农业废弃物静态高温堆腐过程中的生物化学变化

 以养鸡场鸡粪、小麦秸秆为原料，在静态通气条件下研究了堆腐过程中有机物料温度、微生物及酶活性变化。结果表明，发酵罐底部有机物料温度较低，中上部较高；罐内有机物料在7～8 h可以从环境温度上升到50℃，并在50℃以上持续198～483 h。持续高温时间符合消灭病原微生物标准。有机物料温度处于55℃左右的高温阶段，纤维素酶活性[0.457 mg glucose /(g·24h)]和蔗糖酶活性[87.836 mg glucose/(g·24h)]最高，脱氢酶和脲酶活性分别达到高峰值21.62 μl H＋/(g·24h) 和0.932 mg NH3/(g·24h)。堆腐后期降温阶段，多酚氧化酶活性达到最高值6.23 mg gallicin/(g·2h)。细菌和放线菌数在堆肥2 d达到高峰值，分别为2.51×1012 CFU/g和3.68×108 CFU/g，之后缓慢下降；放线菌数变化较平缓。真菌数在堆腐开始较高，随着堆体温度上升而下降；堆腐后期随着温度下降而缓慢上升。整个堆腐过程中，真菌数一直较低，而细菌和放线菌相对较高。

Changes of Biochemical Properties of Agricultural Waste Materials During Composting in High Temperature and Static State

An experiment was conducted with mixed materials of chicken excrement and wheat straw to study the changes of temperature, enzyme, and number of microorganisms during an aeration composting process in a static state. Results showed that the temperature was lower at the bottom while higher at middle and top positions of the device. The temperature of the organic materials in the device rose from the ambient temperature to 50℃ by 7-8 h, and that maintained above 50℃ lasted 198-483 h. The time duration of high-temperature was in agreement with the requirement standard of killing the pathogenic microorganism. When the temperature was up to about 55℃ at the high-temperature stages, the activity of the cellulose enzymes reached a maximum value of 0.457 mg glucose/(g·24h), the sucrose enzyme reached a maximum of 87.836 mg glucose/(g·24h), and the dehydrogenase reached 21.62 μl H＋/(g·24h). The urea enzyme activity was peaked at a value of 0.932 mg NH3/(g·24h). At the later composting stage when temperature became declined, the activity of polyphenol oxidase enzyme reached its maximum of 6.23 mg gallicin/(g·2h). The highest bacterium number was found to be 2.51 1012CFU/g and actinomyces to be 3.68 108CFU/g in two days. Fungi number was relatively high at the beginning of composting while with the temperature rise, it became decreased, and at later stage of compost with temperature decline, fungi rose slowly. As a whole, the number of fungi was low whereas that of bacteria and actinomyces was much higher.