Diploma Thesis Defense by Mr. Fotis Kapsis
Thesis Title: «Combined technologies of constructed wetlands and air nanobubbles for municipal wastewater treatment»
Friday 21 February 2020, at: 13:00, Venue: Hall Κ1 Conference room
Examination Committee
- Professor Nicolas Kalogerakis (advisor)
- Associate Professor Nikolaos Paranychianakis
- Dr. Eleni Manousaki
Abstract
The present thesis was aimed at evaluating the effectiveness of bridging 2 existing technologies, which separately used for wastewater treatment, constructing wetlands and air nanobubbles, for wastewater treatment and in particular in organic load reduction. The contribution of air nanobubbles to plant physiology and growth was also investigated.
For this purpose, an experimental display was created that simulates the operation of a constructed wetland, using specially designed beakers. The plants used were halophytes, and in particular the Juncus acutus L. species, which has been proven to be an ideal candidate for municipal wastewater treatment due to its resistance to the absorption of toxic pollutants, such as heavy metals. The system was installed in the greenhouse of the Laboratory of Biochemical Engineering and Environmental Biotechnology with a working volume of 125.5 ml per experimental pot and a thin gravel substrate that covered the roots of the plants.
The experiment lasted for 20 days, with the appropriate intake solution being added daily to the study group and then the volume of the outlet solution was checked to control the samples and evaporation. In addition, pH, electrical conductivity, redox potential, dissolved oxygen, COD, total nitrogen and total phosphorus were measured every 2 days. At the end of the experimental procedure, measurements were made to control the total, a- and b- chlorophyll, enzyme activity of catalase in plant roots, biomass, water content and leaf number of plants.
From the results obtained after continuous operation of the system, we conclude that the bridging of these two technologies initially had a similar performance to that of the wastewater group, indicating, of course, a tendency to process the organic load better in the end of the experimental procedure, but with no statistical difference. Similar results were obtained from physiological and developmental performance of the plants, where bridging technologies showed that the plants were better at the end of the experiment than the wastewater group, but not enough to make a statistical difference. There is only statistical difference in the water content.
