Abstract
Recent studies have shown that alum addition to litter results in many environmental and economic advantages, such as reductions in metal runoff, lower ammonia emission and improved poultry performance. However, no research has been conducted to evaluate the effects of different types of alum on soluble metals in poultry litter. The objective of this study was conducted to investigate changes in soluble metal from poultry litter with different types of aluminum sulfate (alum) under laboratory condition. The treatments used in this study, which were mixed in the upper 1 cm of litter or sprayed onto the litter surface, were 4 g alum, 8 g alum, 8.66 g liquid alum, 17.3 g liquid alum, 11.2 g A7 (high acid alum), and 22.4 g A7 (high acid alum)/100 g litter. Applying different types of alum to poultry litter reduced (P<0.05) concentrations of soluble Fe (9 to 54%), Cu (9 to 49%) and Zn (11 to 40%), relative to untreated litter, whereas it increased Ca and Mg (P<0.05). Mean soluble Fe and Cu levels in poultry litter from different types of alum decreased in the order: 22.4 g A7 (54% and 49%) > 17.3 g liquid alum (48% and 42%) > 8 g alum (48% and 31%) > 4 g alum (28% and 10%) > 8.6 g liquid alum (10% and 9%) > 11.2 g A7 (8.6% and 9%). Additionally, the high reduction in soluble Zn concentration was 4 g alum (40%), followed by 8 g alum (26%), 22.4 g A7 (25%), 17.3 g liquid alum (23%), 8.66 g liquid alum (18%), and 11.2 g A7 (11%), respectively. In conclusion, the current studies suggest that treating poultry litter with different types of alum can be applied to reduce soluble metal (Fe, Cu, and Zn) and to develop a production to merchandise for poultry litter that would result in reduction in pollutants from these materials. Furthermore, in order to improve environmental management in the poultry industry, the use of alum, liquid alum and high acid alum all should be provided a valid means of reducing negative environmental impact.