Chitosan에 의한 광합성세균 처리 두부고업폐수의 균체 응집효과 = Effects of Chitosan on Cell Flocculation in Soybean Curd Wastewater Treated by Photosynthetic Bacteria

국문 초록 (Abstract)

광합성세균에 의한 식품산업폐수처리시 발생되는 sludge의 효율적인 회수와 균체의 용도개발을 목적으로 생체에 안전하고 다양한 기능성을 보유한 천연 고분자물질을 대상으로 두부공업 폐수처리조내에서의 균체 응집효과를 검토하였다. 음이온성 고분자전해질인 sodium alginate, carrageenan, xanthangum, gum arabic, CMC, agar 등은 응집효과가 미미하였지만 양이온성 고분자 물질인 chitosan은 높은 응집효과를 보였으며 carrageenan과 복합처리에 의해 침전속도가 증가하였고 침전된 입자의 크기가 증대됨을 알 수 있었다. Chitosan에 의한 균체의 최대응집조건은 chitosan 농도 40mg/l, 탈아세틸화도 75% 이상, pH7, 실온, 정치시간 40분 및 저속교반 등이었으며 이 조건에서 chitosan은 균체응집효과 뿐만 아니라 처리된 폐수에서 MLSS 87%, COD 42%를 제거시키는 부가적인 기능을 나타내었다.

다국어 초록 (Multilingual Abstract)

As a mean to recover photosynthetic bacterial(PSB) cells and its practical uses in food industrial wastewater treatment, various biodegradable polyelectrolytes were first investigated for flocculation of suspended colloids in the PSB treatment process of soybean curd wastewater. Anionic polyelectrolytes such as sodium alginate and carrageenan were not effective but a cationic polyelectrolyte chitosan isolated from Portunus trituberclatus showed very effective flocculation activity. The concentration of chitosan, pH and temperature of wastewater for maximal flocculation were 40 mg/l, pH 7 and room temperature, respectively. Test using deacetylated chitosan to various degree showed higher flocculating activities in samples deacetylated over 75% and time for maximum flocculation was 40 min by stirring slowly under the above optimal conditions. Chitosan was not only effective to flocculate cells but also removed COD and MLSS of the wastewater. COD of 42% and MLSS of 87% were removed by addition of chitosan to the soybean curd wastewater treated with PSB.