Anaerobic digestion is a versatile biotechnology to treat waste activated sludge (WAS), the main by-products of biological wastewater treatment, because it can achieve simultaneously energy recovery (biogas) and pollutant reduction (organic matter, pathogens). However, the potential of biogas production from mono-digestion of WAS is usually limited by the imbalance carbon to nitrogen (C/N) ratio of WAS and ammonia accumulation. Anaerobic co-digestion, simultaneous digestion of two or more substrates, should be a feasible option to resolve these disadvantages. The abundant organic wastes from municipal, industrial, and agricultural field have been the ideal co-substrates because they not only can balance the substrate nutrient to obtain the optimal C/N ratio, but also can adjust pH and dilute the toxic materials to mitigate the inhibition to methanogens, consequently improving the yield of biogas, especially methane. This paper classified the main organic co-substrates according to their source and reviewed their application in anaerobic co-digestion of WAS. Then the influence of temperature, pH, organic loading rate, hydraulic retention time, C/N ratio, digester type and pretreatment method on biogas production was extensively discussed. Finally, this review brought forward the challenges and outlooks of anaerobic co-digestion in the future.

厌氧消化是一种通用的生物技术，用于处理生物废水处理的主要副产品废物活性污泥（WAS），因为它可以同时实现能量回收（沼气）和污染物减少（有机物，病原体）。但是，单消化WAS产生沼气的潜力通常受到WAS碳氮比（C / N）和氨气积累不平衡的限制。厌氧共消化，同时消化两种或多种底物，应该是解决这些缺点的可行选择。来自市政，工业和农业领域的大量有机废物已成为理想的共底物，因为它们不仅可以平衡底物养分以获得最佳的C / N比，而且还可以调节pH值并稀释有毒物质，以减轻对产甲烷菌的抑制作用，从而提高沼气（尤其是甲烷）的产率。本文根据主要有机共基质的来源对其进行了分类，并综述了它们在WAS厌氧共消化中的应用。然后广泛讨论了温度，pH，有机负载率，水力停留时间，C / N比，消化器类型和预处理方法对沼气生产的影响。最后，本综述提出了厌氧消化的挑战和未来的前景。讨论了有机负荷率，水力停留时间，C / N比，消化器类型和沼气生产的预处理方法。最后，这篇综述提出了厌氧消化的挑战和未来的前景。讨论了有机负荷率，水力停留时间，C / N比，沼气池类型和沼气生产的预处理方法。最后，这篇综述提出了厌氧消化的挑战和未来的前景。