PN/A-颗粒污泥工艺处理热水解污泥消化液

本研究构建了基于一体式厌氧氨氧化颗粒污泥及絮体污泥的部分硝化-厌氧氨氧化(PN/A)脱氮处理系统,通过运行参数优化调控实现了热水解污泥消化液的高效脱氮。试验结果表明,通过接种厌氧氨氧化菌(AnAOB)生物膜污泥与普通活性污泥、控制高游离氨(FA)(>20mg/L)和限制曝气(DO≤0.2mg/L)等运行条件,能够快速构建短程硝化-厌氧氨氧化反应,亚硝酸盐积累率可达85%以上,脱氮负荷达到0.60kgN/(m³·d)。稀释后的热水解污泥消化液仍对AnAOB活性具有一定的抑制作用,导致反应器总氮负荷降至0.20kgN/(m³·d)以下;但系统内AnAOB丰度总体呈增加趋势,说明AnAOB的增殖未受到完全抑制。系统内混合污泥的平均中位径由53μm缓慢增长至109μm。定量PCR数据及高通量分析显示,该处理系统富集了较高纯度的AnAOB,最大丰度占比可达8.06%,其优势菌属为Kuenenia菌属。此外,在第93运行周期下Kuenenia菌属在颗粒污泥的丰度占比大于AOB,为5.26%;絮体污泥中具有亚硝化效果的单胞菌属Nitrosomonas的丰度占比为1.64%,大于AnAOB。这展现了AOB和AnAOB丰度不同的空间分布特点。

Treatment of thermal hydrolysis sludge digestion supernatant by PN/A-granular sludge process

An integrated PN/A denitrification treatment system was constructed with a mixture of anammox granular sludge and floc sludge. Efficient denitrification of sludge digestion supernatant pretreated with thermal hydrolysis was achieved through the optimization of operating parameters. By inoculating AnAOB biofilm sludge and ordinary activated sludge simultaneously and keeping a high FA (>20mg/L) and low aeration (DO£0.2mg/L), the partial nitrification and anammox reaction was rapidly initiated, and the nitrous accumulation rate got over 85% while the denitrification load reached 0.60kgN/(m³·d). The diluted digestion supernatant still had a certain inhibition on AnAOB activity, resulting in the total nitrogen load of the reactor decreased to less than 0.20kgN/(m³·d). However, the abundance of AnAOB in the system exhibited an overall increasing trend, indicating that the proliferation of AnAOB was not completely restrained. The average median diameter of the sludge mixture in the system increased slowly from 53μm to 109μm. Results of quantitative PCR and high-throughput sequencing showed that the treatment system enriched the AnAOB with a higher purity, the maximum abundance ratio could reach 8.06% with the dominant genus being Kuenenia. In addition, in the 93rd run cycle, the abundance ratio of Kuenenia in granular sludge was higher than that of AOB, which was 5.26%; while in the floc sludge, the abundance of Nitrosomonas for nitrification accounted for 1.64%, higher than that of AnAOB. This demonstrated the different spatial distribution characteristics of AOB and AnAOB abundance.