Based on the acidic and phosphorus-rich properties of phosphogypsum (PG), it was dope-modified (PO-PG) to cement (PO) and used for lead removal from acid mine wastewater. The results showed that PO-PG removed more than 99% of lead at different concentrations (15~100mg/L) with suitable dosage; under the reaction conditions of initial pH=3, PO-PG dosage of 0.2g/L, and 25℃, the effect of PO-PG on the removal of lead from 30mg/L Pb2+ was completely removed in 20min instead of 120min for PO; meanwhile, PO-PG had a high affinity for lead, and the removal effect of lead remained stable in the simulated wastewater with complex composition. Mechanistic analysis showed that isomorphous replacement and surface heterogeneous chemical precipitation were the main mechanisms for lead removal by PO-PG, Ca(OH)2, CaCO3 and Ca5(PO3)3 OH were the main lead removal factors in PO-PG, and Pb2+ is removed by lattice displacement and other chemical reactions with Ca2+ to form a water-insoluble precipitate, and the products of the lead removal mainly included PbCO3, Pb3(CO3)2(OH)2, Pb(OH)2 and Pb5(PO4)3 OH precipitates. In summary, the doping of acidic PG can accelerate the hydration rate of alkaline PO, thus improving the reaction efficiency and alleviating the problem of high pH in PO-treated effluent, in addition to the presence of phosphates in PG can be an effective species for lead removal. This study provides a cost-effective and efficient new method for the removal of lead from acid mine wastewater and can realize the resource utilization of phosphogypsum.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |