Huaming Guo. Naturally occurring contaminants in groundwater in China: impacts and implications. China University of Geosciences (Beijing)

Transcription

1 The Second Water-Energy Workshop at DKU Oct.14-15, 2015 Naturally occurring contaminants in groundwater in China: impacts and implications Huaming Guo School of Water Resources and Environment

2 Content 1. Introduction 2. High As groundwater 3. High U/Rn/Ra groundwater 4. Conclusion

3 1. Introduction Geogenic high As and F - groundwater in China (Wen et al., 2013)

4 1. Introduction Distribution of endemic diseases in China m Areas >0.2 million km 2 Affected populations: Around 30 million (From CGS, 2009) Legend Fluorosis Arsenicosis Kashin-Beck Disease

5 High As groundwater

6 2. High As GW in China Distribution of high As groundwater in China 21 provinces (Guo et al., Appl Geochem 2014) Xinjiang: 1, 2, 3, 4, 5, 6; Qinghai: 7, 8, 9; Inner Mongolia: 10, 11, 12, 13, 14, 15; Jilin: 16; Heilongjiang: 17, 18; Beijing: 19; Shandong: 20; Henan: 21; Anhui and Jiangsu: 22; Jiangsu and Shanghai: 23; Zhejiang: 24; Hubei: 25; Shanxi: 26, 27, 28; Shaanxi: 29, 30; Ningxia: 31; Gansu: 32, 33; Sichuan: 34, 35; Yunnan: 36, 37, 38; Guangdong: 39, 40; Taiwan: 41, 42

7 Chronic effects of arsenic on residents Skin disease outer symptoms Hyperpigmentation Keratosis Sole Palm

8 Cancer Lung, liver, kidney, prostate; Children-leukemia;

9 Blood system disease: Heart diseases; Anemia (poverty of blood); black foot diseases

10 Health effects of high-arsenic groundwater in P.R. China ~ 5.6 M people expose to high As groundwater (>50 ppb) ~ 30,000 people suffer from arsenicosis Sun (2004) and Jin et al. (2003) Shanxi Inner Mongolia Xinjiang Jilin Ningxia Qinghai Percent of unsafe wells (> 50 ug/l) Prevalence rate (%)

11 Drinking water standard for arsenic 1998 European Union Lowing from 50 µg/l to 10 µg/l (for all members since 2003) 2006 USEPA Compliance date for 10 µg/l 2007 China EPA 10 µg/l for centralized water in urban areas 50 µg/l for rural areas

12 Three basins (the Hetao basin, the Yinchuan basin, and the Songnen basin)

13 The Hetao basin Area: 13,000 km 2 Arsenic-related diseases have been identified since 1995.

14 Lake Desert Irrigation channel Drainage channel

15 2. High As GW in China the Hetao basin Water levels of shallow groundwater in the Hetao basin (Zhang et al., 2013; Wang, 2006)

16 Irrigation channels were initiated in Ming Dynasty ( ) and updated in 1958 (180 km) 2. High As GW in China the Hetao basin Drainage channels have been run since 1965 (260 km) Drainage channels Irrigation channels

17 2. High As GW in China the Hetao basin Distribution of groundwater arsenic In the flat plain with SW for irrigation, GW for drinking >10,000 wells for drinking (<10-30 m)

18 2. High As GW in China the Hetao basin Spatial distribution in the Hetao basin (Guo et al., 2008, 2010, Deng et al., 2009, Luo et al., 2012) Depth: mostly m As: µg/l ph: NO 3- : mostly < 0.01 mg/l Water type: Na-Cl-HCO 3 Fe: mg/l SO 2-4 : averagely 224 mg/l DOC: mg/l Mn: ~1.27 mg/l As(III): >60% As ORP: -180 to 68 mv

19 2. High As GW in China the Hetao basin Control of hydrology / hydrogeology In the Hetao basin Concentrations of total As, As(III), and H 2 S increase with the increase in the distance away from the water ways; Eh values show opposite trend; (Guo et al., Environ Pollu, 2012)

20 2. High As GW in China the Hetao basin Control of hydrology / hydrogeology Arsenic distribution near the mountains Depth dependence of groundwater As (Guo et al., STOTEN, 2015)

21 2. High As GW in China the Yinchuan basin Control of hydrology / hydrogeology The Yinchuan basin PF: Proluvial fans DF: Dry farmland PF: Paddy farmland (Guo Q et al., 2014)

22 2. High As GW in China the Songnen basin Control of hydrology / hydrogeology The Songnen basin (Guo et al., Sci Total Environ, 2014)

