Surplus phosphorus (P) above agronomic requirements can negatively affect the water status of connected surface and subsurface water bodies. The in situ stabilization of soil P through soil amendment has been recognized as an efficient way to reduce this environmental pressure. However, the mechanism of how P is stabilized during this process and how plant available P is affected are unknown. This can be achieved by sequential chemical extraction and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy investigations. Therefore, in the present study, P-enriched calcareous and red soils were amended with alum, dolomite, and a 1:1 mixture of alum and dolomite (MAD) at a 20 g/kg soil rate, and soil properties and P fractions were measured after a 45-day period. Results showed that alum amendment significantly decreased CaCl₂-P and Olsen-P contents in calcareous and red soils when compared with dolomite. However, dolomite incorporation maintained relatively high P availability and even increased CaCl₂-P and Olsen-P contents by 1.32% and 40.5% in red soil, respectively, compared to control. Amendment with MAD was not as effectively as the alum in P stabilization. Sequential inorganic P extraction indicated that alum dominantly contributed labile P transformed to Al-P in both soils. P K-edge XANES spectroscopy measurements further explained that alum adsorbed phosphate in calcareous soil and precipitated phosphate as AlPO₄ in red soil. Results of P fractionation and Mehlich-3-extracted Ca showed that dolomite mainly adsorbed loosely bound P in calcareous soil and red soil. However, dolomite incorporation in red soil led to Al-P and Fe-P release. The P sorption isotherms showed that dolomite and alum increased soil P sorption maxima and decreased the degree of P saturation (DPS) in both soils, while dolomite declined the Langmuir bonding energy in red soil. Differences in P stabilization by alum and dolomite addition across soil types were closely related to their characteristics, and soil properties changed, especially soil pH.

Mires and peatlands in general are heavily influenced by anthropogenic stressors like acidification, eutrophication, desiccation and fragmentation. Groundwater-fed mires are, in contrast to rainwater-fed mires, often well protected against desiccation due to constant groundwater discharge. Groundwater-fed mires can however be influenced by groundwater pollution such as groundwater nitrate enrichment, a threat which has received minor attention in literature. The present case study demonstrates how groundwater nitrate enrichment can affect the biogeochemical functioning and vegetation composition of groundwater-fed mires through direct nitrogen enrichment and indirect nitrate-induced sulphate mobilisation from geological deposits. Biogeochemical and ecohydrological analyses suggest that the Dutch groundwater-fed mire studied is influenced by different water sources (rainwater; groundwater of local and regional origin) with differing chemical compositions. The weakly buffered and nitrate-enriched groundwater leads, where it reaches the uppermost peat, to nitrogen enrichment, enhanced isotopic nitrogen signatures and altered the vegetation composition at the expense of characteristic species. Nitrate-induced sulphate mobilisation in the aquifer led to enhanced sulphate reduction, sulphide toxicity and elemental sulphur deposition in the mire. Despite sulphate reduction and nitrate enrichment, internal eutrophication did not play an important role, due to relatively low phosphorus concentrations and/or low iron-bound phosphorus of the peat soil. Future management of groundwater-fed mires in nitrate-polluted aquifers should include the reduction of nitrate leaching to the aquifer at the recharge areas by management and ecohydrological restoration measures on both a local and landscape scale.

In this study, we investigated the effect of acute administration of gold nanorods (AuNRs) on testicular function, sexual hormones, and oxidative stress parameters in male albino rats. Forty mature male albino rats were divided into two equal groups (n = 20/each). The first group received 1 ml saline solution intraperitoneally (i.p.). The second group received single i.p. injection of 75 μg 50 nm AuNRs/kg/bwt. Five rats from each group were sacrificed on days 1, 3, 7, and 14 post treatment and blood samples were collected for hormonal and biochemical analysis. Testes were collected from each group at each time point for histopathology, morphometric, and transmission electron microscope analyses of testis and epididymis. Results indicated that i.p. injection of AuNRs did not produce any histopathological changes. Morphometric analysis of testicular samples revealed that the height of lining epithelium was significantly (P < 0.05) higher in AuNR group on days 3 and 14 post treatment, and the minor axis of seminiferous tubules was higher (P < 0.05) in AuNR-injected rats than in control group. For the epididymis, the number of spermatozoa was significantly (P < 0.05) higher on days 7 and 14 after AuNR injection when compared with control rats. AuNRs were not detected by TEM at all time points of the experiment. Serum analysis demonstrated that total and free testosterone values significantly (P < 0.05) increased on days 1, 3, 7, and 14 post AuNR injection. LH was higher (P < 0.05) in AuNRs-injected rats on days 3, 7, and 14 post injection, while FSH values were higher (P < 0.05) in AuNR group on days 3 and 14. Malondialdehyde significantly (P < 0.05) decreased on days 3, 7, and 14 in AuNR group, while catalase, glutathione peroxidase, and superoxide dismutase values were significantly (P < 0.05) elevated on days 3, 7, and 14 in AuNRs-injected rats compared with control group. In conclusion, intraperitoneal injection of 50 nm AuNRs is safe on the reproductive function and has an antioxidant action.

