剩余污泥在微氧条件下利用VFAs合成PHAs的工况优化  

Working conditions optimization of PHAs synthesis by excess activated sludge fed with VFAs under micro-aerobic conditions

作　　者：谢一涵 方茜[1] 刘煜 曾蕴仪 黄定武 黄紫龙 XIE Yihan;FANG Qian;LIU Yu;ZENG Yunyi;HUANG Dingwu;HUANG Zilong(School of Civil Engineering,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州大学土木工程学院,广州510006

出　　处：《环境工程学报》2020年第4期1052-1058,共7页Chinese Journal of Environmental Engineering

基　　金：广州市科技计划项目(201510010111);广东省自然科学基金资助项目(2017A030313273)。

摘　　要：针对2种脱氮除磷工艺的剩余污泥,在微氧条件下,以花生渣厌氧发酵产生的VFAs为碳源,控制反应时间为5 h,DO≤0.2 mg·L-1,COD为650~750 mg.L-1,对比2种不同工艺的剩余污泥合成聚羟基脂肪酸酯(PHAs)的量,并探究了增设前置曝气对微氧条件下剩余污泥合成PHAs的影响。结果表明,在微氧条件下,连续流中同步亚硝化反硝化脱氮除磷系统二沉池的剩余污泥(R1)和采用A2O工艺的实际水厂的剩余污泥(R2)合成PHAs最高量分别为108.6 mg·g-1和58.58 mg·g-1,R1比R2更具有合成PHAs的能力;在增设前置曝气实验中,曝气时间的延长和曝气量的增大均可促进PHAs的合成;当曝气气量为50 L·h-1时,曝气20 min后,R1合成的PHAs最高为172.5 mg·g-1。氧化还原电位(Eh)是微氧条件下PHAs合成过程中的重要指示参数,当Eh值为最低时,PHAs合成量最多。以上结果可为脱氮除磷工艺剩余污泥利用廉价碳源合成PHAs提供参考。In this study,under micro-aerobic conditions,two types of excessive sludge in nitrogen and phosphorous removal process were fed with volatile fatty acid(VFAs) carbon source produced from anaerobic fermentation of peanut residues to synthesize polyhydroxyalkanoates(PHAs).At the dissolved oxygen(DO) less than 0.2 mg·L-1,chemical oxygen demand(COD) of 650-750 mg·L-1,and reaction time of 5 h,the PHAs production amounts by these two types of sludge were compared.The effect of pre-aeration before feeding VFAs on PHAs production was also studied.The result showed that the maximum amounts of PHAs production from the excess sludge in a secondary tank of the continuous flow synchronous nitrosation-denitrification and phosphorus removal process(RI) and in a wastewater treatment plant with conventional anaerobic-anoxic-oxic process(R2) were 108.6 mg·g-1 and 58.58 mg·g-1,respectively,which indicated that R1 had a better performance on PHAs production than R2.Besides,the results of adding the pre-aeration test in R1 presented that both the aeration time extension and the aeration gas volume increasing could promote PHAs synthesis.When the aeration volume and aeration time were 50 L·h-1 and 20 minutes,respectively,the maximum amount of PHAs synthesis in R1 reached 172.5 mg·g-1.Oxidation-reduction potential(Eh) was an important indicator associated with PHAs production under micro-oxygen conditions,where the maximum PHAs production occurred at the lowest Eh.In a summary,this study provides a new idea for PHAs synthesis by excess activated sludge from biological nitrogen and phosphorous removal process fed with cheap carbon source.

关 键 词：微氧 剩余污泥 前置曝气 挥发性脂肪酸(VFAs) 聚羟基脂肪酸酯(PHAs) 

分 类 号：X705[环境科学与工程—环境工程]