1 Ferrihydrite nanoparticle aggregation induced by 1 dissolved organic matter 2 Luigi Gentile *† , Tao Wang † , Anders Tunlid † , Ulf Olsson ‡ , and Per Persson †§ 3 † Department of Biology, MEMEG unit, Lund University, Sölvegatan 35, 223 62 Lund, Sweden. 4 ‡ Department of Chemistry, Physical Chemistry Division, Lund University, Naturvetarvägen 14, 5 223 62 Lund, Sweden. 6 § Centre for Environmental and Climate Research (CEC), Lund University, Sölvegatan 35, 223 7 62 Lund, Sweden. 8 *Corresponding author: luigi.gentile@biol.lu.se 9 Page 1 of 32 ACS Paragon Plus Environment The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 This document is the Submitted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.jpca.8b05622