Emerging organic contaminants in wastewater are usually analyzed by targeted approaches, and especially estrogens have been the focus of environmental research due to their high hormonal activity. The selection of specific target compounds means, however, that most of the sample components, including transformation products and potential new contaminants, are neglected. In this study, the fate of steroidal compounds in wastewater treatment processes was evaluated by a nontargeted approach based on comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry. The potential of the nontargeted approach to generate comprehensive information about sample constituents was demonstrated with use of statistical tools. Transformation pathways of the tentatively identified compounds with steroidal four-ring structure were proposed. The purification efficiency of the wastewater treatment plants was studied, and the distribution of the compounds of interest in the suspended solids, effluent water, and sludge was measured. The results showed that, owing to strong adsorption of hydrophobic compounds onto the solid matter, the steroids were mostly bound to the suspended solids of the effluent water and the sewage sludge at the end of the treatment process. The most abundant steroid class was androstanes in the aqueous phase and cholestanes in the solid phase. 17β-estradiol was the most abundant estrogen in the aqueous phase, but it was only detected in the influent samples indicating efficient removal during the treatment process. In the sludge samples, however, high concentrations of an oxidation product of 17β-estradiol, estrone, were measured.

Volatile organic compounds (VOCs) decomposition by non-thermal plasma (NTP) has been receiving increasing attention from the scientific communities due to its advantages of easy operation, high efficiency, energy saving, and non-secondary pollution. But most of the researches are doing experiments and existing experiment methods cannot observe the micro physical and chemical processes. In order to make up for the deficiency of the experiment, herein, a numerical method was developed to analyze the decomposition behavior of HCN, C₃H₃N, C₃H₈, C₃H₆, CO, and NO in the VOCs treatment by NTP. Results indicated that increasing electron density or energy was beneficial to VOCs decomposition, but when the electron density and energy was too high, the promotion would be weakened. The influences of initial concentration of O₂ and H₂O on different VOCs decomposition were totally different. The increase of initial concentration of oxygen was beneficial to the decomposition of HCN, C₃H₈, CO, and NO, but the high concentration of oxygen could promote to generate C₃H₆ at the initial reaction stage. The decomposition of HCN and C₃H₃N are not restricted by dry or wet conditions, but the increase of the concentration of water vapor is advantageous to the decomposition of C₃H₈, CO, and NO. Graphical Abstract ᅟ

In early April 2011, radiostrontium was accidentally released from the Fukushima Daiichi Nuclear Power Plant to the Pacific coast of eastern Japan. We developed a simple procedure to analyze radiostrontium levels in marine mussels (Septifer virgatus) and seawater using crown ether (Sr Resin; Eichrom). Then, we used our method to describe the spatial and temporal distribution of radiostrontium in mussels and seawater on the Pacific coast of eastern Japan from 2011 to 2013 and for 2015. Activity of ⁹⁰Sr in mussels and seawater decreased with distance from the Fukushima Daiichi Nuclear Power Plant and between 2011 and 2013 tended to be higher in areas south of the Fukushima Daiichi Nuclear Power Plant than to the north of it. Activity in mussels and seawater also tended to decrease from 2011 to 2013 and by 2015 had reached levels experienced prior to the Fukushima accident. Our results suggest that radiostrontium discharged from the Fukushima Daiichi Nuclear Power Plant was dispersed by coastal currents in a southerly direction along the Pacific coast of eastern Japan from 2011 to 2013, following which its activity decreased to background levels by 2015.

AhHMA4 from Arabidopsis thaliana encodes Zn/Cd export protein that controls Zn/Cd translocation to shoots. The focus of this manuscript is the evaluation of AhHMA4 expression in tomato for mineral biofortification (more Zn and less Cd in shoots and fruits). Hydroponic and soil-based experiments were performed. Transgenic and wild-type plants were grown on two dilution levels of Knop’s medium (1/10, 1/2) with or without Cd, to determine if mineral composition affects the pattern of root/shoot partitioning of both metals due to AhHMA4 expression. Facilitation of Zn translocation to shoots of 19-day-old transgenic tomato was noted only when plants were grown in the more diluted medium. Moreover, the expression pattern of Zn-Cd-Fe cross-homeostasis genes (LeIRT1, LeChln, LeNRAMP1) was changed in transgenics in a medium composition-dependent fashion. In plants grown in soil (with/without Cd) up to maturity, expression of AhHMA4 resulted in more efficient translocation of Zn to shoots and restriction of Cd. These results indicate the usefulness of AhHMA4 expression to improve the growth of tomato on low-Zn soil, also contaminated with Cd.

