Although the (mainly) oxic flow path of this river favours aqueous Sb mobility compared to As, localised redox-driven shifts in speciation of both elements strongly influence their respective mobility and partitioning. V.Greater one-horned rhinoceros (Rhinoceros unicornis) is one of the most iconic wildlife species in the world. Once reduced to fewer than 500 during the 1960s, its global population has been recovering and is now over 3500, thanks to effective conservation programs in India and Nepal, the only two countries in the world where this species is found. It is one of the greatest success stories in biodiversity conservation given that hundreds of other species have disappeared, and thousands of species are on the verge of extinction. However, poaching is not the only threat for the long-term survival of rhinoceros. Loss and degradation of grassland habitat and the drying-up of wetlands are emerging threats predicted to worsen in the future, but the published information on rhinoceros has never been synthesized. In order to better understand the trends and current status of rhinoceros research and identify research gaps inhibiting its long-term conservation, we analyzed the themes discussed in 215 articles covering a period of 33 years between 1985 and 2018. Our findings suggest that studies on both free-ranging and captive rhinoceros are skewed towards biological aspects of the species including morphology, anatomy, physiology, and behaviour. There are no studies addressing the likely effects of climate change on the species, and limited information is available on rhinoceros genetics, diseases, habitat dynamics and the impacts of tourism and other infrastructure development in and around rhinoceros habitat. These issues will need addressing to maintain the conservation success of greater one-horned rhinoceros into the future. Large amounts of jarosites are produced during zinc hydrometallurgy and bioleaching, as well as in acid sulfate soils and acid mine drainage environments. https://www.selleckchem.com/products/mlt-748.html As such, understanding the behavior of jarosite dissolution is important for analyzing the iron cycle process and promoting the control and treatment of jarosites. In general, soluble ferric ions and jarosites coexist in acid environments; however, the relationship between soluble ferric ions and jarosites under anaerobic reductive conditions is still not well understood. In this study, the effect of adding Fe3+ on the promotion of the bio-dissolution of jarosites using Acidithiobacillus ferrooxidans is investigated. With the addition of 12 mM Fe3+, the efficiency and maximum rate of jarosite bio-dissolution were found to reach 84.1% and 2.66 mmol/(L·d), respectively. The addition of Fe3+ at concentrations higher than 12 mM did not further improve the jarosite bio-dissolution. These results indicate that the mechanisms underlying these improvements include (i) the reduction of the zeta potential due to the compression of the diffusion layer of the electric double layer by Fe3+; (ii) bacteria growth enhancement and the stabilization of the pH of cultures via the reduction of soluble Fe3+. Based on these observations, this study serves to promote the development of jarosite bio-dissolution using Acidithiobacillus ferrooxidans and challenges the idea that soluble Fe3+ suppresses the bio-dissolution reaction of solid Fe3+ substances such as jarosite when soluble ferric ions and jarosite coexist. Emerging contaminants such as pharmaceuticals that cannot be completely removed by traditional biological treatments are ubiquitously present in water bodies with detected concentrations ranging from ng L-1 to mg L-1. Advanced oxidation technologies (AOTs) are promising, efficient, and environmentally friendly for the removal of these pharmaceuticals. In this study, we investigated the degradation kinetics of a model pharmaceutical, clonidine (CLD), via hydroxyl radical (OH) in UV/H2O2 and sulfate radical (SO4•-) in UV/peroxydisulfate (PS) systems for the first time. The second-order rate constants (k) of protonated cationic CLD with OH and SO4•- were measured to be (2.15 ± 0.07) × 109 M-1 s-1 and (1.12 ± 0.03) × 109 M-1 s-1, respectively. We also calculated the pKa value of CLD and thermodynamic behaviors for reactions of CLD/HCLD+ with OH and SO4•- at M05-2X/6-311++G**//M05-2X/6-31+G** level with SMD solvation model. The pKa value was calculated to be 8.14, confirming the literature value. H atom abstraction pathway was the most favorable pathway for both OH and SO4•-, while single electron transfer pathway was thermodynamically feasible only for SO4•- for CLD but not for HCLD+. In addition, the reactivities of both tautomeric forms of CLD (i.e., amino and imino CLD) with both radicals were also investigated. This study contributed to a better understanding on the degradation mechanisms of CLD and proposed the possibilities of the elimination of pharmaceuticals by applying AOTs during wastewater treatment processes. Silver nanoparticles (AgNPs) are widely applied in several types of products since they act as a biocide. However, their high level of release into the environment can bring risks to ecosystems. Thus, the toxicity of AgNPs toward duckweed (Landoltia punctata) was investigated by monitoring the growth rate inhibition and the effect on the photosynthetic metabolism through morphological and ultrastructural analysis. The AgNPs were characterized by transmission electron microscopy and the effective diameter (dynamic light scattering) and zeta potential were determined. Plants were grown according to the environmental conditions recommended in ISO/DIS 20079 and then exposed to different concentrations of AgNPs. Inhibition of the growth rate was measured based on the EC50 and changes in the morphology, cellular structures and photosynthetic pigments were evaluated along with the silver accumulation. Although the results showed low growth inhibition when compared to other studies, significant damage to the ultrastructure, decreases in the photosynthetic pigments and starch grains, an increase in the phenolic compounds and physiological changes, such as a loss of color, were observed. Moreover, the accumulation of silver ions was noted and this could lead to bioamplification in consumer organisms, since duckweed belongs to the first level of the food chain. V.