Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Environ Res. 2023 Sep 1;232:116347. doi: 10.1016/j.envres.2023.116347. Epub 2023 Jun 7.
Sludge stabilization was affected by solid content during autothermal thermophilic aerobic digestion (ATAD). Thermal hydrolysis pretreatment (THP) could alleviate the issues of high viscosity, slow solubilization and low ATAD efficiency caused by increased solid content. The influence of THP on the stabilization of sludge with different solid contents (5.24%-17.14%) during ATAD was investigated in this study. The results demonstrated that stabilization was achieved with volatile solid (VS) removal of 39.0%-40.4% after 7-9 days of ATAD for sludge with solid content of 5.24%-17.14%. The solubilization of sludge with different solid contents reached 40.1%-45.0% after THP. The rheological analysis indicated that the apparent viscosity of sludge was obviously reduced after THP at different solid contents. The increase in fluorescence intensity of fulvic acid-like organics, soluble microbial by-products and humic acid-like organics in the supernatant after THP and the decrease in fluorescence intensity of soluble microbial by-products after ATAD were detected by excitation emission matrix (EEM). The molecular weight (MW) distribution in the supernatant elucidated that the proportion of 50 kDa < MW < 100 kDa increased to 16%-34% after THP and the proportion of 10 kDa < MW < 50 kDa decreased to 8%-24% after ATAD. High throughput sequencing showed that the dominant bacterial genera shifted from Acinetobacter, Defluviicoccus and Norank_f__norank_o__PeM15 to Sphaerobacter and Bacillus during ATAD. This work revealed that solid content of 13%-17% was appropriate for efficient ATAD and rapid stabilization under THP.
污泥热稳定受自热嗜热好氧消化（ATAD）过程中固体含量的影响。热水解预处理（THP）可以缓解由于固体含量增加而导致的高粘度、缓慢溶出和低 ATAD 效率等问题。本研究考察了 THP 对不同固体含量（5.24%-17.14%）污泥在 ATAD 过程中的稳定化的影响。结果表明，固体含量为 5.24%-17.14%的污泥在经过 7-9 天的 ATAD 后，挥发性固体（VS）去除率达到 39.0%-40.4%，实现了稳定化。不同固体含量的污泥经 THP 后溶出率达到 40.1%-45.0%。流变分析表明，THP 后不同固体含量的污泥表观粘度明显降低。THP 和 ATAD 后上清液中腐殖酸类有机物、可溶微生物副产物和富里酸类有机物的荧光强度增加，可溶微生物副产物的荧光强度降低，通过激发发射矩阵（EEM）检测到。上清液中分子量（MW）分布表明，THP 后 50 kDa<MW<100 kDa 的比例增加到 16%-34%，10 kDa<MW<50 kDa 的比例减少到 8%-24%。高通量测序表明，在 ATAD 过程中，优势细菌属从不动杆菌属、脱卤球菌属和未分类的 norank_f__norank_o__PeM15 转变为球形杆菌属和芽孢杆菌属。本研究表明，THP 下固体含量为 13%-17%时，有利于高效 ATAD 和快速稳定化。
