Adsorption and photocatalysis are promising strategies to remove pollutants of dyes and antibiotics from wastewater. In this study, we demonstrate a rapid microwave-assisted hydrothermal route for the assembly of 2D copper-porphyrin Metal-Organic Frameworks (Cu-TCPP MOFs) within 1 h. The resulting 2D Cu-TCPP nanosheets with excellent crystallinity and a large surface area (342.72 m²/g) exhibited outstanding adsorption performance for typical dyes with adsorption capacities of about 185 mg/g for rhodamine B, 625 mg/g for methylene blue, and 290 mg/g for Congo red, respectively, as well as for representative antibiotics with adsorption capacities of about 130 mg/g for oxytocin, 150 mg/g for tetracycline, and 50 mg/g for norfloxacin, respectively. Meanwhile, the as-prepared 2D Cu-TCPP showed good photocatalytic degradation activity of pollutants after adsorption under irradiation by visible light, reaching removal efficiencies of 81.2 and 86.3% toward rhodamine B and norfloxacin, respectively. These results demonstrate the promising potential of 2D Cu-TCPP for use in the removal of contaminants from wastewater.

Park playgrounds recently are suffering serious heavy metals contamination in China. It is urgent to assess the ecological risk and identify the sources for heavy metals. A total of 111 topsoil samples were collected from four park playgrounds in Xi’an, and the X-ray fluorescence (XRF) instrument was used to measure the concentrations of heavy metals including chromium(Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), manganese (Mn), and cobalt (Co), respectively. Ecological risk ([Formula: see text]) and potential ecological risk index (RI) were introduced to determine the pollution level and ecological risk, and the absolute principal component score-multiple linear regression (APCS-MLR) model was implemented to identify the sources for heavy metals. The main results were as follows. (1) Except As, the mean concentrations of measured heavy metals of four park playgrounds surpassed the soil background values of Shaanxi Province. (2) In each park playground, the [Formula: see text] was below a “low” risk level ([Formula: see text]=10) for Cr, Ni, Zn, As, and Mn; Cu was between a “moderate” and “considerable” risk level; Pb was between a “low” and “moderate” risk level; and [Formula: see text] was between a “considerable” and “high” risk level for Co. Besides, the RI index was on a “high” risk level (120 < RI < 240) with an obvious spatial distinction. (3) The anthropogenic factors were the main sources for heavy metals, and mixed sources and natural sources were considered as the minor sources for metals. (4) The sources contributions for Co had obvious spatial heterogeneity in each park situated in four different urban planning districts.

The advanced oxidation process based on sulfate radicals (SO₄.⁻) is one of the most promising wastewater treatment technologies. In this study, we utilized potassium hydrogen phthalate (KHP) as an organic pollutant to configure simulated wastewater that was then treated by activation of sodium persulfate (PS) by zero-valent iron (ZVI) to produce SO₄.⁻. Our results showed that the ZVI-PS system had a greater degradation rate in acidic, neutral, and weakly alkaline solutions compared with the Fenton method. After 180 min of reaction time under the experimental conditions (pH = 3.0, temperature = 20 °C, ZVI = 3.57 mM, and PS = 2.52 mM), chemical oxygen demand (COD) was 53.72%, indicating that these reaction conditions were optimal for COD degradation. This reaction was described by the kinetic rate Eqs. Y = K₁X + b (0–10 min) and Y = C + B X + K₂X² (30–180 min) within the above experimental conditions. The results of this study showed that the ZVI-PS system may be an interesting alternative for the treatment of organic pollutants.

The study endeavored to analyze the risk perception, sense of place, and disaster preparedness in response to landslide disaster–prone mountain areas of Gilgit-Baltistan, Pakistan. To this end, we surveyed 315 rural residents of two vulnerable landslide districts (Hunza and Nagar) of Gilgit-Baltistan. To explore the relationships between the dimensions of risk perception, sense of place, and disaster preparedness, we used partial least squares (PLS) structural equation modeling (SEM) to test the hypotheses. The results derived from PLS-SEM have implied that there is a significant negative relationship between risk perception (apprehension and unidentified) with a sense of place (bond with society and place dependence). It was observed that the residents usually overestimate the risks of disasters due to their limited scientific knowledge regarding disaster occurrence, which reduces their dependencies on the place. We revealed that disaster preparedness enhances the place attachment and reduces the apprehension of landslides in the study area. This study devotes to government and relevant agencies to devise policies that can help relocate the vulnerable rural settlements, develop, and educate the masses on disaster mitigation and prevention strategies, and help prepare a suitable landslide management plan.

