鸟粪石沉淀法回收猪场沼液氮磷工艺参数优化模拟研究

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

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。

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 p H, 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 p H 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.