Wastewater containing organic substances is usually treated by the activated sludge process. With the expansion of sewage systems, the amount of activated sludge increases vastly. In Japan, it becomes increasingly difficult to secure landfill sites for disposing the increase amount of excess sludge. Carbonizing activated sludge has been developed as one of the methods to reduce and/or recycle wastes. Carbonized activated sludge is useful because it contains phosphorus to be extracted from it, and to be a good adsorbent. The amount of the acid-soluble phosphorus in carbonized activated sludge was experimentally estimated in this study.
Arid land afforestation can be considered as one of the countermeasures for global warming. A series of experiments has been carried out in Sturt Meadows near Leonora, Australia for developing the techniques for effective plantation in arid land. In that study, we found that unlike other ecosystems, amount of carbon in the litter and soil was much less than carbon in above ground plant bodies in natural forests in Sturt Meadows. In order to analyze the fate of carbon in those experimental sites and investigate what causes this less than usual amount of carbon, we constructed a litter and soil carbon dynamics model. Effect of the number of compartments for litter carbon was investigated and we concluded that the model having only one compartment for litter carbon would suffer from significant error comparing to the models having 2 compartments for litter carbon. For explaining the less than usual amount of soil and litter carbon in Sturt Meadows forests, we have to incorporate the physical loss of the litter in the model. It was estimated a significant amount of litter, ranging 50 to 70% of input litter, was removed from the sites physically, that is, by flooding of water, winds, and other mechanism.
Two methods of simultaneous determination of eight pesticides (azoxystrobin, cyproconazole, flazasulfuron, halosulfuron-methyl, propiconazole, siduron, tetraconazole and triflumizole) in effluent from golf courses by solid phase extraction and GC/MS or HPLC/UV were developed. A water sample containing the pesticides was passed through a solid phase extraction device of a disk of styrene divinyl benzene (SDB) polymer with a vacuum system, and the pesticides retained on the disk were eluted with acetone or acetonitrile. The pesticides in the elute were determined by GC/MS or HPLC/UV. The recoveries for the pesticides spiked to distilled water and river water were 90.0∼102% and 81.3∼101%, and their relative standard deviations were 0.8∼7.3% and 1.2∼7.3%, respectively. The retention behavior of the pesticides onto the material of solid phase extraction was discussed in terms of the octanol-water partition constant (Pow). It was considered that the hydrophobicity was a principal parameter for the retention of the pesticides in this system. These methods were applied to effluent from golf courses. Halosulfuron-methyl and siduron were detected by the proposed method.
The leaching rate of chrome from chromite in sulphuric acid was studied by means of an E-pH diagram of the Cr-Fe-H2O system. The results showed that the leaching rate of chrome changed with the grain size, the concentration and quantity of sulphuric acid and the leaching temperature. The optimum condition for leaching was confirmed as follows: the grain size of chromite sample was 0.074mm, the concentration of sulphuric acid was 75% and the addition of sulphuric acid was 2.5 times of the sample by weight when the temperature and the time of leaching were set at 140°C and 4h, respectively. The leaching rate of chrome was more than 93%.
Several experimental conditions on colony formation unit (CFU) of activated sludge heterotrophic bacteria including ultrasonic homogenization, incubate temperature, agar types, and nutrient composition of agar media were investigated. CFU with 10 fold dilution of Tripticase Soy Agar (TSA), TSA 10%, were relatively larger than CFU with other agar media, and TSA 10% was regarded as a standard agar media for activated sludge heterotrophic bacteria especially cultivated in a laboratory with sterilized substrate. Judging from the results of the correlation analysis of CFU with agar media, NA could be appropriate agar media for a full-scale plant (FSP). Relatively larger CFU with ASEA showed possibility of the activated sludge extract should contain more appropriate nutrient for bacteria in the activated sludge besides its composition should differ by the activated sludge. High correlation between CFU with TSA 10% and CFU with other agar media were not observed except for NA and TSA, which might due to higher variety of bacteria grew on each agar media applied in this study. In other words, higher selectivity of agar media against bacteria growth was demonstrated through the data analysis.
The distribution of chlorophyll intermediates in the rice mutant plants M249 and M134 that accumulate chlorophyllides a and b esterified with incompletely reduced alcohols, such as geranylgeraniol, dihydrogeranylgeraniol and tetrahydrogeranylgeraniol, were determined in five chlorophyll-protein complexes and free pigment resolved by non-denaturing polyacrylamide gel electrophoresis. The a/b ratios of chlorophyll intermediates in mutant thylakoids were similar regardless of reduction state of chlorophyll moieties. In light harvesting complexes and photosystem II core proteins of the rice mutants, the proportions of the intermediates in total chlorophylls were nearly constant. However, the proportions of chlorophyll-geranylgeraniol in P700-chlorophyll a-protein complexes of mutants were clearly lower than those in photosystem II core and antenna complexes. These results suggest that chlorophylls with less-reduced side chain are unlikely to be incorporated into photosystem I core protein complex, and that other photosynthetic protein complexes, such as P680-chlorophyll a-protein complex and light harvesting complexes, are independent of reduction state of the side chain.
Bio-ethanol produced from cellulose in paper sludge is economically attractive as a value-added product. Bio-ethanol production from paper sludge was examined in a process of simultaneous saccharification and fermentation in which both cellulase and yeast were worked together on cellulose sludge in a laboratory-scale experimental system at 37°C. In the experiment, it was confirmed that yeast could ferment glucose to alcohol in a phosphorus buffer solution. Consequently, 12.7ml of bio-alcohol with a concentration of 42.0% was obtained from 30g of paper sludge after distillation of the reacted solution by simultaneous saccharification and fermentation. The experimental results showed that the process of simultaneous saccharification and fermentation to produce bio-ethanol could be a bio-fuel production process in the coming age.