Engineered nanomaterials and industrial nanowastes will be inevitably released into the environment. Recently, the safety of engineered nanomaterials has attracted increasing concerns as studies suggested that the toxicity of nanomaterials is not only from their own intrinsic properties, but also from their effects on the generation, transport and exposure of other toxic substances. Therefore, it is of great importance to develop methods for the removal of nanowastes from environmental media. Experiments showed that with the addition of Triton X-114, the surface of nanomaterials dispersed in aqueous phase will be assembled with the Triton X-114 micelles and the nanomaterials will be transferred into the Triton X-114-rich phase upon heating to above the lower critical solution temperature. This nonionic surfactant based cloud point extraction technique was demonstrated to be able to efficiently recover nanosized copper oxide from water, suggesting that cloud point extraction has great potential in the removal of nanomaterials from wastewater (see the article by LIU JingFu et al. on page 346).