Bio-based adsorbent from polyphenol modification of sugarcane bagasse for enhanced pollutant removal from wastewater

The excessive release of heavy metals and organic dyes in water poses a serious threat to the ecosystem. However, most synthetic adsorbents are unsatisfactory in terms of preparation, economy and properties. Developing an inexpensive and excellent adsorbent that is easy to synthesize is urgent. Fortunately, sugarcane bagasse (SB), a cheap biomass material, can remove a few wastewater pollutants, but it fails to achieve practical application needs. Herein, we proposed a strategy for SB-Fe-TA preparation by precipitation complexation of tannic acid (TA) on SB. Batch experiments showed that the maximum theoretical removals of Pb(II) and methylene blue (MB) by SB-Fe-TA were 797.72 mg/g and 758.95 mg/g, respectively. Moreover, the practical performance test results showed that SB-Fe-TA had high efficiency and universality for mixed pollutants. The continuous-flow reaction testing of the solutions showed that the removal rate of MB was still close to 100 % within 100 h. The excellent properties of SB-Fe-TA were due to the abundant functional groups on the surface. This work provides a novel avenue for developing multi-functional, cheap and efficient bio-based adsorbent for wastewater treatment.