The objective of this study is to enable a better understanding of the effectiveness of solidification/stabilization (S/S) technique in treating polluted sediment, and provide the much needed validation of the longevity of the technology. In this research kaolinite and montmorillonite, with a certain proportion of lime, were used for S/S treatment of sediment polluted with metals. Leachability of metals was examined using the toxicity characteristic leaching procedure (TCLP) and the German standard leaching test (DIN 3841-4 S4) prescribed in national legislative. Results indicated successful S/S treatment using both clays and lime, from the aspect of all leached metals even with pH variations over time and slight changes in structural integrity of specimens. X-ray diffraction (XRD), scanning electron microscope (SEM) analyses and porosity measurement were also performed on the prepared monolithic matrices. XRD qualitative and semi-quantitative analysis proved hydration and pozzolanic product formation with increase in their content and finer crystallites formation over time. SEM analysis confirmed the presence of morphologically dense and stable structures while pore size distribution indicated on mesoporous matrices with ongoing compaction over time. Generally, structural microanalysis indicated the formation of hardened matrices over time and hydration process has been fully completed and further carbonation took place. Unconfined compressive strength measurement gave the satisfying results and matured monolite with 30 % of montmorillonite and 10 % of lime can be considered potentially applicable as non-load-bearing material. In summary, all results indicated that this kind of S/S treatment can achieve satisfactory durability and represent reliable and economically feasible technique for long-term remediation of metal polluted sediment.

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Sustainable and economically feasible polluted sediment treatment is gaining more and more importance. Stabilization/solidification (S/S) technologies are widely used for treatment of sediment and possibilities of using low-cost and readily available materials and binders are increasingly being examined. This work is concerned with aquairing more data about long-term performance of this kind of treatment in therms of metal leaching and microstructural cnaracterization when treating sediment with fly ash and lime. Extraction potential of metals and the effectiveness of the S/S treatment applied, together with compliance with national legislative, were performed by using Toxicity Characteristic Leaching Procedure-TCLP and The German standard leaching test-DIN 3841-4 S4. Leaching test results showed that the applied S/S treatment was effective in immobilizing metals even after seven years of aging. Scanning electron microscope (SEM) and X-ray diffraction analysis confirmed that pozzolanic reactions took place during 28 days and continued along S/S mixture maturation. Compressive strength measurement further proved the treatment efficacy in terms of obtained matrix stability, which enables their subsequent use. It can be concluded that the S/S technique, with the usage abundant materials has a significant potential for treatment of metal polluted sediment.

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Efikasnost neorganskih imobilizacionih agenasa u stabilizaciji otpadnih muljeva rudnika IZVOD Toksični metali, koji se nalaze u mulju jalovišta rudnika olova i cinka Sase, imobilisani su kompaktiranjem sa različitim imobilazacionim agensima (autohtona glina, crveni mulj) u monolite različitih proporcija. Efikasnost imobilizacionih postupaka praćena je korišćenjem difuzionog testa izluživanja (ANS 16.1). Takođe su, određeni i parametri (koeficijenti difuzije, indeksi izlužljivosti) koji će poslužiti za ocjenu efikasnosti prethodno primjenjenih imobilizacionih tehnika. U tretmanu jalovine sa glinom i crvenim muljem se može uočiti smanjenje mobilnosti metala (Cr, Ni, As, Pb i Zn) sa povećanjem procenta dodatog crvenog mulja, dok kod Cu i Cd dolazi do odstupanja. Smeša jalovine sa glinom i crvenim muljem se pokazala kao veoma dobar imobilizacioni agens za sve ispitivane metale.