Department of Civil Engineering, Indian Institute of Technology, Roorkee, 247667, India.
Environmental Hydrology Division, National Institute of Hydrology Roorkee, 247667, India.
Environ Res. 2022 Nov;214(Pt 2):113856. doi: 10.1016/j.envres.2022.113856. Epub 2022 Jul 15.
Sewage sludge is rich source of carbon, nutrients, and trace elements and can be subjected to proper treatment before disposal to fulfill government legislation and protect receiving environments. Anaerobic digestion (AD) is a well-adopted technology for stabilizing sewage sludge and recovering energy-rich biogas and nutrient-rich digestate. However, a slow hydrolysis rate limits the biodegradability of sludge. In the present study we have attempted to explain the potential of thermal hydrolysis to enhance anaerobic digestion of sewage sludge. Thermal pretreatment improves biodegradability and recycling of the sludge as an excellent energy and nutrients recovery source at reasonable capital (CAPEX) and operational (OPEX) costs. Other pretreatments like conventional (below/above 100 °C), temperature-phased anaerobic digestion (TPAD), microwave and chemically mediated thermal pretreatment have also been accounted. This review provides a holistic overview of sludge's characterization and value-added properties, various techniques used for sludge pretreatment for resource recovery, emphasizing conventional and advanced thermal pretreatment, challenges in scale-up of these technologies, and successful commercialization of thermal pretreatment techniques.
污水污泥是碳、营养物和微量元素的丰富来源，在处置前可以进行适当的处理，以满足政府立法和保护接收环境的要求。厌氧消化（AD）是一种成熟的技术，可用于稳定污水污泥并回收富含能量的沼气和富含营养的消化物。然而，水解速度较慢限制了污泥的生物降解性。在本研究中，我们试图解释热解技术提高污水污泥厌氧消化的潜力。热预处理可提高污泥的生物降解性和可回收性，将其作为一种优秀的能源和营养物回收来源，具有合理的资本（CAPEX）和运营（OPEX）成本。其他预处理方法，如常规（低于/高于 100°C）、温度分相厌氧消化（TPAD）、微波和化学介导的热预处理也已得到应用。本综述提供了污水污泥特性和增值特性的全面概述，以及用于污泥资源回收的各种预处理技术，重点介绍了常规和先进的热预处理技术，这些技术在扩大规模方面的挑战，以及热预处理技术的成功商业化。
