An Effective Passive Solar Dryer for Thin Layer Drying of Poultry Manure

Abstract

Animal and poultry manures have been recognized for centuries as organic fertilizers providing essential nutrients to crops and improving soil structure due to their large input of organic matter. Increasing demand for poultry and egg products has led to intensification of the poultry rearing process, resulting in large amounts of poultry manure. Drying can be used to reduce the environmental impact of poultry manure and create a value added product for the farmers (animal feed or organic fertilizer). The aim of this study was to investigate the effect of solar heated air drying on the chemical and biological characteristics of poultry manure and develop a suitable manure solar dryer. The effects of temperature (40-60°C) and manure layer depth (1-3 cm) were evaluated. At the three temperature levels studied, the time required to dry poultry manure in the 1 cm-deep layer was the shortest, followed by the 2 and 3 cm-deep layers, respectively. The optimum depth to dry manure (at which the highest drying effectiveness occurred) was 3 cm. The manure drying rate increased with increasing temperature and was the fastest at 60°C for all manure depths studied. A drying temperature-depth combination of 60°C and 3 cm was the most efficient for the thin layer drying of poultry manure. Drying poultry manure at these conditions provided an effective means of removing moisture and odor and destroying microorganisms, thereby allowing the production of a value added product. This temperature range is feasible with a solar dryer operating in the tropics. A solar dryer operating at a 3 cm manure depth would be capable of drying 336 kg/h. Drying poultry manure with solar heated air resulted in a slight decrease in protein content (from 42 to 41%), a decrease in pH (from 8.4 to 6.6), removal of Salmonellae and a 99% reduction in numbers of total bacteria, yeast, mold and E. coli. Thin layer solar drying of poultry manure proved to be an effective means of converting poultry manure into a value added product while reducing the environmental and health problems that are associated with current disposal options.

Drying Poultry Manure for Pollution Potential Reduction and Production of Organic Fertilizer

“…It improves manure stickiness and hence makes manure handling easier (Ghaly and MacDonald, 2012a). Drying with heated air offers a number of advantages over unheated air drying including: higher rate of oxidation and pathogen destruction (Cummings and Jewell, 1977;Ghaly and MacDonald, 2012b). Drying with heated air can be carried out using a variety of heat sources such as solar energy, electricity, natural gas and other fossil fuels.…”

“…Drying with heated air can be carried out using a variety of heat sources such as solar energy, electricity, natural gas and other fossil fuels. However, solar energy offers many advantages over other energy sources: (a) it is available in abundance all year round and it is relatively cheap to collect and utilize (Hatem and Ghaly, 1994;Ghaly and MacDonald, 2012a) and (b) it has higher rate of oxidation, waste stabilization, odor control and pathogen destruction (Ludington and Sobel, 1977;McCaskey et al, 1985;Ghaly and MacDonald, 2012b).…”

Anchovy Drying Using Infrared Radiation

“…(kgmol −1 .K −1 ) and T was the absolute temperature (K). The moisture ratio in Equation (2) was initially described by law is (Ghaly and MacDonald, 2012a) based on Newton's law of cooling in heat transfer and has often been used to explain the mass transfer in thin layer drying as follows Equation 6:…”

“…This is one of the most important factors affecting the quality of anchovy during storage and subsequent handling. It must have the moisture reduced to add quality and prevent deterioration during storage (Ghaly and MacDonald, 2012a;Sevik, 2013).…”

Inactivation Kinetics of Indicator Microorganisms during Solar Heat Treatment for Sanitizing Compost from Composting Toilet

“…Several studies report the sanitizing of human feces [3], manure [12] and sludge [13] by thermal treatment, but the effectiveness of these systems on compost has not been studied yet. The lack of information about solar heating in tropical conditions indicates the necessity for further studies on the processes and questions the promotion of sanitation in a safe way.…”