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A strong adsorbent TEA-GO for Cu(2+) is prepared using TEA modified GO nanosheets. FT-IR and XPS results show that epoxy groups on GO are eliminated, and simultaneously hydroxyl groups and C-N dominate the surface groups of TEA-GO. The increased equilibrium capacity of TEA-GO for a high initial concentration of Cu(2+) makes it a promising adsorbent for heavy metal ions.

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Wood with abundant nutrition transport channels could be considered as a kind of natural water purifier due to quick and effective passages for separation. Nevertheless, microporosity as the main porous structure of initial wood is not enough to effectively separate small molecules, such as organic dye pollutants. Meanwhile, like most filters, the fouling resulting in blocking and poor water flux will also restrict their large scale. Here, we incorporate Fenton-like catalysis based on Mn3O4 loading for degradation of methylene blue with water transfer and separation channel of fir wood (the interfacial area was estimated up to 6 × 104 m2/m3) to solve the low separating efficiency and fouling problem. The results show that the wood matrix treated by hydrothermal carbonization loading with Mn3O4 nanoparticles (Mn3O4/TiO2/wood) exhibited remarkable catalytic efficiency on methylene blue (MB) moles degradation and the fouling problem could be significantly alleviated during Fenton-like catalysis. The turnover frequency of the wood matrix is 6.072 × 10–3 molMB·molMn3O4 –1·min–1, which is much higher than the values reported in the literature. The flux maintained approached 2045 L·m–2·h–1 with a high rejection rate of more than 95%. Wood with natural interconnected micropores as the main fluid transfer and microreaction channels is a promising material for construction of parallel-series microreactors, to apply to some vital chemical process besides sewage purification and desalination.

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Graphene oxide (GO) membranes represent a next generation of high-flux, ultra-lightweight and energy-efficient membranes for molecular and ionic separation in aqueous solution. In this work, we fabricate free-standing GO membranes with tunable thickness via facile vacuum filtration process. The effect of electrostatic interaction on the separation performance of GO membrane for organic dyes was demonstrated. It is observed that GO is negatively charged in a wide pH range of 1-12 and its surface charge density significantly varied with pH of aqueous solution. The electronegative GO membrane exhibits much higher rejection rate for electronegative organic dyes than that for electropositive molecules. Furthermore, the rejection rate and the strength of electrostatic interaction are directly related. In addition, the rejection behaviors of GO membranes for inorganic salts with different charge or ionic strength are explored as well. The experimental data are fitted well with the theoretical model based on Donnan equilibrium. Our results indicate that GO membranes could be promising candidate for water treatment and desalination application. And adjusting the surface charge density of GO and filtrated molecules is an effective way to achieve high separation performance (e.g. rejection rate).