With rapid urbanization, municipal food waste (MFW), which is an important part of municipal solid waste, has attracted considerable attention owing to its environmental impact and polluting nature. There has been little research on the quantity and distribution of food waste (FW) produced in China. This study focused on a systematic estimation and analysis of MFW produced in administrative divisions at the prefecture-level and above in China for the first time. From the national level to the prefectural level, with the shrinking of the research units, more intuitive support was obtained for relevant decisions. On the basis of the estimated results, suggestions are provided for proper FW treatment technologies and operational scale of the facilities, and the resource utilization potential has also been estimated. The distribution results indicated that FW characteristics have great variability in the different economic regions of China. Furthermore, it was found that the available FW has a resource utilization potential that is equivalent to 4669.1 million m³ of biogas, 3.6 million tons of biodiesel, and 1.5 million tons of organic fertilizer (dry weight). It is worth mentioning that this amount of biogas can replace 7.5 million tons of standard coal. However, only a small part of the generated MFW can be treated in the existing treatment plants in China. Finally, current key bottlenecks of FW treatment in China have been discussed, and detailed suggestions are presented for further improvement of MFW management.

Zinc (Zn) is an essential trace element for most organisms, including human beings. It plays a crucial role in several physiological processes such as catalytic reaction of enzymes, cellular growth, differentiation and metabolism, intracellular signaling, and modulation of nucleic acid structure. Zn containing above 50 metalloenzymes is responsible for proteins, receptors, and hormones synthesis and has a critical role in neurodevelopment. Zn also regulates excitatory and inhibitory neurotransmitters such as glutamate and GABA and is found in high concentration in the synaptic terminals of hippocampal mossy fibers that maintains cognitive function. It regulates LTP and LTD by regulation of AMPA and NMDA receptors. But an excess or deficiency of Zn becomes neurotoxic or cause impairment in growth or sexual maturation. There is mounting evidence that supports this idea of Zn becoming neurotoxic and being involved in the pathogenesis of AD. Zn dyshomeostasis in AD is an area that needs attention as moderate concentration of Zn is involved in the memory regulation via regulation of amyloid plaque. Dyshomeostasis of Zn is involved in the pathogenesis of diseases like AD, ALS, depression, PD, and schizophrenia.

Hollow B-SiO₂@CaTiO₃ nanocomposites were hydrothermally synthesized at a mild reaction temperature of 120 °C using calcium chloride and titanium (IV) isopropoxide as the starting materials and hollow B-SiO₂ microspheres as the supports. CaTiO₃ nanoparticles are anchored at the surfaces of hollow B-SiO₂ microspheres through the formation of Ti–O–B and Ti–O–Si bonds. The interaction between the CaTiO₃ nanoparticles and hollow B-SiO₂ microspheres enlarged the band gap of CaTiO₃ nanoparticles, giving a higher photocatalytic activity in ammonia nitrogen degradation at a lower catalyst loading and a wider range of ammonia nitrogen concentration. When the hollow B-SiO₂@CaTiO₃ (5wₜ%CaTiO₃) photocatalyst was hydrothermally synthesized at 120 °C for 12 h, and the photocatalytic degradation reaction of ammonia nitrogen (50 mg L⁻¹) in an aqueous solution was carried out under the simulated solar light irradiation at 25 °C for 4 h; the degradation extent of ammonium nitrogen reached 91%.

