Study on Mercury Distribution and Speciation in Urban Road Runoff in Nanjing City, China

Abstract

Abstract:The current study was aimed to investigate the mercury pollution in urban road runoff. A total of 34 rainfall events were monitored on 5 independent road catchments from 2015 to 2016 in Nanjing city, China. Events mean concentrations of mercury and the impact factors of mercury pollution in urban road runoff were also carried out in the current study. Results revealed that the concentration of various mercury species was very high. Total mercury, dissolved mercury and particulate mercury were found to be in the range of 0.173-8.254 µg/L, 0.069-6.823 µg/L, and 0.086-2.485 µg/L, respectively. The order of total mercury concentration among the five catchments was as follows: Longpan road > Xinjiekou > Jiulonghu > Zhujiang road > Maqun area. Results revealed the existence of different dominant species of mercury in different urban areas. Particularly, mercury in urban road runoff mainly existed in particulate form in Maqun area, and the concentrations of inactive mercury (0.250-2.821 µg/L) were far more than that of volatile mercury (0.023-0.215 µg/L) and active mercury (0.026-0.359 µg/L). The order of impact factors of rainfall characteristics on Hg pollution in runoff was dry periods > runoff time > duration of rainfall > storm intensity > rainfall. Analysis based on the first flush effect showed that the first flush phenomenon of mercury was not significant.

Algal Organic Matter Drives Methanogen-Mediated Methylmercury Production in Water from Eutrophic Shallow Lakes

“…52,53 Monte Carlo Simulation (MCS) was used to quantitatively estimate the uncertainty. Our estimated median MeHg levels in fish and human exposure risk were comparable to those reported values in previous studies, 34,53 showing the reliability of the results. 2.4.…”

“…(3) The human exposure risk of MeHg from fish consumption was assessed by the points of per-fetus IQ decrements. , Monte Carlo Simulation (MCS) was used to quantitatively estimate the uncertainty. Our estimated median MeHg levels in fish and human exposure risk were comparable to those reported values in previous studies, , showing the reliability of the results.…”

“…, 50–1050 ng·L –1 , ) and comparable with that reported in urban storm water runoff ( e.g. , 173 to 8254 ng·L –1 , Nanjing City, Eastern China). It has been widely recognized that ionic Hg would quickly complex with DOM, especially in high dissolved organic matter (DOC) levels, leading to most of spiked Hg as Hg–DOM complexes .…”

“…This is achieved by obtaining values of Hg methylation potential ( i.e. , MeHg %, quantified by experiment A-2 in this study), THg levels in lake water (collected from previous reports , ), and incorporating DOC-impacted MeHg photodegradation . (2) The probability density and cumulative probability of MeHg in fish were acquired by considering DOC-adjusted bio-concentration factors (BCFs) of MeHg under different eutrophication scenarios .…”

Sponge City: Using the “One Water” Concept to Improve Understanding of Flood Management Effectiveness

“…City subsidence levels indicate massive groundwater withdrawals are evident and substantial. Singh et al [23] reported that in Beijing, the annual groundwater extraction reached 2.6 × 10 9 m 3 /year, which included roughly 1 × 10 6 m 3 /year for exploitation. Gao et al [24] also suggested that the South-to-North canals now provide nearly twothirds of urban water supplies for Beijing, where these amounts were previously supplied by groundwater withdrawal.…”