Simultaneous production of clean water and organic dye from dyeing wastewater by reusable lignin-derived porous carbon

Porous carbon adsorption is regarded as a promising technology for addressing issues of organic dye wastewater remediation and fresh water production. However, there are critical challenges in existing porous carbon adsorbents, including the relatively poor adsorption capacity, low removal rate, large consumption of activator, weak recoverability of organic dye and adsorbent, which need to be further investigated. Herein, we develop a hierarchical porous carbon material directly derived from renewable lignin that can serve as a high-performance and reusable adsorbent for simultaneous production of clean water and organic dye from simulated dye wastewater. Benefitting from the inherent hierarchical microstructures, the lignin-derived porous carbon (LPC) exhibits excellent adsorption capacity (979.29 mg/g) and high removal rate (8.16 mg/(g·min)) for Orange II dye. In addition, the LPC offers an attractive advantage for wastewater treatment that the organic dye, eluting agent and water all can be easily recycled and reused through facile filtration and distillation. Notably, the as-synthesized LPC can significantly reduce wastewater treatment costs by reusing multiple times and thus exhibits infinite possibility to transform a dyeing factory from a wastewater discharger to a clean water and organic dye producer. [Display omitted] •Lignin-derived porous carbon (LPC) with enhanced surface area and chemical properties is developed.•The maximum adsorption capacity of LPC toward Orange Ⅱ reaches up to 979.3 mg/g.•LPC exhibits a high removal rate (8.16 mg/(g min)) to toward Orange Ⅱ.•Organic dyes, clean water, LPC, and eluting agent all can be recycled and reused in a close-looped system.