Study on Mercury Distribution and Speciation in Urban Road Runoff in Nanjing City, China
Abstract
:1. Introduction:
2. Methods
2.1. Site Description
2.2. Rainfall Characteristics
2.3. Hg Analysis
2.4. Events Mean Concentrations (EMCs)
- M: total mass of the contaminant;
- V: total volume of runoff;
- C(t): concentrations of the contaminant at different times;
- Q(t): flow of runoff;
- t: runoff time.
2.5. Measurement of First Flush
- M: total mass of the contaminant;
- V: total volume of runoff;
- m(t): Cumulative mass of the contaminant at time t;
- v(t): Cumulative volume of runoff at time t;
- c(t): concentrations of the contaminant at different times;
- q(t): flow of runoff;
- t: runoff time;
- tr: runoff total duration.
3. Results and Discussion
3.1. EMCs of Various Hg Species
3.2. EMCs of Hg in Different Valence States
3.3. Relationship between EMCs of Hg and TSS
3.4. Influence of Rainfall Characteristics
3.5. First Flush Effect (FF30)
4. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Catchment Identification | Area (m2) | Surrounding Land Use | Road Material | Vehicle Flow Rate (/Day) |
---|---|---|---|---|
Maqun | 1100 | Transports | Pitch | 38,400 |
Longpan road | 1200 | Transports | Pitch | 39,200 |
Zhujiang road | 1300 | Electronic | Pitch, cement | 30,000 |
Xinjiekou | 1500 | Commercial | Pitch, terrazzo | 47,800 |
Jiulonghu | 900 | University campus, thermal power plant | Pitch | 2000 |
Site | Date | Rainfall (mm) | Duration of Rainfall (min) | Runoff Time (min) | Max Storm Intensity (mm/min) | Average Storm Intensity (mm/min) | Min Storm Intensity (mm/min) | Dry Periods (h) |
---|---|---|---|---|---|---|---|---|
Maqun | 12 June 2015 | 1.96 | 185 | 37 | 0.0238 | 0.0106 | 0.0060 | 32.0 |
20 June 2015 | 7.15 | 450 | 65 | 0.0350 | 0.0159 | 0.0017 | 180.5 | |
24 June 2015 | 1.27 | 100 | 85 | 0.0267 | 0.0127 | 0.0011 | 83.8 | |
29 June 2015 | 22.01 | 385 | 15 | 0.2908 | 0.0572 | 0.0017 | 47.6 | |
14 July 2015 | 6.13 | 438 | 213 | 0.0189 | 0.0140 | 0.0012 | 240.5 | |
19 July 2015 | 4.40 | 450 | 26 | 0.0500 | 0.0098 | 0.0026 | 98.3 | |
8 August 2015 | 14.30 | 288 | 38 | 0.3497 | 0.0497 | 0.0031 | 120.7 | |
21 August 2015 | 9.40 | 158 | 8 | 0.4000 | 0.0595 | 0.0019 | 23.0 | |
25 August 2015 | 2.35 | 138 | 42 | 0.0400 | 0.0013 | 0.0124 | 59.0 | |
2 May 2016 | 4.80 | 267 | 21 | 0.0800 | 0.0400 | 0.0188 | 72.4 | |
7 May 2016 | 0.91 | 121 | 52 | 0.0200 | 0.0075 | 0.0031 | 88.3 | |
Longpan road | 21 April 2015 | 12.00 | 480 | 58 | 0.2500 | 0.0921 | 0.0042 | 192.0 |
29 April 2015 | 58.00 | 90 | 30 | 3.7000 | 0.6443 | 0.0073 | 84.1 | |
