Nitrogen and phosphorous removal from groundwater using waste materials

  • Stylianos Gkiouzepas

Student thesis: Doctoral Thesis


The occurrence of high nitrate and phosphate levels in groundwater is a worldwide problem.The study of suitable methods to remove these compounds is crucial for the long-term environmental health of ecosystems. Nitrification and eutrophication occur in areas where there is extensive human activity for agricultural cultivations and industries. The study area for this project, Greece, is affected by nitrate and phosphate in groundwater. The extensive use offertilizers and pesticides and the drilling of groundwater wells have reduced the quality of water on many Greek islands. A case study of Samos Island next to the borders between Greece and Turkey, support the problem in high nitrogen levels. The aim of this study was to determine if passive engineering solutions could be designed using cheap and easily available local materials that can remove nitrogen and phosphorous compounds from groundwater.This study focus on laboratory based experiments with columns. The substrate materials were selected with specific criteria. In the first experiments materials that have already investigated and groundwater from the area that Nitrabar project took place in Northern Ireland was used,where known denitrifier bacteria already exist. The next experimental section used new materials for nitrate and phosphate reduction including perlite, tea waste materials and hazelnut husk wastes. In the this experiment these substrate materials were investigated in batch and column experiments, in short and long term time periods, and with two water sources, tap water and groundwater (Scotland, UK).The investigation of denitrification process in all experiments proved successful. In all experiments removal of nitrate and phosphate compounds was observed. The best reduction was found in the last experiment with the new substrate materials showing a reduction between 90-99% for all nitrogen compounds and the reduction of phosphate levels was more than 80% at all cases. The degradation rates calculated were similar to the previous experiments showed efficiency with the new waste materials. It was interesting to note that each experiment showed an initial growth phase / adaptation lag phase followed by a stable biodegradation phase.
Date of Award25 Aug 2016
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorRobert Kalin (Supervisor) & Charles Knapp (Supervisor)

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