牛场污水资源化利用的前处理方法效果研究
Pretreatment effect of wastewater from cattle farm before its resource utilization
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摘要: 采用固液分离、沉淀、超声波振荡及化学添加方法,对牛场污水资源化利用前进行处理。牛场废弃物经固液分离,再经过沉淀池处理后液体废弃物(即养殖污水)中悬浮物(SS)降低7.14%,大肠菌群数降幅达97.27%,COD 含量降幅达82.51%。试验对比了添加不同比例生石灰、石灰氮和超声波振荡的处理效果,发现随着化学药剂添加比例的提高,养殖污水透光率升高,达到澄清所需时间减少,但同时养殖污水的电导率也显著增加,磷含量显著降低,而钾含量变化较小。其中添加生石灰5 g/L 的处理,2 d 后养殖污水大肠菌群数降至0,透光率达到90% 以上;添加石灰氮5 g/L 的处理,1 d 后养殖污水大肠菌群数降至0,透光率达到95% 以上,且处理3 d 后总氮含量增至600 mg/kg 以上,而超声波振荡处理对所测指标的影响较小。可见,养牛场废弃物经固液分离的液体部分通过沉淀、过滤及化学添加处理后,可经水肥一体化管道就地资源化利用,这可为实现养牛场废水以及类似水质废水的快速处理提供依据。Abstract: Solid-liquid separation,precipitation,ultrasonic oscillation and bio-chemical treatment methods were used to treat wastewater in cattle farm before its utilization. Wastewater were separated before entered precipitation tank and reduced 7.14% suspended solids,97.27% fecal coliform numbers and 82.51% COD contents. Effects of agent addition( CaO and CaCN2) and ultra-sonic oscillation treatment were compared and discussed. The results showed that the increase of agent addition ratios to wastewater increased the transmittance,shortened the time to clarification,and increased the electric conductivity,decreased the total phosphorus content,but had little influence on potassium content. Addition of CaO 5 g/kg decreased fecal coliform number to 0,and increased the transmittance to over 90% after 2 days. Addition of CaCN2 5 g/kg decreased fecal coliform number to 0,and increased the transmittance to over 95% after 1 day,and increased total nitrogen content to 600 mg/kg after 3 days. While ultrasonic oscillation treatment had little influence on these detection indexes. The study suggested that wastewater from cattle farm could be resource utilization through integrative pipes of water and fertilizer locally after separated from solid wastes,treatment in precipitation tank,and addition of proper ration agent. It provided a basis for quick treatment of cattle farm wastewater before its safely resource utilization.