Combining hydrological investigations and radium isotopes to understand the environmental effect of groundwater discharge to a typical urbanized estuary in China

Xiao，Kai1; Li，Gang2,3; Li，Hailong1; Zhang，Yan4; Wang，Xuejing1; Hu，W.1; Zhang，Chengcheng5

2019-12-10

10.1016/j.scitotenv.2019.133872

SCIENCE OF THE TOTAL ENVIRONMENT   影响因子和分区

0048-9697

1879-1026

Pollution of urbanized rivers with excess nutrients due to groundwater discharge is an increasing environmental concern worldwide. Dan'ao river, a typical urbanized river in the Guangdong-Hong Kong-Macao Greater Bay Area, is experiencing heavy water pollution. However, the groundwater-derived nutrient loads had not yet been thoroughly quantified. In order to quantify the contribution of groundwater-derived nutrient inputs, we combined the methods of hydrological investigations and radium isotopes. Groundwater and river water samples were collected from the river upstream to the estuary for the analyses of radium quartets and nutrients including DIN, DIP and DSi. The results showed that the radium activities in both surface water and groundwater decreased from the estuary to the upstream. The groundwater discharge rate was estimated by the radium mass balance model using short-lived radium isotopes (Ra and Ra). The estimated groundwater discharge rate ranged from 1.99 × 10 to 6.67 × 10 m d, comparable to the upstream river discharge rate of 4.23 × 10 m d. The groundwater-derived nutrient fluxes were 165.66–554.98 mmol m d for DIN, 2.47–8.26 mmol m d for DIP and 63.73–213.49 mmol m d for DSi, respectively. They contributed 19%~44% DIN, 16%~39% DIP, and 31%~60% DSi of all the nutrient inputs into the Dan'ao River, respectively. In addition, the nutrient inputs by groundwater discharge has an average DIN:DIP ratio of as high as 190, which is able to potentially affect the riverine and marine nutrient structures. These findings may provide useful information for designing control strategies for reducing massive nutrient inputs to Dan'ao River in the future.

Estuary Eutrophication Radium isotopes Water pollution Water residence time

SCI ; EI

英语

第一 ; 通讯

National Basic Research Program of China ("973" Program)[2015CB452902]

Environmental Sciences & Ecology

Environmental Sciences

WOS:000496802200060

ELSEVIER

20193307323530

Discharge (fluid mechanics) ; Estuaries ; Eutrophication ; Groundwater ; Groundwater pollution ; Heavy water ; Isotopes ; Nutrients ; Radium ; Rivers ; Water pollution

Waterways:407.2 ; Groundwater:444.2 ; Water Pollution:453 ; Radioactive Materials, General:622.1 ; Chemical Products Generally:804

ENVIRONMENT/ECOLOGY

2-s2.0-85070596542

Scopus

1.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution ControlSchool of Environmental Science and EngineeringSouthern University of Science and Technology,Shenzhen,518055,China
2.China Institute of Geo-Environment Monitoring,Beijing,100081,China
3.Hebei Key Laboratory of Geological Resources and Environment Monitoring and Protection,Shijiazhuang,050021,China
4.School of Water Resources and Environmental ScienceChina University of Geosciences,Beijing,100083,China
5.Northwest Institute of Nuclear Technology,Xian,710024,China

Xiao，Kai,Li，Gang,Li，Hailong,et al. Combining hydrological investigations and radium isotopes to understand the environmental effect of groundwater discharge to a typical urbanized estuary in China[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2019,695.

Xiao，Kai.,Li，Gang.,Li，Hailong.,Zhang，Yan.,Wang，Xuejing.,...&Zhang，Chengcheng.(2019).Combining hydrological investigations and radium isotopes to understand the environmental effect of groundwater discharge to a typical urbanized estuary in China.SCIENCE OF THE TOTAL ENVIRONMENT,695.

Xiao，Kai,et al."Combining hydrological investigations and radium isotopes to understand the environmental effect of groundwater discharge to a typical urbanized estuary in China".SCIENCE OF THE TOTAL ENVIRONMENT 695(2019).