Iron-incorporated silica (Fe/SiO₂) with different Fe/Si molar ratio was successfully prepared from rice husk pyrolytic residues (RHR) through alkali pretreatment, co-precipitation, and calcination. Various characterization methods indicated that the Fe/SiO₂ samples possessed mesoporous structure with Fe species incorporated into the framework of silica. The obtained materials were applied in the treatment of hazardous banknote printing wastewater, and under the optimal conditions, colored pollutants, humic acid-like and soluble microbial by-product-like organics were removed significantly. It was found that Fe/SiO₂ acted as both flocculant and catalyst, and the framework iron species catalyzed the oxidative degradation of refractory organics in the presence of H₂O₂. A heterogeneous Fenton-like system was formed in the wastewater treatment process.

Extended stochastic impact by regression on population, affluence, and technology model incorporating ridge regression was used to analyze the driving mechanism of energy-related CO₂ emissions in Kazakhstan during 1992–2014. The research period was divided into two stages based on GDP of Kazakhstan in 1991 (85.70 × 10⁹ dollars), the first stage (1992–2002), GDP < 85.70 × 10⁹ dollars, the stage of economic recovery; the second stage (2003–2014), GDP > 85.70 × 10⁹ dollars, the stable economic development stage. The results demonstrated that (1) population scale and the technological improvement were the dominant contributors to promote the growth of the CO₂ emissions during 1992–2014 in Kazakhstan. (2) Economic growth and industrialization played more positive effect on the increase of the CO₂ emissions in the stable economic development stage (2003–2014) than those in the stage of economic recovery (1992–2002). The proportion of the tertiary industry, the trade openness, and foreign direct investment were transformed from negative factors into positive factors in the stable economic development stage (2003–2014). (3) Due to the over-urbanization of Kazakhstan before the independence, the level of urbanization continued to decline, urbanization was the first factor to curb CO₂ emissions during 1992–2014. Finally, some policy recommendations are put forward to reduce energy-related carbon emissions.

Management procedures (MPs) based on data-limited methods (DLMs) recently developed to give management advices for data-limited stocks worldwide are scarce or yet to be implemented on freshwater species. In this study, case studies (CSs) were developed using length-frequency data (LFD) of common carp species harvested from Dianshan Lake to estimate life-history parameters from existing methods. These CSs were later used to examine their influences when tested with various MPs under scenarios when operating models (OMs) were subjected to observation and estimation uncertainties. The results after management strategy evaluation (MSE) was run for various defined OMs showed that three MPs emerged best for providing managing advice. For high yield to be maintained during short-term periods, MinlenLopt1 suggested the smallest length at full retention (sLFR) to be 42.11 cm; while Slotlim and matlenlim2 suggested that to maintain biomass and stable spawning biomass (SBMSY) and also avoid overfishing from occurring in this fishery, sLFR should be 56.1 cm. Values given by these MPs allowed the removal of species that spawned at least once. Also, life-history parameters derived from CS4 presented the best results, being more reliable in presenting better inputs for effective management of the said fishery.

Constructed wetlands (CWs) have been applied to remediate heavy metal pollution effectively in practice. However, the heavy metal release from CWs has not been paid enough attention. In this study, a 5-month experiment was carried out with three parallel lab-scale vertical flow constructed wetlands (VFCWs) with zeolites as fillers. The artificial rainwater was pumped into VFCWs to study the release characteristic and mechanisms of heavy metals (Cu, Zn, Cr, and Pb). The results showed that significant amounts of Zn and Cu were released from the VFCWs at the end of the experiment while Pb and Cr rarely escaped. The upper layer (0–30 cm) of the VFCWs was the most effective area for heavy metal removal due to the presence of sediments, but it was also the most active area for heavy metal release. To explain this result, the sediments were analyzed before and after being leached by the tap water. The results indicated that Zn and Cu existed mainly in the exchangeable state, and they had strong leachability and bioavailability, causing its releases. Also, competitive adsorption of different metals meant that the metal ions with strong adsorption to zeolite caused the metal ions with weak adsorption to be desorbed from zeolites, and thus, a large amount of Zn escaped from VFCWs. The escape of heavy metals from CWs illustrated that it should be paid more attention in the management.

