Elaboration of a practicable design approach
A major goal of the Subgroup in question was to develop and validate a practicable design algorithm for the purpose of planning, dimensioning and operating wastewater pond systems, for use in both cold and, more importantly, hot climatic zones. This task have been taken into account both a wide temperature range and high salt concentrations; the limits to the application of the process were also determined. In addition, specifically as regards wastewater ponds, additional exogenous influencing parameters such as solar radiation and wind also played a role.
Examination of individual aspects specifically affecting wastewater ponds
In addition to pond size, specific issues in the fields of algal biology, aeration and disinfection were investigated in collaboration with the industrial partner organizations involved.
|Partner organizations||Tasks||Type of investigation|
||Validation of parameters relevant to planning||Empirical|
|Fuchs||Validation of the oxygen transfer rate under various climatic conditions||Industrial-scale test plant|
|Ultrawaves||Validation of the impact of algae formation on wastewater pond systems and investigations into algal-bacterial symbiosis||Semi-industrial test plant|
In some cases, the investigations were based on existing data. In addition, the company’s own industrial-scale and semi-scale investigations were carried out in Spain. Furthermore, data from wastewater ponds, inter alia, in Brazil and New Zealand were included.
Focal points of operations:
- Elaboration of an extended design approach for wastewater pond systems: The German design rules for wastewater ponds (DWA-A 201) are based on simplified, empirical approaches that are adapted to conditions in Germany and can only be applied to other climatic zones to a very limited extent. Consequently, practicable design approaches suitable for use in various temperature zones were defined both on the basis of preliminary investigations in precursor projects and on that of international research.
- Validation of the oxygen transfer rate: In addition to the evaluation of existing formulae and data, additional, empirical data were selectively collected, this being supplemented by experimental investigations into oxygen transfer with and without aeration apparatus.
- Validation of the impact of algae formation on wastewater pond systems and with regard to algal-bacterial symbiosis: On the basis of the evaluation of existing data, experimental investigations were carried out on a wastewater treatment test plant incorporating a symbiotic algal-bacterial biomass. Furthermore, inter alia, comparisons of decomposition performance in wastewater ponds exposed to different algae impacts were carried out.
- Disinfection: The empirical data groundwork on this aspect was extended and made more secure by means of selective measurements. On this basis, guide values could been derived for practical dimensioning and design tasks.
- Validation of planning and operating parameters: In addition to the research fields detailed above, there were further aspects and parameters that were of relevance to planning and functions; the latter, for example hydraulics, water evaporation, gas emissions, sludge formation, and land utilization economics, were investigated for the purpose of defining limits to applications.
IEEM gGmbH - Institute of Environmental Engineering and
Management at the University of Witten/Herdecke
Alfred-Herrhausen-Str. 44, 58455 Witten
Persons to contact:
Prof. Dr. mult. Karl-Ulrich Rudolph, firstname.lastname@example.org
M.Sc. Sebastian Weil, email@example.com
FUCHS Enprotec GmbH
Stocktal 2, 56727 Mayen
Person to contact:
Martin Fuchs, firstname.lastname@example.org
Xylem Water Solutions Herford GmbH (WEDECO) (assoz. Partner)
Boschstr. 4-14, 32051 Herford
Person to contact:
Dipl.-Ing. Martin Preikschat, email@example.com