Remediation of complex remazol effluent using biochar derived from green seaweed biomass

The unique property of biochar, synthesized from a green seaweed (Ulva lactuca), to remediate complex Remazol dye bearing wastewater was investigated. Preliminary trials were targeted to explore the remediation capacity of biochar towards each of Remazol dyes (Remazol brilliant blue R (RBBR), Remazol brilliant orange 3R (RBO3R), Remazol brilliant violet 5R (RBV5R), and Remazol Black B (RBB)) in single-solute system. The results show that equilibrium pH played a vital part with maximum sorption observed at pH 2.0. The isotherm experiments confirmed that biochar exhibited high uptakes of 0.301, 0.292, 0.265, and 0.224 mmol/g for RBO3R, RBBR, RBV5R, and RBB, respectively. Due to the presence of multiple dyes as well as high concentration of auxiliary chemicals, the performance of biochar to remediate Remazol effluent was inhibited markedly compared to single solute systems. Nevertheless, the dye removal efficiency was above 77.5% and the decolorization rate was high with more than 95% of total dye decolorization completed within 240 min. Our results provide novel insights into the potential of biochar to remove Remazol dyes from complex dye wastewaters.本研究针对由绿藻石莼（Ulva lactuca）合成的生物炭（biochar）治理含复杂雷玛唑染料（Remazol dye）废水的独特性能展开了系统探究。预实验旨在明确生物炭在单溶质体系（single-solute system）中对各雷玛唑染料——涵盖雷玛唑亮蓝R（RBBR）、雷玛唑亮橙3R（RBO3R）、雷玛唑亮紫5R（RBV5R）以及雷玛唑黑B（RBB）——的修复能力。研究结果显示，平衡pH值对吸附效果具有决定性影响，在pH=2.0时吸附量达到峰值。等温吸附实验（isotherm experiments）证实，生物炭对RBO3R、RBBR、RBV5R及RBB的吸附量分别可达0.301、0.292、0.265和0.224 mmol/g，吸附性能优异。由于废水中共存多种染料且含有高浓度助剂，相较于单溶质体系，生物炭治理雷玛唑印染废水的性能受到显著抑制。即便如此，染料去除率仍高于77.5%，且脱色速率较快，总染料脱色量的95%以上可在240分钟内完成。本研究结果为生物炭去除复杂印染废水中的雷玛唑染料提供了全新的理论视角与应用潜力参考。