Catch crop candidates (corn, guinea grass) for recovering nutrients from farm soil and aquatic plants (water caltrop, water hyacinth) were utilized to produce L-lactic acid. The efficiencies ofpre-treatment methods for enzymatic saccharification and L-lactate production of two fermentation processes, thermophilic simultaneous saccharification and fermentation (SSF), as well as separate saccharification and fermentation, were compared. Conditions were set at 55 degrees C and pH 5.5 for non-sterile fermentation. Alkaline/peroxide pre-treatment proved the most effective for saccharification in pre-treated corn, guinea grass, water caltrop and water hyacinth with glucose yields of 0.23, 0.20, 0.11 and 0.14 g/g-dry native biomass (24-hour incubation period), respectively. Examination of the two types of thermophilic L-lactate fermentation employed following alkaline/peroxide pre-treatment and saccharification demonstrated that the L-lactate yield obtained using SSF (0.15 g/g in the case of corn) was lower than that obtained using separate saccharification and fermentation (0.28 g/g in the case of corn). The lower yield obtained from SSF is likely to have resulted from the saccharification conditions used in the present study, as the possibility of cellulase deactivation during SSF by thermophilic L-lactate producing bacteria existed. A cellulase that retains high activity levels under non-sterile conditions and a L-lactate producer without cellulose hydrolysis activity would be required in order for SSF to serve as an effective method of L-lactate production.

A methodology for comparative evaluation of the water supply reliability of distribution areas was presented. There are various factors which affect water supply reliability. As they cannot be quantified by the same standard, reliability of water distribution area was examined according to the value of each factor. These factors were organized into an index through the analytical hierarchy process. The reliability of each distribution area of the water supply system in the case study area was comparatively evaluated by the method. The problems and points necessary for improvement of the water supply reliability of each distribution area were indicated.

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Overgrowth of aquatic plants, such as water chestnut, has been reported as a regional problem in various areas. We proposed cascade utilization of water chestnut through the recovery of phenolics, phosphorus, and sugars. Phenolics were extracted using 50 g (wet weight) of biomass with 300 mL of acetone, methanol, or hot water, and the yields of total phenolics were 80.2, 56.2, and 49.7 mg g(-1) dry weight of native biomass, respectively. The rate of eluted phosphorus in the phenolic extraction step was 8.6, 14.8, and 45.3 % of that in the native biomass, respectively, indicating that the use of polar organic solvents suppressed phosphorus elution at the phenolic extraction step. Extraction of phosphorus following the phenolic extraction was combined with alkaline pretreatment (1 % NaOH solution) of biomass for saccharification; 64.1 and 51.0 % of phosphorus in the native biomass were extracted using acetone and methanol for the phenolic extraction, respectively. Saccharification following the alkaline pretreatment showed that the glucose recovery rates were significantly increased (p<0.05) with the phenolic extraction step compared to alkaline pretreatment alone. This finding indicates that extraction of phenolics not only provides another useful material but also facilitates enzymatic saccharification.