Haldaguirre2935

Due to remarkable spatial extent and evident interconnection, these phenomena seem to be unique and, thus, constituting geological heritage. Identification of the latter means that ASGM sites add value to the local environment. A paradox is that illegal and mercury-releasing ASGM needs termination, but such an action will result in the loss of the noted geological heritage value. Solution to this paradox requires careful development of plans for local management. However, it is clear that the presence of the noted heritage requires turning more attention to ASGM and their natural (river valley) context. V.Water-rock interactions in aquifer systems are a key control on water quality but remain poorly understood. Lithium (Li) isotopes are useful for understanding water-rock interactions, but there are few data available for groundwater aquifers. Here we present a Li isotope dataset for rainfall and groundwater samples from a carbonate island aquifer system Rottnest Island, Western Australia. This dataset was complemented by strontium (Sr) isotope and major and trace element data for groundwaters, and leaching experiments on bedrock samples. The δ7Li values and 87Sr/86Sr ratios of fresh groundwaters ranged from +23 to +36‰ and 0.709167 to 0.709198, respectively. Mass balance calculations indicated that silicate weathering supplied ~60 and 70% of dissolved Li and Sr in fresh groundwaters, respectively, with the remainder provided by atmospheric input, and carbonate weathering; for major cations, the majority of calcium and sodium (Na) are supplied by carbonate weathering and atmospheric input, respectively. The estimated low proportion of Sr produced by carbonate weathering was surprising in a carbonate aquifer, and the 87Sr/86Sr data indicated that the silicate Sr source had low Rb/Sr and 87Sr/86Sr ratios. There was an increase in the maximum δ7Li values in fresh groundwaters (+36‰) relative to the maximum value in rainfall and seawater (ca. +31‰). As clay minerals are undersaturated in fresh groundwaters, this increase may be explained by Li isotope fractionation associated with ion-exchange reactions on clays and iron(oxy)hydroxides. In the more saline groundwaters, the minimum δ7Li values decreased with depth to +14.5‰, suggesting increased silicate mineral dissolution in the deeper aquifer. These results reveal the importance of water-rock interactions in a coastal carbonate aquifer, and demonstrate the usefulness of Li isotopes for tracing weathering reactions in an environmental setting where traditional weathering tracers, such as sodium and Sr isotopes, are less appropriate. Crown V. All rights reserved.In this study, the mechanism for converting citrus peel wastes (CPW) into bioflocculants using Alcaligenes faecalis subsp. BI-3231 purchase phenolicus ZY-16 was analysed. The results demonstrated that the ZY-16 strain could produce various lignocellulolytic enzymes, containing cellulase, hemicellulase, pectinase, protease, and ligninase, enhancing the hydrolysis of citrus peel wastes. Molecular distillation removes antimicrobial limonene, which could inhibit bioflocculant production. The optimal fermentation conditions with the highest bioflocculant yield (3.49 g/L) were 38.79 g/L of CPW, 35.54 °C, and pH 4.48. Furthermore, the bioflocculant was used to eliminate microcystins for the first time, and the highest removal efficiency (90.05%) was achieved at a pH of 3.0, after 800 mg/L of bioflocculant was added into the microcystins solution (10 mg/L) for 60 min. Therefore, this paper demonstrated that CPW could be a cost-effective feedstock for the production of bioflocculants, which have potential application in microcystin removal. Mercury is a global pollutant that harms human and wildlife health through chronic exposure. The role of urban forests in Hg biogeochemistry has been understudied in cities without historical mining or current coal combustion. This study aimed to quantify total Hg concentrations and pools in urban forests to determine whether adjacent land-use impacts Hg accumulation. Three cities in the northeastern United States were studied Hartford, Connecticut; Poughkeepsie, New York; and Springfield, Massachusetts. We identified ~20 urban forests sites in a ~10 km by ~10 km grid for each city and sampled foliage and soil at each site. Foliage from Populus exhibited significantly lower Hg concentrations (15.6 ± 2.1 ng g-1) than mean foliar Hg concentrations (23.7 ± 0.6 ng g-1) but most deciduous genera had comparable concentrations. Average forest floor Hg concentrations (195 ± 21 ng g-1) and Hg pools (1.9 ± 0.5 mg m-2) were similar to previous, non-urban studies in the region. Average A horizon (182 ± 19 ng g-1) and B horizon (125 ± 14 ng g-1) Hg concentrations were double those of regional forest soils. Mineral soil Hg pools for the top 30 cm (49 ± 6 mg m-2) averaged two to ten times higher than rural, montane forests in the region. Soil pH, LOI, and %clay were poorly correlated with mineral soil Hg concentrations. Instead, highest foliar and soil Hg concentrations and pools were in urban forests adjacent to high and medium intensity developed areas in Springfield and Hartford. To differentiate the impact of land-uses not captured by the National Land Cover Database (NLCD) system, we implemented new land-use categories. Industrial areas had highest foliar and soil Hg concentrations and pools of any land use. Our results show increasing land-use increases Hg accumulation in urban forests. As one of the important nitrogen (N) and phosphorus (P) pollution sources of waters, the paddy water N and P runoff losses are still poorly understood in the double rice cropping system under the interaction of chemical fertilizer and pesticide. In the subtropical hilly region of China, we conducted a 1.5-year continuous and high-frequency monitoring of paddy water N and P concentrations, runoff N and P losses, and grain yield in a double rice-cropping system with different chemical fertilizer and pesticide application rates. The results showed that the high-risk periods for N loss were in the first 5 days after the base fertilizer (BF) application and the first 10 days after the topdressing fertilizer application in both early and late rice seasons, while the high-risk periods for P loss were in the first 5 days after BF application in the early rice season and the first 15 days after BF application in the late rice season. The N and P runoff losses in the early rice season were greater than those in the late rice season, due to that the N and P fertilizers use efficiencies were lower, and thus paddy water N and P concentrations were higher in the early rice season.