23 Hydrological settings control groundwater As. How did biogeochemical processes regulate this hydrological control?

24 2. Geochemical processes EM3 Biogeochemical controls (the Hetao basin) EM2 EM1 Pathway 1:Microbial reduction of Fe(III) oxides and As release Pathway 2:Resorption of Fe(II) and As Pathway 3:Pyrite and siderite precipitation Guo et al., GCA, 2013

25 Biogeochemical controls (the Hetao basin) Flat plain Alluvial fans Bacterial sulfate reduction (S enrichment factor = -9.3 ): SO CH 2 O H 2 S + 2HCO 3 - Bacterial disproportionation of sulfur (ε 18 O/ε 34 S = 0.60): 3S FeOOH 2FeS + SO H + Guo et al., GCA, Submitted

26 Biogeochemical processes controlling As cycling Guo et al., GCA, Submitted

27 (Guo et al., STOTEN, 2014) Biogeochemical controls (the Songnen basin) End-member 2 End-member 1 End-member 1: Evident microbial degradation of DOC End-member 2: Limited microbial activities. Mixture of End-member 1 and End-member 2 for most samples

28 Health impacts of high As groundwater irrigation F2: Non-specifically sorbed As in soils As= 178 μg/l F4: Amorphous Fe/Al oxide-bound As As= 8.2 μg/l (Tong & Guo et al., STOTEN, 2014)

29 Natural radioactive contaminants (U, Rn and Ra)

30 Toxicity - Uranium Radioactive Toxicity: Chemical Toxicity (U): (1) Renal effect (Kurttio et al., EHP, 2002) (2) Bone metabolism (Kurttio et al., EHP, 2005) Drinking water guideline (1) 30 μg/l (WHO, EPA) (2) 10 μg/l (German value)

31 Uranium in groundwater in the Hetao basin In the alluvial fans, 62% samples had U >30 μg/l (WHO); In the transition area, 20% samples U >30 μg/l; In the flat plain, no samples U >30 μg/l; (Guo et al., STOTEN, 2015)

32 Groundwater U enrichment processes U was mobilized under oxic conditions Carbonate complexes enhanced U mobility (Guo et al., STOTEN, 2015)

33 Elemental mapping of schist sample (LA-ICP-MS) Mn Fe Si Al Ca Mg Na K As U P Biotite Schist sample: U around 8 mg/kg; Mica: 40-50% U is associated with Fe-containing biotite

34 Elemental mapping of carbonate sample (LA-ICP-MS) U: 0.21 mg/kg; Chalcopyrite: 8.5% U is associated with Ca carbonate veins Calcite vein (Guo et al., STOTEN, 2015)

35 Ultimate Sources of groundwater U: Schist, phyllite, and carbonate veins Schist phyllite carbonate veins

36 The fate of groundwater U High SI Uraninite in the flat plain with low U concentrations Low U groundwater is plotted in the uraninite-dominance area Uraninite would be the fate of groundwater U (Guo et al., STOTEN, 2015)

37 Groundwater U in the Ili basin H 2 S (mg/l) U (*0.1 μg/l) (Yue & Wang, APGEO, 2011)

38 U (μg/l) U (μg/l) Groundwater U in the Shihongtan (Min et al., J Geochem Explor 2007)

39 Radon in groundwater in the Hetao basin 40% samples have Rn concentrations >11 Bq/L (EPA) High concentration in the alluvial fans, while low concentration in the flat plain Along the flow path, Rn shows a decreasing trend, similar to U concentrations. U

40 Redox controls on Rn concentration Rn concentrations are generally high in high U groundwater. Other sources?

41 Radium in groundwater of the Hetao basin 224 Radium concentrations are generally low in the alluvial fans, while high in the flat plain It shows a different trend from Rn concentration.

42 High Mn concentration is associated with high 224 Ra concentration. Reduction of Mn oxides would release Ra from sediments. Other sources ( 226 Ra U decay)?

43 5. Conclusion Groundwaters with high As, U, or Rn are widelydistributed in inland basins. Those geogenic contaminants have negative impacts on human health These groundwaters are related to special geological (Quaternary sediments), geochemical (high salinity and alkalinity), and hydrogeological (low recharge and flow rate) conditions. Redox conditions and ph are the key factors controlling element enrichment.

44 Acknowledgements Students Yongfeng Jia, Qi Guo, Yuxiao Jiang, Di Zhang, Yang Wu, Yang Zhang, Yinzhu Zhou, Yongsheng Cao, Shuangbao Han, Chao Wei, Shanyang Li, Zeyun Liu ( Geosciences, Beijing); Major Funders National Natural Science Foundation of China (NSFC); Ministry of Education, P.R. China (MOE) ; Ministry of Science and Technology, P.R. China (MOST);, P.R. China (CUGB)

45 Thanks for your attention Welcome questions