随着含有重金属添加剂饲料的使用,规模化养殖场畜禽粪便中重金属含量增加。为减少重金属的危害,该文以猪粪为发酵原料,重金属Cr为研究对象,硼泥为钝化剂,在接种物量为30%、TS为10%、温度为35℃、pH值为7的条件下进行40 d厌氧发酵试验。...随着含有重金属添加剂饲料的使用,规模化养殖场畜禽粪便中重金属含量增加。为减少重金属的危害,该文以猪粪为发酵原料,重金属Cr为研究对象,硼泥为钝化剂,在接种物量为30%、TS为10%、温度为35℃、pH值为7的条件下进行40 d厌氧发酵试验。研究添加2.5%、5.0%、7.5%3种比例的硼泥对猪粪厌氧发酵中重金属Cr的形态变化、有效态钝化效果及发酵前后沼渣光谱特征的影响,采用BCR连续提取法(European community bureau of reference sequential extraction)分析重金属Cr的形态变化,采用傅里叶红外光谱(Fourier transform infrared spectrometer, FTIR)对物料光谱特征的变化进行研究。结果表明:猪粪厌氧发酵过程中添加硼泥有利于重金属Cr从有效态转化为稳定态,当添加7.5%硼泥处理时有效态Cr转化为稳定态Cr的效果较好;猪粪在厌氧发酵过程中添加硼泥能提高重金属Cr的钝化效果,且随着硼泥添加量的增加,钝化效果越好;通过显著性分析,添加7.5%硼泥处理时钝化效果较好,达到63.79%,显著优于猪粪单独发酵和添加2.5%与5.0%硼泥的处理(P<0.05);FTIR显示厌氧发酵后,沼渣中酰胺化合物、碳水化合物、蛋白质、脂肪族化合物等有机物分解减少,芳香族等腐殖质增加,且添加7.5%硼泥时有机物腐殖化程度最好。因此猪粪在厌氧发酵过程中添加适量硼泥,可以降低沼渣中重金属Cr的生物有效性,促进有机物转化为腐殖质,研究结果可为减少猪粪中重金属的有效性和提高厌氧发酵质量提供参考。展开更多
The grid drop concept is introduced and used to develop a micromechanism-based methodology for calculating watershed flow concentration. The flow path and distance traveled by a grid drop to the outlet of the watershe...The grid drop concept is introduced and used to develop a micromechanism-based methodology for calculating watershed flow concentration. The flow path and distance traveled by a grid drop to the outlet of the watershed are obtained using a digital elevation model （DEM）. Regarding the slope as an uneven carpet through which the grid drop passes, a formula for overland flow velocity differing from Manning＇s formula for stream flow as welt as Darcy＇s formula for pore flow is proposed. Compared with the commonly used unit hydrograph and isochronal methods, this new methodology has outstanding advantages in that it considers the influences of the slope velocity field and the heterogeneity of spatial distribution of rainfall on the flow concentration process, and includes only one parameter that needs to be calibrated. This method can also be effectively applied to the prediction of hydrologic processes in un-gauged basins.展开更多
To determine the influence of agricultural meteorological disasters on agriculture in Heilongjiang Province,the disaster areas associated with different types of disasters and their variation characteristics were anal...To determine the influence of agricultural meteorological disasters on agriculture in Heilongjiang Province,the disaster areas associated with different types of disasters and their variation characteristics were analyzed based on the statistical data of agricultural disasters from 1983 to 2013 in Heilongjiang Province,China.The moving average and the Mann-Kendall test were applied to identify the variation trends of drought,flooding,hailstorms and freezing(based on the disaster ratio and the disaster intensity index).Then,the Morlet wavelet analysis method was used to identify the periodicity of these four kinds of agricultural meteorological disasters.Finally,a fuzzy comprehensive evaluation method was adopted to analyze the degrees of agricultural loss induced by these disasters.The following results were obtained:1)The disaster ratio and disaster intensity index for drought exhibited increasing trends;the disaster ratio and disaster intensity index for flooding exhibited decreasing trends;for hailstorms,the disaster ratio exhibited no obvious trend of change,whereas the disaster intensity index exhibited an increasing trend;and for freezing,the disaster ratio also exhibited no obvious trend of change,whereas the disaster intensity index exhibited a decreasing trend.2)Mutation points were observed in the disaster ratio series for drought,flooding and hailstorms,whereas no mutation point was evident in the disaster ratio series for freezing.3)Multiple time-scale characteristics were observed in the disaster ratio series for all four types of agricultural meteorological disasters.Furthermore,the disaster ratio series for the different types of disasters had different main periodicities.4)From the perspective of the degree of agricultural loss induced by each type of disaster,drought was identified as the most severe type of agricultural meteorological disaster,followed by flooding,freezing,and hailstorms.The degree of agricultural loss caused by each type of disaster was different during different periods.Finally,based on the results,several strategies were identified for mitigating the effect of agricultural meteorological disasters in Heilongjiang Province.展开更多
