Identification of fouling materials in the microfiltration of seawater laden with marine algae

Abstract

In this study, fouling materials were identified in the microfiltration (MF) of seawater laden with marine algae. To this end, raw seawater spiked with either the dinoflagellate species without cell walls (Heterosigma akashiwo) or with cell walls (Prorocentrum micans) was filtered through a laboratory-scale MF system. Based on the results, polysaccharides, which were excreted by the marine algae, accumulated within the MF system and subsequently resulted in membrane fouling. Cell walls are closely related with polysaccharide excretion. The dinoflagellate species without cell walls released more polysaccharides than those with cell walls based on the unit surface area of the species. High-performance size exclusion chromatography analysis revealed that organic substances (1.1 and 22 kDa, molecular weight) were accumulated in the MF system. These organic substances could be the biofouling agents in MF systems during marine algal blooms.

Keywords:

• Red tide
• Dinoflagellate
• Marine algae
• Polysaccharide
• Molecular weight distribution
• Membrane fouling

Acknowledgments

This research was supported by a grant (code 15IFIP-B065893-03) from the Industrial Facilities & Infrastructure Research Program funded by the Ministry of Land, Infrastructure and Transport of the Korean government. Also, this research was supported by a grant (NRF-2010-0029081) from the National Research Foundation of Korea Grant funded by the Korean Government. The authors would also like to thank Jaeweon Cho from GIST for his help in the HPLC–SEC measurements and the Hwan Kyeong Bio Co., Ltd for supplying the automatic chlorophyll analyzer.

Notes

Presented at 2015 Academic Workshop for Desalination Technology held in the Institute for Far Eastern Studies Seoul, Korea, 23 October 2015