제올라이트를 이용한 생물막 형성시 미생물의 부착에 금속이 미치는 영향에 관한 연구

초록

Natural zeolite is widely used as sorbents and bio-media materials because it is cheap as well as it has efficient porous structures and large cation exchange. In this study, the effect of metal cations (Na+, Ca2+, Mg2+, Al3+) adsorbed to natural zeolite on the microorganism attachment was investigated. Metal-modified zeolites (MMZ) were prepared with 0.01 M, 0.02 M and 0.1 M NaCl, CaCl2, MgCl2 and AlCl3 solutions respectively, which concentrations were equivalent to 10%, 20% and 100% of cation exchange capacity (CEC) of natural zeolite. Pseudomonas putida was used as microorganism which was cultivated in Beef Extract Medium at 26℃. The microorganism attachment to MMZ was increased more than natural zeolite. The amount of bacterial adhesion to MMZ and natural zeolite were Mg2+ > natural > Na+ > Al3+ > Ca2+ under 10% of CEC, Mg2+ > Ca2+ > Al3+ > natural > Na+ under 20% of CEC and Ca2+ > Mg2+ > natural > Al3+ > Na+ under 100% of CEC. Especially, Mg-modified zeolite (Mg-MZ) showed the highest amount of bacterial adhesion, which increased the microorganism attachment 60% higher than natural zeolite under 10% of CEC. However, the amount of bacterial adhesion was decreased as the concentration of metal cations modified to zeolite were increased, showing that the increased amounts were 60% under 10% of CEC, 50% under 20% of CEC and 10% under 100% of CEC in Mg-MZ. Additionally, the effect of Mg2+ in solution on the bacterial adhesion was investigated in order to compare it with the effect of Mg2+ adsorbed to zeolite. The maximum quantity of bacterial adhesion to Mg-MZ was not different from the amount of microorganism attachment to the natural zeolite when Mg2+ solution was added.

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