Ecological Engineering 39 (2012) 133–137 Contents lists available at SciVerse ScienceDirect Ecological Engineering j ourna l ho me page: www.elsevier.com/locate/ecoleng Short communication Testing the usability of sea mussel (Mytilus sp.) for the improvement of seawater quality—An experimental study Renata Brzozowska a,∗ , Zhenghong Sui b , Kyoung Ho Kang c,1 a Department of Environment Protection Engineering, Warmia and Mazury University in Olsztyn, Prawochenskiego St. 1, 10-957 Olsztyn, Poland b Ocean University of China, Qingdao 266003, People’s Republic of China c Division of Marine Technology, Chonnam National University, Dundeok-dong, San 96-1, Yeosu-city, 550-749 Jeollanam-do, Republic of Korea a r t i c l e i n f o Article history: Received 5 April 2011 Received in revised form 8 September 2011 Accepted 28 October 2011 Available online 10 December 2011 Keywords: Mytilus sp. Seawater quality Heavy metals Organic compounds Bioremediation a b s t r a c t The aim of the present study has been to analyze the effect of Mytilus sp. on the quality of raw seawater (organic compounds and heavy metals concentrations). The experiment was conducted under laboratory conditions. Two groups of the sea mussel were used in the experiments: small (S group; mean shell length 28.54 ± 1.69 mm) and large ones (L group; mean shell length 35.07 ± 1.83 mm). The highest removal efficiency of organic compounds, Zn, Pb and Ni was observed for the water retention time in a reactor of 9 or 12 h. The differences between removal efficiencies of COD, Zn, Pb and Ni were significant and mainly dependent on the water retention time, less – on the mussels’ size (two-way ANOVA, p < 0.05). Unlike the other examined heavy metals, Cr revealed no significant concentration changes, which may suggest that sea mussels are unable to remove Cr from seawater quickly. The results suggest that it might be possible to use Mytilus sp. as a kind of biofilter for the improvement of seawater quality. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Water pollution of different types becomes a vital problem in many countries worldwide. That negative phenomenon is difficult to control or eliminate and therefore the issue requires further investigations and prompt solutions. Heavy metals, in particular, are regarded as burdensome pollutants. The function of coastal waters as a receiver of polluted runoff water from land implies that the use of this water for various purposes (e.g. aquaculture) might need operations for its quality improvement (e.g. Borsje et al., 2011). Common methods for water treatment and removal of pol- lutants employ several physical and chemical processes (Elliott et al., 2008; Kowal and ´ Swiderska-Bró ˙ z, 2009). Until now, biological methods have been of little use in water quality improvement. Bivalve mollusks can act as habitat modifiers because of the way they take up food. Filtering processes create a possibility of removing chemical compounds, such as organic compounds, heavy metals and nutrients, from water (Todd and Josephson, 1996; Ostroumov, 2005; Zhou et al., 2006; Elliott et al., 2008). ∗ Corresponding author. Tel.: +48 89 523 37 27; fax: +48 89 523 4752. E-mail addresses: rbrzoza@uwm.edu.pl (R. Brzozowska), suizhengh@ouc.edu.cn (Z. Sui), mobidic@chonnam.ac.kr (K.H. Kang). 1 Tel.: +82 61 659 3165; fax: +82 61 659 3160. Using bivalves as a bioremediation means is a new method proposed for the improvement of seawater quality (Zhou et al., 2006; Gren et al., 2009; Borsje et al., 2011). Gifford et al. (2004) dis- cussed utilization of the pearl oyster as a tool for bioremediation. These authors assessed theoretically quantities of heavy metals and organic pollutants bound via deposition in the pearl oyster’s biomass. Mytilus sp. is a sea bivalve genus, which occurs along many coastlines around the world (Gosling, 2003). These mussels are widely cultured, not only in southern Europe, but off the Pacific coast of China, Japan and Korea as well. This mussel genus is very competitive and, in some cases, able to colonize the entire available substratum (Lachowicz, 2005). Moreover, previous studies have shown that Mytilus sp. possesses an extremely well-developed fil- tering ability (Denis et al., 1999). Until now, much research on sea bivalves has focused on assim- ilation of organic compounds and heavy metals from the dissolved phase or food (e.g. Fisher et al., 1996; Gifford et al., 2004; Metian et al., 2009; Punt et al., 1998) or confirmed the fact that water quality could be improved (Ostroumov, 2005; Zhou et al., 2006). The aforementioned papers neglect the question of quantitative evaluation of the seawater quality improvement. The aim of this project has been to test the hypothesis whether Mytilus sp. is able to remove chemical substances such as heavy metals and organic compounds from raw seawater, which could allow us to obtain the seawater purification effect. Another 0925-8574/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.ecoleng.2011.10.017