外加碳源对污水灌溉系统氮素迁移转化影响的实验研究

Effect of additional organic carbon on nitrogen transport in waste water irrigation

基于室外土柱实验装置,开展苜蓿作物生长条件下污水灌溉土地处理慢渗系统氮素迁移转化的实验研究,探讨在灌溉原污水中添加碳源对污灌系统氮素平衡和作物生长的影响,试验中考虑了不同碳氮比的影响。结果表明,随着灌溉原污水中有机碳含量的增加,苜蓿的干物质量和吸氮量逐渐减少,土壤氮素淋溶量逐渐增大,反硝化和氨挥发引起的氮素气态逸出量有所增加,氮素气态逸出和作物对氮素的吸收利用是该类污灌系统去除氮素的最主要途径。在本文特定作物和土壤条件下,增加灌溉原污水中的有机碳含量将不利于污灌系统对氮素的去除。

The nitrogen transport in waste water irrigation for growth of alfalfa was experimentally studied in laboratory. The effects of additional organic carbon on balance of nitrogen in waste water and growth of plant were investigated. The results show that following the increase of organic carbon the dry matter yield of alfalfa and nitrogen uptake gradually decreased, but the cumulative drainage volume and cumulative leaching of nitrogen increased. The nitrogen removal by denitrification and volatilization of ammonia also increased with the increase of organic carbon. Under the conditions of this experiment, the increase of additional organic carbon content is not in advantage of the removal of nitrogen in waste water irrigation system.