关键词: 好氧堆肥化, 废弃秸秆, 稀土元素, 腐熟度, 嗜热短芽芽孢杆菌

Abstract:

Aerobic composting technology has become one of the important ways to return waste crop straw to the field. With the increasing popularity of rare earth agricultural use, it is of academic significance to study the effect of rare earth elements on the composting process and compost quality of waste straw. The results showed that lanthanum, a rare earth element, was beneficial to improve the metabolic activity of Bacillus thermophiles GX5 and other indigenous microorganisms in the piles, promote the degradation and transformation of lignocellulose, and improve the compost maturity. When lanthanum was present in the composting system with addition of Bacillus thermophilus GX5, the pile temperature increased to 70.3℃ on the third day and maintained above 55℃ for 5 days. The dehydrogenase activity of the pile was 11.02U/g. The enzyme activities of cellulose degrading enzyme, lignin peroxidase and laccase were 4.55U/g, 2.82U/g and 0.21U/g, respectively. During the maturity stage, the degradation rates of hemicellulose, cellulose and lignin reached 47.6%, 40.6% and 31.1%, the E₄/E₆ value was 3.24, the nitrification index was 1.87, and the seed germination index was 221.80%. The compost quality met the relevant standards of organic fertilizer in China (such as NY/T 525—2021).

Key words: aerobic composting, waste crop straw, rare earth elements, maturity, Bacillus thermophilus