Master's Thesis Defense by Ms Maria Loufopoulou

"Heavy Metals Removal from Treated Wastewater, using Constructed Wetlands"

MSc Thesis Title: Heavy Metals Removal from Treated Wastewater, using Constructed Wetlands

Tuesday 11 December 2018, at:13:30, Venue: Hall K2.A7

Examination Committee

  • Professor Nicolas Kalogerakis (advisor)
  • Associate Professor Danae Venieri
  • Associate Professor Petros Gikas

Abstract:

In this thesis, the possibility of heavy metals’ removal from treated wastewater, using constructed wetlands, is being investigated.

Constructed wetlands (CWs) are low-cost, eco-technological, mechanical systems that aim at the efficient process of sewage or polluted water, having as an action area the rhizosphere of the vegetation that grows, where all natural, biological and chemical processes are taken place.

The main aim of this MSc thesis is to present the possibility of removing heavy metals from sewage by the method of constructed wetlands and the use of halophytes, e.g. plants able to tolerate a wide range of able to grow in salty environments and also to cope with a wide range of environmental stresses. For this purpose, a horizontal subsurface flow constructed wetland, planted with Juncus acutus plants was installed at the Municipal Wastewater Treatment Plant of the city of Chania. Experiments were carried out to remove cadmium (Cd), nickel (Ni), zinc (Zn), chromium (Cr) and hexavalent chromium (Cr (VI)) from secondary treated urban wastewater. Samples were collected daily at the inlet and outlet of the system and analyzed for pH, EC, ORP, DO and concentrations of Cr (VI), Cr, Cd, Ni and Zn. Furthermore, COD, BOD, TSS, TDS, total N and total P measurements from the influent and the effluent of the CW, were performed at regular basis.

Briefly, after a series of experiments, the results have shown that this could be a promising method for tertiary treatment of municipal wastewater contaminated with HM, but further investigation is needed.