7 May 2015 | 100.00 | 180 | 47 | 2.0000 | 0.5884 | 0.0023 | 156.0 | |
14 May 2015 | 23.50 | 204 | 29 | 0.2000 | 0.1966 | 0.0038 | 27.2 | |
18 May 2015 | 18.00 | 210 | 64 | 0.3900 | 0.1210 | 0.0083 | 82.3 | |
2 May 2016 | 4.80 | 267 | 21 | 0.0800 | 0.0400 | 0.0188 | 72.4 | |
7 May 2016 | 0.91 | 121 | 52 | 0.0200 | 0.0075 | 0.0031 | 88.3 | |
Zhujiang road | 29 April 2015 | 58.00 | 90 | 30 | 3.7000 | 0.6443 | 0.0073 | 84.1 |
7 May 2015 | 100.00 | 180 | 47 | 2.0000 | 0.5884 | 0.0023 | 156.0 | |
14 May 2015 | 23.50 | 204 | 29 | 0.2000 | 0.1966 | 0.0038 | 27.2 | |
18 May 2015 | 18.00 | 210 | 64 | 0.3900 | 0.1210 | 0.0083 | 82.3 | |
2 May 2016 | 4.80 | 267 | 21 | 0.0800 | 0.0400 | 0.0188 | 72.4 | |
7 May 2016 | 0.91 | 121 | 52 | 0.0200 | 0.0075 | 0.0031 | 88.3 | |
Xinjiekou | 7 May 2015 | 100.00 | 180 | 47 | 2.0000 | 0.5884 | 0.0023 | 156.0 |
14 May 2015 | 23.50 | 204 | 29 | 0.2000 | 0.1966 | 0.0038 | 27.2 | |
18 May 2015 | 18.00 | 210 | 64 | 0.3900 | 0.1210 | 0.0083 | 82.3 | |
2 May 2016 | 4.80 | 267 | 21 | 0.0800 | 0.0400 | 0.0188 | 72.4 | |
7 May 2016 | 0.91 | 121 | 52 | 0.0200 | 0.0075 | 0.0031 | 88.3 | |
Jiulonghu | 7 May 2015 | 100.00 | 180 | 47 | 2.0000 | 0.5884 | 0.0023 | 156.0 |
14 May 2015 | 23.50 | 204 | 29 | 0.2000 | 0.1966 | 0.0038 | 27.2 | |
18 May 2015 | 18.00 | 210 | 64 | 0.3900 | 0.1210 | 0.0083 | 82.3 | |
2 May 2016 | 4.80 | 267 | 21 | 0.0800 | 0.0400 | 0.0188 | 72.4 | |
7 May 2016 | 0.91 | 121 | 52 | 0.0200 | 0.0075 | 0.0031 | 88.3 |
Hg | Methods |
---|---|
THg | 50 μL stormwater, taken by pipette, was placed in a nickel boat, and Hydra II A mercury analyzer was utilized to measure the absolute values of Hg concentrations directly. |
DHg | Stormwater samples were filtered through a 0.45 μm filter membrane, and 50 μL sample was analyzed by the method of THg. |
PHg | PHg = THg-DHg [18,19] |
Hg0 | Concentrated sulfuric acid by sub-boiling distillation was used to acidify 100 mL stormwater; then, N2 was used to blow the samples at a rate of 350 to 400 mL/min for 30 min, and Hg0 was captured onto the gold tube. Finally, samples were analyzed by Hydra IIC mercury analyzer. |
Hg2+ | Stormwater samples, which have been measured for Hg0, continue to be used to analysis Hg2+. Hg2+ in water samples was reduced to Hg0 by 5 mL of 20% SnCl2. N2 was used to blow the samples at a rate of 350 to 400 mL/min for 30 min, and Hg0 as a redox product was captured onto the gold tube. Finally, samples were analyzed by Hydra IIC mercury analyzer. |
Hgre | Hgre = THg-Hg0−-Hg2+ |
Site | Date | Hg (μg/L) | DHg/PHg | log Kd | TSS (mg/L) | ||
---|---|---|---|---|---|---|---|
THg | DHg | PHg | |||||
