College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China.
College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan 610225, China.
Sci Total Environ. 2020 Nov 20;744:140912. doi: 10.1016/j.scitotenv.2020.140912. Epub 2020 Jul 13.
A novel activator, corn biochar, was produced to activate persulfate to dewater waste activated sludge (WAS). Results demonstrated that the biochar-activated persulfate oxidation can effectively improve the dewatering performance of WAS. After treating WAS by biochar-activated persulfate oxidation (biochar dosage: 2.1 g/L, persulfate concentration: 7.5 mM) at the original WAS pH, standardized-capillary suction time (SCST) increased to 4.21 times and moisture content (MC) decreased to 43.4%, indicating an excellent performance of WAS dewatering. The decrease of residual persulfate with the increasing biochar dosage during WAS dewatering process illustrated that the role of persulfate in improving WAS dewatering was because of the biochar activation. The behaviors of extracellular polymers (EPS) proved that the protein in tightly bound EPS (TB-EPS) linked to WAS dewatering, and its content significantly reduced to 10.5 mg/g-volatile solids (VS) after WAS treatment. Three-dimensional fluorescence spectroscopy for EPS once again proved that the disintegration of tryptophan protein and humic acid (hydrophobic organic substances in EPS) was responsible for the improvement of WAS dewatering. To sum up, the biochar-activated persulfate oxidation was a feasible application in improving WAS dewatering.
一种新型的激活剂——玉米生物炭，被用于激活过硫酸盐以对剩余活性污泥（WAS）进行脱水处理。结果表明，生物炭激活过硫酸盐氧化可以有效地改善 WAS 的脱水性能。在原始 WAS pH 值下，通过生物炭激活过硫酸盐氧化（生物炭用量：2.1 g/L，过硫酸盐浓度：7.5 mM）处理 WAS 后，标准毛细吸留时间（SCST）增加到 4.21 倍，水分含量（MC）降低到 43.4%，表明脱水性能非常出色。在 WAS 脱水过程中，随着生物炭用量的增加，残留过硫酸盐的减少表明，过硫酸盐在改善 WAS 脱水性能方面的作用是由于生物炭的激活。胞外聚合物（EPS）的行为证明了与 WAS 脱水相关的紧密结合 EPS（TB-EPS）中的蛋白质，并且在处理 WAS 后其含量显著降低至 10.5 mg/g-挥发性固体（VS）。EPS 的三维荧光光谱再次证明，色氨酸蛋白和腐殖酸（EPS 中的疏水性有机物质）的解体是改善 WAS 脱水性能的原因。总之，生物炭激活过硫酸盐氧化是一种可行的改善 WAS 脱水的应用方法。
