Estimation of dynamic load of mercury in a river with BASINS-HSPF model

Abstract

a pervasive toxic pollutant. This study investigated the dynamic loads of Hg from the Cedar-Ortega Rivers watershed into the Lower St. Johns River (LSJR), Florida, USA, using the better assessment science integrating point and nonpoint sources (BASINS)-hydrologic simulation program-FORTRAN (HSPF) model. Materials and methodsThe site-specific BASINS-HSPF model was developed for dynamic loads of Hg based on watershed, meteorological, and hydrological conditions. The model was calibrated and validated with existing field data. It was then applied to predict the daily and annual loads of Hg from the watershed outlet into the LSJR in response to rainfall events and water fluxes. Results and discussion In general, the predicted average daily total Hg flux during the 10-year simulation period was about 0.69 gha −1 year −1 . This finding was within the range of 0.22-1.41 gha −1 year −1 reported in the Florida Everglades area. Simulations further revealed that the effects of rainfall events on Hg loading were significant, particularly in a very wet period. A maximum total Hg flux was predicted during this wet period at a rate of 122.59 gha −1 year −1 .Conclusions Results from this study provide a useful case study on estimating Hg contamination in watersheds. The approaches used in this study could be transferred to estimate the dynamic loads of Hg in watersheds from other regions.

A novel semi‐dry method for the simultaneous removal of Hg and SO2 using spray drying absorption method

“…In order to minimize the harm caused by these toxic substances as much as possible, research on pollutant purification has been carried out. Most of the technologies currently used for flue gas purification involve separate removal and the main desulphurization technologies include limestone gypsum, ammonia, dense coherent tower, circulating fluidized bed and spray drying absorption (SDA) . While as for mercury (Hg) removal, due to the insoluble nature of Hg 0 , it is difficult to remove directly.…”

“…Most of the technologies currently used for flue gas purification involve separate removal and the main desulphurization technologies include limestone gypsum, ammonia, dense coherent tower, circulating fluidized bed and spray drying absorption (SDA). 2 While as for mercury (Hg) removal, due to the insoluble nature of Hg 0 , it is difficult to remove directly. In recent years, oxidation methods seemed to be a promising technology, which was to convert Hg 0 to soluble Hg 2+ .…”

“…In recent years, oxidation methods seemed to be a promising technology, which was to convert Hg 0 to soluble Hg 2+ . In addition, the simultaneous removal of multiple pollutants was the current focus, such as the simultaneous removal of SO 2 and nitric oxide (NO) or the simultaneous removal of SO 2 and Hg. 3 Among them, the wet method has been widely used due to its high removal efficiency and relatively mature technology.…”