文摘随着含有重金属添加剂饲料的使用,规模化养殖场畜禽粪便中重金属含量增加。为减少重金属的危害,该文以猪粪为发酵原料,重金属Cr为研究对象,硼泥为钝化剂,在接种物量为30%、TS为10%、温度为35℃、pH值为7的条件下进行40 d厌氧发酵试验。研究添加2.5%、5.0%、7.5%3种比例的硼泥对猪粪厌氧发酵中重金属Cr的形态变化、有效态钝化效果及发酵前后沼渣光谱特征的影响,采用BCR连续提取法(European community bureau of reference sequential extraction)分析重金属Cr的形态变化,采用傅里叶红外光谱(Fourier transform infrared spectrometer, FTIR)对物料光谱特征的变化进行研究。结果表明:猪粪厌氧发酵过程中添加硼泥有利于重金属Cr从有效态转化为稳定态,当添加7.5%硼泥处理时有效态Cr转化为稳定态Cr的效果较好;猪粪在厌氧发酵过程中添加硼泥能提高重金属Cr的钝化效果,且随着硼泥添加量的增加,钝化效果越好;通过显著性分析,添加7.5%硼泥处理时钝化效果较好,达到63.79%,显著优于猪粪单独发酵和添加2.5%与5.0%硼泥的处理(P<0.05);FTIR显示厌氧发酵后,沼渣中酰胺化合物、碳水化合物、蛋白质、脂肪族化合物等有机物分解减少,芳香族等腐殖质增加,且添加7.5%硼泥时有机物腐殖化程度最好。因此猪粪在厌氧发酵过程中添加适量硼泥,可以降低沼渣中重金属Cr的生物有效性,促进有机物转化为腐殖质,研究结果可为减少猪粪中重金属的有效性和提高厌氧发酵质量提供参考。
基金supported by the National Nature Science Foundation of China (Grant No. 50609005)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China (Grant No. 101075)
文摘The grid drop concept is introduced and used to develop a micromechanism-based methodology for calculating watershed flow concentration. The flow path and distance traveled by a grid drop to the outlet of the watershed are obtained using a digital elevation model （DEM）. Regarding the slope as an uneven carpet through which the grid drop passes, a formula for overland flow velocity differing from Manning＇s formula for stream flow as welt as Darcy＇s formula for pore flow is proposed. Compared with the commonly used unit hydrograph and isochronal methods, this new methodology has outstanding advantages in that it considers the influences of the slope velocity field and the heterogeneity of spatial distribution of rainfall on the flow concentration process, and includes only one parameter that needs to be calibrated. This method can also be effectively applied to the prediction of hydrologic processes in un-gauged basins.
基金This work was supported by the National Key R&D Program of China(No:2017YFC0406004)the National Natural Science Foundation of China(No:51109036,51179032)+5 种基金the Natural Science Foundation of Heilongjiang Province of China(No:E2015024)the Research Fund for the Doctoral Program of Higher Education of China(No:20112325120009)the Foundation for Reserve Academic Leader in Province Lead Team of Heilongjiang Province of China(No:500001)the Research Foundation for Postdoctors of Heilongjiang Province of China(No:LBH-Q12147)the Projects for Science and Technology Development of Water Conservancy Bureau in Heilongjiang Province of China(No:201402,No:201404,No:201501)the Academic Backbones Foundation of Northeast Agricultural University(No.16XG11).
文摘To determine the influence of agricultural meteorological disasters on agriculture in Heilongjiang Province,the disaster areas associated with different types of disasters and their variation characteristics were analyzed based on the statistical data of agricultural disasters from 1983 to 2013 in Heilongjiang Province,China.The moving average and the Mann-Kendall test were applied to identify the variation trends of drought,flooding,hailstorms and freezing(based on the disaster ratio and the disaster intensity index).Then,the Morlet wavelet analysis method was used to identify the periodicity of these four kinds of agricultural meteorological disasters.Finally,a fuzzy comprehensive evaluation method was adopted to analyze the degrees of agricultural loss induced by these disasters.The following results were obtained:1)The disaster ratio and disaster intensity index for drought exhibited increasing trends;the disaster ratio and disaster intensity index for flooding exhibited decreasing trends;for hailstorms,the disaster ratio exhibited no obvious trend of change,whereas the disaster intensity index exhibited an increasing trend;and for freezing,the disaster ratio also exhibited no obvious trend of change,whereas the disaster intensity index exhibited a decreasing trend.2)Mutation points were observed in the disaster ratio series for drought,flooding and hailstorms,whereas no mutation point was evident in the disaster ratio series for freezing.3)Multiple time-scale characteristics were observed in the disaster ratio series for all four types of agricultural meteorological disasters.Furthermore,the disaster ratio series for the different types of disasters had different main periodicities.4)From the perspective of the degree of agricultural loss induced by each type of disaster,drought was identified as the most severe type of agricultural meteorological disaster,followed by flooding,freezing,and hailstorms.The degree of agricultural loss caused by each type of disaster was different during different periods.Finally,based on the results,several strategies were identified for mitigating the effect of agricultural meteorological disasters in Heilongjiang Province.
