【摘要】：江漢平原東部地區(qū)地下水硝態(tài)氮和氨氮污染嚴(yán)重,地表水-地下水相互作用強(qiáng)烈,季節(jié)性水文條件變化極其顯著.選取典型試驗(yàn)場(chǎng)地,對(duì)試驗(yàn)場(chǎng)內(nèi)沉積物(025m)氮形態(tài)進(jìn)行測(cè)定,并對(duì)地下水氮含量及其他水化學(xué)指標(biāo)進(jìn)行連續(xù)性監(jiān)測(cè).研究表明:沉積物NO_3~--N含量較高(25.8119.48mg/kg),是可交換態(tài)氮的主要組成部分,NH_3_-N含量與TOC和TN均呈一定的正相關(guān)性,表明NH_3-N含量主要受沉積物中埋藏有機(jī)質(zhì)的控制.試驗(yàn)場(chǎng)深度較深(≥2m)地下水氮的含量和形態(tài)對(duì)地下水位波動(dòng)有明顯響應(yīng):雨季開始,地下水位抬升,含水介質(zhì)還原性增強(qiáng),NO_3~--N生成受抑制且通過(guò)反應(yīng)消耗,礦化作用加強(qiáng),導(dǎo)致NH_3-N成為氮的主要賦存形態(tài);雨季結(jié)束,地下水水位下降,含水介質(zhì)的氧化性增強(qiáng),NO_3~--N的生成受到促進(jìn),硝化作用增強(qiáng)而反硝化作用減弱,導(dǎo)致NO_3~--N的濃度增加.近地表人類活動(dòng)(外源輸入)對(duì)試驗(yàn)場(chǎng)淺表地層(2m)地下水氮形態(tài)有明顯的影響.自然或者人為因素引起的水文條件變化導(dǎo)致地下水流場(chǎng)的變化,從而改變含水介質(zhì)固有的氧化還原環(huán)境,是導(dǎo)致試驗(yàn)場(chǎng)氮季節(jié)性變化的主要原因.
[Abstract]:In the eastern part of Jianghan Plain, the pollution of nitrate nitrogen and ammonia nitrogen in groundwater is serious, the interaction between surface water and groundwater is very strong, and the seasonal hydrological conditions change remarkably. The nitrogen forms of sediment (0.25 m) in the test site were determined, and the nitrogen content of groundwater and other hydrochemical indexes were continuously monitored. The results show that the content of NO_3~--N (25.8119.48mg/kg) is high in sediment, and it is the main component of exchangeable nitrogen. The content of NH3- N in the sediment is positively correlated with TOC and TN, indicating that the content of NH_3-N is mainly controlled by buried organic matter in sediment. The nitrogen content and form of groundwater in deeper depth (鈮，

本文編號(hào)：2139287