Uporaba elektrokemijskih procesov pri remediaciji tal, onesnaženih s kovinami : doktorska disertacija

Voglar, David (author), Leštan, Domen (mentor)

V doktorskem delu smo predstavili novo tehnologijo pranja tal s kelatnim ligandom EDTA v pilotnem merilu. S postopki pranja tal smo odstranili potencialno toksične elemente (PTE) iz tal od 69 do 84 % Pb, od 22 do 64 % Zn in od 52 do 70 % Cd. Novost pri pranju tal je ločitev trdne in tekoče faze ter hkratno izpiranje z EDTA mobiliziranih PTE v komorni filter stiskalnici. Potretiranju tal smo uspešno reciklirali do 76 % EDTA z kislinskim izobarjanjem in predhodnim alkalnim tretiranjem procesne raztopine, kjer smo iz kompleksa z EDTA odstranili večino PTE in vso Fe. Pralno raztopino smo tretirali z elektrokemijskimi naprednimi oksidacijskimi postopki (ENOP). Z obarjanjem na jekleno nerjavečo katodo smo odstranili preostale PTE (do 99.9 % Pb, 98.9 % Zn in do 99.4 % Cd) v raztopini in preostali EDTA (do 99.9 %). Tako smo lahko celotno pralno raztopino ponovno uporabili v procesu pranja/spiranja tal. Materialni stroški, elektrika in potrošni material segajov okvire dosedanjih razvitih metod čiščenja tal. Najcenejši postopek pranja tal, ki smo ga razvili, predstavlja strošek 50.5 Ž na tono tal, kjer direktno odlagamo toksične odpadke na varna odlagališča in 56.1 Ž na tono tal, kjer stabiliziramo toksične odpadke z bitumnom za varno odlaganje na primernih odlagališčih.

• Language: Slovenian
• Keywords: onesnaženost tal, kovine, potencialno toksični elementi, sanacija, izpiranje, etilendiamintetraocetna kislina
• Work type: Dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [D. Voglar]
• Year: 2013
• Number of pages: VIII, 115 f.
• PID: 20.500.12556/RUL-17794
• UDC: 502.521:504.5(043.3)
• COBISS.SI-ID: 3615910
• Publication date in RUL: 11.07.2014

Secondary language

• Language: English

Abstract

The aim of the doctoral thesis was to presente a new pilot scale technology of chemical soil washing. Soil washing with EDTA chelating agent, removed potentially toxic metals (PTMs) from the soil (from 69 to 84 % of Pb, from 22 to 64 % of Zn and from 52 to 70 % of Cd). The novelty of soil washing is separating the solid-liquid phases and simultaneous leaching mobile EDTA PTMs complex in a chamber filter press. After soil treatment the EDTA was successfully recycled up to 76 % with acid precipitation and with alkaline pre-treatment of process solutions, which removed the PTE and all Fe from the EDTA complex. Treated washing solution by electrochemical advanced oxidation processes (EAOP), removed the remaining PTE (up to 99.9 % Pb, 98.9 % Zn and 99.4 % Cd) and EDTA (up to 99.9 %) in the solution with the electrodeposition of metals on the stainless steel cathode. The entire process solution was recycled and used for soil washing/rinsing. The material costs, electricity and consumables, were within the frame of currently available technologies. The best costs of this mode of operation amount to 50.5 Ž per ton of soil for direct disposal of toxic solid wastes and 56.1 Ž per ton of soil for waste stabilization with bitumen and disposal as non-hazardous material.