School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
Waste Manag. 2019 Jul 1;94:68-76. doi: 10.1016/j.wasman.2019.05.047. Epub 2019 May 30.
Thermal hydrolysis has proven to be a successful approach to make sewage sludge more amenable to anaerobic digestion. Three heat pretreatment scenarios were compared in this study, i.e. thermal alkaline treatment (LAT, 0.1 M NaOH, 80 °C), low temperature thermal treatment (LT, 80 °C) and high temperature thermal treatment (HT, 170 °C). The biodegradability of pretreated sludge was testified by using biochemical methane potential (BMP) test, meanwhile, the repartition and complexities of organic matters in sludge subjected to various pretreatments were characterized by a revised chemical extraction protocol combined with 3D fluorescence spectroscopy. The cumulative methane yield of sewage sludge was significantly increased by LAT (+135%), LT (+95%) and HT (+112%) as compared to the control. Nevertheless, results show that the solubilization degree of sludge was insignificantly correlated to BMP values, meanwhile high correlation values were observed for the soluble polysaccharide concentration in hydrolysate. The degradation rates of bioaccessible fraction of soluble particulate organic matter (SPOM) and readily extractible organic matter (REOM) were improved after thermal pretreatments at varied levels, which indicates that the chemical accessibility is positively correlated with the bioaccessibility. Furthermore, the biodegradable index F was proposed to evaluate the biodegradability of organic matter, which is helpful for the optimization of various pretreatment strategies.
热水解已被证明是一种成功的方法，可以使污水污泥更适合厌氧消化。本研究比较了三种热预处理方案，即热碱处理（LAT，0.1 M NaOH，80°C）、低温热处理（LT，80°C）和高温热处理（HT，170°C）。通过生化甲烷潜力（BMP）测试证明了预处理污泥的生物降解性，同时，通过修订的化学提取方案结合三维荧光光谱法对污泥中有机物的分布和复杂性进行了表征。与对照相比，LAT（+135%）、LT（+95%）和 HT（+112%）显著提高了污水污泥的累积甲烷产量。然而，结果表明，污泥的溶解程度与 BMP 值没有显著相关性，同时在水解液中观察到可溶性多糖浓度与 BMP 值具有很高的相关性。在不同程度的热预处理后，生物可利用的可溶性颗粒有机物质（SPOM）和易提取有机物质（REOM）的降解率得到提高，这表明化学可及性与生物可及性呈正相关。此外，提出了可生物降解指数 F 来评估有机物的可生物降解性，这有助于优化各种预处理策略。
