Anaerobic digestion is an attractive technology for resource management of organic waste and stubble. The state of biochemical reactions and activities in anaerobic digestion determines the process stability. Biochemical activities, such as syntrophic, metabolic, catalytic, and enzymatic activities, regulate the anaerobic efficiency for improved methane yield. Inhibitors, such as access to volatile fatty acids, ammonia, sulfur, and heavy metals, may slow down the anaerobic digestion and may cause reactor failure. However, additives for various biochemical activities may help to diminish the effect of inhibitors as well as improve process stability for enhanced methane yield. This manuscript presents an overview of various additives for enhancing the biochemical activities. The overview consists of the application of (a) conductive material for improving syntrophic activity, (b) trace metals for metabolic activities, (c) nanoparticles for improving catalytic activity, metabolism, and symbiosis during AD, (d) biological additives for enzymatic action, and (e) application of zeolite for introducing cation exchange properties in anaerobic digestion. Also, a comparison of various additives as per biochemical activity has also been performed for a deeper insight into the application of additives in anaerobic digestion.

No abstract

The present study investigates the application of Multi Criteria Decision Modelling (MCDM) on batch anaerobic codigestion of kitchen food waste (FW) and the fresh septic tank sludge (STS) for robust output. The batch experiment was carried out at a temperature of 37 ± 2 °C.

No abstract

Solid state anaerobic digestion (SSAD) of water poor feedstock may be a promising technology for energy recovery. Feedstocks having high solid concentration like lignocellulosic biomass, crop residues, forestry waste and organic fraction of municipal waste may be the appropriate feedstock for its biochemical conversion into energy carries like biomethane through SSAD.Compared to liquid state anaerobic digestion (LSAD), SSAD can handle higher organic loading rates (OLR), requires a less water and smaller reactor volume, may have lower energy demand for heating or stirring and higher volumetric methane productivity. Besides these, pathogen inactivation may also be achieved in SSAD of biodegradable waste. Around 60% of recently built AD systems have adopted SSAD technology. However, the process stability of an SSAD system may have several constraints like limited mass transfer, process inhibitors and selection of digester type and should be addressed prior to the implementation of SSAD technology. In this article, a comprehensive overview of the key aspects influencing the performance of SSAD