Lyngbya wollei is a filamentous cyanobacterium that causes numerous adverse impacts in reservoirs and lakes, such as toxin production, harboring fecal bacteria, devaluing property, impeding navigation/recreation, and degrading wildlife habitat. This study assessed a chemical treatment program in a Southeastern USA reservoir using a chelated copper formulation (Captain® XTR) in combination with diquat dibromide (Tribune®) over 2 years. The treatment program consisted of multiple applications during the summer and fall months. Overall, biomass decreased significantly (α = 0.05) in the two treated coves, by 97 and 80%, whereas L. wollei increased significantly (α = 0.05) in the untreated reference cove, by 25,127%. During the study, the quantity of algaecide applied was decreased in one of the treatment coves to adjust for the reduction in L. wollei biomass, as well as reduction in treated area, as part of an adaptive management strategy. The measured exposure demonstrated the residence time of the copper algaecide was short, with most of the copper dissipating in hours, which was attributed to sorption to L. wollei, sediments, and dilution. The biomass monitoring procedure, used transects spaced in 150 m intervals and sampled algae at 0–2 m, 5–7 m, and 10–14 m distances from shore, was effective at discerning changes in L. wollei biomass in the treated and untreated coves. This study indicated that the treatment program was effective for reducing L. wollei biomass and demonstrated the utility of the surveying technique to implement adaptive management of this filamentous cyanobacterium.

The extreme persistence, bioaccumulative, and toxicity tendencies of per- and polyfluoroalkyl substances (PFAS) have contributed to the ever-increasing quest for effective and low-cost technologies for removing PFAS from aqueous solutions. Therefore, in the present study, maize tassel (MT) was activated using phosphoric acid. The chemically activated maize tassel (CAMT) was thereafter applied as an adsorbent for removing perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) from aqueous media in comparison with the inactivated MT. The adsorption behaviors of PFOS and PFOA onto MT and CAMT were investigated via adsorption experiments. It was found that the isothermal data fit better with the Freundlich isotherm model than with the Langmuir isotherm model. Maximum adsorption capacities of 1552.5 mg g⁻¹ (3.10 mmol g⁻¹) and 380.32 mg g⁻¹ (0.92 mmol g⁻¹) were recorded for PFOS and PFOA, respectively, using CAMT, when the Freundlich model was applied. Equilibrium was attained within 60 min using both MT and CAMT. The pseudo-second-order kinetics model suited the kinetics data better. It was observed from the thermodynamic studies that the adsorption mechanism of PFOS and PFOA on MT and CAMT is spontaneous and feasible. All the values for the Gibb’s free energy change (ΔG⁰, kJ mol⁻¹) obtained in the present study were below − 20 kJ mol⁻¹. The adsorption of PFOS and PFOA using CAMT is exothermic in nature (enthalpy, ΔH⁰ was negative) whereas the adsorption of PFOS and PFOA using MT is endothermic. The PFOS and PFOA adsorption processes using both MT and CAMT were greatly influenced by electrostatic and hydrophobic interactions. Graphical abstract

Shiga toxin-producing Escherichia coli (STEC) is one of the most commonly heard sources of foodborne outbreaks but presently lacks studies of in the Kathmandu Valley. This study explored the presence of STEC in river water (n = 17), groundwater (n = 83), feces (n = 50), and manure (n = 20) in the Kathmandu Valley, Nepal. Samples that were confirmed to be E. coli–positive using the Colilert assay in previous studies were selected to examine the presence of the sfmD, stx1, and stx2 genes using quantitative polymerase chain reaction. Based on Colilert/sfmD gene ratios, the percentage of viable cells of E. coli in the fecal (2.0% ± 2.5%), manure (0.1% ± 0.1%), river water (3.4% ± 3.1%), and groundwater samples (3.9% ± 5.8%) were determined. The presence of the stx1 gene was observed in the fecal (6%), river water (53%), and groundwater (2%) samples, whereas the stx2 gene was detected in the fecal (8%), manure (5%), and river water (71%) samples. Interestingly, the stx/sfmD gene ratios in the groundwater samples were greater than 100%, suggesting the presence of other stx1/stx2-harboring microorganisms. These findings indicated the importance of continuing investigation into waterborne sources of STEC contamination within the Kathmandu Valley.