Abstract

Thermally activated coal gangue and lanthanum-modified coal gangue were prepared by thermal activation and hydrothermal methods, respectively. Their structures and properties were characterized by X-ray diffraction (XRD), attenuated total reflection flourier transformed infrared spectroscopy (ATR-FTIR) and transmission electron microscopy (TEM). Thermally activated coal gangue and coal gangue modified by lanthanum were used in a closed water body and compared to polymeric ferric sulfate. The results show that gangue modified by lanthanum exhibits stronger chemical oxygen demand by chromium method (CODcr), total phosphorus (TP) and ammonia nitrogen (NH₄-N) removal capacities in overlying water than thermally activated coal gangue. The concentrations of CODcr, TP and NH₄-N in overlying water during the stable period reached 11–14 mg/L, 0.023–0.028 mg/L and 0.16–0.20 mg/L, respectively. Thermally activated coal gangue had a good removal effect on CODcr but a poor inhibition effect on the TP. Compared to the thermally activated coal gangue and polymerized ferric sulfate, the lanthanum-modified coal gangue exhibited a better capacity to fix phosphorus in sediment, and the phosphorus extracted by hydrochloric acid (HCL-P) and residual phosphorus (Res-P) levels in the sediment increased, where HCL-P accounted for 57.40% of the TP, exceeding the control group’s value by 34.15%. Thermally activated coal gangue showed a limited capacity to fix phosphorus in sediment, while polymeric ferric sulfate improved phosphorus extracted by bicarbonate dithionite (BD-P) content in the sediment.

Graphical abstract

中文翻译：

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改性煤石在封闭水域中用于磷的修复和去除的用途

摘要

热活化煤and石和镧改性煤gang石分别通过热活化和水热法制备。通过X射线衍射（XRD），全反射衰减衰减红外光谱（ATR-FTIR）和透射电子显微镜（TEM）对它们的结构和性质进行了表征。在封闭的水体中使用了热活化煤石和镧改性的煤石，并与聚合硫酸铁进行了比较。结果表明，与热活化煤gang石相比，镧改性的煤ue石具有较高的化学需氧量，铬法（CODcr），总磷（TP）和氨氮（NH ₄ -N）去除上覆水中的能力。CODcr，TP和NH ₄的浓度稳定时期上覆水中的氮素分别达到11-14 mg / L，0.023-0.028 mg / L和0.16-0.20 mg / L。热活化煤石对CODcr的去除效果好，但对TP的抑制效果差。与热活化煤石和聚合硫酸铁相比，镧改性的煤石具有更好的固定沉积物中磷的能力，而盐酸中提取的磷（HCL-P）和残留磷（Res-P）的含量较高。沉积物增加，其中HCL-P占TP的57.40％，比对照组的值高34.15％。热活化煤石在沉积物中固定磷的能力有限，而聚合硫酸铁可改善沉积物中碳酸氢盐连二亚硫酸盐（BD-P）含量提取的磷。

图形概要