β-シクロデキストリン架橋物をプレンドした光硬化型球状含水ゲルの調製と微生物固定化担体としての応用

摘要

コンパクトでより高性能な排水処理システムを実現するため，ポリエチレングリコールを主成分とする光硬化性含水ゲル(ENTG)に，β-シクロデキストリン(βCyD)をへキサメチレンジイソシアナート(HDI)により架橋重合したポリマー(βCyD/HDI)微粉末を混合し，有機物の濃縮機能をもつ混合型球状含水ゲル(ENTG-mix-βCyD/HDI)を調製した.βCyD/HDIの混合比10，20,30,40wt%と,ENTG含水ゲルに，それぞれフェノール(PhOH)分解菌を吸着固定化して生体固定化担体を調製した.次に，初期濃度500mg/LのPhOHを含むモデル排水500mLに，生体固定化担体10wt%を添加し，回分式で，室温でばつ気した際のPhOH残留濃度をGC法でモニターした.ENTG生体固定化担体と比較して，除去速度が最大で1.6倍増加した.10ヶ月問使用後の性能劣化はほとんどなかった.%In recent years, the development of reformative technology to remove aromatic pollutants from industrial wastewater is attempted. We have carried out effective removal of phenol from wastewater by immobilizing phenol degradation bacteria onto hydrogels which are able to concentrate phenol. The spherical hydrogels were obtained by a photo-crosslinking reaction after gelation with calcium alginate. ENTG-mix-βCyD/HDI hydrogels were crosslinked polyethylene glycol units (ENTG) in the presence of βCyD/HDI powdery polymer obtained by crosslinking of βCyD with hexamethylene diisocyanate (HDI). Phenol degradation bacteria were immobilized onto the hydrogel and cultured for one month in a bubbling vessel. The changes of phenol concentration in model wastewater were determined by gas chromatography. The hydrogels were used for batchwise removal tests for 4 times at the initial phenol concentration of 500 mg/L. From the results of the average time for phenol degradation, activities of immobilized biocatalyst having βCyD component were greater than that of hydrogel without βCyD component. After use for10 months, the effective performance was kept without decline.