Assessment of groundwater contamination by nitrates associated with wastewater irrigation: A case study in Shijiazhuang region, China

Abstract

Abstract:In arid and semi-arid regions there is usually a shortage of irrigation water; thus, wastewater water, as well as other lowquality water resources, may become an important source of water and nutrients. However, (pre)treated wastewater may contain elements and compounds that can damage the environment. It also has the potential to affect water quality adversely in an aquifer that may be the source of drinking water in the area. In order to assess the impacts of wastewater on the environment, groundwater samples were taken and analysed in typical croplands in the North China Plain, where urban wastewater or groundwater have been used for irrigation for several decades. Concentrations of nitrate NO 3 in groundwater in the study area varied from 50 to 130 mg l 1 in the croplands irrigated by wastewater, but in the croplands irrigated by pumping wells, away from the Dongming Canal, NO 3 concentrations are less than 35 mg l 1 . It was found that values of υ 15 N ranged from C5 to C13‰, and dominantly from C7 to C11‰, and the NO 3 concentration in most wells with depths of less than 40 m was higher than the drinking water standard set by the WHO. Cluster analysis was used to classify the spatial distribution of nitrates resulting from the wastewater. Identification of chemical patterns is found to be effective for the comprehensive assessment of the spatial distribution of groundwater quality. It is also emphasized that the wastewater in this area controls the NO 3 distribution in the groundwater, and should be used carefully to protect both soil and groundwater from NO 3 pollution.

Tracing infiltration and recharge using stable isotope in Taihang Mt., North China

“…Taihang Mt. region is the most important recharge source for the adjacent North China Plain (NCP), an important crop production region in China, where more and more serious water problems such as the water table declines continuously and worsening of water quality occurs (Liu and He 1996;Liu et al 2001;Yang et al 2002;Tang et al 2004). The proper simulation of this recharge requires detailed knowledge of hydrological processes integrating precipitation, soil water along the profile and groundwater.…”

Bioremediation of Wastewater for Reutilization in Agricultural Systems: A Review

“…The treatment of wastewater started during the industrial revolution; since then, it has been considered an environmental and social problem. In the nineteenth and twentieth centuries, many studies have tried to understand the composition of wastewater with the aim of devising better ways to remove and dispose wastewater contaminants (Tang, 2004;Parreiras, 2005).…”

Impact of septic tank systems on local groundwater quality and water supply in the Pearl River Delta, China: case study

“…Nitrate (NO 3 ) is the most common nitrogen species. NO 3 contamination of groundwater is typically a result of nitrogen movement into the unsaturated (vadose) zone, and the occurrence of transformation processes in either the unsaturated or saturated zones (Tang et al, 2004b). Sources of NO 3 can be clarified by pe-pH diagrams for the N-O 2 -H 2 O system.…”