Beschreibung:
Chicken manure (CM) is of a very complex and heterogeneous nature; thus, it is essential to analyze its properties to give it proper management. Direct use in agriculture as organic fertilizer is considered a popular treatment option for CM, which causes undesirable emissions of chemicals to the ecosphere. The alternative use of CM as a source for energy generation and nutrient recovery has been studied in recent years. The objectives of this study are: (i) to compare the physical-chemical properties of CM generated in European farms with mechanized extraction of their residues and traditional Cuban farms, in terms of analysis of fresh samples (pH, Chemical Oxygen Demand, ammonium nitrogen and proximate analysis); and (ii) to assess the quality of these residues as raw material for hydrothermal carbonization for energy and nutrients recovery. Results revealed that CM from traditional Cuban farms showed higher biodegradation than those from European mechanized farms. High contents of macro and micronutrients were quantified (specifically calcium, potassium, and phosphorous) and no toxic trace elements were found. The high heating values on a dry basis (experimental) ranged from 13.92 to 16.88 MJ kg-1, being lower in broiler hen litters due to their high ash content. According to the thermogravimetric analysis, it was determined that the temperature interval of the highest mass loss was around 300 ºC. Due to the high moisture, high heating value, and high fixed carbon content, CM appears to be a suitable raw material for hydrothermal carbonization to obtain energy and nutrients. The results will provide essential data on the composition of broiler and layer CM from different production systems, contributing engineers and farmers to determine appropriate uses for them, especially for power generation