猪场沼液本土微生物富集的氮磷回收特性

Characteristics of nitrogen and phosphorus recovery from biogas slurry enriched by indigenous microflora in pig farms

为提高规模化养殖场的沼气工程中沼液增值化利用水平,本研究对低碳氮比(C/N)沼液采用葡萄糖碳源添加进行沼液本土微生物富集培养,以实现沼液废水处理和养分回收增值化利用。对初始C/N为1.5的猪场沼液分别添加2、4、6、8和10 g/L的葡萄糖碳源,碳源添加后OD_(600)均呈先升后降趋势,且在第2~3天达到最大值,葡萄糖碳源添加量为6 g/L时总蛋白增长率(145.8%)为各组最高。综合经济性,选取最佳沼液本土微生物富集培养条件为葡萄糖添加量6 g/L、处理时间2 d,此时沼液的总氮和总磷去除率分别为66.1%、77.5%,同时通过沼液本土微生物富集增加生产了2.44 g/L的生物干质量和0.72 g/L的总蛋白,回收了29.0%的总氮和59.7%的总磷。研究结果表明,沼液本土微生物富集培养可有效用于沼液氮磷养分回收,获得微生物干质量和蛋白增长,同时可作为沼液深度处理的预处理手段。

In the biogas project of large-scale farms,the environmental nitrogen and phosphorus pollution is often caused by the inability of biogas slurry to be consumed nearby,which makes the recovery technology of nitrogen and phosphorus nutrient from biogas slurry more concerned.In this article,the low C/N ratio biogas slurry was enriched and cultured by adding glucose carbon source to realize the value-added utilization of wastewater and recovery of nutrient from biogas slurry.The biogas slurry in pig farms with initial C/N of 1.5 was added with 2 g/L,4 g/L,6 g/L,8 g/L and 10 g/L glucose carbon sources,respectively.The OD_(600) increased first and then decreased after adding carbon sources,and reached the maximum at 2-3 d.The total protein growth rate of 6 g/L was the highest in each group.The results showed that the optimal conditions for enrichment culture of the indigenous microflora in biogas slurry were the addition of 6 g/L glucose and 2 d treatment based on the comprehensive economy.Under the optimal conditions,the removal rate of TN and TP from biogas slurry were 66.1%and 77.5%,respectively.0.72 g/L total protein was produced by enrichment of the indigenous microflora in biogas slurry.The biomass dry weight increased by 146.1%.29.0%of total nitrogen and 59.7%of total phosphorus were recovered.It is indicated that the enrichment culture of the indigenous microflora in biogas slurry can be effectively used for the recovery of nitrogen and phosphorus nutrient.Microbial dry weight and protein growth can be used as a pretreatment method for the advanced treatment of biogas slurry in pig farms.