The production of oxytetracycline (OTC) consists of acidification, filtration, decoloration and subsequent crystallization. Techniques for isolation and purification of OTC have remained largely unchanged for many years. The commonly used resin decoloration process is costly and has a lower production yield, which also generate a strong waste stream. In this work, an attempt was made to use ultrafiltration (UF) to replace conventional resin decoloring unit operation. UF membranes with molecular weight cutoff (MWCO) 4960.5u were employed. The experimental results show that UF is a promising alternative to resin absorption to obtain sufficiently pure OTC solution for crystallization. The recovery yield of OTC increases from 95.3% using resin adsorption to 98.6% with UF. When UF is combined with the pretreatment of OTC filtered broth by the flocculant K2Fe (CN)6-ZnSO4, OTC crystallization yield would farther increase from 90. 58% to 93.3% with an improved purity.%土霉素的生产包括酸化、过滤、脱色和结晶等步骤,多年来土霉素的提纯技术一直没有大的改变.常用的树脂脱色过程成本高,收率低,还因树脂再生产生酸、碱废水而增加污水处理费用.本研究试用超滤取代树脂脱色单元操作以克服其上述缺点.在实验中使用了切割分子量为4960.5u的超滤膜,实验结果表明超滤是取代树脂脱色的有效手段,可以充分纯化土霉素结晶液并改善结晶,脱色过程收率由树脂法的95.3%提高到98.6%.如果超滤与净化剂预处理相结合,可以提高土霉素质量,并使土霉素结晶收率由90.58%提高到93.3%.
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