recent years, the construction of sewer systems in small communities such as farming or fishing villages, etc. had lagged behind that of urban areas. However, construction of small-scale sewer systems in farming and fishing villages has been actively carried out in recent years. This report explains the history of the promotion of small-scale sewer systems, why submerged filter beds are being employed in many cases, and introduces the design, operation and maintenance of representative waste-water treatment plants in farming and fishing villages which incorporate de-nitrogen and dephosphorization.

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.

scholarly journals Evaluating the performance of a simple phenomenological model for online forecasting of ammonium concentrations at WWTP inlets

2020 ◽  
Vol 81 (1) ◽  
pp. 109-120 ◽  
Author(s):  
Luca Vezzaro ◽  
Jonas Wied Pedersen ◽  
Laura Holm Larsen ◽  
Carsten Thirsing ◽  
Lene Bassø Duus ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Integrated Control ◽  
Model Performance ◽  
Forecast Model ◽  
Flow Sensors ◽  
Sewer Systems ◽  
Wastewater Systems ◽  
Water Quality Forecasting ◽  
Modelling Approach

Abstract A simple model for online forecasting of ammonium (NH4+) concentrations in sewer systems is proposed. The forecast model utilizes a simple representation of daily NH4+ profiles and the dilution approach combined with information from online NH4+ and flow sensors. The method utilizes an ensemble approach based on past observations to create model prediction bounds. The forecast model was tested against observations collected at the inlet of two wastewater treatment plants (WWTPs) over an 11-month period. NH4+ data were collected with ion-selective sensors. The model performance evaluation focused on applications in relation to online control strategies. The results of the monitoring campaigns highlighted a high variability in daily NH4+ profiles, stressing the importance of an uncertainty-based modelling approach. The maintenance of the NH4+ sensors resulted in important variations of the sensor signal, affecting the evaluation of the model structure and its performance. The forecast model succeeded in providing outputs that potentially can be used for integrated control of wastewater systems. This study provides insights on full scale application of online water quality forecasting models in sewer systems. It also highlights several research gaps which – if further investigated – can lead to better forecasts and more effective real-time operations of sewer and WWTP systems.

scholarly journals Full-scale practice of domestic wastewater source separation and collection in a semicentralized treatment system: a case study

2018 ◽  
Vol 78 (10) ◽  
pp. 2193-2203 ◽  
Author(s):  
Xueli Ren ◽  
Hongbin Chen ◽  
Yong Cheng ◽  
Luxue Wu ◽  
Haixin Jiang
Keyword(s):  
Urban Areas ◽  
Domestic Wastewater ◽  
Domestic Sewage ◽  
Full Scale ◽  
Office Building ◽  
Practical Significance ◽  
Public Building ◽  
Future Design ◽  
System A

Abstract Semicentralized supply and treatment systems (SCSTSs), which can realize water, nutrition, and energy recycling via separate water supply and discharge systems, have been developed for fast-growing urban areas. The world's first full-scale SCSTS was implemented in Qingdao in China. Greywater (GW) and blackwater (BW) are collected and treated separately, but the parallel setting of the BW and GW pipelines means that connection mistakes can easily occur. Taking Qingdao as an example, this article analyzes the occurrences of BW and GW pipeline misconnections and the changes in influent pollutants, to assess the feasibility of separating domestic sewage at the source. The misconnection rates were estimated by comparing the measured values with the theoretical values. The results show that cross-connections occurred in some buildings, and the average misconnection rates were 31.9%, 15.2%, 60.6%, and 0.2%, respectively, in hotels, residences, an office building, and a public building. The overall misconnection rate in the SCSTS was 27.9%. These findings suggest that measures should be taken to avoid or reduce misconnections. This study can provide a reference for the future design and construction of SCSTSs and has important practical significance for protecting the environment.

scholarly journals Decentralized domestic wastewater systems in developing countries: the case study of Harare (Zimbabwe)

2016 ◽  
Vol 7 (3) ◽  
pp. 1069-1078 ◽  
Author(s):  
Innocent Chirisa ◽  
Elmond Bandauko ◽  
Abraham Matamanda ◽  
Gladys Mandisvika
Keyword(s):  
Developing Countries ◽  
Domestic Wastewater ◽  
Wastewater Systems

scholarly journals Investigation into untreated greywater reuse practices by suburban households under the threat of intermittent water supply

2019 ◽  
Vol 9 (4) ◽  
pp. 627-634 ◽  
Author(s):  
N. Nel ◽  
H. E. Jacobs
Keyword(s):  
Distribution System ◽  
Potable Water ◽  
Water Source ◽  
Online Forums ◽  
Household Level ◽  
Suburban Communities ◽  
Case Study Site ◽  
The City ◽  
Greywater Reuse

