Anaerobic digestion of poultry manure is a potentially-sustainable means of stabilizing this waste while generating biogas. However, technical, and environmental protection challenges remain, including high concentrations of ammonia, low C/N ratios, limited digestibility of bedding, and questions about transformation of nutrients during digestion. This study evaluated the effect of primary biological treatment of poultry manure on the biogas production process and reduction of ammonia emissions. Biogas yield from organic matter content in the aerobic pretreatment groups was 13.96% higher than that of the control group. Biogas production analysis showed that aerobic pretreatment of poultry manure has a positive effect on biogas composition; methane concentration increases by 6.94–7.97% after pretreatment. In comparison with the control group, NH3 emissions after aerobic pretreatment decreased from 3.37% (aerobic pretreatment without biological additives) to 33.89% (aerobic pretreatment with biological additives), depending on treatment method.
Intensive agriculture operations increase emissions of harmful gases into the environment. According to scientists, as much as 83-91% of total ammonia emission to the environment is accounted for by livestock operations (Bluteau and Daniel, 2009; Sanz et al., 2010). The reduction of ammonia emissions is one of the most widely considered matters within modern farming. Ammonia emissions not only lead to poor quality of air in livestock barns, but also contribute to the acidification of soils and surface waters, eutrophication, deforestation, etc. (Erisman et al., 2008; Menzi et al., 2006; Pereira et al., 2010), which in turn have a major effect on the atmosphere, the environment and the sensitive natural ecosystem.
Increasing control of localized air pollution caused by ammonia is identified, including limiting the maximum emissions from agriculture. In EU countries, the agricultural sector is the source of above 94% of the total anthropogenic emissions of ammonia, of which manure removal systems account for 56%. In view of the reason for the agricultural waste management by formation and propagation of ammonia gas—the bacterial and enzymatic degradation of organic components in excrement—it is important to evaluate the effect of biotreatment of 100% natural composition (contain Azospirillum sp. (N) (number of bacterial colonies −1 × 109 cm−3), Frateuria aurentia (K) (number of bacterial colonies −1 × 109 cm−3), Bacillus megaterium (P) (bacterial colony count −1 × 109 cm−3), seaweed extract (10% by volume), phytohormones, auxins, cytokinin, gibberellins, amino acids, and vitamins) on the emission of ammonia from organic waste. Experimental research was carried out to determine significant differences of dynamics in agrochemical composition of manure, NH3 gas emissions, depending on biotreatment, manure storage duration, and ventilation intensity of the barn. Gas emission was obtained via laser gas analyzer using a spectroscopic method in a specially reconstructed wind tunnel chamber. About 32% manure biotreatment effect on reduction of ammonia emissions was established. The maximum effect of the biodegradable compound on gaseous propagation was assessed after 28–35 days of manure storage and proved all biotreatment effect time of 49–56 days. By the saving nitrogen loses priority, manure biotreatment could reduce nitrogen losses from manure and inorganic N fertilizers by approximately 5%, also could reduce approximately 5911.1 thousand tones nitrogen fertilizer in the world and reduce approximately 5.5 Eur ha−1. “The biotreatment impact assessment confirmed that proper application of biotreatment can reduce ammonia emissions from manure and environmental pollution from agriculture”.
Experimental data were applied for the modelling optimal cowshed temperature environment in laboratory test bench by a mass-flow method. The principal factor affecting exponent growth of ammonia emission was increasing air and manure surface temperature. With the manure temperature increasing from 4°C to 30°C, growth in the ammonia emission grew fourfold, that is, from 102 to 430 mg m−2h−1. Especial risk emerges when temperature exceeds 20°C: an increase in temperature of 1°C contributes to the intensity of ammonia emission by 17 mg m−2h−1. The temperatures of air and manure surface as well as those of its layers are important when analysing emission processes from manure. Indeed, it affects the processes occurring on the manure surface, namely, dehydration and crust formation. To reduce ammonia emission from cowshed, it is important to optimize the inner temperature control and to manage air circulation, especially at higher temperatures, preventing the warm ambient air from blowing direct to manure. Decrease in mean annual temperature of 1°C would reduce the annual ammonia emission by some 5.0%. The air temperature range varied between −15°C and 30°C in barns. The highest mean annual temperature (14.6°C) and ammonia emission (218 mg m−2h−1) were observed in the semideep cowshed.
Avoiding heat stress in cows is an important condition for animal productivity and the maintaining of animal health. For this, it is necessary to provide an optimal microclimate in cowsheds using systems of air cooling. The paper analyzes one of these systems—an air humidification–cooling system. The research was carried out in a semi-insulated box-type cowshed containing 244 places. The changes in temperature, relative humidity, and temperature humidity index (THI) were studied for the air coming from outside and for the air inside the cowshed. Considering the fact that the cows were in the cowshed most of the time (51.5%) under heat stress, the use of a cooling system is appropriate. It was established that a cooling system is capable of compensating for heat released by animals. It was determined that with an increase in air temperature the relative efficiency of a cooling system increases. An intensive constant air exchange provided using fan operation avoids an excessive growth of relative humidity in a cowshed. To reduce the consumption of electricity and water, the paper suggests regulation of both the power of the fans of the system and the water supply to the nozzles not using temperature but using THI. Theoretically, when THI is used to regulate the operation of the cooling system, the consumption of electrical energy is reduced by 17.8%, and the consumption of water is reduced by 43.2% when compared to the option when the temperature is used to regulate the operation of a cooling system.
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