Enhancing Anaerobic Digestion of Waste Activated Sludge

本研究旨在探讨废旧活性污泥法与厌氧膜生物反应器(ANMBR)相结合的强化污泥消化技术。ANMBRs将水力停留时间与固体停留时间脱钩，并已被发现在高有机负荷率下实现大量固体破坏，同时产生增稠产品。据推测，污泥的预处理将允许更大的ANMBR处理能力。该过程将比使用连续流动搅拌槽反应器进行消化更稳定，并将实现与传统厌氧消化相似的病原菌减少，因为 延长的固体停留时间。因此，这种整合有可能大幅降低与污泥消化相关的资本和运营成本，同时保持稳定的运营和高质量消化产品的生产。然而，在这些技术的集成在实践中被接受之前，需要解决与系统集成、膜污染和模拟相关的问题。对于一体化系统，需要对前处理(即强度)和消化(即水力停留时间和固体停留时间)条件进行优化。由于在预处理过程中经常会产生更多的胶体物质，因此处理后的污泥可能会增加膜污染，这一点令人担忧。对预处理和消解的模拟很少受到关注，因此，目前在不进行昂贵的中试的情况下分析和设计这些系统是具有挑战性的。拟议项目的目标是： 1)优化组合使用过氧化氢(H_2O_2)和超声波作为一种创新的预处理方法，以最大限度地提高ANMBR的处理能力，并将膜污染降至最低 2.)优化ANMBR参数实现前处理与ANMBR消化相结合 3.)进一步发展污泥前处理和ANMBR消化模型

This proposal addresses a study of the integration of waste activated sludge (WAS) pretreatment technologies with anaerobic membrane bioreactors (AnMBR) for enhanced sludge digestion. AnMBRs decouple the hydraulic residence time from the solids residence time and have been found to achieve substantial solids destruction at high organic loading rates while producing a thickened product. It is hypothesized that pretreatment of the sludges would allow for even greater AnMBR throughput. The process would be more stable than the use of continuous flow stirred tank reactors for digestion and would achieve pathogen reduction that is similar to conventional anaerobic digestion due to the extended solids residence times. Hence, this integration has the potential to substantially reduce the capital and operating costs associated with sludge digestion while maintaining stable operation and production of a high quality digestion product. There are, however, issues associated with system integration, membrane fouling and simulation that need to be addressed before the integration of these technologies will be accepted in practice. Pretreatment (i.e. intensity) and digestion (i.e. hydraulic residence time and solids residence time) conditions need to be optimized for an integrated system. The potential for enhanced membrane fouling with pretreated sludges is of concern because of the increased colloidal matter that is often generated in pretreatment processes. Simulation of pretreatment and digestion has received little attention and hence it is currently challenging to analyze and design these systems without conducting costly pilot testing. The objectives of the proposed project are to: 1.) Optimize the combined use of hydrogen peroxide (H2O2) and ultrasound as an innovative pretreatment to maximize AnMBR throughput and minimize membrane fouling 2.) Optimize AnMBR parameters for integrating pre-treatment with AnMBR digestion 3.)Further develop models of sludge pre-treatment and AnMBR digestion