In this study, a low-cost and easily recyclable porous green adsorbent (magnetic porous loofah biochar, MPLB) was synthesized by modifying the almost zero-cost loofah biochar material with Fe3O4. The successful synthesis of the material was demonstrated by XRD, FTIR, SEM, VSM, and BET. In addition, the material exhibits outstanding magnetic separation performance (40.01 umg/g) allowing for rapid recovery within just 90 s. The adsorption process of phenol on MPLB was found to be spontaneous and endothermic. The experimental data fit exceptionally well with the pseudo-second-order kinetic model and Langmuir model (R2 > 0.99), indicating that the dominant adsorption mechanisms involved monolayer adsorption and chemisorption. These interactions were attributed to host–guest interaction, π–π conjugation, hydrogen bonding, and pore filling. The maximum adsorption capacity calculated using the Langmuir model at 298 K is 39.4 mg/g. Importantly, even after undergoing seven cycles of recycling, MPLB retained 78% of its initial adsorption capacity. In simulated experiments employing MPLB for phenol removal in actual wastewater, an impressive removal rate of 96.4% was achieved. In conclusion, MPLB exhibits significant potential as an effective adsorbent for phenol removal in wastewater.

Effective removal of phenol from wastewater by magnetic porous loofah biochar
    Abstract
        Graphical abstract
    1 Introduction
    2 Experiment
        2.1 Reagents
        2.2 Synthesis of MPLB
        2.3 Adsorption experiment of phenol
        2.4 Cycle experiment
        2.5 Actual oily wastewater
        2.6 Kinetics and isotherm models
        2.7 characterization equipment
    3 Results and discussion
        3.1 Characterization
            3.1.1 XRD
            3.1.2 VSM and BET
            3.1.3 FTIR
            3.1.4 SEM
        3.2 Effect of pH
        3.3 Effect of adsorption time and temperature
        3.4 Kinetic studies
        3.5 Study on adsorption thermodynamics and adsorption isotherm
        3.6 Reuse performance and performance research in actual oily wastewater
        3.7 Discussion on adsorption mechanism
    4 Conclusions
    Acknowledgements 
    References

• Shirui Shan(Department of Xuchang Vocational Technical College, Xuchang 461000, People’s Republic of China) Corresponding author
• Honglin Wu(Department of Guilin Institute of Information Technology, Guilin 541214, People’s Republic of China)
• Jian Yang(Guang’an District, Department of Jinghe Town Junior Middle School, Guang’an City 638007, People’s Republic of China)
• Di Jiao(Department of Tianjin Branch of CNPC Offshore Engineering Co., Ltd, Tianjin 300450, People’s Republic of China)
• Mengqin Huang(Department of Chengdu, No. 30 Kindergarten Tongrui Branch, Chengdu 610057, People’s Republic of China)
• Fu Li(Department of Weihai Jiamei Chemical Co., Ltd., Weihai 264200, People’s Republic of China)