The correlation between biosorption with Aureobasidium pullulans strain CH-1 and polymer sorption on poly(GMA-CO-EGMA)-en of heavy metals from waste waters

Abstract

The intact microbial cells as well as derived microbial products can be highly efficient bioacummulators of both soluble and participate forms of metals, especially from dilute external concentrations (1,2). The reason for testing Aureobasidium pullulans as a biosorbent is the fact that this fungus presents a ubiquitous saprophite that occurs commonly in the phytoshere (3). Therefore, it has enabled the use of carbohydrate wastes as substrates for the production of pullulan such as the peat hydrolysate. The metal removal and recovery processes include: precipitation, adsorption and biosorption, electrowinning and electocoagulation, cementation, membrane separation, solvent extraction and ion exchange (4). Galvanic waste effluent contain heavy metals ions, such as Cu2f, Cr1+, Cr6+, Cd2+, Ni2+, etc., which present environmental hazard. Having all this in mind, the aim of this paper is to examine the possibility of applying Aureobasidium pullulam CH-1 (Collection of Microorganisms, IChTM) as a biosorbent of metals and biosynthesis of pullulan at the same time on peat hydrolisate, distribution of sorbed metals between biomass and pullulan, as well as the correlation between biosorption Aureobasidium pullulam CH-1 and polymer sorption on poly(GMA-co-EGDMA)-en of heavy metals from galvanic waste effluent.

Ispitivanje Aureobasidium pullulans, soj CH-1 kao biosorbenta je urađeno na kiselom hidrolizatu treseta sa lokaliteta Vlasinskog jezera. Kiseli hidrolizat treseta je dobijen na isti način kao i otpadne vode pri industrijskoj obradi treseta. Rezultati su pokazali da Aureohusidium pullulans, soj CH-1 može istovremeno da vrši biosorpciju metala i biosintezu pululana pri fermentacijama na kiselom hidrolizatu treseta. U cilju poređenja, za sorpciju teških metala iz galvanskih otpadnih voda, osim Aureobasidium pullulans soj CH-1 korišćen je i makroporozni kopolimer, poli(gicidilmetakrilat-co-etilenglikoldimetakrilat) modifikovan sa etilendiaminom, poli(GMA-co-EGDMA)-en. Rezultati uporednih eksperimenata biosorpcije na Aureobasidium pullulans soj CH-1 i sorpcije na polimernom sorbentu su pokazali da se oba postupka mogu uspešno koristiti za uklanjanje teških metala iz galvanskih otpadnih voda. Pokazalo se da je pri datim eksperimentalnim uslovima, za uklanjanje cinka uspešniji postupak biosorpcija, dok je poli(GMA-co-F.GDMA)-en znatno efikasniji za uklanjanje bakra iz galvanskih otpadnih voda.