Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

Abstract

Nitrogen contamination of surface water is a worldwide environmental problem with intensive agriculture and high population densities. We assessed the spatial and seasonal variation in concentrations of total nitrogen and different nitrogen species present in surface-water in Beijing, China. Also, chemical (NO , and total nitrogen from 2.4 to 17.0 mg$L -1 . Inorganic nitrogen accounted for between 60 and 100% of total nitrogen at the ten monitoring sites. Nitrate nitrogen, ammonium nitrogen, and total nitrogen concentrations at the 2 downstream monitoring sites in south-eastern Beijing were significantly higher than those at the other eight upstream monitoring sites (P < 0.01). Examination of seasonal variation showed that there was a significant inverse relationship between nitrate nitrogen concentrations and precipitation, and that nitrate nitrogen concentrations peaked in the dry seasons. The information given by the δ 15 N nitrate values and nitrate nitrogen concentrations, combined with the NO - -N=C1ratio distribution, showed that domestic sewage was the major source of nitrate in Beijing. Methods to control and reduce sewage pollution are urgently needed to help manage surface water quality in Beijing.

Spatial distribution, temporal variation and risks of parabens and their chlorinated derivatives in urban surface water in Beijing, China

“…Accordingly, a large amount of domestic wastewater along the river was directly discharged into the water body, leading to high level of parabens in this river. It's also important to note that the amount of influent may exceed the processing capacity of WWTP F, especially during heavy rainfall, the untreated or partially treated raw sewage was released directly into this river (Ren et al, 2014). Therefore, discharge of domestic wastewater and leakage of WWTP influent would be the main sources of parabens in Xiaotaihou River.…”

Quantitative evaluation of reactive nitrogen emissions with urbanization: a case study in Beijing megacity, China

“…Although the number of such treatment plants in Beijing is increasing, from 4 in 2000 to 24 in 2012, with average sewage treatment rates as high as 80 %, the increased facilities are unable to treat all the wastewater from the city, which results in the discharge of raw and even treated sewage directly into the rivers. The direct and indirect discharge of sewage are assumed to be the main sources of dissolved Nr release and significantly contribute to the N pollution of urban rivers in Beijing (Gu et al 2009;Ren et al 2014).…”

Variation in nitrate isotopic signatures in sewage for source apportionment with urbanization: a case study in Beijing, China

“…Sources of N pollution in urban surface and groundwater should be identified before an efficient remediation measure is devised (Xu et al 2016), and sewage is supported as the typical urban N source (Yue et al 2010;Xue et al 2012;Ren et al 2014;Zhang et al 2015b). Nitrate (NO 3 − ) is the main form of N embedded in the discharged effluents in Chinese cities.…”

“…The updated δ 15 N-NO 3 − (4.0-19.0 ‰) and δ 18 O-NO 3 − (3.5-16.8 ‰) value ranges indicated for sewage were concluded by Xue et al (2009). They were recently referred by most field studies worldwide related to NO 3 − source identification (Nestler et al 2011), including the field studies in America (Kaushal et al 2011), Belgium (Xue et al 2012;Xue et al 2013), and China (Cao et al 2012;Chen et al 2012;Liu et al 2013;Yue et al 2013;Ren et al 2014). However, the data of NO 3 − isotope could vary considerably depending on the local sewage treatment process, especially with regard to the degree of nitrification and denitrification (Anisfeld et al 2007).…”

“…In a local case study conducted by Ren et al (2014), they found that the domestic sewage was the main source of the water pollution in Kunming Lake from May to September, which locates in Haidian district receiving the inflow from Qinghe River, through the NO 3 − source apportionment method by comparing the δ 15 N (9.5-19.2 ‰) of the water samples with the referenced ranges provided by Xue et al (2009). With tighter ranges in rainy and warm seasons, we could clearly identify the treated sewage was a dominant source resulting in the higher δ 15 N value of the water samples.…”