Studi tentang kandungan raksa (Hg) pada gastropoda di perairan sungai Kaligarang-Semarang+The study of mercury (Hg) contain on gastropod in the water Body of Kaligarang river-Semarang

Abstract

The research was conducted in the Kaligarang river which aimed to study of gastropod containing Hg and Hg contamination effect on gastropod to community structure of gastropod as a pollution impact of Hg. Concentration of Hg analysis at the sample of water, sediment and gastropod used Neutron Activation Analysis method (AAN), i.e.: (1) preparation of primary and secondary standard, (2) preparation of water sample, sediment and gastropod, (3) irradiation and counting. The sample of primary and secondary standard was irradiated in the atomic reactor of Kartini Jogjakarta for 12 hours at Lazy Susan position (neutron flux order 1.05x1011n.cm-2.s4). The whole sample were then turned out from atomic reactor and kept for 22 hours. So, the radionuclide that shorten to half of the ordinary time can be decayed completely and then counting was done for the sample. The counting of sample used multi channel gamma spectrometer. The data resulted from counting was analyzed quantitatively on the determination of gamma ray (y) energy. Hg concentration in gastropod organ of mantle and tissues was known that Hg in the tissues have three times bigger than that in the mantle. The lowest ratio of Hg contained in gastropod was found at the sampling site I (16.025 mg/ L) while the highest was found at the sampling site IV (41.6 mg/ L). Based on the Keywords: Mercury, Neutron Activation analysis, Gastropod, Community Structur