Here, we present ton-scale produced SPIONs coated with PCB-attractive self-assembled monolayers (SAMs) consisting of simple, commercially available and strongly binding phosphonic acid derivates. Comparable core-shell SPION systems have previously been shown to be not only non-toxic, but also very efficient for removing a broad range of simple hydrocarbons, charged dyes as well as micro-and nanoplastics of various sizes from water. As Figure ) illustrates, the via molecular self-assembly functionalized nanoparticles can be added to aqueous PCB solutions so that the large functional surface can interact non-covalently with the pollutants. The superparamagnetism of the cores enables facile magnetic PCB extraction from the aqueous solution, which is quantified by washing the contaminant carrying SPIONs in hexane and analyzing the PCB concentration via gas chromatography coupled to mass spectrometry (GC-MS). Representative for the 209 congeners, non-chlorinated 1,1'-biphenyl (biphenyl), once-chlorinated 3-chloro-1,1'-biphenyl (PCB 2), twice-chlorinated 3,5-dichloro-1,1'-biphenyl (PCB 14) and four times-chlorinated 3,3',4,4'-tetrachloro-1,1'-biphenyl (PCB 77) are removed individually, but also competitively in mixtures in dependence of the functional surface of the SPIONs (see Figure ) ). The SPION surface is complementary decorated with three different phosphonic acid derivates to address the PCBs. 1-Methyl-3-(propylphosphonic acid) imidazolium bromide (simplified as the cation only PAC3Imi+) is used to provide positive charges on the SPION surface for attractive electrostatic interactions with the electronegative chlorine atoms. On the other hand, n-hexadecylphosphonic acid (PAC16) and 10-phenyldecylphosphonic acid (PAC10Ph) provide hydrophobic interaction sites combined with, in the latter case, an additional electron-rich phenyl ring to interact with the electron-deficient rings of the chlorinated pollutants. The electronic properties of the molecules are featured in Figure ) by means of electrostatic potential maps, which were calculated by density functional theory (see supplementary information). In suitable contaminant-to-SPION ratios that enable quantitative comparison between the systems, preferred interaction of biphenyl, PCB 2 and PCB 14 with hydrophobic PAC16@SPIONs and PAC10Ph@SPIONs is shown, while PCB 77 -despite being less water soluble than the other pollutants -is more efficiently extracted by the positively charged PAC3Imi+@SPIONs. Moreover, these orthogonal surface functionalities can be combined on the SPION surface by a mixed (binary) SAM comprising PAC3Imi+ and PAC16 or PAC10Ph translating into tailorable adsorption behavior between the extrema. These nanoparticulate water cleaning agents do not only remove the investigated PCBs just as well from river water (Regnitz in Erlangen, Germany), but can be recycled without any sign of degradation and only small performance losses for three out of four pollutants.