Maqun | 12 June 2015 | 0.335 | 0.085 | 0.250 | 0.34 | 4.49 | 95 |
20 June 2015 | 2.760 | 0.786 | 1.974 | 0.40 | 4.16 | 174 | |
24 June 2015 | 0.437 | 0.175 | 0.262 | 0.67 | 4.49 | 48 | |
29 June 2015 | 0.337 | 0.102 | 0.235 | 0.43 | 4.44 | 84 | |
14 July 2015 | 3.347 | 0.862 | 2.485 | 0.35 | 4.05 | 256 | |
19 July 2015 | 0.667 | 0.236 | 0.431 | 0.55 | 4.30 | 92 | |
8 August 2015 | 3.001 | 0.778 | 2.223 | 0.35 | 3.77 | 484 | |
21 August 2015 | 0.439 | 0.215 | 0.224 | 0.96 | 4.51 | 32 | |
25 August 2015 | 0.173 | 0.069 | 0.104 | 0.66 | 4.20 | 96 | |
2 May 2016 | 0.373 | 0.127 | 0.246 | 0.52 | 4.45 | 68 | |
7 May 2016 | 0.455 | 0.136 | 0.319 | 0.43 | 4.28 | 123 | |
Mean | 1.120 | 0.234 | 0.796 | 0.515 | 4.38 | 141 | |
Median | 0.439 | 0.136 | 0.262 | 0.43 | 4.31 | 95 | |
Range | 0.173~3.347 | 0.069~0.862 | 0.104~2.485 | 0.34~0.96 | 3.77~4.51 | 32~484 | |
Longpan road | 21 April 2015 | 4.311 | 3.300 | 1.011 | 3.26 | — | — |
29 April 2015 | 8.254 | 6.823 | 1.431 | 4.77 | — | — | |
7 May 2015 | 5.241 | 4.872 | 0.369 | 13.20 | — | — | |
14 May 2015 | 2.892 | 0.491 | 2.401 | 0.20 | — | — | |
18 May 2015 | 0.519 | 0.267 | 0.252 | 1.06 | — | — | |
2 May 2016 | 3.256 | 2.431 | 0.825 | 2.95 | — | — | |
7 May 2016 | 5.230 | 3.767 | 1.463 | 2.57 | — | — | |
Mean | 4.243 | 3.151 | 1.092 | 4.00 | — | — | |
Median | 4.311 | 3.300 | 1.011 | 2.95 | — | — | |
Range | 0.519~8.254 | 0.267~6.823 | 0.252~2.401 | 0.20~13.20 | — | — | |
Zhujiang road | 29 April 2015 | 0.813 | 0.318 | 0.495 | 0.64 | — | — |
7 May 2015 | 1.332 | 0.953 | 0.379 | 2.51 | — | — | |
14 May 2015 | 1.882 | 0.745 | 1.137 | 0.66 | — | — | |
18 May 2015 | 0.711 | 0.498 | 0.214 | 2.33 | — | — | |
2 May 2016 | 1.345 | 0.917 | 0.428 | 2.14 | — | — | |
7 May 2016 | 1.025 | 0.782 | 0.243 | 3.22 | — | — | |
Mean | 1.185 | 0.702 | 0.483 | 1.92 | — | — | |
Median | 1.179 | 0.622 | 0.355 | 2.24 | — | — | |
Range | 0.711~1.882 | 0.318~0.953 | 0.214~1.137 | 0.64~3.22 | — | — | |
Xinjiekou | 7 May 2015 | 3.862 | 2.171 | 1.691 | 1.28 | — | — |
14 May 2015 | 1.892 | 0.873 | 1.019 | 0.86 | — | — | |
18 May 2015 | 1.243 | 0.531 | 0.712 | 0.75 | — | — | |
2 May 2016 | 2.659 | 1.528 | 1.131 | 1.35 | — | — | |
7 May 2016 | 2.005 | 1.229 | 0.776 | 1.58 | — | — | |
Mean | 2.332 | 1.351 | 1.432 | 1.16 | — | — | |
Median | 2.005 | 0.531 | 1.691 | 1.28 | — | — | |
Range | 1.243~3.862 | 0.531~2.171 | 0.712~1.691 | 0.75~1.58 | — | — | |
Jiulonghu | 7 May 2015 | 2.027 | 1.464 | 0.563 | 2.60 | — | — |
14 May 2015 | 0.986 | 0.663 | 0.323 | 2.05 | — | — | |
18 May 2015 | 2.045 | 1.096 | 0.949 | 1.15 | — | — | |
2 May 2016 | 1.962 | 1.593 | 0.369 | 4.32 | — | — | |
