Influence of Gypsum-Containing Waste on Ammonia Binding in Animal Waste Composting

The possibility of using gypsum-containing waste–citrogypsum, which is a by-product of the chemical biosynthesis of citric acid, was considered as an additive for composting poultry manure from poultry farms that practice litter-free poultry keeping. The research was carried out on an experimental batch of 1500 tons. The production of the batch was carried out by mixing citrogypsum with a moisture content of 30% and litterless chicken manure with a moisture content of no more than 80% in a ratio of 1:2. The resulting mixture was placed on an open landfill in piles 3 m wide, 1 m high and 400 m long and was mixed twice with a compost turner. Further processing consisted of mixing the mass once every seven days. The controlled parameters were changes in humidity, temperature, pH and nitrogen content during composting. In the course of the experiment, it was found that the introduction of citrogypsum into the composition of the compost helps to optimize the moisture, temperature and pH of the mixture, and a decrease in ammonia emission to 87% was recorded, with an increase in nitrogen content of 2.4 times compared to the initial value. It was concluded that citrogypsum can be used in composting poultry waste to reduce volatilization of ammonia and preserve nutrients.