Reduction of Hydraulic Conductivity Due to Microbial Effects
Reduction of Hydraulic Conductivity Due to Microbial Effects
复制标题
由于微生物作用导致水力传导率降低
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
M. Nakano
中科院分区：
文献类型：
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作者：
K. Seki;T. Miyazaki;M. Nakano
通过柱试验研究了微生物对水田土壤饱和导电性k的影响。50 ppm葡萄糖溶液在118 d的时间内，表层1 cm层的Ks降低了2个数量级。在渗滤液与杀菌剂（NaN3）交替后，Ks迅速增加。近地表细菌的数量没有增加，但近地表真菌的数量增加了数百倍。因此，证明了钾还原的首要原因是真菌和微生物合成产物的菌丝堵塞土壤孔隙。Ks降低的第二个原因是厌氧细菌产生的气体堵塞了孔隙空间。在15天内，所有深度的氧化还原电位都低于150 mV，这足以满足CH4的产生。从产量和分解速率的计算说明了CO2在渗滤中全部被分解，而CH4没有完全被分解。估计有14%的充气孔隙被CH4气体堵塞，这是导致Ks降低的原因之一。
A series of column experiments were carried out to elucidate the effects of microorganisms on reduction in the saturated hydraulic conductivity, Ks, of paddy field soil. The Ks of surface 1 cm layer decreased 2 orders of magnitude during 118 day period of percolation of 50 ppm glucose solution. After the alternation of percolation to germicide (NaN3), Ks increased rapidly. Population of bacteria near the surface did not increase, but that of fungi near the surface increased hundred times. Therefore it was proved that the first cause of Ks reduction is clogging of soil pores by hyphae of fungi and microbial synthesized products. The second cause of Ks reduction is occlusion of pore space by gas produced by anaerobic bacteria. The redox potential of all depths was below-150 mV at 15 day, which was sufficiently met for the CH4 production. From calculation of production and resolving rate, it was explained that all CO2 resolved in percolation, and that CH4 did not resolve perfectly. It is estimated that 14% of gas filled pore was occluded by CH4 gas and the occlusion contributed to the Ks reduction.