Adsorption of six neutral (chlorpyrifos, α-endosulfan, fenthion, parathion, parathion metyl, and cis permethrin) and six basic (pirimicarb, prochloraz, prometryn, pirimiphos ethyl, quinoxyfen, and triadimefon) pesticides was measured in ten natural soils in order to unravel the parameters influencing soil sorption. Linear regression confirmed that organic carbon content of soil is the determinant factor of soil sorption along with a secondary role of clay in the case of basic pesticides. Concerning pesticides themselves, their potential to be absorbed is governed by hydrophobic, electrostatic, and polar interactions. Electrostatic interactions can be expressed by considering the molecular fraction of positively charged species (F⁺). The combination of these parameters led to good prediction models, where the two expressions of lipophilicity, octanol-water partition (logP) and distribution coefficient (logD), showed similar performance. Finally, the role of electrostatic interactions to soil sorption and their successful expression by F⁺ parameter was further confirmed using artificial adjustment of the acidity of one soil at different pH values not covered by the natural acidity of the investigated soils.

Zeolitic imidazole frameworks (ZIFs), a new adsorbent with a high chemical and thermal stability and a high adsorption capacity, are used for adsorptive removal of azo dyes. The synthesized ZIF-67 was characterized with Fourier transform infrared spectroscopy (FTIR), thermogravimetric–differential thermal analysis (TG–DTA) and zeta potential instrument. The adsorption of some azo dyes on ZIF-67 in the single dye systems showed that the removal efficiencies are congo red > methyl orange > methyl red > methyl blue. The highest adsorption capacity of congo red and methyl orange were 3900 and 1340 mg/g, respectively. In a binary dye system the adsorption capacity of congo red decreased, while the removal efficiency of methyl orange increased in comparison with the single systems, indicating that a competitive adsorption of congo red and methyl orange over the ZIF-67 occurred. The experimental data indicate that the electrostatic attraction between ZIF-67 and congo red is the major driving force and the π–π stacking is also responsible for dye adsorption. After 5 cycles of ZIF-67 adsorption and desorption, the congo red removal efficiency maintained more than 95%. Graphical Abstract The adsorption of Congo red and Methyl orange on the ZIF-67

Acid rain caused a severe loss on agricultural productivity, aggravating the challenge for achieving sustainable food production to feed the increasing globe population. To clarify the mechanism on adaptation of rice root to acid rain, we studied the root morphology and growth regulated by nutrient absorption under hydroponic conditions. Our results show that acid rain (pH 5.0 or 3.5) increased the density of root hair and root volume by increasing concentrations of K⁺, Na⁺, and Ca²⁺ in rice roots, and the root dry weight was increased. However, strong acid rain (pH 2.5) decreased the root length, surface area, volume, and number of root tips by decreasing the concentrations of K⁺, Na⁺, and Mg²⁺ in rice root, and fresh and dry weight were both decreased. After a 5-day recovery, the root morphology of rice seedlings treated with acid rain (pH 5.0 or 3.5) was recovered to the control levels, and the concentrations of K⁺, Na⁺, Ca²⁺, and Mg²⁺ also had no difference from the control (p < 0.05). However, the root growth treated with strong acid rain (pH 2.5) was still lower than the control because the inhibition on root activity and hydrolytic activity of plasma membrane H⁺-ATPase might have exceeded the self-regulating capacity of rice seedlings, and the absorption of mineral nutrient could not sustain the growth. Hence, we concluded that the adaption of root morphology of rice seedlings to acid rain was related to regulation of mineral nutrient absorption in rice root.

