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Phosphorus in UK Rivers: the Impact of Urban Waste Water Treatment Directive

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Phosphorus in UK Rivers: the Impact of Urban Waste Water Treatment Directive Durham E-Theses Phosphorus in UK Rivers: The Impact of Urban Waste Water Treatment Directive CIVAN, AYLIN How to cite: CIVAN, AYLIN (2016) Phosphorus in UK Rivers: The Impact of Urban Waste Water Treatment Directive, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/11774/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 Phosphorus in UK Rivers: The Impact of Urban Waste Water Treatment Directive Aylin Civan Erdogan Master of Science by Research Department of Earth Sciences Durham University 2016 Abstract Excessive phosphorus levels leading to eutrophication in natural waters as a result of growing population, urbanisation and intensified agriculture has long been a major environmental concern at a global scale. Many remediation strategies and actions have been undertken since the implementation of Urban Waste Water Treatment Directive (UWWTD) in 1992. The UWWTD was implemented to reduce direct phosphorus inputs into rivers from effluents of sewage treatment works. Nevertheless, the long-term outcomes and effectiveness of theses actions still remain unknown. An understanding of the prospective results and effectiveness of these implementations is only possible with a retrospective analysis of riverine phosphorus dynamics. Therefore, this thesis explored the evolution of P concentration and flux from across the UK with datasets available from 230 river sites between the period of 1974 and 2012. These datasets were examined with the purpose of detecting the traces of the events that are likely to be governing the changes in phosphorus levels over the this time period i.e. the implementation of the UWWTD. Trend and change point analyses conducted on Total reactive phosphorus (TRP) and Total phosphorus (TP) data indicated that the concentrations and fluxes have been declining since the mid- 1980s correlatingwith declining phosphate-fertilizer usage. The sites with the largest declines were from the Midlands and South East regions of England, whereas Scotland has seen almost no change. Significant step changes were encountered in most of the TRP concentration records, and most of these step changes were detected in the period 1993-1997 suggesting that the UWWTD was the key factor leading to these step changes. To validate this hyphothesis, Principal component analysis (PCA) was conducted to be able to track down the urban source contributor. Water quality (TRP, BOD, Suspended solids, Nitrate concentration and Conductivity) data from 5 example sites were analysed however, in none of the case examples was there an explicit principle component that could be construed with an urban or any other source contributor. Therefore, the PCA technique was not found to be a suitable technique to analyse this type of datasets. i Declaration and Copyright I confirm that no part of the material presented in this thesis has previously been submitted by me or any other person for a degree in this or any other university. Where relevant, material from the work of others has been acknowledged. Signed: Date: © Copyright, Aylin Civan Erdogan, 2016 The copyright of this thesis rests with the author. No quotation from it should be published without prior written consent and information derived from it should be acknowledged. ii Acknowledgements First and foremost, I would like to express my most sincere gratitude and appreciation to my supervisor Professor Fred Worrall for all his guidance, support and endless patience throughout this thesis work. I would like to thank The General Dictorate of State Hydraulic Works of Turkey for funding all my expenses and allowing me to have such a great working experience in Durham University. I am grateful to the Environment Agency for supplying all the HMS datasets that have been used in this thesis. Also, I would like to thank Sarah Wheater of Environment Agency for taking time to explain how to use the datasets. Thanks to all the all staff and postgraduates in Department of Earth Sciences at the University of Durham for creating such a nice atmosphere to work in. Many thanks to all my friends in the Department of Earth Sciences, but especially, Ines, Ilaria and Giacomo, thank you for all the coffee breaks, pizza and game nights, and many other joyful moments we shared – you certainly made it the best year of my life. I’d like to thank my parents, Sema and Sefer Civan, who deserve more than I can ever give in return for all kinds of support they have given. I owe them so much. Finally, my special gratitude goes to my best friend and husband, Ali Riza, who has been holding my hand for eight long years and has never stopped being loving, caring and patient with me. iii iv Table of Contents Chapter 1: ..................................................................................................................... 1 Introduction .................................................................................................................. 1 1.1. Overview and Rationale .................................................................................... 1 1.1.1. Phosphorus and its role .............................................................................. 1 1.1.2. Phosphorus as an important contributor of Eutrophication........................ 3 1.1.3. Sources of Phosphorus loadings into rivers ............................................... 4 1.1.4. Technologies for Phosphorus Removal and Recovery .............................. 7 1.1.5. Measures and implementations to reduce phosphorus inputs in the UK ... 9 1.2. Review on UK phosphorus levels ................................................................... 10 1.3. Aims and Objectives ....................................................................................... 11 Chapter 2: ................................................................................................................... 13 TRP and TP Concentration and Flux from the UK .................................................... 13 2.1. Introduction ..................................................................................................... 13 2.2. Methodology ................................................................................................... 14 2.2.1. Study Sites ................................................................................................ 14 2.2.2. Analysis of Variance (ANOVA) and Covariance (ANCOVA) ............... 17 2.2.3. Time Series and Trend Analysis .............................................................. 19 2.2.4. Change Point Analysis ............................................................................. 20 2.3. Results for Total Reactive Phosphorus ........................................................... 24 2.3.1. TRP Concentration ................................................................................... 24 v 2.3.2. TRP Flux .................................................................................................. 26 2.3.3. TRP Trend Analysis ................................................................................. 29 2.3.3.1. Overall Trends ....................................................................... 29 2.3.3.2. Trends in the Last Decade ..................................................... 33 2.3.4. Change Point Analysis ............................................................................. 37 2.4. Total Phosphorus ............................................................................................. 43 2.4.1. TP Concentration ...................................................................................... 43 2.4.2. TP Flux ..................................................................................................... 46 2.4.3. TP Trend Analysis .................................................................................... 48 2.4.3.1. Overall Trends ....................................................................... 48 2.4.3.2. Trends in the Last Decade ..................................................... 49 2.4.4. Change Point Analysis ............................................................................. 52 2.5. Discussion ....................................................................................................... 59 Chapter 3: ................................................................................................................... 65 Case Studies on Five Catchments .............................................................................. 65 3.1. Introduction ..................................................................................................... 65 3.2. Selection of Sites ............................................................................................. 66 3.3. Methodology ..................................................................................................
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