Development of disposal method of sweet potato shochu distilled slops by water jet process

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10660311
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 生物資源科学
• Research Institution: SAGA UNIVERSITY
• Principal Investigator: HAYASHI Nobuyuki Dept. Applied Biological Sciences, Fac. Agriculture, SAGA University, Associate Professor, 農学部, 助教授 (50173018)
• Co-Investigator(Kenkyū-buntansha): ANDO Hiroki Dept. Chemistry, Prefectural Industrial Research Center, Kagoshima, Researcher, 研究員 ; FUJITA Shuji Dept. Applied Biological Sciences, Fac. Agriculture, SAGA University, Professor, 農学部, 教授 (90039339)
• Project Period (FY): 1998 – 1999
• Keywords: distilled slops of sweet potato shochu / Water jet treatment / cell crushing / pressure dehydration / chitosan flocculant / solid-liquid separation

Research Abstract

The protocol of London in l993 put shochu distillers under an obligation to quit ocean dumping of distilled slops by 2000. However, it is very difficult to cry out the waste treatment on land because distilled slops of sweet potato shochu has around 50,000 of BOD. Potato cells that one of the main solid portion in slops float in fluid just like balloon with much amount of water. Therefore, the obtained solid fraction after liquid-solid separating treatment, represented by centrifugal decantation, contains 90% of water. This fact indicates that the separated solid waste is perishable and is difficult consecutive utilization until new disposal method development. This study focused on the improvement of liquid-solid separation efficiency by crushing the cells floating in waste fluid using the newly developed water jet crusher. Pumped out slops fluid is led to collide by frontal clash at 250 - 1000 kgf/cmィイD12ィエD1. As a result of the observation with microscope, the number of crashed cells were increased with increasing extruding pressure and almost of all cells were crashed at l000 kgf/cmィイD12ィエD1. Water jet treated slops fluid showed more than two times higher dehydration speed at filter press test. Obtained dehydrated cake has only 45% of water. Flocculation and centrifugal separation were also performed on water jet treated slops. While there was little difference with intact fluid on solid-liquid separation efficiency, an important findings that the chitosan flocculant effectively coagulates at one tenth concentration of poly-aluminum chloride (PAC).