Environmental fate in river and sea water was studied for 6 organic phosphate esters; tributyl phosphate (TBP), tris (butoxyethyl) phosphate (TBXP), trioctyl phosphate (TOP), tricresyl phosphate (TCP), triphenyl phosphate (TPP), and tris (dichloropropyl) phosphate (CRP). In the river waters, the degradation rates of TPP and TCP, both having phenyl ester groups were faster than those of other phosphate esters. The rates of the phosphate esters having liner alkyl ester groups such as TBP, TBXP, and TOP, were faster as the length of alkyl chain become shorter. The rate of CRP which has chlorine atoms was much slower. The decay characteristics in the polluted sea water was similar to that in the river water. Moreover, the degradation rates in the clean sea water were much slower.

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Various pollutants caused by urban activities are accumulated in our environment, and the accumulated pollution loads have a great amount of potential for the water pollution. According to the occurrence of rainfall, these pollution loads are flushed out through a road surface and gutters etc., and the loads are directly flowed into the receiving water, where the pollution loads are increased.
For the purpose of reducing these nonpoint-pollution loads, we must firstly survey the quantity of accumulated load amount of the road surface, we investigate the composit and the local distribution of accumulated load amount, and we must examine how these loads are flushed out by rainfall.
In this paper, in the first half, the accumulated load amount is determined and the characteristics of the accumulation are examined in each use area. In the latter half, runoff characteristics of accumulated loads by rainfall are considered by simulating the runoff accumulated load amount.
The accumulated load amount of the road surface is determined in each use area, and it has become clear that the accumulated load amount of the road surface has a large difference among each use area and that it is flushed out in great quantities at comparatively initial rainfall. It is concluded that in this way we will be able to simulate the runoff accumulated loads of the road surface, and we can obtain a useful information on the prevention of water quality.

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Vertical distribution of DIP, DOP, POP, chlorophyll-a concentrations and photosynthetic activity were monthly investigated from April 1979 to September 1980 in the northern area of Hiroshima Bay. The mean value of POP/ chl, a ratio was 2.40 (mg P/mg chl. a). For seawater in which Skeletonema costatum is contained more than 50 % in the composition, it was found that the ratio of POP/ chl. a were dependent on photosynthetic activity, being mainly influenced by solar radiation and water temperature. Further, when photosynthetic activity was extrapolated to zero, the ratio of POP/ chl. a, that is, phosphorus content in detritus was 0.05-0.08 (μg-at P/μg chl. a). DOP/POP ratios also fluctuated with photosynthetic activity.

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Sulfonated peat humic acid prepared on the reaction of peat humic acid with sulfuric acid boron trifluoride complex at 100°C for 90 min was used as adsorbent for mercury (II).
After shaking 100 ml of 1 ppm mercury (II) chloride aqueous solution with 5100 mg of adsorbent for 24 hr at 23°C, the residual concentration of mercury (II) in the supernatant solution was determined.
It was found that the sulfonated peat humic acid selectively adsorbed mercury (II) from aqueous solution over a wide range of pH with high efficiency. The adsorption behaviour of sulfonated peat humic acid was found to be the Langmuir's isotherm.
The presence of foreign metals such as sodium, calcium, cadmium (II), copper (II), lead (II), manganese (II) and iron (III) did not interfere with the adsorption of mercury (II) from aqueous solution containing 1000 times as much foreign ions as mercury (II). But presence of chloride reduced the adsorption when the concentration of chloride ion is more than 1000 ppm.
Sulfonated peat humic acid which adsorbs mercury (II) can be easily regenerated by the treatment with 4 N hydrochloric acid.

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Addition of Fe³⁺ to water containing metallic mercury increased the dissolved mercury (I) concentration, and gas-agitation of the solution allowed the dissolved mercury to volatilize readily at an enriched concentration.
From the results of chemical analysis of the solution, the above phenomenon can be explained as follows :
Fe³⁺ and metallic mercury interact to form Hg²⁺ and Fe²⁺, after which Hg²⁺ disproportinates into Hg²⁺ and Hg^o, and Hg^o volatilizes. Moreover, Hg²⁺ is reduced to Hg²⁺ by Fe²⁺, which becomes oxidized to Fe³⁺. The Fe³⁺ formed reacts again with metallic mercury.
A cycle involving these reactions enhances dissolution and volatilization of the mercury.

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