Optimization of a Wastewater Treatment Plant using modelling tools Kabd WWTP (Kuwait) Carla Vázquez Gómara MSc Thesis Identifier UWS-SE.20-04 March 2020 Optimization of a Wastewater Treatment Plant using modelling tools Kabd WWTP (Kuwait) Master of Science Thesis by Carla Vázquez Gómara Supervisors Professor Damir Brdjanovic, PhD, MSc Mentors Dr. Hector García (IHE Delft) Dr. Tineke Hooijmans (IHE Delft) Examination Committee Professor Damir Brdjanovic, PhD, MSc Dr. Héctor García (IHE Delft) Dr. Abdalrahman Alsuilaili (Kuwait University) This research is done for the partial fulfilment of requirements for the Master of Science degree at the IHE Delft Institute for Water Education, Delft, The Netherlands. Delft 25/03/2020 i Although the author and IHE Delft Institute for Water Education have made every effort to ensure that the information in this thesis was correct at press time, the author and IHE Delft do not assume and hereby disclaim any liability to any party for any loss, damage, or disruption caused by errors or omissions, whether such errors or omissions result from negligence, accident, or any other cause. © Carla Vázquez Gómara. March 2020. This work is licensed under a Creative Commons Attribution-Non Commercial 4.0 International License ii Abstract This study was conducted to evaluate the performance of the Kabd WWTP in Kuwait and find solutions to the current issues they are facing, through the application of a model-based approach using the modelling software BioWin. Kabd WWTP was constructed in 2010 and started operating in 2012. It was designed to treat domestic wastewater for biological organic matter and nitrogen removal, by using an activated sludge process treatment consisting on four parallel treatment lines followed by a tertiary treatment, the latter required in order to be able to reuse the produced wastewater for agricultural uses. To develop this study, a protocol was proposed which was based on the STOWA protocol and the guidelines proposed by Meijer and Brdjanovic (2012). The protocol included six steps: project definition, model scheme, data acquisition, data evaluation, calibration and scenario study. The historical data from previous years was gathered from the lab routine analysis records and the Data Control System records, whereas current data was collected by performing a five day sampling campaign. The results of the campaign showed that the plant was not complying with the effluent standards in terms of COD, BOD, TSS and ammonia. It was identified that the secondary clarifiers were performing poorly and that the nitrification process was not fully happening. The model was calibrated based on the STOWA guidelines for calibration. The kinetic parameters calibrated in the case of Kabd WWTP were: Maximum specific grow rate for autotrophic biomass, Substrate (NH4) half saturation constant, Aerobic decay rate, Denitrification DO half saturation constant and Denitrification N2 producers. The model was successfully implemented under steady state conditions and it was used to evaluate the performance of the plant. An increase on the SRT from 5 to 6 days was proposed to solve the problems with high ammonia in the effluent, and also to reduce the daily generated sludge. The model was also used to determine that the plant will be able to comply with the effluent standards until the influent flow reaches Q=200,000 m3/day. Finally, an anaerobic digester was implemented substituting the existing aerobic digester, which showed that the market value of the electricity generated in the plant could reach 686,930 USD per year. iii iv Acknowledgments I would like to express my deepest appreciation to IHE Delft Water Institute and especially Dr. Héctor García and Dr. Tineke Hooijmans for their valuable time, advice and constant guidance throughout the whole research process, leading this study in a meaningful direction. In addition I would like to extend my gratitude to all the people who helped me during my stay in Kuwait, starting with Dr. Alsulaili who arranged and supervised all the work, but also to Sarah, Mariam and Abdelrahman, who were a huge help in daily tasks and also a great company. Finally I would also like to thank the staff on the Kabd WWTP, who provided me with all the data I needed and let me work there with them, and especially to Engineer Suresh Babu, for his valuable time and explanations during all my visits. v vi Table of Contents Abstract .................................................................................................................... iii Acknowledgments .................................................................................................... v Table of Contents ................................................................................................... vii List of Figures ........................................................................................................... x List of Tables ........................................................................................................... xi Abbreviations .......................................................................................................... xii List of symbols ...................................................................................................... xiv Introduction ........................................................................................ 1 1.1 Background .................................................................................................................. 1 1.2 Problem statement ....................................................................................................... 2 Literature review ................................................................................ 3 2.1 Activated sludge process: General description ............................................................ 3 2.1.1 VLR reactor .......................................................................................................... 5 2.1.2 Toxicity and bacteria inhibition ........................................................................... 6 2.2 Water reclamation and reuse ....................................................................................... 6 2.2.1 General overview of the tertiary treatment .......................................................... 7 2.2.2 Water reuse in Kuwait .......................................................................................... 7 2.3 Anaerobic digestion ..................................................................................................... 8 2.3.1 Concept of anaerobic digestion ............................................................................ 8 2.3.2 Anaerobic digestion process ................................................................................. 9 2.4 Wastewater treatment plant modelling ...................................................................... 10 2.4.1 General overview of modelling .......................................................................... 10 2.4.2 Modelling protocols and procedures .................................................................. 11 2.4.3 Simulators ........................................................................................................... 12 2.4.4 BioWin: Applications and limitations ................................................................ 13 Kabd Wastewater treatment plant description .............................. 15 3.1 Geographical situation and wastewater management overview ................................ 15 3.2 Process description .................................................................................................... 16 3.2.1 Preliminary treatment ......................................................................................... 16 3.2.2 Secondary treatment ........................................................................................... 17 vii 3.2.3 Tertiary treatment ............................................................................................... 18 3.2.4 Sludge treatment line .......................................................................................... 19 3.3 Effluent discharge standards ...................................................................................... 19 3.4 Operational issues ...................................................................................................... 20 Research question and objectives ................................................. 21 4.1 Research questions .................................................................................................... 21 4.2 Objectives .................................................................................................................. 21 Materials and methods .................................................................... 22 5.1 Kabd WWTP model protocol .................................................................................... 22 5.2 Project definition ....................................................................................................... 22 5.3 Model flow scheme ................................................................................................... 23 5.4 Data acquisition ......................................................................................................... 24 5.4.1 Historical data .................................................................................................... 25 5.4.2 Sampling campaign ...........................................................................................