Acute pollution of recipients in urban areas

1997 ◽  
Vol 36 (8-9) ◽  
pp. 179-184 ◽  
Author(s):  
W. Rauch ◽  
P. Harremoës
Keyword(s):  
Water Pollution ◽  
Urban Areas ◽  
Deterministic Model ◽  
Treatment Plant ◽  
Drainage System ◽  
Ammonia Concentration ◽  
Total System ◽  
Continuous Simulation ◽  
Operational Modes ◽  
Positive Effect

Oxygen and ammonia concentration are key parameters of acute water pollution in urban rivers. These two abiotic parameters are statistically assessed for a historical rain series by means of a simplified deterministic model of the integrated drainage system. Continuous simulation of the system performance indicates that acute water pollution is caused by intermittent discharges from both sewer system and wastewater treatment plant. Neglecting one of them in the evaluation of the environmental impact gives a wrong impression of total system behavior. Detention basins and alternative operational modes in the treatment plant under wet weather loading have a limited positive effect for minimizing acute water pollution.

The importance of the treatment plant performance during rain to acute water pollution

1996 ◽  
Vol 34 (3-4) ◽  
pp. 1-8 ◽  
Author(s):  
W. Rauch ◽  
P. Harremoës
Keyword(s):  
Water Pollution ◽  
Deterministic Model ◽  
Water Quality Management ◽  
Treatment Plant ◽  
Drainage System ◽  
Oxygen Depletion ◽  
Plant Performance ◽  
Total System ◽  
Combined Sewer Overflows ◽  
The Difference

Rain causes not only pollution loads from combined sewer overflows but also from treatment plants. High hydraulic load conditions can affect the secondary clarifier performance, resulting in a massive loss of sludge from the plant. The consequence to the oxygen concentration in the recipient can be described by the same simplified mechanism, because the principle remains the same. The difference that has to be accounted for, is the different organic characteristics of the discharged water. The analysis of a hypothetical urban drainage system by means of a deterministic model reveals the importance of the treatment plant in this respect. Oxygen depletion in urban rivers is caused by intermittent discharges from both sewer system and wastewater treatment plant. Neglecting one of them in the evaluation of the environmental impact gives a wrong impression of total system behavior. Linear sensitivity analysis provides useful information for water quality management. The significant parameters in terms of acute water pollution are identified.

scholarly journals Predicted and Measured Concentration of Pharmaceuticals in Surface Water of Areas with Increasing Anthropic Pressure: A Case Study in the Coastal Area of Central Italy

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2807
Author(s):  
Alessio Cardini ◽  
Elisa Pellegrino ◽  
Laura Ercoli
Keyword(s):  
Surface Water ◽  
Rural Areas ◽  
Urban Areas ◽  
Central Italy ◽  
Treatment Plant ◽  
Drainage System ◽  
Measured Concentration ◽  
Environmental Concentration ◽  
Anthropic Pressure

This study investigated the occurrence of 12 pharmaceuticals (PhCs) in surface water in Central Italy, aiming to improve the estimation of the predicted environmental concentration (PEC) by normalizing the loads to the number of inhabitants of the drainage system in rural, periurban, and urban areas. We performed two sampling campaigns assessing the concentration of PhCs (measured environmental concentration (MEC)) in surface water and in effluent from a wastewater treatment plant. The reliability of PEC calculated by the refined formula was assessed and compared to the ratio obtained by the unrefined formula. MECs of diclofenac, estradiol, estrone, ibuprofen, metformin, naproxen, sulfamethoxazole, atenolol, carbamazepine, and dehydro-erythromycin were significantly higher in urban than in periurban and rural areas, and increases were 12-, 3600-, 256-, 33-, 18-, 120-, 10-, 5-, 2-, and 1-fold, respectively. Refinement of PEC improved estimation of PhC concentrations for all areas, especially for the urban one. The environmental risk was predicted as low for atenolol, carbamazepine, erythromycin, metformin, and naproxen; low/medium for diclofenac and ibuprofen; and high for clarithromycin, estradiol, estrone, and sulfamethoxazole. Overall, the highest risk was posed by PhCs in effluent, while a progressively decreasing risk was estimated for urban, periurban, and rural areas.

