Lead leached out from the metal lead-sinker attached to fishing nets or contained in ropes are likely to cause the environmental contamination, consequently, resulting in ecotoxicity. However, it is very difficult to find out the data on the disposal reality of fishing nets, lead-containing form of/in fishing net and its content. In previous studies, we presented the containing form of lead and the lead concentration leached out by the containing forms. As a result, the leaching concentration of lead was the highest under the supposition condition of lead-sinker deposited on sandy tidal flat. In this study, as a subsequent study, we investigated long-term leaching characteristics from lead-sinker deposited on sandy tidal flat. We used a serial batch leaching experiment to investigate the long-term leaching characteristics, and the experimental conditions were as follows; solid to liquid ratio 1:20, shaking time 24 hours (repetition of 7 times), room temperature, and shaking rate 170 rpm. As a result, lead leaching concentration after shaking for 24 hours was 0.215 mg/L, showing the highest leaching concentration, and then the leaching concentrations between 2-7 times were greatly decreased. Analysis result by Visual Minteq 3.1 said most of the leached lead component could be extracted as crystal such as Anglesite (PbSO4), Cerrusite (PbCO3), Cotunnite (PbCl2), and Pb(OH)2 by sulfate and carbonate in seawater.

Bioethanol was produced from Laminaria japonica hydrolystaes by sequential acidic (0.108 N HCl)/distilled water and enzymatic hydrolysis (Celluclast® 1.5 L) using Saccharomyces coreanus immobilized into/on aluminum silicate. Reducing sugar were hydrolyzed 140.5 and 122.7 mg/g-dry biomass under a acidic-enzymatic condition and a distilled waterenzymatic condition, respectively. In addition, the 8 repetition batch fermentations were carried out with the immobilized S. coreanus to verify the advantage of immobilization cell. As a result, we can obtain the ethanol of 12.1 ~ 24.3 mg/gdry biomass, and reuse the support, aluminium silicate, for 8 repetition batch fermentations without any breakdown.

This study focused on immobilization of Saccharomyces coreanus to support materials and ethanol fermentation bythe immobilized yeast. Three porous media as support material were surveyed; synthetic zeolite, aluminum silicate andgranular activated carbon. Amount of yeast (determined by organic matter content) immobilized into/on support materialswas lowest in fermentation using aluminum silicate as supports. Glucose as substrate of ethanol fermentation was easilysorbed more than ethanol into/on 3 types of support materials. Of these, absorbed amount of glucose and ethanol into/on activated carbon was highest. The ethanol was actively produced for 16 hours in fermentation processes by yeastimmobilized into/on aluminum silicate and activated carbon, produced after 16 hours by yeast immobilized into/on zeolite.The produced ethanol concentration after 24h was as follows; 24.2g/L by using aluminum silicate, 19.3g/L by activatedcarbon and 16.1g/L by zeolite.