Dynamic odour emission modelling software for wastewater treatment systems

ODOURsim^® is a powerful and revolutionary windows based software package specifically developed for the modelling and simulation of odours generated in municipal and industrial wastewater treatment plants.

The software enables dynamic odour formation and emission modelling to provide enhanced dispersion contour plot realism and defensible odour management plans. Whether you are improving the design of an existing installation or designing a new facility you will find that ODOURsim^® :

• is a sophisticated solution that can be used easily by consultants and designers;

• concentrates on modelling the formation and emission of H₂S odour from specific process components;

• is unique in producing dynamic predictions that demonstrate variation of emission rate in response to changing flow, load and meteorological conditions;

• interfaces with existing dispersion modelling packages to help generate realistic and meaningful odour contour plots;

• provides an essential design tool to help develop odour management and abatement strategies for existing and planned installations:

• employs a liquid-phase H₂S model and uses mass-transfer calculations for various process components to evaluate the impact on emission rates;

• avoids the inaccuracies inherent in using a constant H₂S dispersion rate;

Plotting Techniques

ODOURsim^® uses wastewater characteristics that are convenient and inexpensive to measure (e.g. flow, COD, sulphide, pH and temperature) as input parameters, along with process sizes (physical dimensions and design parameters) and meteorological data (available from sources such as the Met Office in the UK). The software then carries out sophisticated computations to give predictive odour emission readings in different areas of the treatment works, e.g. trickling filter or sedimentation tank.

The software allows the impact of variations in wastewater flow, quality and meteorological conditions on emission rates to be examined over time. The resulting dynamic emission rate data can then be used within dispersion models to produce a more representative odour contour plot rather than relying on an unreal assumption of a constant emission rate. The effect is illustrated in the two time plots (above) and in the corresponding emission/flow graph (below). Here ODOURsim^® has been used to model a sewer feeding a set of primary sedimentation tanks. The software reveals emission peaks at high flow conditions because the sewer flows full, allowing H₂S to form under anaerobic conditions, and because high flows enhance emissions from the sedimentation tank weirs. These variations in emission rate have a profound impact on the resultant odour contour plots.

Above: ODOURsim^® plots odour emission at different times of the day

Above: Emission peaks for the sewer and sedimentation tank system

Powerful GUI interface

The ODOURsim^® software package has:

• a user-friendly and powerful windows-based Graphical User Interface (GUI);

• robust and efficient computational procedures for calculating underlying chemical and biological processes leading to odour formation and emission;

• the ability to generate detailed reports of a complete simulation;

• disaster recovery functionality to allow the software to resume simulation in the event of an interruption or hardware failure;

• the ability to integrate with data formats of existing dispersion modelling software.

Above: Powerful GUI interface

Impressive graphical output

Water Innovate’s ODOURsim^® software produces detailed reports and graphical output which can greatly assist with issues such as air pollution control, planning permission, compliance with regulations and performance standards. The software is an invaluable design tool when:

• identifying emission problems in existing plants;

• extending existing wastewater treatment works;

• designing and building new facilities.

Rigorous testing has produced a robust and user friendly product.

Above: Powerful GUI interface