Distribution of aluminum species in the hydrosphere—I Aluminum in the ocean

Abstract

This paper attempts to solve the apparent controversy concerning the concentration of dissolved aluminum in ocean water and furthermore to present some information on the kinds and the distribution of various species in natural waters. The aluminum was determined fluorimetrically using Pontachrome Blue-Black R. Aluminum in sea water was subdivided into the following categories: Coarse, particulate Al; retained on a 0.45 μ pore-size Millipore filter. Dissolved Al; passing through a 0.45 μ Millipore filter and responding to the PBBR dye without further treatment. Total dissolved and fine disperse Al; passing through the 0.45-μ Millipore filter and responding to the PBBR dye after treatment with sulphuric acid. Dissolved aluminum of open ocean water was found generally to fall within the range of 1 ± 1μ g Al 1 . A limit of 10 μ g Al l . for total dissolved and fine disperse Al is indicated. High values of previous workers are believed due partly to contamination by Al dissolved from glassware subjected to severe pH conditions and partly to selection of samples from bay- and other nearshore waters. Values for particulate Al in open ocean water were found to range from 1 to 120 μg Al 1 . Continental run-off waters differ by several orders of magnitude from far offshore ocean water in their content of aluminum silicate sol. Particulate aluminum consequently appears to be a promising tracer for river water during the mixing process in the marginal parts of the ocean.