Advanced oxidation of bisphenol A (BPA) in aqueous system by O₃/Na₂S₂O₈ was investigated, the degradation of BPA was affected by ozone concentration, persulfate dosages, initial pH, and BPA concentration. Experimental results indicated that the degradation of BPA was proved to follow the pseudo-first order kinetics model and was enhanced with the increase of O₃ concentration and the decrease of initial BPA concentration. pH played a significant role in the BPA removal especially under the alkaline condition. Free radical species in the O₃/Na₂S₂O₈ system were identified by using tertiary butyl alcohol (TBA) and ethanol (ETOH) as two probes, the results found that the major free radical was SO₄ ⁻ · at acidic condition (pH = 3), and the concentration of ·OH increased with the pH increased. Eight products were detected during the reaction according to liquid chromatograph-mass spectrometry analysis. Most of the intermediates contained quinonoid derivatives, carboxylic acid, and the relevant mechanism for BPA degradation by O₃/Na₂S₂O₈ system were proposed.

The morphological, physiological, and biochemical parameters of 6-week-old seedlings of Scots pine (Pinus sylvestris L.) were studied under deficiency (1.2 nM) and chronic exposure to copper (0.32, 1, 2.5, 5, and 10 μM CuSO₄) in hydroculture. The deposit of copper in the seed allowed the seedlings to develop under copper deficiency without visible disruption of growth. The high sensitivity of Scots pine to the toxic effects of copper was shown, which manifested as a significant inhibition of growth and development. The loss of dominance of the main root and a strong inhibition of lateral root development pointed to a lack of adaptive reorganization of the root system architecture under copper excess. A preferential accumulation of copper in the root and a minor translocation in aerial organs confirmed that Scots pine belongs to a group of plants that exclude copper. Selective impairment in the absorption of manganese was discovered, under both deficiency and excess of copper in the nutrient solution, which was independent of the degree of development of the root system. Following 10 μM CuSO₄ exposure, the absorption of manganese and iron from the nutrient solution was completely suppressed, and the development of seedlings was secured by the stock of these micronutrients in the seed. The absence of signs of oxidative stress in the seedling organs was shown under deficiency and excess of copper, as evidenced by the steady content of malondialdehyde and 4-hydroxyalkenals. Against this background, no changes in total superoxide dismutase activity in the organs of seedlings were revealed, and the increased content of low-molecular-weight antioxidants was observed in the roots under 1 μM and in the needles under 5 μM CuSO₄ exposures.

The automobile exhausts are one of the major sources of particulate matter in urban areas and these particles are known to influence the atmospheric chemistry in a variety of ways. Because of this, the oxidation of dissolved sulfur dioxide by oxygen was studied in aqueous suspensions of particulates, obtained by scraping the particles deposited inside a diesel truck exhaust pipe (DEP). A variation in pH showed the rate to increase with increase in pH from 5.22 to about ∼6.3 and to decrease thereafter becoming very slow at pH = 8.2. In acetate-buffered medium, the reaction rate was higher than the rate in unbuffered medium at the same pH. Further, the rate was found to be higher in suspension than in the leachate under otherwise identical conditions. And, the reaction rate in the blank reaction was the slowest. This appears to be due to catalysis by leached metal ions in leachate and due to catalysis by leached metal ions and particulate surface both in suspensions. The kinetics of dissolved SO₂ oxidation in acetate-buffered medium as well as in unbuffered medium at pH = 5.22 were defined by rate law: k ₒbₛ = k ₀ + k cₐₜ [DEP], where k ₒbₛ and k ₀ are observed rate constants in the presence and the absence of DEP and k cₐₜ is the rate constant for DEP-catalyzed pathway. At pH = 8.2, the reaction rate was strongly inhibited by DEP in buffered and unbuffered media. Results suggest that the DEP would have an inhibiting effect in those areas where rainwater pH is 7 or more. These results at high pH are of particular significance to the Indian subcontinent, because of high rainwater pH. Conversely, it indicates the DEP to retard the oxidation of dissolved SO₂ and control rainwater acidification.