Ghazisaidi Hamed, Garcia Rafael A, Tran Honghi, Yuan Runlin, Allen D Grant
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada.
United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Biobased and Other Animal Coproducts Research Unit, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
Polymers (Basel). 2020 Nov 22;12(11):2755. doi: 10.3390/polym12112755.
Synthetic polymers are widely used in the treatment of biosludge (waste activated sludge) to enhance its dewaterability. This paper discusses the results of a systematic study using hemoglobin (Hb) from animal blood and methylated hemoglobin (MeHb), a derivative in which a methyl group replaces the hydrogen carboxyl groups, to replace synthetic polymers to improve the dewatering efficiency of biosludge. With regular hemoglobin, no improvement in biosludge dewatering was found. With 10% of methylated hemoglobin per total solids content, however, the dry solids content of biosludge increased from 10.2 (±0.3) wt% to 15.0 (±1.0) wt%. Zeta potential measurements showed a decrease in the negative surface charge of the particles in biosludge from -34.3 (±3.2) mV to -19.0 (±2.1) mV after the treatment with methylated hemoglobin. This, along with an unchanged particle size distribution after conditioning, suggests that charge neutralization is likely the main cause of particle flocculation. With charges neutralized, the extracellular polymeric substances (EPS) around the biosludge flocs become loose, releasing the trapped water, thus increasing dewaterability.
合成聚合物被广泛用于生物污泥（废弃活性污泥）处理，以提高其脱水性能。本文讨论了一项系统研究的结果，该研究使用动物血液中的血红蛋白（Hb）和甲基化血红蛋白（MeHb，一种甲基取代氢羧基的衍生物）来替代合成聚合物，以提高生物污泥的脱水效率。使用普通血红蛋白时，未发现生物污泥脱水性能有所改善。然而，当甲基化血红蛋白占总固体含量的10%时，生物污泥的干固体含量从10.2（±0.3）wt%增加到了15.0（±1.0）wt%。ζ电位测量结果表明，用甲基化血红蛋白处理后，生物污泥中颗粒的负表面电荷从-34.3（±3.2）mV降至-19.0（±2.1）mV。这一点，再加上调理后颗粒尺寸分布不变，表明电荷中和可能是颗粒絮凝的主要原因。随着电荷被中和，生物污泥絮体周围的胞外聚合物（EPS）变得松散，释放出截留的水，从而提高了脱水性能。
