Modelling COD and N removal in the water and in the benthic biofilm for the River Wupper in Germany

2006 ◽  
Vol 53 (10) ◽  
pp. 163-171 ◽  
Author(s):  
M. Wichern ◽  
O. Kehl ◽  
V. Erbe ◽  
M. Luebken ◽  
P.A. Wilderer

The River Wupper, a tributary of the River Rhine, is at several locations influenced by anthropogenous nitrogen input, hydraulic structures, and influents from other tributaries. These influences have an impact both on the water quality and on the hydrodynamic conditions. The model approaches used for this article are based on work of Rauch et al. and the River Water Quality Model No. 1; they allow the simulation of the nitrogen conversion in the River Wupper. They are compatible with the activated sludge models and can thus be used also for integrated approaches. The calibration and validation of the model was realized using actual data of the River Wupper over a length of 60 km with one dam, 10 weirs, three wastewater treatment plants and 11 tributaries. The model considers the nitrogen conversion and COD removal and has a strong focus on biofilm processes in the benthic zone. Additional information is given about the sedimentation processes, the physical oxygen input processes, biofilm detachment processes, molecular diffusion, the influence of the laminar border layer and the changing of COD fractions and biofilm densities.

2001 ◽  
Vol 43 (5) ◽  
pp. 51-60 ◽  
Author(s):  
P. Reichert

Various simplifications of the river water quality model no. 1 are applied to data sets from the river Glatt in Switzerland. In a first application, the biomass responsible for nitrogen and oxygen conversion processes is quantified based on known reaeration rates, measured concentrations of ammonia, nitrite and oxygen and assumed growth parameters of algae and bacteria. In a second application, the model is extended to calculate chemical equilibria of inorganic carbon compounds dissolved in the water and daily variations in pH. The influence of partially unknown inflow concentrations and of calcite precipitation on fluctuations in electrical conductivity and pH are discussed. In the last model, the processes of growth of sessile algae and bacteria, detachment of algae, and grazing by benthic organisms are introduced. Due to lack of data for quantifying these processes, this last model application is speculative. Nevertheless, it is interesting because it shows a direction to which river water quality modelling would have to proceed in order to increase its predictive capabilities.


2014 ◽  
Vol 46 (3) ◽  
pp. 313-324 ◽  
Author(s):  
P. G. Whitehead ◽  
M. N. Futter ◽  
S. Comber ◽  
D. Butterfield ◽  
L. Pope ◽  
...  

The issues of diffuse and point source phosphorus (P) pollution in river systems are presented using a catchment model to assess nutrient behaviour, seasonal effluent standards and biosolid substitution. A process-based, dynamic water quality model (INCA-P) has been applied to four UK catchments, namely, the Rivers Tywi, Wensum, Lunan and Hampshire Avon, to simulate water fluxes, sediments, total phosphorus and soluble reactive phosphorus (SRP) concentrations. The model has been used to assess impacts of both agricultural runoff and point P sources from wastewater treatment plants (WWTPs) on water quality. With increasing costs for P fertilizer and P reduction at WWTPs, a strategy of recycling P from WWTPs as biosolids to substitute for fertilizers in vulnerable catchments has been investigated. Significant reductions in P concentrations are achieved if this substitution were implemented on a large scale. Reductions in SRP of between 6% and 41% can be achieved using this strategy. The effects of implementing new WWTP standards are shown to reduce SRP by 30%. Seasonal consent standards applied in only summer months could reduce SRP by 53% and achieve a substantial reduction in treatment costs year round.


Author(s):  
Erika Ruskule

Water wise use and conservation is one of the key prerequisites for economic sustainable development. Accession to the European Union, Latvia is committed to meeting the EU environmental requirements. Water Framework Directive (Directive 2000/60/EC, 2000) is a legal act, which provides water protection and sustainable management principles and tasks of the European Union. It provides uniform protection and management system for all waters: rivers, lakes, coastal waters and groundwater, providing that they must also achieve good water quality by 2015. year. The Directive provides for the identification of the current water situation and to obtain additional information by following the water monitoring and for basic background information to establish an action program to improve water quality. Therefore, the Latvian conditions are important to assess the flow of nutrients, their sources and amounts of Latvian detention basins using existing models and innovations in methods and model systems for the retention of part of the calculation. Therefore, in this publication are offered in various countries of the world models will be useful in Latvian processing of data.


2019 ◽  
Vol 22 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Mariacrocetta Sambito ◽  
Cristiana Di Cristo ◽  
Gabriele Freni ◽  
Angelo Leopardi

Abstract In the last decade, the growth of the micro-industry in urban areas has produced an increase in the frequency of xenobiotic polluting discharges in drainage systems. Wastewater treatment plants are usually characterized by low removal efficiencies in respect of such pollutants, which may have an acute or cumulative impact on environmental and public health. To facilitate the early isolation of illicit intrusions, this study aims to develop an approach for positioning water quality sensors based on the Bayesian decision network (BDN). The analysis is focused on soluble conservative pollutants, such as metals. The proposed methodology incorporates several sources of information, including network topology, flows and non-formal ‘grey’ information about the possible locations of contamination sources. The methodology is tested using two sewer systems with increasing complexity: a literature scheme from the Storm Water Management Model (SWMM) manual and a real combined sewer in Italy. In both cases, the approach identifies the optimal sensor location gaining advantage from additional information, which reduces the computational effort needed to obtain the solution. In the real case, the application of the method yielded a better solution with regards to the real position of the implemented sensor network.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.


