污泥焚烧飞灰磷含量较高,但存在形式复杂且生物利用率低。开发污泥焚烧飞灰磷回收技术成为缓解磷危机的重要途径。采用高温煅烧法探究Na2SO4和K2SO4对污泥焚烧飞灰中磷形态转化及生物有效性的影响。结果表明,添加硫酸盐能显著促进NAIP向AP转化,最佳Na2SO4和K2SO4添加比均为10%,此时AP占IP比达到最大,分别为76.59%和55.41%。当添加比为20%时,磷的生物有效性达到峰值,分别为41.8%和48.8%。但AP含量与磷的生物有效性呈现出相反的趋势。XRD分析表明,硫酸盐添加剂能促使飞灰中生成多种AP矿物,但部分AP (如CaP2O6)因柠檬酸溶解性较差而导致其生物有效性低。综上,硫酸盐添加剂可以同时提高AP转化效率和生物有效性,其中K2SO4在提升磷的生物有效性方面更具优势。该研究结果可为从污泥焚烧飞灰中回收磷资源提供理论参考。The phosphorus content of incinerated sewage sludge ash is relatively high, but it exists in complex forms and has low bioavailability. The development of incinerated sewage sludge ash phosphorus recovery technology has become an important way to alleviate the phosphorus crisis. High-temperature calcination method is used to explore the effects of Na2SO4 and K2SO4 on the transformation of phosphorus forms and bioavailability in incinerated sewage sludge ash. The results showed that the addition of sulfate significantly promoted the conversion of NAIP to AP, with the optimal ratios of Na2SO4 and K2SO4 both being 10%. At this point, the proportion of AP to IP reached its maximum, at 76.59% and 55.41%, respectively. When the addition ratio is 20%, the bioavailability of phosphorus reaches its peak at 41.8% and 48.8%, respectively. However, the AP content showed an opposite trend to the bioavailability of phosphorus. XRD analysis shows that sulfate additives can promote the formation of various AP minerals in fly ash, but some APs (such as CaP2O6) have low bioavailability due to poor citric acid
