School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China.
School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling, Luoyu Road 1037, Wuhan, Hubei, 430074, China.
Chemosphere. 2021 Dec;284:131297. doi: 10.1016/j.chemosphere.2021.131297. Epub 2021 Jun 22.
An investigation was conducted for waste activated sludge pretreated by different methods (e.g., ultrasonic, thermal, ozone, and acid/alkaline) in order to establish correlations between amino acids and parameters related to sludge dewaterability (e.g., capillary suction time (CST), specific resistance to filtration (SRF), proteins (PN) and polysaccharides (PS) in different fractions of extracellular polymeric substances (EPS), zeta potential, and particle sizes). The results indicated that glycine, serine, and threonine were the key identified amino acids correlated with parameters related to sludge dewaterability. To be exemplified, glycine showed positive correlations with the normalized CST (regression coefficient (R) = 0.72, p < 0.05), the normalized SRF (R = 0.74, p < 0.05), PN in soluble EPS (R = 0.89, p < 0.05), PS in soluble EPS (R = 0.56, p < 0.05), tryptophan-like PN in soluble EPS (R = 0.60, p < 0.05), and tryptophan-like PN in loosely-bound EPS (R = 0.58, p < 0.05). After adding extra glycine, serine, and threonine into sludge samples, sludge dewaterability was deteriorated. The hydrophilic functional groups of CO and C-OH were found to be more predominant in sludge with the presence of these amino acids. The Lewis acid-base interaction predominated in determining the net attraction among sludge flocs. Moreover, the presence of glycine, serine, and threonine resulted in high repulsive hydrophilic interaction, which deteriorated sludge dewaterability. This study emphasized the importance of amino acids in sludge dewatering and amino acids might be incorporated into parameters reflecting sludge dewaterability.
为了建立氨基酸与污泥脱水性能相关参数（如毛细吸水时间（CST）、比过滤阻力（SRF）、胞外聚合物物质（EPS）不同组分中的蛋白质（PN）和多糖（PS）、zeta 电位和粒径）之间的相关性，对不同方法预处理的剩余活性污泥（如超声、热、臭氧和酸碱）进行了研究。结果表明，甘氨酸、丝氨酸和苏氨酸是与污泥脱水性能相关参数相关的关键鉴定氨基酸。例如，甘氨酸与归一化 CST（回归系数（R）= 0.72，p < 0.05）、归一化 SRF（R = 0.74，p < 0.05）、可溶 EPS 中的 PN（R = 0.89，p < 0.05）、可溶 EPS 中的 PS（R = 0.56，p < 0.05）、可溶 EPS 中色氨酸样 PN（R = 0.60，p < 0.05）和松散结合 EPS 中色氨酸样 PN（R = 0.58，p < 0.05）呈正相关。向污泥样品中额外添加甘氨酸、丝氨酸和苏氨酸后，污泥脱水性能恶化。发现含有这些氨基酸的污泥中 CO 和 C-OH 的亲水官能团更为突出。Lewis 酸碱相互作用在确定污泥絮体之间的净吸引力方面占主导地位。此外，甘氨酸、丝氨酸和苏氨酸的存在会导致高排斥性亲水相互作用，从而使污泥脱水性能恶化。本研究强调了氨基酸在污泥脱水过程中的重要性，并且氨基酸可能被纳入反映污泥脱水性能的参数中。
