藻菌共生体处理猪场沼液的参数优化研究

Optimization of parameters for treatment of livestock farming wastewater by algal-bacterial symbiosis

猪场沼液高色高浊、氮磷浓度高,采用藻菌共生体可同步高效去除碳氮磷、节能降耗、资源回收,符合新时代对污水处理的需求。从污染物去除、微生物生长等角度对光照强度、曝气量和藻菌接种比例这3个参数进行优选发现,曝气量对氮去除的影响最大,而3个参数对碳、磷去除的影响较小。经加权评价得出三因素排序:曝气量>光照强度>藻菌接种比例,最优参数组合:光照强度为550μmol/(m^(2)·s),曝气量为0.2 L/min,藻菌接种比例为1∶1。最优组的TP、COD、TN、NH_(4)^(+)-N分别为0.48、219.2、125.2、64 mg/L,TP、COD、TN、NH_(4)^(+)-N去除率分别为95.46%、88.58%、61.58%、80.21%。各组中藻菌絮体粒径均呈增大趋势,且随藻菌接种比例的增大而减小。

Pig farm biogas slurry is high in color and turbidity with high content of nitrogen and phosphorus.The use of microalgae-bacteria symbiosis can simultaneously and efficiently remove carbon,nitrogen and phosphorus,save energy and reduce consumption,and recover resources,meeting the needs of the new era for wastewater treatment.In this study,the three parameters of light intensity,aeration intensity and the proportion of microalgae and bacteria were optimized from the perspectives of pollutant removal and microbial growth.It was found that the amount of aera⁃tion had the greatest impact on nitrogen removal,while the three parameters had little impact on carbon and phos⁃phorus removal.After weighted evaluation,the sequence of three factors followed aeration amount>light intensity>in⁃oculation proportion,and the optimal parameter combination is light intensity at 550μmol/(m^(2)·s),aeration rate at 0.2 L/min,microalgae-bacteria inoculation ratio at 1∶1.The concentrations of TP,COD,TN and NH_(4)^(+)-N in the group with the best comprehensive score were 0.48,219.2,125.2,64 mg/L respectively,and the removal rates were 95.46%,88.58%,61.58%and 80.21%respectively.The particle size of microalgae-bacteria flocs in each group in⁃creased,and decreased with the increase of the microalgae-bacteria proportion.