Flue gas desulphurization gypsum (FGD) is a major solid waste in coal-fired energy plants, and the appropriate reuse of this resources is still a major challenge. In this study, the feasibility of FGD as a calcium source to produce hydroxyapatite (FGD-HAP) for the immobilization of lead (Pb) and cadmium (Cd) in spiked soil was investigated. The effects of FGD and FGD-HAP on soil properties and redistribution, bioaccessibility and plant uptake of Pb and Cd were examined. Results showed that application of FGD and FGD-HAP could significantly improve the enzymes activities of contaminated soils, but the effectiveness was more pronounced with FGD-HAP. Addition of only 1% FGD-HAP could effectively reduce bioavailable Pb and Cd concentration in soil as measured by CaCl₂ extraction by 60.6% and 65.4%, respectively. On the other hand, plant available Pb and Cd could significantly decrease by 93.8% and 73.2% after amendment of 5% FGD-HAP. Significant changes in the micro-scale distribution of heavy metals before and after FGD-HAP treatment demonstrated that while heavy metals were predominantly associated with iron/manganese oxides in untreated soil, high correlation between heavy metals and phosphorus/sulfur was observed in FGD-HAP treated soil. In addition, results of the leaching tests showed that incorporation of FGD-HAP enhanced the retention capacity of heavy metals in soil, indicating that application of FGD-HAP could diminish the environmental risk of leachable heavy metals to groundwater. Overall, this study highlighted the potential value of FGD-HAP as a low-cost and high-efficient amendment for remediation of Pb and Cd contaminated soils.

烟气脱硫石膏（FGD）是燃煤电厂的主要固体废物，如何合理利用这些资源仍然是主要挑战。在这项研究中，研究了烟气脱硫作为钙源生产羟基磷灰石（FGD-HAP）的可行性，该技术可用于固定加标土壤中的铅（Pb）和镉（Cd）。研究了烟气脱硫和烟气脱硫对土壤特性和铅，镉的再分配，生物利用度和植物吸收的影响。结果表明，烟气脱硫和烟气脱硫的应用可以显着提高被污染土壤的酶活性，但烟气脱硫的效果更为明显。用CaCl ₂测定，仅添加1％的FGD-HAP可以有效降低土壤中的生物有效性Pb和Cd浓度提取率分别为60.6％和65.4％。另一方面，修正了5％FGD-HAP后，植物中有效的Pb和Cd可能分别下降93.8％和73.2％。FGD-HAP处理前后重金属的微观尺度分布的显着变化表明，尽管未处理土壤中重金属主要与铁/锰氧化物相关，但在FGD-HAP中观察到重金属与磷/硫之间的高度相关性处理过的土壤。此外，浸出试验的结果表明，FGD-HAP的掺入提高了土壤中重金属的保留能力，表明FGD-HAP的使用可以降低可浸出重金属对地下水的环境风险。总体，