K5/ 2125 - Integration of aquatic chemistry with bio-process models

Funded by: Water Research Commission

April 2012 – June 2014

Partner organisations: eThekwini Water and Sanitation; University of Cape Town (Department of Civil Engineering); University of Queensland; Umgeni Water; University Laval (Dept of Water and Wastewater Engineering); Sasol Technologies; CEIT - Centro de Estudios e Investigaciones Técnicas de Gipuzko, Spain; Paper Manufacturers of South Africa 

Project description

In April 2012, the WRC awarded the Pollution Research Group to lead a multi-partner investigation and development project into The Integration of Aquatic Chemistry with Bio-process Models. This project derives from a special task-force put together by the International Water Association (IWA) for developing a physicochemical framework for modelling water and wastewater processes. Wastewater treatment models are increasingly being used for the design and improvement of public facilities as well as industrial installations, which affect the water environment. However, there is a significant shortage of researchers who understand aquatic chemistry in water and wastewater systems, and therefore demonstrate limited capacity in using these treatment models. The overall objective of this project is to develop learning and training materials on aquatic chemistry and physicochemical aquatic and bio-process wastewater treatment models. 

A substantial part of the project involves the transfer of technology already developed by previous projects and which incorporate the principles of the IWA task group. Case studies are being undertaken to demonstrate the application of the models to local wastewater treatment systems, including: 

1. An application of the UCTADM2 anaerobic digestion model, developed by University of Cape Town under WRC K5/1822, to predict the impact of high strength industrial waste on the methane production, effluent COD and digester stability, in connection with WRC K5/2001 "Co-digestion of sewage sludge and industrial concentrates." 
2. An existing project on the optimisation of paper mill water circuits, supported by PAMSA, will provide local data for testing the application of paper mill water circuits model developed by CEIT. 
3. An existing project on the modelling of anaerobic digestion of Sasol effluent will provide data on a system which is very different from standard municipal treatment conditions. This will use a modified version of the UCTADM2 model. 
4. A further investigation of novel processes being developed by Professor Ekama of UCT, for treating highly saline sewage resulting from using seawater as sewage carriers.
5. An investigation into the capacity of biomass for proton exchange and metal complexation, as part of a programme to establish titration methods to characterise anaerobic digestion streams being undertaken as part of the WRC K5/2001 co-digestion project.

In addition to the case studies, course material on aquatic chemistry and physicochemical processes will be amassed and expanded upon for the purposes of establishing a training workshop and post-graduate level course. 

Publications and reports

Journal papers

• Westergreen, S. Brouckaert, C.J., Foxon, K.M., 2012. Modelling of ionic interactions with wastewater treatment biomass, Water Science & Technology, 65(6):1014-20 (available on IWA Publishing http://www.iwaponline.com/wst/toc.htm)

Posters

Conference Papers and Presentations

• Van Zyl, P.J., Lees, C.M., Brouckaert, C.J., Ekama, G.A., and Foxon, K.M., 2012. Dynamic Modelling of Anaerobic Digestion of Fischer-Tropsch Reaction Water: Different Approaches to Physico-chemical Modelling. Paper presented at the 3rd IWA/WEF Wastewater Treatment Modelling Seminar. Mont-Sainte-Anne, Quebec, Canada. February 26-28 2012