Construction of Non-Polar Porous Material and the Selective Adsorption Characteristic for Oil Substances in Coal Chemical Wastewater

Abstract

To address the challenge of recovering high concentrations of dissolved and emulsified oils from coal chemical wastewater, a non-polar porous material (pSt-X) was constructed in this study for the selective adsorption of oil substances. The results revealed that pSt-X had an adsorption capacity of 215.52 mg/g, which had remained stable for multiple recycling sessions, with an adsorption capacity constantly above 95 %. The pSt-X has significantly larger particle size (0.7 mm~1 mm), which simplifies the process of adsorption regeneration and effectively prevents the loss of the adsorbent powder problem. The pSt-X adsorbent demonstrated remarkable selectivity towards dissolved and emulsified oils, exhibiting removal rates of 90.2 % and 81.7 %, respectively. Moreover, pSt-X proved remarkable selectivity in removing aromatic hydrocarbons (AHs) and phenols, with impressive removal rates of 77.8 % and 85.9 %, respectively. The selective separation mechanism of pSt-X for oil substances was further analyzed, indicating that its selective adsorption of oils was primarily driven by hydrophobic, π-π, and hydrogen bonding interactions owing to its non-polar and porous structure and hydrophobic properties. These research findings have both theoretical and practical implications for the accurate separation and green recovery of oil substances in coal chemical wastewater.

Keywords: Coal chemical wastewater, Oil substances, Non-polar porous material, Selective adsorption, Green recovery