Anaerobic digestion (AD) for food waste (FW) treatment has faced many challenges, especially ammonia nitrogen, acid, and salinity inhibition at a high organic loading rate (OLR). Therefore, a systematic understanding of the issues arising during the FW AD process is a necessity under a high OLR (over 3 g-VS/L d). Primarily, in terms of ammonia nitrogen inhibition, ammonia ions inhibit methane synthesis enzymes, and free ammonia (FAN) contributes to the imbalance of microbial protons. Regulation strategies include substrate C/N ratio regulation, microbial domestication, and ammonia nitrogen removal. In addition, with regard to acid inhibition, including volatile fatty acid (VFA) and long-chain fatty acid (LCFA) accumulation, the elevated acid concentration can contribute to reactive oxygen species stress, and a solution to this includes the addition of alkaline agents and trace elements or the use of microbial electrochemical and biofortification technology and micro-aeration-based AD technology. Furthermore, in terms of salinity inhibition, high salinity can result in a rapid increase in cell osmotic pressure, which can cause cell rupture, and water washing and bio-electrochemical AD are defined as solutions. Future research directions are proposed, mainly in terms of avoiding the introduction of novel containments into these regulation strategies and applying them in large-scale AD plants under a high OLR.

Owing to advantageous properties such as high mechanical strength and wear and hydrolysis resistance, polyvinylidene fluoride (PVDF)-based materials have been widely used to fabricate membranes utilizing in anaerobic membrane bioreactors (AnMBRs) for wastewater treatment. Though AnMBRs can be regarded as high-rate bioreactors, membrane fouling caused by organic, inorganic, and biological contaminants remains an inevitable challenge. In order to alleviate this issue, this review systematically summarizes modification methods including crosslinking, surface coating, and assembly for the loading of functional materials and inorganic nanoparticles onto the membrane surface. Additionally, this review indicates that modified PVDF-based membranes with enhanced conductive or antifouling properties can be effectively applied in AnMBRs, and better chemical oxygen demand (COD) removal efficiency can be achieved compared with those utilizing pristine PVDF membranes. Different from previous reviews, this review proposes technology intensification strategies utilizing pristine PVDF membranes including electrochemical AnMBR (electro-AnMBR) and anaerobic fluidized bed membrane bioreactor (AFMBR). Both of them have demonstrated enormous potential for mitigating membrane fouling relative to conventional AnMBR configurations. Spontaneously, this review underscores the critical need to integrate these intensification strategies with modified PVDF-based membranes as relative studies in this combined area. Therefore, this review provides comprehensive guidance on modification methods of PVDF membranes and technology intensification strategies utilizing modified PVDF-based membranes.