Photo-oxidation of Sb(III) in the seawater by marine phytoplankton-transition metals-light system

• Published in: Chemosphere (Oxford) 2006-11, Vol.65 (8), p.1432-1439
• Main Authors: Li, Shun-Xing, Zheng, Feng-Ying, Hong, Hua-Sheng, Deng, Nan-Sheng, Zhou, Xia-Yi
• Format: Article
• Language: English
• Subjects: Animals; Antimony; Antimony - chemistry; Antimony - metabolism; Applied sciences; Bacillariophyceae; Biogeochemistry; Chemical speciation and transformation; Chlorella autotrophica; Dunaliella salina; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Eukaryota - metabolism; Exact sciences and technology; External geophysics; Geochemistry; Light; Marine; Marine phytoplankton; Mineralogy; Nannochloropsis; Natural water pollution; Oxidation-Reduction; Phaeodactylum tricornutum; Photochemistry; Photooxidation; Physical and chemical properties of sea water; Physics of the oceans; Phytoplankton - chemistry; Phytoplankton - metabolism; Pollution; Pollution, environment geology; Porphyridium purpureum; Seawater - chemistry; Seawaters, estuaries; Silicates; Spectrometry, Fluorescence; Tetraselmis levis; Tetraselmis subcordiformis; Transition Elements - metabolism; Water geochemistry; Water treatment and pollution
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2006.04.017

The photo-oxidation of Sb(III) to Sb(V) by marine microalgae (diatom, green and red algae) with or without the presence of transition metals (Fe(III), Cu(II) and Mn(II)). The influence of marine phytoplankton on the photochemistry of antimony was confirmed for the first time. The conversion ratio of Sb(III) to Sb(V) increased with increasing algae concentration and irradiation time. Different species of marine phytoplankton were found to have different photo-oxidizing abilities. The photochemical redox of transition metals could induce the species transformation of antimony. After photo-induced oxidation by marine phytoplankton and transition metals, the ratio of Sb(V) to Sb(III) was in the range of 1.07–5.48 for six algae ( Tetraselmis levis, Chlorella autotrophica, Nannochloropsis sp., Tetraselmis subcordiformis, Phaeodactylum tricornutum, and Porphyridium purpureum), and only 0.92 for Dunaliella salina. The distribution of antimony in the sunlit surface seawater was greatly affected by combined effects of marine phytoplankton (main contributor) and transition metals; both synergistic and antagonistic effects were observed. The results provided further insights into the distribution of Sb(III) and Sb(V) and the biogeochemical cycle of antimony, and have significant implications for the risk assessment of antimony in the sunlit surface seawater.