有机负荷对UASB处理高浓度食品废水厌氧制氢及反应器运行特征的影响

Effects of Organic Loading on Anaerobic Hydrogen Production and Reactor Operation Characteristics of UASB Treatment of High Concentration Food Wastewater

针对有机负荷率(OLR)对高浓度食品废水厌氧产氢性能不明确的现状,在25℃下,开展了UASB处理不同OLR食品有机废水厌氧产期及反应器运行特征的探究。结果表明,OLR提高利于颗粒污泥浓度增加,OLR由20gCOD/(L·d)提高至50 gCOD/(L·d),污泥质量浓度由8.4~8.6 g/L提高至10.8~11.2 g/L。此外,OLR在40.0 gCOD/(L·d)时,COD去除率最高为92.5%~94.2%,氢气产量最大为38.9~40.3 mL/gVSS,远高于其他工况。OLR还对污泥特征具有显著影响。进水OLR由20 gCOD/(L·d)提高至40 gCOD/(L·d)时,胞外聚合物(EPS)的含量由101 mg/g提高至121 mg/g,EPS含量增加率约为50%。过量OLR导致系统内酸化严重降低pH影响了微生物活性。研究结果为UASB处理高浓度有机废水提供了一定的理论依据和数据支撑。

Because of the unclear effect of organic loading rate(OLR) on the anaerobic hydrogen production performance of high-concentration food wastewater, the anaerobic production period and reactor operation characteristics of UASB treating different OLR food organic wastewater were studied at 25 ℃. The results showed that the increase of OLR was beneficial to the increase of granular sludge concentration, OLR increased from 20gCOD/(L·d) to 50 gCOD/(L·d), and sludge concentration increased from 8.4~8.6 g/L to 10.8~11.2 g/L. In addition, when the OLR is 40.0 g COD/(L·d), the highest COD removal efficiency was 92.5%~94.2%, and the maximum hydrogen production was 38.9~40.3 mL/g VSS, which was much higher than other working conditions. The OLR also has a significant impact on sludge characteristics. When the influent OLR increased from 20 g COD/(L·d) to 40 gCOD/(L·d), the content of extracellular polymer(EPS) increased from 101 mg/g to 121 mg/g, and the increase rate of EPS content was about 50%. The excessive OLR leads to acidification in the system, seriously reducing the pH and affecting microbial activity. The research results provided a certain theoretical basis and data support for the treatment of high-concentration organic wastewater by the UASB.