1994 ◽  
Vol 29 (2-3) ◽  
pp. 221-232
Author(s):  
M.J. McCormick

Abstract Four one-dimensional models which have been used to characterize surface mixed layer (ML) processes and the thermal structure are described. Although most any model can be calibrated to mimic surface water temperatures, it does not imply that the corresponding mixing processes are well described. Eddy diffusion or "K" models can exhibit this problem. If a ML model is to be useful for water quality applications, then it must be able to resolve storm events and, therefore, be able to simulate the ML depth, h, and its time rate of change, dh/dt. A general water quality model is derived from mass conservation principles to demonstrate how ML models can be used in a physically meaningful way to address water quality issues.


2014 ◽  
Vol 49 (4) ◽  
pp. 372-385
Author(s):  
Shawn Burdett ◽  
Michael Hulley ◽  
Andy Smith

A hydrologic and water quality model is sought to establish an approach to land management decisions for a Canadian Army training base. Training areas are subjected to high levels of persistent activity creating unique land cover and land-use disturbances. Deforestation, complex road networks, off-road manoeuvres, and vehicle stream crossings are among major anthropogenic activities observed to affect these landscapes. Expanding, preserving and improving the quality of these areas to host training activities for future generations is critical to maintain operational effectiveness. Inclusive to this objective is minimizing resultant environmental degradation, principally in the form of hydrologic fluctuations, excess erosion, and sedimentation of aquatic environments. Application of the Soil Water Assessment Tool (SWAT) was assessed for its ability to simulate hydrologic and water quality conditions observed in military landscapes at 5th Canadian Division Support Base (5 CDSB) Gagetown, New Brunswick. Despite some limitations, this model adequately simulated three partial years of daily watershed outflow (NSE = 0.47–0.79, R2 = 0.50–0.88) and adequately predicted suspended sediment yields during the observation periods (%d = 6–47%) for one highly disturbed sub-watershed in Gagetown. Further development of this model may help guide decisions to develop or decommission training areas, guide land management practices and prioritize select landscape mitigation efforts.


1994 ◽  
Vol 29 (12) ◽  
pp. 31-40 ◽  
Author(s):  
Pia Prohaska Brinch ◽  
Kim Rindel ◽  
Kathryn Kalb

Due to the introduction of stricter nutrient effluent standards, many existing wastewater treatment plants performing only primary or secondary treatment are about to be upgraded. As the space available at the plants is, however, often limited, processes are required which will accommodate the need for increased treatment capacity without requiring much more space. In the hydrolysis of primary or pre-precipitated sludge direct-degradable organic carbon is produced which can speed up the reaction rate and increase both biological phosphorus and nitrogen removal. Full-scale tests with dosing of hydrolysate for biological P and N removal, respectively, have shown that this is a most viable process. The use of on-line monitoring has improved the process further.


1994 ◽  
Vol 29 (3) ◽  
pp. 95-106
Author(s):  
Alfred P. Benoist ◽  
Gerard H. Broseliske

For priority pollutants, the international Rhine Action Programme (RAP) aims to meet the quality objectives for the Rhine, set by the International Rhine Commission (IRC), by the year 2000. An assessment must be carried out to define additional measures exceeding best available technology (BAT) for point sources and best environmental practice (BEP) for diffuse sources for those priority pollutants still violating the quality objectives of the Rhine after implementing BAT and BEP only. To carry out the required assessments, an excessive amount of work and money is needed, including the application of sophisticated calculation models. For prioritizing reasons, the Institute for Inland Water Management and Waste Water Treatment (RIZA) initiated a project called EVER, which was conducted by DHV Water BV. EVER is the abbreviation of the Dutch equivalent for Effective Distribution of Emission Reductions (Effective Verdeling van Emissie Reducties). The aim of this project is to carry out a first and crude evaluation of the impact of abatement measures (BAT and BEP), as set by the IRC for the period 1985-1995. For those pollutants still showing a violation of the quality objectives for the Rhine in the year 1995, a range finding method is used, to predict the costs and impact of abatement measures exceeding BAT and BEP on the water quality of the Rhine. So, EVER is a management tool to prioritize the work to be done within the frame-work of the IRC, triggering the application of e.g. sophisticated calculation models for a selected number of priority pollutants. In EVER, the prognosis of the reduction of specific discharge rates for approximately forty priority pollutants is given for twelve sub-catchment areas for the year 1995. This prognosis is used to predict concentrations at eight international monitoring locations in the Rhine basin, using the discharges and concentrations of the year 1985 as a reference. The predicted concentrations for the year 1995 are compared with the (preliminary) water quality objectives as set by the IRC. The results indicate, that for six of the selected pollutants the number of available data is too small for sound predictions. Fifteen of the selected pollutants will satisfy the water quality objectives in 1995. Twenty (half) of the selected pollutants will still violate the quality objectives at several monitoring locations. These twenty pollutants are the basis for priorities to be set within the frame-work of the IRC for phase 3 (1995-2000) of the RAP. For these pollutants, additional abatement measures exceeding BAT and BEP are selected in EVER for the manageable groups of sources (anthropogenic non-point sources, industrial sources and municipal sources). Each measure is analyzed separately for costs and effectiveness. Finally the results of this project are integrated into a matrix system which will enable us to select the most effective mix of pollution abatement measures at the lowest costs. The result of the selected additional measures exceeding BAT and BEP shows that 17 pollutants will still violate the quality objectives.


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