Studies on the Release of Ammonium Nitrogen from the Bottom Sediments in Freshwater Regions

Osaka Bay is the most polluted enclosed sea area, in which is located the eastern part of the Seto Inland Sea, Japan. There are four kinds of sources on loadings of nutrients to Osaka Bay, which are land including rivers and industrial effluents beside coast, ocean sea water, release from bottom sediment to sea water, and wet and dry deposition from air. The pollutant loadings inflowing from the land to Osaka Bay have been cut by various policies since 1970’s. The concentrations of nutrients in the inner part of Osaka Bay have showed an obvious decreasing tendency. However, the water quality in offshore sea has not satisfied the environmental standard on nutrients. We investigated the amount of nutrients released from bottom sediments. The core samples were taken at two stations in the inner part of Osaka Bay once a month from February to November, 2015. The core incubation experiment in laboratory was conducted for 24 hours according to Tada et.al. The concentrations of ammonium nitrogen (NH4-N) and phosphate phosphorus (PO4-P) were measured by an automatic analyzer. The flux showed similar range with the values investigated in 1986. The results suggested that the flux of nutrients from bottom sediments in the inner part of Osaka Bay has not decreased during summer season at least since 1985. Therefore, the contribution of release from bottom sediment on the nutrients budget would relatively become larger in inner part of Osaka Bay.

Download Full-text

Studies on the Release of Ammonium Nitrogen from the Bottom Sediments in Freshwater Regions

Japanese Journal of Limnology (Rikusuigaku Zasshi) ◽

10.3739/rikusui.38.100 ◽

1977 ◽

Vol 38 (3) ◽

pp. 100-106 ◽

Cited By ~ 4

Author(s):

Kokichi KAMIYAMA ◽

Setsuo OKUDA ◽

Akira KAWAI

Keyword(s):

Bottom Sediments ◽

Ammonium Nitrogen

Download Full-text

Geochemical studies of surface bottom sediments and soils of small watercourses

E3S Web of Conferences ◽

10.1051/e3sconf/202016901005 ◽

2020 ◽

Vol 169 ◽

pp. 01005

Author(s):

Evgeni Nesterov ◽

Timofei Belyakov ◽

Stanislav Dubrova ◽

Pavel Egorov

Keyword(s):

Bottom Sediments ◽

Analytical Data ◽

Laboratory Data ◽

Petroleum Products ◽

Ammonium Nitrogen ◽

Polluted Soils ◽

Phosphate Ion ◽

Nickel Zinc ◽

Sources Of Pollution ◽

Geochemical Studies

Analytical data on samples of bottom sediments of the Novaya river watercourse made it possible to identify areas of pollution, sources of pollution and determine the nature of the influence of the anthropogenic factor on the state of the river. It was found that bottom sediments are divided into slightly polluted, moderately polluted, and dangerously polluted. Soils on the total indicator of pollution belong to the permissible category. The list of defined indicators includes: hydrogen index (pH), total metal content (cadmium, copper, lead, mercury, nickel, zinc), arsenic, petroleum products, benz(a)pyrene, ammonium nitrogen, phosphate ion, organic matter. Based on the results of the interpretation of the laboratory data, it was found that in accordance with the Regional standard, the precipitation the majority of samples are slightly polluted; at some samples, are moderately polluted; at a quarter of samples are dangerously polluted.

Download Full-text