Effect of Static Magnetic Fields on the Composition of Marine Biofouling in Seawater Transportation Pipelines

The use of seawater for mining purposes in Chile has progressively increased in recent years as fast as the interest on the negative effects of biofouling on the inner part of pipelines used to transport seawater. To prevent biofouling, chemical antifouling compounds are traditionally used, thus, causing negative environmental impacts. The aim of this research has, therefore, been to evaluate the efficiency of static magnetic fields (SMF) generators to mitigate the biofouling. Hence, experimental activities have been conducted on high density polyethylene (HDPE) pipes equipped with neodymium magnets during two experimental periods in the year of 2019, i.e., autumn–winter (A–W) and spring–summer (S–S), and under two types of SMF, i.e., continuous-type (PCS) and pulse-type (PPS). Physicochemical parameters and cell viability of microorganisms composing the biofilm were investigated. Metagenomic analyses on biofilm were conducted as well. The results showed that the cell viability was the highest, i.e., 757,780 cells/cm2, during S–S and the lowest, i.e., 349,151 cells/cm2, in A–W, both under PCS. In S–S, as well as A–W, biofilm was characterized for the most abundant eukaryotic operational taxonomic units (OTUs) under PPS conditions. The presence of OTUs, such as Articiflavibacter spp., Chaetonotida spp. and Desmodorida spp., was observed only from SMF tests.