Field scale interaction and nutrient exchange between surface water and shallow groundwater in the Baiyang Lake region, North China Plain

Abstract

Fertilizer input for agricultural food production, as well as the discharge of domestic and industrial water pollutants, increases pressures on locally scarce and vulnerable water resources in the North China Plain. In order to: (a) understand pollutant exchange between surface water and groundwater, (b) quantify nutrient loadings, and (c) identify major nutrient removal pathways by using qualitative and quantitative methods, including the geochemical model PHREEQC) a one-year study at a wheat (Triticum aestivum L.) and maize (Zea mays L.) double cropping system in the Baiyang Lake area in Hebei Province, China, was undertaken. The study showed a high influence of low-quality surface water on the shallow aquifer. Major inflowing pollutants into the aquifer were ammonium and nitrate via inflow from the adjacent Fu River (up to 29.8 mg/L NH 4 -N and 6.8 mg/L NO 3 -N), as well as nitrate via vertical transport from the field surface (up to 134.8 mg/L NO 3 -N in soil water). Results from a conceptual model show an excess nitrogen input of about 320 kg/ha/a. Nevertheless, both nitrogen species were only detected at low concentrations in shallow groundwater, averaging at 3.6 mg/L NH 4 -N and 1.8 mg/L NO 3 -N. Measurement results supported by PHREEQC-modeling indicated cation exchange, denitrification, and anaerobic ammonium oxidation coupled with partial denitrification as major nitrogen removal pathways. Despite the current removal capacity, the excessive nitrogen fertilization may pose a future threat to groundwater quality. Surface water quality improvements are therefore recommended in conjunction with simultaneous monitoring of nitrate in the aquifer, and reduced agricultural N-inputs should be considered.

Risk Assessment of Potentially Toxic Elements (PTEs) Pollution at a Rural Industrial Wasteland in an Abandoned Metallurgy Factory in North China

“…The modified Community Bureau of Reference (BCR) sequential extraction procedure was used for PTE form analysis of all the soil samples. The four extracted fractions of PTEs were defined as the water/acid soluble fraction (F1), reducible fraction (F2), oxidizable fraction (F3), and residual fraction (F4) [ 1 , 18 , 19 , 20 ].…”

Pesticide use in the wheat-maize double cropping systems of the North China Plain: Assessment, field study, and implications

“…The field site was managed according to the local customs of the area (described in more detail in Brauns et al, 2016). The successive winter wheat-summer maize rotation encompassed the growing season for wheat from October 2012 to June 2013 and that of maize from June 2013 to October 2013.…”

Reactive and Mixing Processes Governing Ammonium and Nitrate Coexistence in a Polluted Coastal Aquifer

“…Nitrate (NO 3 − ) and ammonium (NH 4 + ) are often recognised as major contaminants in both surface water and groundwater [1][2][3]. The causes can be multiple, including fertilizers leaching in agricultural environments [4][5][6][7], storm and sewage water spillages in urban environments [8][9][10], natural elevated background concentrations [11,12] and spillages of complex chemical mixtures below industrial plants [13,14].…”