7 May 2016 | 1.410 | 0.972 | 0.438 | 2.22 | — | — | |
Mean | 1.686 | 1.074 | 0.612 | 2.47 | — | — | |
Median | 1.962 | 1.096 | 0.623 | 2.22 | — | — | |
Range | 0.986~2.045 | 0.663~1.593 | 0.323~0.949 | 1.15~4.32 | — | — |
Sites | Land Using Type | EMCs (μg/L) | Reference | |
---|---|---|---|---|
THg | ||||
near Ontario lake in Canada | Urban | 0.015 | [12] | |
Beijing, China | Urban | 0.1075 | [16] | |
Shanghai, China | Urban | 0.510 | [29] | |
Tianjin, China | City road A | Urban | 0.520 (0.412–2.76) | [30] |
City road B | Urban | 0.730 (0.174–1.223) | ||
Industrial district | Industry | 0.660 (0.104–1.182) | ||
Nanjing, China | Urban | 2.036 (0.173–8.254) | Current study |
Hg | TSS | Significance Level |
---|---|---|
THg | 0.807 | 0.01 |
DHg | 0.768 | 0.01 |
PHg | 0.819 | 0.01 |
Hg° | 0.850 | 0.05 |
Hg2+ | 0.923 | 0.01 |
Hgre | 0.954 | 0.01 |
Site | Date | FF30 of Hg | ||
---|---|---|---|---|
THg | DHg | PHg | ||
Longpan road | 21 April 2015 | 0.479 | 0.485 | 0.508 |
29 April 2015 | 0.471 | 0.489 | 0.384 | |
7 May 2015 | 0.378 | 0.337 | 0.907 | |
14 May 2015 | 0.276 | 0.636 | 0.195 | |
18 May 2015 | 0.535 | 0.233 | 0.372 | |
2 May 2016 | 0.523 | 0.638 | 0.583 | |
7 May 2016 | 0.492 | 0.448 | 0.473 | |
Zhujiang road | 29 April 2015 | 0.132 | 0.793 | 0.217 |
7 May 2015 | 0.179 | 0.205 | 0.181 | |
14 May 2015 | 0.496 | 0.102 | 0.332 | |
18 May 2015 | 0.319 | 0.284 | 0.177 | |
2 May 2016 | 0.255 | 0.639 | 0.291 | |
7 May 2016 | 0.364 | 0.584 | 0.195 | |
Xinjiekou | 7 May 2015 | 0.287 | 0.305 | 0.287 |
14 May 2015 | 0.483 | 0.402 | 0.483 | |
18 May 2015 | 0.373 | 0.356 | 0.386 | |
2 May 2016 | 0.404 | 0.399 | 0.329 | |
7 May 2016 | 0.378 | 0.428 | 0.372 | |
Jiulonghu | 7 May 2015 | 0.570 | 0.160 | 0.355 |
14 May 2015 | 0.450 | 0.036 | 0.692 | |
18 May 2015 | 0.407 | 0.282 | 0.482 | |
2 May 2016 | 0.529 | 0.183 | 0.622 | |
7 May 2016 | 0.358 | 0.157 | 0.475 | |
Range | 0.132~0.570 | 0.036~0.793 | 0.177~0.907 |
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Singh, R.P.; Wu, J.; Kumar, A.J.; Fu, D. Study on Mercury Distribution and Speciation in Urban Road Runoff in Nanjing City, China. Water 2017, 9, 779. https://doi.org/10.3390/w9100779
Singh RP, Wu J, Kumar AJ, Fu D. Study on Mercury Distribution and Speciation in Urban Road Runoff in Nanjing City, China. Water. 2017; 9(10):779. https://doi.org/10.3390/w9100779
Chicago/Turabian StyleSingh, Rajendra Prasad, Jiaguo Wu, Alagarasan Jagadeesh Kumar, and Dafang Fu. 2017. "Study on Mercury Distribution and Speciation in Urban Road Runoff in Nanjing City, China" Water 9, no. 10: 779. https://doi.org/10.3390/w9100779