城市污泥与猪粪混合堆肥过程中湿度空间变异

对城市污泥与猪粪混合堆肥过程中堆体内湿度的空间变异性进行了研究 ,利用克里格法对湿度进行最优插值 .结果发现 :不同堆肥期湿度半变异函数在堆体水平方向上用对数函数拟合效果较好 ,在垂直方向上用线性函数拟合效果较好 .升温期、降温期和腐熟期各剖面的等湿线呈不同的分布特征 ,高温期呈较规则的“拱形”分布 .升温期、高温期及腐熟期 ,仓门附近的湿度变化较大 ,降温期堆体中轴线附近的湿度变化较大 .升温期堆体湿度最佳 ,从高温期开始 ,堆体中下部出现高湿区 ,且不断缩小 ;同时 ,堆体的顶部和两侧壁出现低湿区 ,且向堆体的中下部扩大 .由升温期到降温期 ,湿度空间变异不断增大 ,但腐熟期开始减小 .最后讨论了形成湿度空间变异的原因 ,并提出相应提高堆肥效率和质量的措施 .

Variations of moisture content during co-composting of biosolid and pig manure

The spatial variability of moisture content in co-composting of biosolid and pig manure was studied using semivariogram and Kriging method. It was indicated that the semivariogram functions of moisture content on the horizontal and longitudinal levels of a pile at different stages of composting were well modeled by the logarithm and the linear equations, respectively. At the stage of high temperature composting, iso-moisture lines were relatively homogenous and were in N|shape for the 3 profiles while they were different at the stages of temperature starting, dropping and maturing. The moisture content was optimistic at the stage of temperature starting, however, the zone of high moisture content occurred at the lower middle part of the pile at the stage of high temperature composting and shrank gradually since the meanwhile the zones of lower moisture content appealed at the top and the two sides of the pile, and spread towards the lower middle part of the pile. Spatial variation of moisture increased until the stage of the cooling. The factors effecting spatial variation of moisture were discussed and corresponding measures for improving composting were put forward.