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ISPITIVANJE EFIKASNOSTI LUŢENJA METALA IZ JALOVINE RAZLIĈITIM
KONCENTRACIJAMA RAMNOLIPIDA
TESTING THE EFFICIENCY OF DIFFERENT RHAMNOLIPID CONCENTRATIONS ON

METAL REMOVAL FROM TAILINGS

Autor: Etir Chalabi Šesta beogradska gimnazija- II razred

Regionalni centar za talente Beograd II Mentor: docent dr Vladimir Beškoski, dipl. biohem.
Hemijski fakultet, Univerzitet u Beogradu
REZIME

Zagađenje zemljišta teškim metalima predstavlja ozbiljnu pretnju čovekovom zdravlju i životnoj sredini pri čemu posebnu
opasnost predstavljaju jalovine. Ramnolipidi su anjonski glikolipidni biosurfaktanti koji imaju sposobnost da mobilišu metale
tako što sa njima grade komplekse ili micele što doprinosi povećanju njihove rastvorljivosti [1,2].
Cilj ovog rada bio je da se ispita uticaj različitih koncentracija ramnolipida na efikasnost luženja teških metala iz jalovine.
Ramnolipidi su produkovani postupkom fermentacije pomoću bakterijskog soja Pseudomonas aeruginosa D3. Nakon odvajanja
biomase, ramnolipidi su ekstrahovani iz fermentacione tečnosti. Prisustvo mono- i di-ramnolipida potvrđeno je tankoslojnom
hromatografijom. U eksperimentu luženja teških metala kao supstrat je korišćen uzorak flotacione jalovine iz Bora. Ispitivanje
efikasnosti izluženja rađeno je pomoću 0.05%, 0.1% i 0.15% rastvora ramnolipida u NaOH (pH=11), a kao kontrola je korišćen
NaOH bez ramnolipida. Iz uzorka borske jalovine rađena je ekstrakcija batch tehnikom na mućkalici u toku noći. Uzorci dobijeni
nakon luženja, kao i uzorak same jalovine, razloženi su mokrom digestijom, a analiza sadržaja teških metala rađena je ICP
(Inductively Coupled Plasma) metodom.

Produkcija ramnolipida fermentacijom dala je prinos 637,8 mg/L. Tankoslojnom hromatografijom na silika gel ploči uočene su
dve komponente u produkovanoj smeši ramnolipida čije su Rf vrednosti bile u skladu sa literaturno dostupnim. Dobijeni sadržaji
metala u uzorku borske jalovine uglavnom su u skladu sa prethodno publikovanim. U eksperimentu luženja najveća efikasnost
izluženja za najveći broj metala postignuta je kontrolnim rastvorom NaOH bez ramnolipida, dok se kod rastvora ramnolipida
različitih koncentracija najveće izluženje postiže pomoću 0.1% rastvora ramnolipida. Kljuĉne reĉi: zagađenje zemljišta, teški
metali, bioremedijacija, ramnolipidi

SUMMARY

Soils contaminated with heavy metals represent a serious threat for environment and human health. Particularly dangerous are
tailings. Rhamnolipids are anionic glycolipid biosurfactants that have the ability to mobilize and remove metals by complexing
them or by forming micelles and so increasing their solubility [1,2].

In this study, the possible effect of different rhamnolipid concentrations on mobilization and removal of metals from tailings was
examined. Rhamnolipids were produced in fermentation process by Pseudomonas aeruginosa D3. After separating biomass,
rhamnolipids were extracted from fermentation liquid. Mono- and di-rhamnolipid presence was confirmed with thin layer
chromatography. In metal leaching experiment, a sample of Bor flotation tailings was used as a substrate. Testing the efficiency of
rhamnolipids on metal leaching was done with 0.05%, 0.1% and 0.15% rhamnolipid solution in NaOH (pH=11) and NaOH
solution without rhamnolipids was used as control. Leaching experiment was done by using batch technique. The samples
obtained after leaching, as well as the sample of Bor tailings, were digested for metal content determination on ICP.

Production of rhamnolipids by fermentation obtained yield of 637.8 mg/L. By using thin layer chromatography on a silica gel
plate, two components in rhamnolipid mixture were observed, with Rf values consistent with previously published. The resulting
metal content in the sample of Bor tailings are generally consistent with previously published. For most metals, the highest
efficiency on metal removal was obtained with control, NaOH solution without rhamnolipids. When it comes to different
rhamnolipid concentrations, the highest leaching levels were achieved with 0.1% rhamnolipid solution.

Key words: soil pollution, heavy metals, bioremediation, rhamnolipids