干湿循环下4种护坡基质对氮素吸附试验研究

Comparison of Nitrogen Uptake and Water Purification Ability of Four Farmland Drainage Ditch Slope Substrate in Wetting-Drying Test

为净化农田排水沟水质,分别选取玉米芯、干树叶、锯木渣与土的混合物和全土作为排水沟护坡4种基质,通过室内不同浓度进水和干湿循环条件对其吸收氮素净化水质的能力进行了比较研究。结果表明:对于TN浓度变化,当氮浓度较高和较低时,树叶的净化能力均最好,净化率分别为91.13%和95.08%,其次为玉米芯和原土,净化率分别为78.25%和94.73%;对于NH+4-N浓度变化,当氮浓度高时,树叶具有较高的净化能力,净化率为75.07%,其次为玉米芯,净化率为29.12%,当氮浓度低时,树叶净化能力强,净化率为80.87%,其次为锯末渣,净化率为45.67%;对于NO-3-N浓度变化,当氮浓度高和低时,树叶具有较高的净化能力,净化率为49.52%和76.5%,其次为锯木渣,净化率为55.47%。随着循环次数的增加,基质对TN和NO+3-N的净化能力降低,选取合适的护坡基质,有助于农田水质净化。

In order to purify the water quality of farmland irrigation.Four Farmland drainage ditch slope Substrate uptake of nitrogen （N） and their water purification capacity were investigated in hydrostatic conditions and wetting-drying test including corncob, dried leaf, sawdust and soil. The results indicated that ： TN concentration, high and low N concentration, dried leaf have the best purification capacity, purifying rate is 91.13% and 95.08%, followed by the corncob and soil is 78.25% and 94.73%; NH4^＋-N concentration, high N concentration, dried leaf have the best purification capacity, purifying rate is 75.07%, followed by the corncob is 27.12%, Low N concentration, dried leaf have the best purification capacity, purifying rate is 80.87%, followed by the sawdust is 45.67% ;NO^-N concentration, high and low N concentration, dried leaf have the best purification capacity, purifying rate is 49.52% and 76.5%, followed by the sawdust is 55.47%. The purification capacity of TN and NO3^-N decreases as the number of loops goes up.the experimental data suggested that appropriate substrates improved the water of farmland irrigation.