Removal of Methylene Blue from Aqueous Solutions Using Waste Wood Biomass as Adsorbent

Abstract

Sintetska bojila imaju široku primjenu u različitim granama industrije. Zbog svojih fizikalno-kemijskih karakteristika, često su kao onečišćujuće tvari prisutna u industrijskim otpadnim vodama. Najčešće korištena metoda za uklanjanja bojila iz otpadnih voda je adsorpcija. Cilj ovog rada je bio istražiti učinkovitost otpadne biomase drvne industrije kao adsorbensa (biosorbensa) za uklanjanje metilenskog modrila (MB) iz vodenih otopina. Kao biosorbensi su korištene piljevine bukve, hrasta lužnjaka, euroameričke topole, jele, ariša i duglazije. Provedeni su šaržni adsorpcijski eksperimenti pri sljedećim uvjetima: koncentraciji biosorbensa 4 mg/L, koncentraciji bojila 50 mg/L , temperaturi 25 °C te vremenu adsorpcije 360 minuta. Najveći postotak uklanjanja MB iz vodenih otopina postignut je korištenjem piljevina euroameričke topole i jele, koje su korištene u daljnjim istraživanjima. Šaržni adsorpcijski eksperimenti su provedeni s ciljem ispitivanja utjecaja koncentracije biosorbensa (1-10 g/L) početne koncentracije bojila (10, 30, 50 i 100 mg/L) te pH vrijednosti (4-9) na uklanjanje bojila pri 25 °C. Postotak uklanjanja MB je iznosio 87 % ( adsorpcijski kapacitet je iznosio 4,81 mg/g) kada je kao biosorbens korištena piljevina euroameričke topole, dok postotak uklanjanja MB za piljevinu jele iznosio 79 % (adsorpcijski kapaciteti iznosio je 4,43 mg/g). Na osnovu dobivenih rezultata može se zaključiti kako otpadna biomasa drvne industrije ima velik potencijal za uklanjanje sintetskih bojila iz vodenih otopina.Synthetic dyes are widely used in various industries. Due to their physicochemical characteristics, synthetic dyes are often present in industrial wastewater as pollutants. The most commonly used method for removing dyes from wastewater is adsorption. The aim of this study was to investigate the efficacy of using wood waste biomass as adsorbents (biosorbens) for the removal of methylene blue (MB) from aqueous solutions. The biosorbents used were beech sawdust, oak, poplar, larch and douglas fir. Batch adsorption experiments were performed under the following conditions: 4 g/L biosorbent, concentration of MB was 50 mg/L at temperature 25 °C and adsorption time of 360 minutes. The highest removal efficiency of MB from aqueous solutions was achieved using poplar and fir sawdust, which were used in further studies. Batch adsorption experiments were performed to investigate the effect of biosorbent concentration (1-10 g/L), initial dye concentration (10, 30, 50, and 100 mg/L) and pH (4-9) on MB removal at 25 °C. The MB removal percentage was 87% (adsorption capacity of 4.81 mg/g) when sawdust of poplar was used as biosorbent, while removal rate for fir sawdust was 79% (adsorption capacity of 4.43 mg/g). Based on the results obtained, it can be concluded that the waste wood biomass of the wood industry has great potential for the removal of synthetic dyes from aqueous solutions