残留过氧化氢对微波-过氧化氢-碱预处理后污泥水解酸化的影响

前期研究发现,由于残留过氧化氢的影响,经过微波-过氧化氢-碱MW-H2O2-OH(p H=10)预处理的污泥进行水解酸化时存在产酸滞后期.因此,本研究通过批量试验,考察了残留过氧化氢对MW-H2O2-OH(p H=10和p H=11,MHO10和MHO11)预处理后污泥水解酸化的影响.结果表明,过氧化氢酶比二氧化锰具有更高效率的过氧化氢分解能力,能够在10 min内完全降解过氧化氢.水解酸化的8 d时间内,四组试验的SCOD(溶解性COD)浓度和总挥发性脂肪酸(VFA)浓度均呈现先增加后降低的趋势,优化水解时间均为0.5 d;MHO10组、MHO10+过氧化氢酶组(MHO10C)和MHO11+过氧化氢酶组(MHO11C)的优化水解酸化时间均为3 d,MHO11组的优化水解酸化时间为4 d.残留过氧化氢对MHO10预处理后污泥的水解酸化有抑制作用,存在产酸滞后期.与MHO10预处理相比,MHO11预处理释放的SCOD提高了19.29%,释放了更多的有机物,进而显著提高了总VFA产量,5 d时总VFA产量显著提高了84.80%,且MHO11组可以轻微缩短产酸滞后期.投加100mg·L-1过氧化氢酶,明显缩短解除了MHO10组和MHO11组0.5 d的产酸滞后期,并提高了总VFA产量,3 d时,MHO10C组、MHO11C组的总VFA浓度分别比MHO10组提高了23.61%、50.12%.MHO10组、MHO10C组和MHO11C组VFA的主要组分均为乙酸、异戊酸、正丁酸,而MHO11组VFA的主要组分为乙酸、丙酸、异戊酸,在各组的优化水解酸化时间,3种主要的VFA组分之和均占总VFA的75%以上,其中乙酸所占比例均在41%以上.

Effect of Residual Hydrogen Peroxide on Hydrolysis Acidification of Sludge Pretreated by Microwave -H2O2-Alkaline Process

Previous studies have found that in the hydrolysis acidification process, sludge after microwave -H₂O₂-alkaline(MW-H₂O₂-OH,pH=10) pretreatment had an acid production lag due to the residual hydrogen peroxide.In this study, effects of residual hydrogen peroxide after MW-H₂O₂-OH (pH=10 or pH=11) pretreatment on the sludge hydrolysis acidification were investigated through batch experiments.Our results showed that catalase had a higher catalytic efficiency than manganese dioxide for hydrogen peroxide, which could completely degraded hydrogen peroxide within 10 min.During the 8 d of hydrolysis acidification time, both SCOD concentrations and the total VFAs concentrations of four groups were firstly increased and then decreased.The optimized hydrolysis times were 0.5 d for four groups, and the optimized hydrolysis acidification times were 3 d for MW-H₂O₂-OH(pH=10) group, MW-H₂O₂-OH(pH=10)+catalase group and MW-H₂O₂-OH (pH=11)+catalase group.The optimized hydrolysis acidification time for MW-H₂O₂-OH (pH=11) group was 4 d.Residual hydrogen peroxide inhibited acid production for sludge after MW-H₂O₂-OH (pH=10) pretreatment, resulting in a lag in acidification stage.Compared with MW-H₂O₂-OH (pH=10) pretreatment, MW-H₂O₂-OH (pH=11) pretreatment released more SCOD by 19.29% and more organic matters, which resulted in the increase of total VFAs production significantly by 84.80% at 5 d of hydrolysis acidification time and MW-H₂O₂-OH (pH=11) group could shorten the lag time slightly.Dosing catalase (100 mg·L^-1) after the MW-H₂O₂-OH (pH=10 or pH=11) pretreatment not only significantly shortened the lag time(0.5 d) in acidification stage, but also produced more total VFAs by 23.61% and 50.12% in the MW-H₂O₂-OH (pH=10)+catalase group and MW-H₂O₂-OH (pH=11)+catalase group, compared with MW-H₂O₂-OH (pH=10)group at 3d of hydrolysis acidification time.For MW-H₂O₂-OH (pH=10) group, MW-H₂O₂-OH(pH=10)+catalase group and MW-H₂O₂-OH(pH=11)+catalase group, the dominant VFAs were acetic, iso-valeric and n-butyric acids.For MW-H₂O₂-OH(pH=11) group, the dominant VFAs were acetic, propionic and iso-valeric acids.In the optimized hydrolysis acidification time for each group, percentages of the three main acids accounted for more than 75% of total VFAs, and percentages of acetic acid accounted for more than 41% of total VFAs.