The pollution and sources of mercury in Tokyo Bay were investigated on the basis of about one year of observations. The outputs (557 kg yr^-1) of mercury considerably exceeded the inputs (107kg yr^-1), and the imbalance between the inputs and outputs for mercury was much larger than that for Cd, Cr, Cu, Pb and Zn. These suggest that there are other major inputs of mercury to Tokyo Bay. In Japan, large amounts of organomercurous fungicides were extensively used in fields in the past, and most of the mercury from these was retained in soil. In this study, the mercury concentration in rivers was measured primarily in ordinary runoff. These lead to the hypothesis that field soil discharged into stormwater runoff is a major source of mercury in Tokyo Bay. As a preliminary approach to validating this hypothesis, we measured the concentrations of mercury and other trace metals (Cd, Cr, Cu, Pb and Zn) in river water during a typhoon. The increase in mercury concentration in stormwater runoff was much higher than the increases in other metal concentrations, which tends to support the hypothesis.

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We have investigated the conversion rate of organic nitrogen into NH₄⁺(ammonium), NO₂^-(nitrite), and NO₃^-(nitrate), and that of organic phosphorus into PO₄^3-(phosphate) in jellyfish during storage at room temperature. Jellyfish, such asAurelia aurita, Chrysaora melanaster, andStomolophus nomurai, were stored in glass or plastic containers. Supernatant solutions of the jellyfish were periodically taken from the containers and centrifuged and filtered. NH₄⁺and PO₄^3-in the filtrate were determined using conventional absorptiometry. Capillary zone electrophoresis (CZE) developed by us was used to determine the concentrations of NO₂^-and NO₃^-. After 10 days, 79% of Total-N (total nitrogen) and 60% of Total-P (total phosphorus) were contained in the supernatant solution ofA. auritaas NH₄⁺and PO₄^3-, respectively. On the other hand, 81% of Total-N and 74% of Total-P were contained in the supernatant solution ofC. melanasteras NH₄⁺and PO₄^3-, respectively after 20 days. After 60 days, 97% of Total-N and 93% of Total-P were contained in the supernatant solution ofA. aurita; 93% of Total-N and 100% of Total-P forC. melanaster. NO₂^-and NO₃^-concentrations in the jellyfish were lower than 0.8 mg/l within 60 days. The dried precipitate was weighed to reveal the transparency of the supernatant solutions. The amount of suspended solid in the supernatant solutions was≤0.01%(w/w) after 10 days. As a result of storing jellyfish for more than 60 days in other experiments, the longer the storage time, the higher the concentration of NH₄⁺and PO₄^3-in the supernatant solutions and transparency. We also proposed a concentration procedure for the supernatant solutionsin vacuo(70 hPa) at 40°C to reduce the amount of Na⁺(sodium) in the solutions and those volumes. The former is to decrease the possibility of salt injury for plants and the latter is to decrease the cost of transfering fertilized jellyfish to consumption places such as vegetable fields. Jellyfish suspensions were diluted as an alternative procedure to relieve the salt injury. Vegetables were cultivated using the diluted suspensions. The usefulness of jellyfish as a liquid fertilizer was elucidated through the experiments.

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The purification vessel was developed in order to remove suspended solids from seawater. The fiber media and granular materials are used this vessel. The purification experiment was performed for about 30 days in Amagasaki port and Amagasaki canal in the autumn. The port and canal are located in the head of Osaka bay. The experimental results showed that suspended solids were completely removed by the filters. For the Amagasaki port and the Amagasaki canal, the removal rates of SS were 48% and 58%, respectively. Those for COD were 30% and 36%, respectively. The value of COD was positively correlated with the value of SS. Inpartic, the higher correlation between COD and SS was found in the experimental results in the Amagasaki canal. The removed materials contained the organic materials. Therefore, it is assumed that the organic matter can be removed with the treatment by the purification vessel.

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We performed a continuous industrial MSMPR crystallization of sodium chloride (NaCl) by means of evaporation at different impurity concentrations in a liquor solution such as seawater. We sieved the suspended crystals in the crystallizer, and determined the growth and nucleation rates using the population balance of the crystal size distribution (CSD). We observed the crystals at each stage in the sieves with a microscope, and measured the degrees of roundness and agglomeration. We also measured the impurity concentration represented by potassium ions in the crystals. The suspension density was useful for correlating the growth and nucleation rates. The impurity concentration in the crystals increased as that in the solution increased. We described the impurity concentration as a function of the crystal size, and it was larger at a size range of less than 300μm and had minimum values and increased slightly by again increasing crystal size. The degrees of roundness and the aggregation of the crystals were significant factors for correlating the impurity concentration in the crystals. We propose modeling by operative variables for the growth rate, nucleation rate, suspension density, degrees of roundness, and aggregation, and the distribution coefficient of impurity as a function of crystal size for NaCl industrial crystallization.

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Marine sponges were collected from the Seto Inland Sea and the Mindanao Sea. Brominated compounds in 10 species of marine sponges were investigated using GC-MS. Eleven compounds were identified and determined by GC-MS in Dysidea sp.: 2, 4-dibromophenol (1), 2-(4'-dibromophenoxy)-3-bromophenol (3), 2-(4'-dibromophenoxy)-3, 5-dibromophenol (4), 2-(4'-dibromophenoxy)-4, 6-dibromophenol (5), 2-(2', 4'-dibromophenoxy)-3, 5-dibromophenol (6), 2-(2', 4'-dibromophenoxy)-4, 6-dibromophenol (7), 3, 5-dibromo-2-(3', 5'-dibromo, 2'-methoxyphenoxy) phenol (8), 2-(2', 4'-dibromophenoxy)-4-chloro, 3, 5-dibromophenol (9), 2-(2', 4'-dibromophenoxy)-3, 4, 5-tribromophenol (10), and 2-(2', 4'-dibromophenoxy)-4, 5, 6-tribromophenol (11). These major components in the brominated compounds of Dysidea sp. and Phyllospongia sp. were identified as: (4),(6) and (10),(6) and (7) respectively. We detected no brominated compounds in other marine sponges.

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The transport of carbohydrates was facilitated across an anion-exchange membrane via the complexation with borate ion fixed on the membrane. Although the carbohydrates distributed on the membrane were barely desorbed into pure water, their transport was enhanced by the addition of sodium borate in the receiving phase, and their transport rates increased with their increasing distribution to the borate ion type membrane.

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We attempted to make agricultural cultivation solution from seawater with a simple two-step process using calcined hydrotalcite and natural zeolite. Cl^-in seawater can be reduced by calcined hydrotalcite, and Na⁺ can be reduced by ion exchange with natural zeolite. The obtained solution was neutral, and includes the nutrients, K⁺, Mg²⁺, and Ca²⁺, and low levels of Na⁺ and Cl^-. Although Radish sprouts did not grow in seawater, they could be grown in the prepared solution. These results suggest that it is possible to make a solution for agricultural cultivation from seawater using this process.

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