Adsorption recovery of phosphate from waste streams by Ca/Mg-biochar synthesis from marble waste, calcium-rich sepiolite and bagasse

作者：Deng, Wangde; Zhang, Dongqing^*; Zheng, Xiaoxian; Ye, Xingyao; Niu, Xiaojun^*; Lin, Zhang; Fu, Mingli; Zhou, Shaoqi

来源：JOURNAL OF CLEANER PRODUCTION, 2021, 288: 125638.

DOI：10.1016/j.jclepro.2020.125638

• Biochar
• Phosphate
• Marble waste
• Calcium-rich sepiolite
• Adsorption
• Phosphorus recovery

In this study, marble waste and calcium-rich sepiolite were employed as Ca and Mg sources, and the agricultural waste was used as carbon source to synthesize two modified-biochar composites (Mar-BC800 and Sep-BC800) for removing phosphate from waste streams. The results show that Mar-BC800 and Sep-BC800 exhibited excellent performance for phosphate adsorption from aqueous solution in a wide pH range of 3-11, and the maximum adsorption capacity of phosphate by Mar-BC800 and Sep-BC800 was 263.17 and 128.21 mg/g, respectively. The adsorption process was best described by the pseudo second-order model and Langmuir model, and the dominating sorption mechanism for phosphate is that Ca2+ or Mg2+ with phosphate to form Ca-5(PO4)(3)OH, Mg-3(PO4)(2) and Mg-3(PO4)(2)4H(2)O precipitate. Furthermore, Mar-BC800 and Sep-BC800 are simple to produce, the methods used to produce modified biochar are green, economic and environmentally-friendly, and the phosphate adsorbed modified biochar can applied as fertilizer to farmland soil, which have the functions of increasing soil fertility and improving soil physical and chemical properties.

• 单位
  茂名学院