基于微藻培养的养猪废水氨氮吹脱预处理

摘要

The ammonium mass concentration is very high in piggery wastewater,which may inhibit the growth of microalgae.The inhibitory ammonia levels for three microalgae strains were analyzed in order to solve the problem.Then the ammonia stripping method was used to decrease the ammonia mass concentration in piggery wastewater.The effects of the pH,aeration rate,and the initial ammonia mass concentration of wastewater on the removal efficiency were analyzed.Results showed that the inhibitory ammonia level for Chlorella vulgaris 1068 and Desmodesmus sp.CHX1 was both 130 mg/L,and 90 mg/L for Botryococcus braunii 765.Microalgae can grow well in the wastewater pretreated by stripping,and the process of stripping conforms to the first-order kinetic equation.Increasing the pH,aeration or the initial ammonium mass concentration was helpful to increase the removal efficiency of ammonia nitrogen.Appropriate operating parameters were obtained by considering the economic inputs and ammonia nitrogen removal efficiency.The wastewater should be stripped at an aeration rate of 1.5 L/min for 36 h,so that Chlorella vulgaris 1068 and Desmodesmus sp.CHX1 can grow well.The wastewater should be stripped at an aeration rate of more than 1.5 L/min for 42 h,or at an aeration rate of 1.5 L/min for more than 42 h in order to meet the growth condition of Botryococcus braunii 765.%针对养猪废水中氨氮质量浓度过高,会限制微藻生长这一问题,研究3种能源微藻对不同氨氮质量浓度养猪废水的适应性,探讨利用吹脱法对养猪废水中氨氮进行预处理的可行性,考察pH、曝气量和氨氮初始质量浓度对氨氮吹脱效果的影响.结果表明,当废水中氨氮质量浓度≤130 mg/L时,小球藻1068和近具刺链带藻CHX1能够很好地生长,葡萄藻765在氨氮质量浓度为90 mg/L的废水中生长良好.经吹脱预处理的养猪废水可以满足小球藻、葡萄藻和近具刺链带藻3种微藻生长,且吹脱去除氨氮过程符合一级动力学方程.提高pH和曝气量有助于提高氨氮吹脱去除效率.在综合考虑经济投入和氨氮去除效果2个因素后,确定满足小球藻1068和近具刺链带藻CHX1生长的养猪废水吹脱预处理工艺参数如下:曝气量为1.5 L/min、曝气时间为36 h;满足葡萄藻765生长的养猪废水吹脱预处理工艺参数为:曝气量＞1.5 L/min、曝气时间为42 h,或曝气量为1.5 L/min、曝气时间＞42 h.