| Sažetak | Globalnim razvojem i povećanjem broja stanovnika dolazi do onečišćenja voda različitim štetnim tvarima, posebice teškim metalima. Takve vode su neuporabljive za ljudsku potrošnju jer mogu uzrokovati brojne ekološke i zdravstvene probleme. Postoje različite metode obrade voda onečišćenih teškim metalima, a njihov glavni nedostatak je visoka cijena. Iz toga su razloga istraživanja usmjerena na pronalaženje prirodnih, lako dostupnih materijala koji imaju mogućnost vezivanja teških metala, a ekonomski su i ekološki prihvatljivi. U ovom završnom radu provedeno je uklanjanje olova iz vodene otopine šaržnim postupkom na biosorbensima (koštice maslina, pelet komine maslina, ostaci hridinskog ježinca, koštice višnje i koštice trešnje) različitih veličina čestica (0,56-1,00 mm; 0,09-0,56 mm i 0,045-0,09 mm) prikupljenima u lokalnim pogonima za proizvodnju i preradu hrane. Za sve ispitane biosorbense učinkovitost uklanjanja olova povećava se smanjenjem veličine čestica zbog veće aktivne površine, ukazujući na adsorpciju kao glavni mehanizam vezivanja olova. Najbolju učinkovitost od 62,8% pokazale su koštice višnje, zatim 44,4% koštice trešnje, 29,6% ostaci hridinskog ježinca te 27,5%. koštice maslina, dok je za pelet komine maslina dobivena najmanja učinkovitost od 16,8%. Zbog visoke početne koncentracije olova od 2,705 mmol/L (≈ 560 mg/L) teško je bilo za očekivati postizanje konačne koncentracije ispod maksimalno dopuštene vrijednosti od 0,5 mg/L. Nižu ostatnu koncentraciju olova možda bi bilo moguće postići višestupanjskim šaržnim postupkom s novim obrocima biosorbenasa, za što su potrebna dodatna ispitivanja. Unatoč tome, čvrsti otpad i nusproizvodi iz poljoprivredno-prehrambenog sektora mogu biti korisni materijali za uklanjanje teških metala iz onečišćenih voda. Osim što bi pridonijeli smanjenju troškova obrade voda, smanjila bi se i količina otpada koji se neiskorišten nekontrolirano odlaže u okoliš. |
| Sažetak (engleski) | Global development and population growth lead to increasing water pollution by various harmful substances, especially by heavy metals. Such waters are unusable for human consumption and can cause numerous environmental and health problems. There are different methods for treatment of waters contaminated with heavy metals, and their main disadvantage is the high cost. For this reason, researches are focused on finding natural, easy available economically and environmentally friendly materials with ability of binding different heavy metals. In this final thesis, the removal of lead from an aqueous solution on biosorbents (olive pits, olive pomace pellets, remains of the sea urchin, sour cherry pits and cherry pits) of different particle sizes (0.56-1.00 mm; 0.09-0.56 mm and 0.045-0.09 mm) by batch method was performed. The biosorbents were collected in local food production and processing plants. For all tested biosorbents, the efficiency of lead removal increases by decreasing the particle size due to the higher surface area, pointing on the adsorption as the main removal mechanism. The best efficiency of 62.8% was achieved by sour cherry pits, then 44.4% for cherry pits, 29.6% for the remains of the sea urchin and 27.5% for the olive pits, while for the olive pomace pellet the lowest efficiency of 16.8% was achieved. Due to the high initial lead concentration of 2.705 mmol/L (≈ 560 mg/L), it was difficult to expect the final lead concentration below the maximum permissible value of 0.5 mg/L. Lower remaining lead concentration might be possible to achieve by multi-stage batch process with fresh biosorbents, but this requires further experiments. Nevertheless, solid waste and by-products from food production and processing can be useful materials for removal of heavy metals from polluted waters. Except the contribution in reduction of water treatment costs, the amount of uncontrolled disposal of unused waste into the environment could also be reduced. |
