鸟粪石沉淀法回收猪场沼液氮磷工艺参数优化模拟研究

针对规模化养殖场沼液难以农田消纳的问题,探索化学方法回收沼液中氮磷的工艺条件和优化参数。本研究选择猪场沼液为研究对象,采用鸟粪石沉淀法,进行单因素影响试验,选取p H、镁氮比、磷氮比为自变量,以氮磷回收率为响应值,通过BoxBehnken响应面试验设计对工艺参数进行优化。结果显示:猪场沼液氮磷回收的最佳工艺为:p H 10,镁氮比为1.1,磷氮比为0.6,氨氮回收率为65.21%,磷酸盐回收率为89.47%,实际值氨氮回收率为65.01%,磷酸盐回收率为90.81%,差值分别为0.20%、1.34%,回归模型拟合较好。

Simulation of optimization of process parameters of nitrogen and phosphorus recovery in biogas slurry derived from swine manure by struvite precipitation method

The present study focuses on exploring the process conditions of nitrogen and phosphorus recovery from biogas slurry and optimizing the process parameters using a chemical method to alleviate the difficulties faced by large-scale farms in the digestion of biogas slurry. The biogas slurry of swine manure was assessed. By using the struvite precipitation method, the influence of factors such as pH, magnesium:nitrogen ratio, and phosphorus:nitrogen ratio on the nitrogen and phosphorus recovery rate was investigated and optimized using the Box-Behnken response surface methodology design. The optimum conditions for the recovery of nitrogen and phosphorus in biogas slurry from swine manure were a pH of 10, a magnesium:nitrogen ratio of 1.1, and a phosphorus:nitrogen ratio of 0.6. Under the above optimized conditions, the recovery rates for ammonia and phosphate were 65.21% and 89.47%, respectively. In the actual experiments, the recovery rates for ammonia and phosphate were 65.01% and 90.81%, respectively, with difference values of 0.20% and 1.34%, respectively, indicating good fit with the regression model.