Investigation of aerobic solid fraction fermentation process parameters for organic material

Abstract

The parameters of aerobic solid fraction fermentation of a mixture of solid swine manure, poultry litter with addition of carbon containing plant materials have been investigated. A bioreactor design has been developed. Qualitative rating of the process and end product has been made by measuring such parameters as: process temperature, mixing process, air supply for aeration, pH and ash. A rational mixing mode for mixture has been found by investigating the dependency of temperature and costs time for fermentation of a mixture. The effective rotational speed of the reactor with periodic stirring and aeration of the compost is 10 rpm. This mode allows providing qualitative mixing and saturation of compost with air, to maintain the temperature range of thermophilic mode within 61-63 ºC. With this mode of operation, the full fermentation time of the compost is 8 days. Adding wood shavings and straw to the fermented mixture allows increasing the organic value of the resulting compost. The final compost was characterized by good qualitative characteristics, a significant level of humification and no odor emissions. This method of aerobic solid fraction fermentation of organic material represents an effective, low cost approach that could be an interesting opportunity for animal farms.

Determining of the influence of reactor parameters on the uniformity of mixing substrate components

“…The content of the control component in the substrate was 3 % of the total mass of the material in the chamber. According to earlier studies [8], the smallest value of the coefficient of variation of the actual distribution of the control component in samples was 11.4 % at the drum's frequency of rotation equal to ω = 1.05 rad/s. Fig.…”

“…As a result of reducing the movement speed of substrate particles, they stick to the surface of the blades and other elements of a drum's structures, the quality of agitation deteriorates. This is evidenced by the increase in the smallest value of the coefficient of variance of the actual distribution of the control component in samples to 22.78 %, according to study [8], which, in turn, worsens the conditions of the substrate composting process.…”

“…The issue of improving the efficiency of the process of compost production has been tackled by using both manufacturing [5,6] and structural methods [7]. In particular, technological methods include the following: ensuring optimal thermal mode at each stage of composting [8], the application of air aeration [9], etc. The structural methods include the design or improvement of the structure of basic units and working elements of equipment such as drum, stirrers, blades, modules for substrate loading and unloading the finished product, etc.…”