A Study of the Planning of Water Pollution Control for Second Songhua River in China

1991 ◽  
Vol 23 (1-3) ◽  
pp. 41-48
Author(s):  
Yin Jun
Keyword(s):  
Water Pollution ◽  
Mathematical Model ◽  
Pollution Control ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Initial Structure ◽  
Stable Model ◽  
Control Plan ◽  
Songhua River ◽  
The Second Songhua River

The paper takes the Second Songhua River as an object for research and selects Thomas's BOD-DO stable model as the initial structure on the basis of overall investigations and analyses on water pollution in every reach. In view of the characteristics of the river being located at the north, values k’1, k’2 and k’3 in dry season of winter were determined and calculated, and a series analyses have been made. The self-purification ability of the river and the total elimination amount of the main pollutants BOD5 were also calculated. In order to minimize the required cost, we distributed the cost to the main pollution sources, which are to be controlled. We firstly set a cost function of sewage treatment plant by series design and calculated the related cost parameters, then calculated two kinds of optimal distributing models of BOD5 elimination, which were a mathematical model of extreme value of conditions and a matrix mathematical model. Now they have been applied to the practical pollution control plan for the Second Songhua River.

Treatment of tunnel wash water and implications for its disposal

2014 ◽  
Vol 69 (10) ◽  
pp. 2029-2035 ◽  
Author(s):  
M. Hallberg ◽  
G. Renman ◽  
L. Byman ◽  
G. Svenstam ◽  
M. Norling
Keyword(s):  
Traffic Safety ◽  
Urban Areas ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Particulate Material ◽  
Wash Water ◽  
Polluted Water ◽  
Solids Concentration ◽  
Low Concentrations ◽  
Road Tunnels

The use of road tunnels in urban areas creates water pollution problems, since the tunnels must be frequently cleaned for traffic safety reasons. The washing generates extensive volumes of highly polluted water, for example, more than fivefold higher concentrations of suspended solids compared to highway runoff. The pollutants in the wash water have an affinity for particulate material, so sedimentation should be a viable treatment option. In this study, 12 in situ sedimentation trials were carried out on tunnel wash water, with and without addition of chemical flocculent. Initial suspended solids concentration ranged from 804 to 9,690 mg/L. With sedimentation times of less than 24 hours and use of a chemical flocculent, it was possible to reach low concentrations of suspended solids (<15 mg/L), PAH (<0.1 μg/L), As (<1.0 μg/L), Cd (<0.05 μg/L), Hg (<0.02 μg/L), Fe (<200 μg/L), Ni (<8 μg/L), Pb (<0.5 μg/L), Zn (<60 μg/L) and Cr (<8 μg/L). Acute Microtox® toxicity, mainly attributed to detergents used for the tunnel wash, decreased significantly at low suspended solids concentrations after sedimentation using a flocculent. The tunnel wash water did not inhibit nitrification. The treated water should be suitable for discharge into recipient waters or a wastewater treatment plant.

scholarly journals Toward Decentralised Sanitary Sewage Collection Systems: A Multiobjective Approach for Cost-Effective and Resilient Designs

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1886
Author(s):  
Arezoo Zahediasl ◽  
Amin E. Bakhshipour ◽  
Ulrich Dittmer ◽  
Ali Haghighi
Keyword(s):  
Treatment Plant ◽  
Drainage System ◽  
Cost Effective ◽  
Optimization Approach ◽  
Hydraulic Design ◽  
Multiobjective Approach ◽  
Layout Generation ◽  
Plant Allocation ◽  
Problem Solving Process

In recent years, the concept of a centralized drainage system that connect an entire city to one single treatment plant is increasingly being questioned in terms of the costs, reliability, and environmental impacts. This study introduces an optimization approach based on decentralization in order to develop a cost-effective and sustainable sewage collection system. For this purpose, a new algorithm based on the growing spanning tree algorithm is developed for decentralized layout generation and treatment plant allocation. The trade-off between construction and operation costs, resilience, and the degree of centralization is a multiobjective problem that consists of two subproblems: the layout of the networks and the hydraulic design. The innovative characteristics of the proposed framework are that layout and hydraulic designs are solved simultaneously, three objectives are optimized together, and the entire problem solving process is self-adaptive. The model is then applied to a real case study. The results show that finding an optimum degree of centralization could reduce not only the network’s costs by 17.3%, but could also increase its structural resilience significantly compared to fully centralized networks.

