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长江三角洲农田地下水反硝化对硝酸盐的去除作用 被引量:10
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作者 颜晓元 周伟 《土壤学报》 CAS CSCD 北大核心 2019年第2期350-362,共13页
长江三角洲(简称"长三角")农田氮素投入量高,但是否像其他高氮投入农田一样在土壤剖面累积了大量硝酸盐尚不清楚。通过连续两年的野外观测结合室内培养实验,发现长三角地区3种不同类型的高氮投入农田1~4 m地下水硝态氮(NO_3^... 长江三角洲(简称"长三角")农田氮素投入量高,但是否像其他高氮投入农田一样在土壤剖面累积了大量硝酸盐尚不清楚。通过连续两年的野外观测结合室内培养实验,发现长三角地区3种不同类型的高氮投入农田1~4 m地下水硝态氮(NO_3^--N)剖面分布特征存在明显差异,水稻田地下水NO_3^--N浓度始终很低(<1mg·L^(-1)),不同深度之间无差异。蔬菜地和葡萄园1 m处地下水NO_3^--N年平均浓度分别为5.6和17.5 mg·L^(-1),但是地下水NO_3^--N浓度随着深度增加急剧下降,至4m处,NO_3^--N浓度降至小于1 mg·L^(-1),与水稻田无差异。蔬菜地和葡萄园地下水高浓度NO_3^--N仅出现在施肥期间,非施肥期地下水NO_3^--N浓度较低,这表明长三角农田不存在明显的NO_3^--N累积。原状土柱培养实验结果表明,0~4 m土壤均存在较强的反硝化活性。通过对地下水中反硝化产物N2及N2O的直接定量测定,发现反硝化对地下水NO_3^--N的去除效率随着深度而增加,至4m处,反硝化对地下水NO_3^--N的去除效率分别为86%(水稻田)、93%(蔬菜地)和89%(葡萄园)。这表明反硝化能有效去除地下水NO_3^--N,是长三角地区农田土壤剖面未产生NO_3^--N累积的重要原因。反硝化产生的溶解性气态氮主要通过地下水流入临近水域,对于蔬菜地和葡萄园而言,溶解性气态氮流失量与NO_3^--N淋溶损失量相当,是一个重要的氮素去向,值得关注。 展开更多
关键词 地下水反硝化 硝酸盐去除 气态氮流失 种植模式 N2直接定量法
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Evaluation of nitrate source in groundwater of southern part of North China Plain based on multi-isotope 被引量:1
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作者 方晶晶 周爱国 +4 位作者 马传明 刘存富 蔡鹤生 甘义群 刘运德 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期610-618,共9页
Nitrate pollution in groundwater is a serious water quality problem that increases the risk of developing various cancers.Groundwater is the most important water resource and supports a population of 5 million in Anya... Nitrate pollution in groundwater is a serious water quality problem that increases the risk of developing various cancers.Groundwater is the most important water resource and supports a population of 5 million in Anyang area of the southern part of the North China Plain. Determining the source of nitrate pollution is the challenge in hydrology area due to the complex processes of migration and transformation. A new method is presented to determine the source of nitrogen pollution by combining the composition characteristics of stable carbon isotope in dissolved organic carbon in groundwater. The source of groundwater nitrate is dominated by agricultural fertilizers, as well as manure and wastewater. Mineralization, nitrification and mixing processes occur in the groundwater recharge area, whereas the confined groundwater area is dominated by denitrification processes. 展开更多
关键词 δ^12NNO3 δ^18ONO3 δ^13CDOC esophageal cancer GROUNDWATER
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Evaluation of nitrate removal effect on groundwater using artificial neural networks
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作者 赵志伟 崔福义 左金龙 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第6期823-826,共4页
Considering the non-linear, complex and muhivariable process of biological denitrification, an activated sludge process was introduced to remove nitrate in groundwater with the aid of artificial neural networks (ANN... Considering the non-linear, complex and muhivariable process of biological denitrification, an activated sludge process was introduced to remove nitrate in groundwater with the aid of artificial neural networks (ANN) to evaluate the nitrate removal effect: The parameters such as COD, NH3-N, NO3^- -N, NO2^- -N, MISS, DO, etc. , were used for input nodes, and COD, NH3-N, NO3^- -N, NO2^- -N were selected for output nodes. Experimental ANN training results show that ANN was able to predict the output water quality parameters very well. Most of relative errors of NO3^- -N and COD were in the range of ± 10% and ±5% respectively. The results predicted by ANN model of nitrate removal in groundwater produced good agreement with the experimental data. Though ANN model can optimize effect of the whole system, it cannot replace the water treatment process. 展开更多
关键词 artificial neural networks (ANN) NITRATE DENITRIFICATION GROUNDWATER
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