The modified activated carbon (MAC) derived from commercial coconut shell activated carbon (AC) with mixture of seven metal salts was used as an adsorbent to remove target residual organic compound (sucrose) from aqueous solutions in batch modes. The results indicated that the highest adsorption capacity of sucrose onto MAC reached when the AC was modified at the ratio of impregnation of AC with mixture of seven metal salts, including nitrate silver (AgNO₃), manganese nitrate (Mn (NO₃)₂), potassium bichromate (K₂Cr₂O₇), nitrate cobalt (Co (NO₃)₂·6H₂O), nitrate copper (Cu (NO₃)₂·3H₂O), nitrate nickel (Ni (NO₃)₂·6H₂O) and nitrate iron (Fe (NO₃)₂·9H₂O) of 3% (w/w). The most appropriate conditions for sucrose adsorption onto MAC in batch experiments obtained at pH 7, contact time of 120 min, 800 mg MAC/50 mL of sucrose solution with initial concentration of 1500 mg/L. At this condition, the highest adsorption capacity of sucrose onto MAC reached 28.28 mg/g. The Langmuir, Freundlich, and Sips adsorption isothermal equilibrium models can adequately describe the adsorption properties of sucrose on MAC. The adsorption kinetic of sucrose onto MAC obeyed pseudo-first-order and pseudo-second-order models with the chemical sorption process. The saturated MAC was recovered by heat from an oven. The highest recovery efficiency of saturated MAC obtained at 180 °C in 120 min. The highest adsorption capacity of sucrose onto recovered MAC was 24.31 mg/g, appropriately adsorption capacity of initial MAC.

There is a problem in the original publication of this paper (Figure 2 Graphs are in Portuguese). Shown in this paper is the correct version.

The capacities of fatty esters and commercial biodiesel (i.e., mixture of fatty esters with fossil diesel) for solubilizing polycyclic aromatic hydrocarbons (PAHs) were investigated and were attributed to the property of fatty esters forming aggregates and internally accommodating such compounds. Different systems formed by solely fatty esters and commercial biodiesel were investigated to study the effect of the structure of fatty esters on the solubility of PAHs. In the presence of ethyl oleate, the solubility of naphthalene increased by 23 ± 1.3%, that of phenanthrene by 1.4 ± 0.7%, and those of anthracene and pyrene by 1.1 ± 0.6%. The maximum solubility values of PAHs indicated that fatty esters exerted a positive effect on solubility in the same way as a surfactant (ionic and neutral). In the presence of a mixture of fatty esters, the maximum concentration of naphthalene solubilized was 105.5 ± 2.5 mg/L, a 3.7-fold increase compared to its solubility in water. The same behavior was observed for other compounds like pyrene and phenanthrene. However, they were dissolved in different proportions due to the different physico-chemical properties and chemical structure of each compound. Considering the presence of PAHs in fossil diesel, the potential of fatty esters was assessed when mixed with fossil diesel, commercial available as biodiesel, which showed increase in the solubility of PAHs in the aqueous phase. In the absence of fatty esters, when only fossil diesel was present, the maximum concentrations of naphthalene and phenanthrene were 136.3 ± 3.9 and 1.28 ± 0.07 μg/L, respectively, while the maximum values in the presence of a blend of fossil diesel and biodiesel were 437.6 ± 16.7 and 26.8 ± 4.5 μg/L for naphthalene and phenanthrene, respectively. Therefore, it was reasonable to affirm that fatty esters interfered in the solubilities of PAHs, which might be associated with the formation of aggregates.

This paper presents the results of determining the pseudo-total concentration of five heavy metals in the soil on which the destruction of ammunition, mines, and explosive devices is carried out by the method of open detonation. In the analyzed area, the concentrations of cadmium, lead, nickel, copper, and zinc were determined, while from the physical properties of the soil were determined the granulometric composition and the pH. The aim of the study is to determine the origin and total load on heavy metals and, based on that, to assess the dangers and impact of the site in terms of the soil pollution by heavy metals. In accordance with the regulations of Bosnia and Herzegovina, the results of the soil testing showed a significant load of copper (up to seven times) and cadmium (up to six times), and exceeding the allowed values for nickel and zinc in some places. Lead was the only metal whose concentration was within the maximum allowed and according to that the soil was classified as unpolluted. A sample of soil from the edge of the pit is the only sample in which all heavy metals, except Ni, were within the maximum allowable concentration. In regard to the concentration of the examined metals, the soil of the pit is classified as medium polluted from the aspect of copper, cadmium, and nickel and highly contaminated with zinc. The concentrations of copper and zinc in the examination area correspond to contaminated soil that represents ecological risk, which requires soil remediation.

