Potencijal upotrebe piritne izgoretine u tretmanu otpadnih voda i mogućnost njene dalje sanacije primenom imobilizacionih agenasa

Abstract

Predmet izučavanja ove disertacije bio je ispitivanje mogućnosti korišćenja piritne izgoretine u tretmanu otpadnih voda tekstilne industrije kao i dalji tretman mulja nastalog nakon ovog procesa. Naime, nakon iskorišćenja ovog otpada u Fenton procesima, iskorišćena piritna izgoretina u najvećem procentu čini mulj koji zaostaje nakon tretmana. Kako se piritna ruda još u procesu proizvodnje sumporne kiseline koristi neprečišćena, zaostali mulj koji je potencijalno toksičan i ne može se direktno odlagati bez prethodnog tretmana. Stoga, primenjena je tehnika stabilizacija i solidifikacija (S/S) uz korišćenje portland cementa, kalcijum-oksida, prirodnog zeolita, letećeg pepela, kaolinita, bentonita i autohtone gline za imobilizaciju metala. Istraživanja u ovoj disertaciji vršena su u dve faze. Prva faza imala je za cilj optimizaciju operativnih uslova Fenton tretmana pri kojima se postiže najviši stepen obezbojavanja i mineralizacije ispitivanih efluenata. Takođe ispitivanje je uključilo i karakterizaciju nastalih efluenata kako bi se procenila efikasnost primenjenog, i mogućnost daljeg tretmana. Druga faza uključivala je karakterizaciju nastalog mulja nakon tretmana obojenih efluenata i njegov tretman solidifikacijom i stabilizacijom. Vršeno je određivanje efikasnosti primenjenih imobilizacionih agenasa u S/S tretmanu i dominantnog mehanizma izluživanja metala koji opisuju njihov transport iz dobijenih solidifikata. Primenjeni su i modifikovani testovi izluživanja sa ciljem što bolje simulacije realnih uslova. Rezultati dobijeni simulacijom uslova će dalje omogućiti modelovanje ponašanja metala u smislu dugoročnog "izluživanja" iz tretiranog otpada kao i procenu najefikasnijih agenasa za imobilizaciju različitih metala u ovom tipu otpada. TakoĎe primenjeni su testovi izluživanja sa jednom ekstrakcijom kako bi se osiguralo slaganje rezultata sa maksimalno dozvoljenim koncentracijama aktuelnih pravilnika. Na osnovu dobijenih rezultata zaključeno je da se piritna izgoretina može uspešno koristiti kao izvor katalitičkog gvožđa u Fenton tretmanima obojenih efluenata i može se smatrati efektivnom metodom predtretmana za nebiodegradabilne otpadne vode, čineći ih pogodnijim za konvencionalni biološki tretman. Takođe u drugoj fazi istraživanja, na osnovu dobijenih rezultata, zaključeno je da je mulj tertian sa navedenim imobilizacionim agensima uspešno solidifikovan i stabilizovan materijal. Optimalane su smeše koje kao jedan od imobilizacionih agenasa sadrže leteći pepeo, prevashodno u kombinaciji sa cementom i krečom. Dobijeni podaci su neprocenjivi sa aspekta ekonomski i ekološki prihvatljivog upravljanja opasnim industrijskim otpadom.

This work is concerned with exploring the possibility of using pyrite cinders in the treatment of textile industry effluents and further treatment of sludge generated after this process. Namely, after the utilization of this waste in Fenton processes slag that remains after treatment is mostly composed of used pyrite cinder. As the pyrite ore, in the production of sulfuric acid, is used untreated, sludge that remains is potentially toxic and cannot be disposed directly without treatment. Therefore, the stabilization and solidification (S/S) technique with the usage of portland cement, calcium oxide, zeolite, fly ash, kaolinite, bentonite and native clay was used for metal immobilization. The research in this dissertation was carried out in two phases. The first phase aimed to optimize the operational conditions of Fenton treatment in which the highest degree of decolourization and mineralization was achieved in tested effluents. Also the research has included the characterization of generated effluents in order to evaluate the effectiveness of the treatment applied, and the possibility of further treatment. The second phase involved the characterization of the generated sludge after the treatment of effluents that contained dyes and its treatment with solidification and stabilization technique. The determination of used immobilization agents effectiveness was Conducted to determine the efficacy of immobilization agents in S / S treatment and the dominant mechanism of leaching of metals that describe their transport from the received solidificate . Were applied and modified leaching tests with the aim of better simulation of real conditions. The results obtained by condition simulation will enable the modeling of behavior of metals in terms of long-term leaching period from the treated sludge and assess the most effective agents for the immobilization of various metals in this type of waste. Also, single-extraction leaching tests were applied to ensure the accordance of obtained results with the maximum permissible concentrations of current regulations. Based on these results, it was concluded that the pyrite cinders can be successfully used as a source of catalytic iron in Fenton treatment of effluents containing dyes, and can be considered an effective pretreatment method for non-biodegradable waste waters, making them amenable to conventional biological treatment. Also in the second phase, based on the results obtained, it was concluded that the sludge treated with aforementioned immobilization agents represents a successfully solidified and stabilized material. The optimal mixtures are those that contain fly ash as one of the used immobilization agents, primarily in combination with cement and lime. The obtained data are invaluable in terms of economic and environmentally sound management of hazardous industrial waste.