Seasonal changes of fouling-forming microalgae on lithium manganese oxide disks in seawater, East Sea, Republic of Korea

Abstract

For investigation of biofouling characteristics of marine microalgae on lithium manganese oxide disk (LD), which is manufactured for recovery of mineral resources from seawater, we carried out an exposing test for LD at Okgye, East Sea, Korea. The amount and species composition of the attached microalgae on the LD surfaces were determined based on the exposing period and season. The immersion test was conducted for 7 d, 14 d and 21 d for each of the three different seasons of May, August and October. The number of microalgae attached to the LD is dependent in season and exposing duration. In May and October, the microalgae adhered approximately 4,000 cells/cm2 after 7 d and after 14 d, more than 2-fold were attached that exceeding 10,000 cells/cm2 . In spring and summer, centric diatom, Guinardia sp. and Cyclotella sp. were dominated in seawater, and they predominantly adherent in short exposure periods of within 7 d. However, dominant adherent species were succeeded to Cylindrotheca sp., pennate diatom, as longer exposure times. The microalgae morphology, which favored attachment was also a major cause of prolonged fouling upon exposure of LD surface.