Solid-state anaerobic digestion (SS-AD) generally occurs at solid concentrations higher than 15%. In contrast, liquid anaerobic digestion (AD) handles feedstocks with solid concentrations between 0.5% and 15%. Animal manure, sewage sludge, and food waste are generally treated by liquid AD, while organic fractions of municipal solid waste (OFMSW) and lignocellulosic biomass such as crop residues and energy crops can be processed through SS-AD. Some advantages of SS-AD include smaller reactor capacity requirements, less energy used for heating, and no processing energy needed for stirring. Due to its lower water content, the digestate of SS-AD is much easier to handle than the effluent of liquid AD. However, SS-AD systems also have disadvantages such as larger amounts of required inocula and much longer retention time. The principles and applications of the SS-AD process are reviewed in this paper. The variation in biogas production yields of different feedstocks is discussed as well as the need for pretreatment of lignocellulosic biomass to enhance biogas production. The effects of major operational parameters, including C/N ratio, solids content, temperature, and inoculation on the performance of SS-AD are summarized. While an increase in operating temperature can improve both the biogas yield and the production efficiency, other practices such as using AD digestate or leachate as an inoculant or decreasing the solid content, may increase the biogas yield but have negative impact on production efficiency. Different reactor configurations used in current commercial scale SS-AD systems and the impact of economics on system selection are also discussed.

Solid-state anaerobic digestion for methane production from organic waste

VIII. Location of Tannase IX. Purification of Tannase X. Properties of Tannase A. pH Optimum and Stability B. Temperature Optimum and Stability C. Molecular Mass D. Enzyme Inhibition E. Kng of Tannase F. Carbohydrate Content XI. Isozymes of Tannase XI. Mode of Action of Tannase XIII. Immobilization of Tannase XIV. Applications of Tannase A. Instant Tea B. Beer Chillproofing C. Wine Making D. Production of Gallic Acid E. Animal Feed Additives F. Miscellaneous

Production and Application of Tannin Acyl Hydrolase: State of the Art

Municipal solid waste (MSW) management is becoming a serious issue in all over the world. Anaerobic digestion (AD) is one of the technologies to convert that waste into useful form of energy. But megacities like Singapore having limited resources, cannot fulfill the cow dung or other animal manure requirements in AD. Therefore there is a need to study critically the operating parameters and also the pretreatment technologies available for treating the substrate so that one can get the maximum output with limited input. To fulfill the need, the present paper deals with the review of various operating parameters and their effects on AD. This paper also reviews different pretreatment methods including mechanical, thermal, chemical and biological methods to improve the effectiveness of AD of MSW.

A comprehensive review on operating parameters and different pretreatment methodologies for anaerobic digestion of municipal solid waste

Esterase plays a major role in the degradation of natural materials and industrial pollutants, viz, cereal wastes, plastics, and other toxic chemicals It is useful in the synthesis of optically pure compounds, perfumes, and antioxidants The potential applications of esterase with reference to agriculture, food, and pharmaceutical industries, are discussed in this review Promising applications in this avenue can be supported by appropriate production strategies

Production and applications of esterases

Dry anaerobic digestion (DAD) is an attractive method for the stabilization of solid organic waste with high solid concentration (22–40%). This article provides different aspects for bio-energy production through dry anaerobic digestion suggested by different researchers. Basic fundamental aspects like reactions occurring in the process, microbial species involved in the process, effect of feedstocks and operational parameters like pH, temperature, C/N ratio, VFA concentration, etc. with types of reactors are summarized. A number of scenarios and the effect of changing individual parameters of the environmental impacts of dry anaerobic digestion process for biogas production are considered. Mobility of mass nutrient and energy flow in the above said process are also parts of this review article. We conclude that long term research and development for improvement and optimization of operational parameters in dry anaerobic digestion is necessary.

M.V. Ramesh

Papers

Idiosyncrasies of solid-state fermentation systems in the biosynthesis of metabolites by some bacterial and fungal cultures