Wind Bidstrup (shelfliquid55)

Calcareous soil has a strong buffering capacity for neutralizing acid and stabilizing cadmium (Cd) because of the high calcium carbonate (CaCO3) content. Selleckchem CDK2-IN-4 However, it is not clear whether the buffering capacity of calcareous soil can be maintained after long-term wastewater irrigation. We selected a typical area in western China that has been irrigated with wastewater for over 50 years to study the temporal changes of soil properties and their effects on Cd uptake by wheat. The results showed that compared with the background level before the 1960s, the soil pH and CaCO3 content in 2018 were lower by 0.80 units and 35%, respectively, while the soil organic matter (SOM) content, Olsen phosphorus (P) content, and soil total Cd content in 2018 increased by 1.54, 13.05, and 164 times, respectively. Due to the significant decrease in the soil pH and CaCO3, the high load of soil total Cd and electrical conductivity, the low soil clay content, and the coupling of SOM with soil nitrogen and P, the input Cd was activated. Furthermore, the activated Cd was effectively taken up by wheat roots and transported to grains with the assistance of dissolved organic carbon. Our results highlight that long-term wastewater irrigation caused irreversible damage to soil buffering capacity, resulting in the Cd activation and the enhancement of Cd uptake by wheat.Recently, the exposure of nanoplastics (NPs) in the environment has received extensive attention. Research concerning their fate and transport in the aquatic environment is very important and urgent. In this study, the influence of two sources of natural organic matter (NOM) on the behaviour of NPs were investigated in view of the complexity of NOM. Humic acid (HA), Suwannee River humic acid (SRHA) and Upper Mississippi River NOM (MRNOM) were chosen to represent pedogenic NOM, while bovine serum albumin (BSA) was on behalf of aquagenic NOM. The results showed that NOM could reduce the aggregation and sedimentation of NPs, exhibiting excellent stabilization effect. The stability effect was affected by the concentrations and the sources of NOMs. For pedogenic NOMs, the stabilization effect was caused by adsorption modes with different microscopic morphologies through specific functional groups, while it was induced by the mode of steric stabilization in the presence of BSA. Spectroscopic method and micromorphology study further provided a new insight into exploring the possible mechanism of the interaction between NPs and NOMs.Seawater flue gas desulfurization (SFGD) has shown great effectiveness in the controlling of sulfur dioxide (SO2) emission and the removing of mercury (Hg) from flue gases of coal-fired power plants. Some problems pertaining to SFGD for Hg control, however, remain to be solved (1) environmental impact from the discharge of Hg-containing seawater to the ocean, and (2) re-emission of gaseous Hg from the aeration tank to the atmosphere. This study synthesizes the copper/sulfur co-impregnated activated carbon (Cu-S-AC) to simultaneously capture aqueous Hg(II) and inhibit gaseous Hg0 re-emission from actual SFGD wastewater. Cu-S-AC exhibited greater Hg(II) adsorption than both raw activated carbon (AC) and sulfur-impregnated activated carbon (S-AC) at an initial Hg(II) concentration of higher than 8000 ng/L. The Hg(II) adsorption of Cu-S-AC was slightly greater at pH 7 and 8 than that under acidic conditions. The Hg(II) adsorption was well-fitted with both linear and Freundlich isotherms. The results of thermodynamic analyses veiled the endothermic and spontaneous adsorption of Hg(II) on Cu-S-AC. In addition, the pseudo-second-order equation provided the best correlation coefficient for the Hg(II) adsorption on Cu-S-AC. Notably, the increases of pH and temperature increased the Hg0 re-emission. Nevertheless, Cu-S-AC addition significantly inhibited the Hg0 re-emission (92%) from SFGD wastewater.In this work, the performance of the atmospheric pressure