Wood fiber aerogel-based super hydrophilic and lipophobic porous structure as a photothermal material for efficient solar steam

We demonstrate in this paper a super-hydrophilic and oleophobic green porous photothermal material based on wood fiber as a novel oil-repellent photothermal material for efficient solar vapor generation (WF-SP). WF-SP is an excellent light-absorbing material with the advantages of a porous nanostructure, super-hydrophilic, low thermal conductivity, high-temperature resistance, and oleophobicity. Based on these advantages, WF-SP exhibits good solar photothermal conversion performance with solar vapor generation efficiencies of 85.4%, 75.3%, and 70.2% at 1 kW m−2, 2 kW m−2, and 3 kW m−2 radiation intensities, respectively. The results provide new possibilities for the design and preparation of low-cost, green, and pollution-free photothermal materials with high solar thermal conversion efficiency for solar photothermal conversion vapor generation.</p

Preparation of a Magnetic Core–Shell Bioreactor for Oil/Water Separation and Biodegradation

With the frequent occurrence of offshore oil spills, the effective separation and treatment of oily wastewater are essential to the environment. In this work, the core–shell bioreactor (abbreviated as Fe3O4/MHNTs-CNF@aerogel) was prepared with a core composed of camphor leaf cellulose-based aerogels for loading microorganisms and a shell derived from hydrophobic silane-modified halloysite doping with Fe3O4 for selective absorption of oil and maganetic recycling. The core–shell-structured bioreactor Fe3O4/MHNTs-CNF@aerogel has excellent self-floating properties and can float on water for up to 100 days. The whole core–shell structure not only has excellent oil/water separation performance but also has good microbial degradation performance. By applying it in water containing 5% diesel for the biodegradation test, the biodegradation efficiency of Fe3O4/MHNTs-CNF@aerogel for diesel can reach 82.4% in 10 days. The efficiency was 20% higher than for free microorganisms, and it still had excellent degradation ability after three degradation cycles, with a degradation rate of over 75%. In addition, the result obtained from the study on environmental tolerance shows that Fe3O4/MHNTs-CNF@aerogel possessed a strong tolerance ability under different pH and salinity conditions. The Fe3O4/MHNTs-CNF@aerogel also has superior mechanical properties; i.e., nearly no deformation occurs at 30 kPa. Compared with those conventional oil/water separation materials which can only absorb or separate the oils for water with limited capacity and taking the risk of secondary contamination, our core–shell-structured bioreactor is capable of not only selectively absorbing oil from water through its hydrophobic shell but also degrading it into a nontoxic substance by its microorganism-loaded core, thus showing great potential for practical application in oily wastewater treatment