Abstract Untreated greywater reuse at the household level is an accessible water source to supplement non-potable water requirements in times of emergency water curtailments but poses various risks to the consumer, the wider community, infrastructure and the environment. Little information is known about unregulated, untreated greywater reuse practices under emergency conditions in suburban communities where consumers have become accustomed to reliable potable water supplied via a pressurised, piped distribution system. There is a lack of knowledge regarding the sources of greywater used, collection methods, storage and distribution of greywater, the application points, the level of treatment (if any) and the perceived risks associated with the greywater reuse. The City of Cape Town was selected as a case study site for research into greywater reuse under the threat of ‘Day Zero’ and stringent water restrictions, implemented during the 2017/2018 summer season. A consumer survey and analysis of relevant online forums was conducted in order to obtain the necessary information. Greywater reuse practices from a sample group of 351 consumers were identified and classified. Untreated greywater reuse was found to be common, mainly for garden irrigation and toilet flushing. The results point to high-risk activities in the study group.

scholarly journals Adapted optimization model for planning regional wastewater systems: case study

2017 ◽  
Vol 76 (5) ◽  
pp. 1196-1205 ◽  
Author(s):  
J. A. Zeferino ◽  
M. C. Cunha ◽  
A. P. Antunes
Keyword(s):  
Water Quality ◽  
Economies Of Scale ◽  
Simulated Annealing Algorithm ◽  
Wastewater Treatment Plants ◽  
Environmental Parameters ◽  
Treated Wastewater ◽  
Planning Approach ◽  
Wastewater Systems ◽  
Pump Stations

Wastewater systems are of crucial importance to the promotion of sustainable development. Through an integrated planning approach, the costs can be minimized and the resulting benefits maximized. A planning approach at regional level exploits the economies of scale, while achieving a better environmental performance. In this paper we set out a decision support approach for the planning of regional wastewater systems. Optimization models are used, aimed at finding optimal configurations for the location, type and size of the system's infrastructure: sewers, pump stations, and wastewater treatment plants. Solutions are evaluated in terms of the cost of installing, operating and maintaining the infrastructure, and the water quality in the river that receives the treated wastewater. The river water quality varies in accordance with the effluent discharges, and is assessed using environmental parameters. The models are solved with a simulated annealing algorithm complemented by a local improvement procedure. Its application is illustrated through a case study in the Una river basin region, in Brazil.

scholarly journals Conventional Sewer Systems Are Too Time-Consuming, Costly and Inflexible to Meet the Challenges of the 21st Century

2020 ◽  
Vol 12 (16) ◽  
pp. 6518 ◽  
Author(s):  
Gunilla Öberg ◽  
Geneviève S. Metson ◽  
Yusuke Kuwayama ◽  
Steven A. Conrad
Keyword(s):  
Population Growth ◽  
21St Century ◽  
Urban Areas ◽  
Future Generation ◽  
Conventional Model ◽  
Sewer Systems ◽  
The World ◽  
The Future

There is an urgent need for innovation in the sanitation sector because the conventional model (toilet-to-sewer-to-treatment) is too time-consuming and costly, and alternatives are lacking. We estimate the challenge ahead by developing scenarios for 60 of the fastest-growing urban conglomerates in the World. We find that the majority would need to build out their sewer systems at a rate that is ten to 50 times higher than the highest rate for any project in the World Bank’s database, which is unrealistic. We also carry out a case study of Lagos, Nigeria, which suggests that, in any given year, 14–37% of Lagos State’s budget would need to be invested to provide sanitation to the presently underserviced population while keeping up with population growth, which also is unrealistic. Our study provides clear evidence that the conventional model for sanitation is unworkable for rapidly growing urban areas. We conclude there is an urgent need to encourage and fund projects that promote innovations that can tackle the three core challenges: can be built sufficiently quickly, are flexible, and affordable. This is not likely to happen unless the future generation is systematically trained and educated to creatively support innovation in sustainable sanitation.

scholarly journals Groundwater Contribution to Sewer Network Baseflow in an Urban Catchment-Case Study of Pin Sec Catchment, Nantes, France

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 689
Author(s):  
Fabrice Rodriguez ◽  
Amélie-Laure Le Delliou ◽  
Hervé Andrieu ◽  
Jorge Gironás
Keyword(s):  
Urban Areas ◽  
Soil Parameters ◽  
Catchment Scale ◽  
Urban Catchment ◽  
Groundwater Levels ◽  
Sewer Systems ◽  
Sewer Network ◽  
Urban Catchments ◽  
Groundwater Contribution

Sewer systems affect urban soil characteristics and subsoil water flow. The direct connection observed between baseflow in sewer systems under drainage infiltrations and piezometric levels influences the hydrological behavior of urban catchments, and must consequently be considered in the hydrologic modeling of urban areas. This research studies the groundwater contribution to sewer networks by first characterizing the phenomenon using experimental data recorded on a small urban catchment in Nantes (France). Then, the model MODFLOW was used to simulate the infiltration of groundwater into a sewer network and model dry weather flows at an urban catchment scale. This application of MODFLOW requires representing, in a simplified way, the interactions between the soil and the sewer trench, which acts as a drain. Observed average groundwater levels were satisfactorily simulated by the model while the baseflow dynamics is well reproduced. Nonetheless, soil parameters resulted to be very sensitive, and achieving good results for joint groundwater levels and baseflow was not possible.

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