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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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Potassium fertilizer plays a critical role in increasing the food production. Carnallite is concentrated by reverse froth flotation and used as a raw material to produce potassium fertilizer (KCl) in agriculture. However, all the surfactants used in the carnallite reverse flotation process are conventional monomeric surfactants contain a single similar hydrophobic group in the molecule, which results in a low production efficiency. In this work, a new morpholine-based Gemini surfactant, 1,4-bis (morpholinododecylammonio) butane dibromide (BMBD), was prepared and originally recommended as a collector for reverse froth flotation separation of halite (NaCl) from carnallite ore. The flotation results indicated BMBD had higher flotation recovery and stronger affinity of halite against carnallite compared with conventional monomeric surfactant N-(n-Dodecyl) morpholine (DDM). Fourier transform infrared spectra suggested that BMBD molecules were adsorbed on halite surface rather than the carnallite surface. Additionally, BMBD molecules can strongly reduce the surface tension of NaCl saturated solution. Considering the BMBD’s unique properties, such as double reactive centers to mineral surfaces, double hydrophobic groups, and stronger surface tension reducing ability, made it be a superior collector for reverse flotation desalination from carnallite ores than DDM.

Phosphorite is generally used in the manufacture of phosphate fertilizer and plays a vital role in the development of agricultural and food production. Nonetheless, how to obtain phosphorite concentrates efficiently and sustainably has become an urgent problem. In this study, a newly designed trisiloxane surfactant, N-(2-Aminoethyl)-3-aminopropyltrisiloxane (AATS), has been prepared and utilized as an emerging collector for reverse flotation of phosphorite ore. Its collecting ability was compared with the conventional surfactant 1-dodecamine (DDA). In the collector concentration tests, AATS with lower concentrations showed stronger collecting ability for quartz. In the pH tests, AATS always performed better than DDA in the acidic or alkaline condition. In bench-scale flotation experiments, the P 2 O 5 recovery of phosphorite concentrates with 150 g/t AATS was 10.77% higher than that with 300 g/t DDA, which proved that AATS can be applied to the sustainable production of phosphorite concentrates. For a 4000 t/ d phosphorite ore processing plant, the profit could be increased 7,014,702.07 USD every year by using AATS as the collector. Therefore, this work provides a promising approach to enhance the production efficiency of phosphate fertilizer and to promote the sustainable development of agriculture.

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