Integrated modelling: comparison of state variables, processes and parameters in sewer and wastewater treatment plant models

1997 ◽  
Vol 36 (5) ◽  
pp. 373-380 ◽  
Author(s):  
C. Fronteau ◽  
W. Bauwens ◽  
P.A. Vanrolleghem
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Drainage System ◽  
Integrated Modelling ◽  
Urban Drainage ◽  
State Variables ◽  
Sewer System ◽  
Wastewater Treatment Process ◽  
Urban Drainage System

All the parts of an urban drainage system, i.e. the sewer system, the wastewater treatment plant (WWTP) and the river, should be integrated into one single model to assess the performance of the overall system and for the development of design and control strategies assisting in its sustainable and cost effective management. Existing models for the individual components of the system have to be merged in order to develop the integrated tool. One of the problems arising from this methodology is the incompatibility of state variables, processes and parameters used in the different modelling approaches. Optimisation of an urban drainage system, and of the wastewater treatment process in particular, requires a good knowledge of the wastewater composition. As important transformations take place between the emission from the household and the arrival at the treatment facility, sewer models should include these transformations in the sewer system. At present, however, research is still needed in order to increase our knowledge of these in-sewer processes. A comparison of the state variables, processes and parameters has been carried out in both sewer models (SMs) and activated sludge models (ASMs). An ASM approach is used for the description of reactions in sewer models. However, a difference is found in the expression for organic material (expressed in terms of BOD) and heterotrophic biomass is absent as a state variable, resulting in differences in processes and parameters. Reconciliation of both the models seems worthwhile and a preliminary solution is suggested in this paper.

scholarly journals Modelling Pluvial Flooding in Urban Areas Coupling the Models Iber and SWMM

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2647
Author(s):  
Esteban Sañudo ◽  
Luis Cea ◽  
Jerónimo Puertas
Keyword(s):  
Urban Areas ◽  
Flow Model ◽  
Overland Flow ◽  
Drainage System ◽  
Urban Drainage ◽  
Dynamic Link Library ◽  
Storm Water Management Model ◽  
Urban Street ◽  
Sewer Network ◽  
Overland Flow Model

Dual urban drainage models allow users to simulate pluvial urban flooding by analysing the interaction between the sewer network (minor drainage system) and the overland flow (major drainage system). This work presents a free distribution dual drainage model linking the models Iber and Storm Water Management Model (SWMM), which are a 2D overland flow model and a 1D sewer network model, respectively. The linking methodology consists in a step by step calling process from Iber to a Dynamic-link Library (DLL) that contains the functions in which the SWMM code is split. The work involves the validation of the model in a simplified urban street, in a full-scale urban drainage physical model and in a real urban settlement. The three study cases have been carefully chosen to show and validate the main capabilities of the model. Therefore, the model is developed as a tool that considers the main hydrological and hydraulic processes during a rainfall event in an urban basin, allowing the user to plan, evaluate and design new or existing urban drainage systems in a realistic way.

Model-based evaluation of a new upgrading concept for N-removal

2002 ◽  
Vol 45 (6) ◽  
pp. 169-176 ◽  
Author(s):  
S. Salem ◽  
D. Berends ◽  
J.J. Heijnen ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Mathematical Modelling ◽  
Scale Up ◽  
Treatment Plant ◽  
Ammonia Concentration ◽  
Pilot Scale ◽  
Full Scale ◽  
Model Based ◽  
N Removal ◽  
Quantitative Basis ◽  
Treatment Concepts

Mathematical modelling is considered a time and cost-saving tool for evaluation of new wastewater treatment concepts. Modelling can help to bridge the gap between lab and full-scale application. Bio-augmentation can be used to obtain nitrification in activated sludge systems with a limited aerobic sludge retention time. In the present study the potential for augmenting the endogenous nitrifying population is evaluated. Implementing a nitrification reactor in the sludge return line fed with sludge liquor with a high ammonia concentration leads to augmentation of the native nitrifying population. Since the behaviour of nitrifiers is relatively well known, a choice was made to evaluate this new concept mainly based on mathematical modelling. As an example an existing treatment plant (wwtp Walcheren, The Netherlands) that needed to be upgraded was used. A mathematical model, based on the TUDP model and implemented in AQUASIM was developed and used to evaluate the potential of this bioaugmentation in the return sludge line. A comparison was made between bio-augmentation and extending the existing aeration basins and anoxic tanks. The results of both modified systems were compared to give a quantitative basis for evaluation of benefits gained from such a system. If the plant is upgraded by conventional extension it needs an increase in volume of about 225%; using a bioaugmentation in the return sludge line the total volume of the tanks needs to be expanded by only 75% (including the side stream tanks). Based on the modelling results a decision was made to implement the bioaugmentation concept at full scale without further pilot scale testing, thereby strongly decreasing the scale-up period for this process.

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