The co-occurrence of increasing air temperature and heavy metal contamination of soils has important effects on plants. This study investigated needles resistance in Pinus sylvestris L. var. mongholica Litv. seedlings exposed to elevated air temperature and cadmium (Cd) for 3 years and assessed Cd accumulation. Elevated air temperature (1.96 °C) stimulated Cd accumulation in plants, and Cd uptake by roots was significantly (p < 0.05) greater than uptake by needles under elevated temperature. Elevated air temperature significantly (p < 0.05) decreased malondialdehyde content in needles exposed to Cd. Peroxidase and catalase activity in needles increased under elevated temperature + 1.0 mg Cd kg⁻¹ dry weight soil and decreased under elevated temperature + 5.0 mg Cd kg⁻¹ dry weight soil relative to Cd alone. Elevated temperature significantly (p < 0.05) increased chlorophyll, carotenoids, carbon, nitrogen, hydrogen, sulfur, proline, soluble sugars, flavonoids, saponins, and phenolic compounds in needles under Cd stress. Secondary metabolites, proline, soluble sugars, sulfur, glutathione, phytochelatins, and cysteine contents increased with increasing Cd levels irrespective of temperature. Overall, 3 years of exposure to elevated air temperature can enhance needles stress resistance in seedlings exposed to Cd pollution by stimulating antioxidant enzymes, osmotic adjustment, and production of secondary metabolites and thiol-containing chelators and Cd accumulation in seedlings.

Metals in overbank deposits may originate from natural or anthropogenic sources. The objective of this work is to study the anthropogenic influence over these deposits through the study of Pb contents together with Pb isotopic ratios in a group of selected overbank profiles sampled in several basins across Spain. The 16 selected overbank profiles show specific characteristics, due to land use (anthropogenic activity developed in the area where a profile is located), as well as the lithologies that supply material to the sediments. These profiles are expected to present some kind of anthropogenic influence as a consequence of mining, industrial, urban, or agricultural activities, while two profiles were sampled in areas where population is scarce and no significant impact is likely. The elements Pb, U, and Th were analyzed as well as the isotopic ratios of ²⁰⁶Pb, ²⁰⁷Pb, and ²⁰⁸Pb. Lead ratios and Pb contents were used in this work as a tool to trace Pb origin (natural or anthropogenic) in the studied profiles. This study offers an overview of the ranges that can be reached by Pb contents and by Pb isotopic ratios (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb) under several contrasting conditions. Lead contents vary from 12.7 to > 5000 mg/kg and ²⁰⁶Pb/²⁰⁷Pb ratio from 1.162 to 1.407. It was proven that the anthropogenic activity is reflected in some of the overbank profiles, showing a variation in Pb contents that agrees with shifts in the isotopic ratios. These changes are more relevant in urban areas, while in mining areas, changes are weaker. It was also proven that the Pb contents and Pb ratios are heavily dominated by the geology too.

The Wudalianchi scenic area in NE China has been named an UNESCO “Global Geopark” and “Biosphere Reserve.” During this investigation, the sources of nitrate and the hydrologic system through which it is dispersed were assessed using geochemical data and a multiple isotopic approach. The cold waters from the south and north springs originated from the deep subsurface. Isotopically, these waters exhibited relatively negative δD and δ¹⁸O values and nitrate in the water was substantially depleted ¹⁵N, suggesting that the mineral water was primarily derived from depth. Lakes within the Wudalianchi region were primarily composed of water from these deep mineral springs and precipitation. Chemical fertilizers were the primary source of nitrate to the Wudalianchi lakes. Groundwater was found in shallow mineral springs and wells plotted above the local meteoric water line, implying that shallow groundwater was primarily derived from precipitation. Elevated concentrations of nitrate in shallow mineral springs and well waters during the summer, autumn, and winter suggest that shallow groundwater within the Yaoquan volcanic area was also polluted by nitrate from human activities. Denitrification of shallow groundwater is slow, reducing the potential for “self-remediation”. The concentration data are supported by nitrogen (N) isotope data; wells and springs exhibited N isotopic ratios between − 5‰ and + 5‰ (typical of fertilizers and precipitation) and exhibited higher oxygen (O) isotope values than water in the Wudalianchi lakes. These relationships suggest that nitrate in shallow mineral springs, wells, and lakes near the Yaoquan volcano was derived from the mixing of chemical fertilizers with local summer rainfall.

Little was known about the arsenic metabolism and arsenic methylation associated with the changes of skin lesions after reducing the arsenic in drinking water (WAs). Therefore, urinary concentrations and proportions of arsenic species were determined for recovery (RC), improvement (IC), persistent (PE), aggravation (AC), new incidence (NC), and no sign (HC) groups based on the changes of skin lesions between before (in 2004) and after (in 2017) WAs reduction. The results indicate that the urinary concentrations of inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and total arsenic (TAs) were much higher for RC and IC groups than for the other groups in 2004, while these values varied slightly among the groups in 2017. The urinary %iAs of all the groups was significantly decreased after WAs reduction. In contrast, the urinary %DMA of RC, IC, AC, and NC groups was increased. From 2004 to 2017, the PE and HC groups had lower decrease rate of %iAs and %MMA, and increase rate of %DMA, primary methylation index (PMI), and secondary methylation index (SMI) after WAs reduction. The adjusted odd ratios (ORs) showed that the RC, IC, AC, and NC groups were positively related with %iAs and %MMA and were negatively correlated with %DMA, PMI, and SMI before WAs reduction. It can be concluded that higher urinary %iAs and %MMA before WAs reduction increased the probability of skin lesions recovery and improvement, and the risks of skin lesions aggravation and incidence. Higher increase rate of urinary %DMA was positively associated with of skin lesions recovery and improvement. Moreover, higher urinary %iAs and %MMA or lower increase rate of urinary %DMA might increase the risk of skin lesions aggravation.