猪粪沼液蒸发浓缩工艺参数优化及养分保留效果评估

Optimization of Process Parameters for Evaporation-Concentration of Pig Manure Biogas Slurry and Evaluation of Nutrient Retention

摘要:

针对沼液高含水量导致的储存、运输难题及环境污染风险，研究蒸发浓缩技术在沼液资源化利用中的应用潜力。通过控制变量试验，考察蒸发温度、蒸发面积和风速对沼液浓缩效果的影响。结果表明，随着蒸发温度从15℃升高至85℃，沼液体积浓缩倍数从1.01提升至1.69；蒸发面积从6.36×10^-3 m²增至17.67×10^-3 m²时，浓缩倍数由1.02增至1.06；风速从0 m/s提升至11 m/s时，浓缩倍数提高至3.57。同时，低温条件(15℃)下氨氮和总氮含量最高，分别为536.14 mg/L和689.12 mg/L；高温条件(85℃)下总磷和总钾浓度达到最大值，分别为37.56 mg/L和315.93 mg/L。风速增加虽导致氨氮和总氮浓度下降，但促进了总磷和总钾的富集，在11 m/s时总磷和总钾浓度分别增至78.21 mg/L和645.73 mg/L。蒸发浓缩技术可有效降低沼液体积、提升养分浓度，通过优化操作条件可实现浓缩效率和营养成分保留的平衡，为沼液农业高效利用提供技术支持。

Abstract:

In response to the storage and transportation difficulties and environmental pollution risks caused by the high water content of biogas slurry, this paper studies the potential application of evaporation concentration technology in the resource utilization of biogas slurry. The effects of evaporation temperature, evaporation area, and wind speed on the concentration efficiency of biogas slurry were investigated through controlled variable experiments. The results showed that as the evaporation temperature increases from 15℃ to 85℃, the volume concentration factor of biogas slurry increases from 1.01 to 1.69. When the evaporation area increases from 6.36× 10^-3m² to 17.67×10^-3m², the concentration factor increased from 1.02 to 1.06. As the wind speed increases from 0 m/s to 11 m/s, the concentration factor increases to 3.57. Meanwhile, under low temperature conditions(15℃), the content of ammonia nitrogen(NH₄⁺-N) and total nitrogen(TN) were the highest, at 536.14 mg/L and 689.12 mg/L, respectively. Under high temperature conditions(85℃), the total phosphorus and total potassium concentrations reached their maximum values of 37.56 mg/L and 315.93 mg/L, respectively. Although the increase in wind speed led to a decrease in ammonia nitrogen and total nitrogen concentrations, it promoted the enrichment of total phosphorus and total potassium. At 11 m/s, the total phosphorus and total potassium concentrations increased to 78.21 mg/L and 645.73 mg/L, respectively. Evaporation-concentration technology can effectively reduce the volume of biogas slurry and increase nutrient concentration. By optimizing operating conditions, a balance between concentration efficiency and nutrient retention can be achieved, providing technical support for the efficient utilization of biogas slurry in agriculture.