A microwave (MW) heat-activated the persulfate (PS) process was employed to treat paracetamol (PAM) in wastewater, and the powder-activated carbon (PAC) be used is used as a catalyst to accelerate this reaction process. The PAM added (100 mg) to the solution was nearly completely removed within 70 min, and the PH, temperature, PAC, and PS dosage have great influence on the degradation process; the total organic carbon (TOC) removal rate reached 98%. The PAC¹ still had a good catalytic effect after being reused six times. The radical mechanism was investigated to determine the type of dominant active species involved in PAM degradation. Sulfate radicals ([Formula: see text]) were the dominant oxidizing agent for PAM degradation under acidic conditions. The degradation mechanism was proposed based on the PAM degradation intermediates, which were identified using ultra-high-performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry. Three types of possible reaction pathways for PAM were identified as follows: including hydroxylation of the benzene ring, amine group oxidation at the benzene ring, and amine (HN–C=O) functional group N–C bond cleavage.

A raw illite-smectite mixed-layered clay (RI/S) was ground for preparing nano-sized I/S clay (NI/S) and subsequently amino-functionalized via grafting of 3-aminopropyltrithoxysilane (APTES) (NH₂-RI/S and NH₂-NI/S, respectively). The samples were characterized by particle size analysis, specific surface area measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and ²⁹Si nuclear magnetic resonance (²⁹Si NMR). Compared to RI/S, NI/S has a narrow particle size distribution and appears in a platelet-like morphology due to the disintegration/exfoliation of RI/S after grinding. Based on the ²⁹Si NMR spectra, the appearances of tri-silicate units indicate the chemically grafting of APTES molecules on NH₂-RI/S and NH₂-NI/S, respectively. NH₂-NI/S can adsorb greater amounts of Pb(II) cations and Cr(VI) anions rather than NH₂-RI/S since NH₂-NI/S grafts more amounts of amine groups (-NH₂). The isotherm data for adsorption of Pb(II) cations and Cr(VI) anions can be described by the Langmuir model at different temperatures (i.e., 10 °C, 30 °C, and 50 °C), respectively. The maximum adsorption amounts of Pb(II) cations and Cr(VI) anions onto NH₂-NI/S calculated by the Langmuir isotherm model are 131.23 mg/g and 36.91 mg/g at 50 °C, respectively. The adsorptions of Pb(II) cations and Cr(VI) anions onto NH₂-NI/S involve in the surface complexation of NI/S and amine groups.

Finding chromium-accumulating plants is of great interest for phytoremediation of soil contaminated by chromium (Cr). Inspired by Traditional Chinese Medicine, we examined the Cr-resistance and Cr-accumulation of Lonicera japonica Thunb. After a two-phase study using both soil and water culture, we found that L. japonica could be a novel Cr-accumulating plant, which contains an average Cr(III) content of 1297.14 mg.kg⁻¹ in its leaves. The Cr enrichment factor and the Cr transport coefficient of Lonicera japonica was 5.19 and 1.79, respectively. Lonicera japonica is the fifth Cr-accumulating plant discovered worldwide, and the first Cr-accumulating woody plant ever discovered. The results support the conclusions drawn from studies of Cr-accumulating Leersia hexandra that oxalic acid production can increase Cr tolerance whereas citric acid or malic acid has no effect, suggesting that oxalic acid might be a common reason for Cr tolerance in all Cr-accumulating plants. Moreover, this study revealed that the production of anthocyanin and carotene can also increase Cr(III) tolerance, suggesting that anthocyanin and carotene might also account for Cr tolerance in Cr-accumulating plants. We believe that the discovery of Lonicera japonica as a Cr-accumulating plant will offer great opportunities in phytoremediation, and the success should be a strong sign that Traditional Chinese Medicine harbors more secrets to be uncovered with modern science.