摘要
针对传统脱氮过程效率低、费用高等难题,该文采用膜吸收法对废水中的氨氮进行去除,并对该过程中废水无机碳的影响进行分析,以优化氨氮膜吸收过程参数。研究结果表明,在非曝气条件下,当HCO_(3)^(-)∶NH_(4)^(+)-N摩尔比达到1.4以上时,在无须外加碱的条件下,采用膜吸收法可以高效去除废水中的氨氮。响应面分析发现,各因素对氨氮去除效率的影响大小表现为曝气速率>反应时间>HCO_(3)^(-)∶NH_(4)^(+)-N摩尔比。曝气可以改变废水中H_(2)CO_(3)(CO_(2))、HCO_(3)^(-)和CO_(3)^(2-)之间的动态平衡,从而有利于游离氨的生成与去除。通过回归模型预测氨氮去除最佳条件为HCO_(3)^(-)∶NH_(4)^(+)-N摩尔比1.57,曝气速率0.525 L/min,反应时间5.98 h,预测的氨氮去除率为99.68%,实际值为98.40%,与预测结果一致。采用膜吸收法对富含HCO_(3)^(-)的厌氧沼液中高浓度氨氮进行去除,在无须外加碱的条件下,氨氮去除率可以达到81.15%;在最佳曝气速率为1.0 L/min,处理时间为6 h的条件下,最终氨氮去除率可以达到98.32%。此研究可为废水中氨氮的高效去除提供技术支撑。
In this study,membrane extraction method was adopted to remove ammonia nitrogen from wastewater for solving the problems of low efficiency and high cost during the traditional nitrogen removal process.The influence of inorganic carbon in wastewater was analyzed to optimize the parameters of ammonia nitrogen membrane absorption process.The results showed that under non-aeration conditions,when the molar ratio of HCO_(3)^(-)∶NH_(4)^(+)-N reached more than 1.4,the ammonia nitrogen in wastewater can be effectively removed by membrane extraction method without adding alkali.The result of response surface analysis showed that the influence of various factors on ammonia nitrogen removal efficiency was aeration ratereaction timeHCO_(3)^(-)∶NH_(4)^(+)-N molar ratio.Aeration can change the dynamic balance between H_(2)CO_(3)(CO_(2)),HCO_(3)^(-)and CO_(3)^(2-)in wastewater,which was beneficial for the generation and removal of free ammonia.According to the regression model,the optimal conditions for ammonia nitrogen removal were HCO_(3)^(-)∶NH_(4)^(+)-N molar ratio of 1.57,aeration rate of 0.525 L/min,reaction time of 5.98 h.The predicted ammonia nitrogen removal rate was 99.68%,and the actual removal rate was 98.40%,which was consistent with the predicted result.The membrane extraction method was used to remove ammonia nitrogen from the anaerobic biogas slurry which is rich in HCO_(3)^(-),and the ammonia nitrogen removal rate reached 81.15%without adding alkali.The optimal aeration rate was 1.0 L/min and the optimal treatment time was 6 h.Under this condition,the final ammonia nitrogen removal rate reached 98.32%.This study could provide a reference for the efficient removal of ammonia nitrogen from wastewater.
作者
杜阳
华天予
肖壮波
屈云贺
赵明星
阮文权
施万胜
DU Yang;HUA Tianyu;XIAO Zhuangbo;QU Yunhe;ZHAO Mingxing;RUAN Wenquan;SHI Wansheng(School of Environment and Civil Engineering,Jiangnan University,Wuxi 214122,China;Wuxi City Environmental Technology Co.,Ltd.,Wuxi 214026,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2023年第7期190-197,共8页
Environmental Science & Technology
基金
国家重点研发计划项目(2021YFC2102203)。
关键词
膜吸收
响应面分析
无机碳
曝气速率
沼液
membrane extraction
response surface analysis
inorganic carbon
aeration rate
biogas slurry
