*1.3. Characteristics of Agricultural Wastes and Wastewaters*

Today, agro-wastes are known as the best alternative source for renewable energy production. This depends upon their classification and physicochemical properties, as they consist of different proportions of lignocellulosic hemicellulosic, including lignin in some complex and hardy agro-waste materials. These play an important role in converting the agro-waste to hydrolysate used in bioenergy production processes. The properties conferred to agro-waste depends upon its sources' location, climatic conditions, characteristics, etc. Thus, the physical and chemical properties of such agro-waste are discussed in the following sub-sections. Carbohydrates (2300–3500 mg/L), sugars (0.65–1.18 percent), proteins (0.12–0.15 percent), and starch (65–75 percent) are discharged in starch processing wastewater (SPW), which is an important energy-rich feedstock that may be converted to a wide variety of useful products [10]. Worldwide, the varied structure of lipids, proteins, fibers, excessive organic matter, parasites, meat processing effluents, and veterinary medicines is recognized as hazardous [11]. Due to the broad range of slaughterhouse wastewater (SWW) and pollutant concentrations, SWW is often evaluated using bulk criteria. SWW contains substantial amounts of biological oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and total suspended solids (TSS) [12]. Substrates such as cellulose and chitin are readily available and cheap biopolymeric resources that may be used to generate electricity. These green materials also account for a significant percentage of organic compounds in industrial and municipal wastewaters [13]. There have been just a few reports on the use of these particle substrates in MFCs.
