The heteroadsorption of pollutants by multiple nanoparticles (NPs) has attracted much attention due to extensive application of diverse NPs. Natural organic matters (NOMs) could bind with NPs and then influence pollutants heteroadsorption. In this study, two model NOMs, fulvic acids (FA) and alginate, were selected, and the impact of surface-coated FA and alginate on the heteroadsorption of 17 alpha-ethynylestradiol (EE2) by multi-walled carbon nanotubes (CNTs) and inorganic NPs (INPs) (SiO2 and Al2O3) were investigated. The results showed that the coated FA and alginate had different impacts on EE2 heteroadsorption: the coated FA promoted the EE2 heteroadsorption, while the coated alginate did not noticeably affect or even slightly inhibited EE2 heteroadsorption by CNTs and INPs. This is ascribed to the different molecular structures of FA and alginate. FA, enriched in aromatic moieties, could disperse CNTs and INPs due to stronger steric hindrance and then promote EE2 heteroadsorption. In contrast, the egg-box-like structure of alginate could promote the heteroaggregation through bridging CNTs and INPs, but it had little effect on EE2 heteroadsorption because of its hydrophilic characteristics. Besides, although FA could promote the heteroadsorption of EE2, less EE2 adsorption was observed when FA was coated on CNTs than that was coated on INPs, which is also contrast to that of alginate. This is due to that the adsorption sites on CNTs surface were blocked by FA when FA was coated on CNTs. (C) 2015 Elsevier B.V. All rights reserved.