In this study, Jordanian diatomaceous earth (JDA) and commercial diatomaceous earth (standard diatomaceous earth, SDA) were used for adsorption of samarium (Sm)(III) and neodymium (Nd)(III) ions from aqueous solutions using batch technique as a function of initial concentration of metal ions, adsorbent dosage, ionic strength, initial pH solution, contact time, and temperature. Both adsorbents were characterized by Fourier transform infrared (FTIR), X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller surface area, and cation exchange capacity (CEC). Maximum metal ion uptake was observed after 100 min of agitation, and the uptake has decreased with increasing temperature and reached a maximum at pH ≈ 5. Different types of adsorption isotherms and kinetic models were used to describe the Nd(III) and Sm(III) ion adsorption. The experimental data fitted within the following isotherms in the order Langmuir > Dubinin–Radushkevich (DR) > Freundlich and the pseudo-second-order kinetic model based on their coefficient of determination (R²), chi-square (χ²), and error function (Fₑᵣᵣₒᵣ%) values. Maximum adsorption uptakes, according to the Langmuir model, were obtained as 188.679 mg/g and 185.185 mg/g for Sm(III) and 169.492 mg/g and 149.254 mg/g for Nd(III) by JDA and SDA, respectively. The results of thermodynamic parameters showed that the adsorption of Sm(III) and Nd(III) ions onto JDA and SDA is a feasible, spontaneous, exothermic, and entropy driven. The best recovery for Sm(III) and Nd(III) was obtained when the 0.05 M EDTA + 0.05 M H₃PO₄ mixture was used as an eluent.

Unapproved and illegal buildings have sprawled into the Northern Piedmont of the Qinling Mountains. The problem of illegal villas has aroused widespread public opinion and concern. The ecological environment of the Qinling Mountains has been seriously affected by the resurgence of illegal villas. This paper introduces the characteristics and distribution of illegal villas, analyzes the hazards caused by illegal villas, and describes control measures for illegal villas and land consolidation and ecological remediation in the Northern Piedmont of the Qinling Mountains. The results show that illegal planning and illegal development, as well as local governments’ irregularities, including control, governance, punishment, demolition, and compensation for illegal buildings in the expropriation of premises, have caused the problem of illegal construction of villas in the Northern Piedmont of the Qinling Mountains. Control measures for illegal villas are demolition, land consolidation, and ecological remediation. Policy implications for protection of Qinling Mountains are provided.

Constructed wetland (CW), an ecological wastewater treatment technology, is low cost and easily to operate. Vertical flow constructed wetland (VF-CW) systems have been used to treat various wastewaters across the world. The present work exhibits the detail study of five type’s multi-layered vertically constructed wetlands operated at 24 h hydraulic retention time under semi-continuous vertical flow mode. Except N-NO₃⁻, all the pollutants were sufficient removal in iron scraps constructed wetland (ISs-CW). The highest average pollutant removal efficiency achieved in ISs-CW was 85.04%, 77.57%, 85.99%, 62.01% and 88.91% for N-NH₄⁺, N-NO₂⁺, total nitrogen, total phosphate and sulphate respectively. The present CWs planted with Eichhornia crassipes is a promising system for municipal wastewater treatment. The first-order kinetic modelling was best suited for the removal rate since it presents higher R², rate constant (k) and B values.

Styrene is one of the essential components in making thousands of everyday products. Occupational exposure to styrene causes pulmonary, neurological, genetic and ocular complications, and leukemia and affects reproduction. The aim of this study was to assess the health risks of exposure to styrene in the electronics industry of Neyshabur, Iran. This descriptive and analytical cross-sectional study was carried out in three electronics industries, in Neyshabur city, in 2017–2018. Occupational exposure to styrene was measured according to the NIOSH1501 method, using a low-flow rate sampling pump (0.2 L/min) and an active charcoal absorber tube. Health risk assessment was done according to the Singapore semi-quantitative method and the United States Environmental Protection Agency (OEHHA) method. The average occupational exposure to styrene in men employed in the compact plastic parts production halls was 79.61 mg m⁻³ (range 28–208.33). 45.8% of exposed subjects (27 people) encountered exposure above the permitted limit. The average lifetime carcinogenic risk of styrene was 1.4 × 10⁻³; therefore, 100% (59 people) had a definite risk of getting cancer. The highest lifetime risk of getting cancer was observed in plastic injection device users (1.9 × 10⁻³) and then in shift managers (1.6 × 10⁻³). The results of this study indicate a definite risk of getting cancer for all workers. Strategies to reduce workers exposure to styrene through engineering controls and routine measurements are necessary.

The issue of contaminated sites has been highlighted as an immediate priority in the 13th Five-Year Plan of China. Identification and prioritization of contaminated sites are of key importance for proposing effective strategies for the regional management of contaminated sites. In this study, three advanced multi-attribute methodologies, the risk-based priority methodology, the regional risk assessment methodology, and the dominance-based rough set approach (DRSA), were comparatively employed to screen contaminated sites in, Guangxi, Southwest of China. The results of the three prioritizations show that the highest ranking site identified by the three methods had great agreement. In regard to the screening attributers, while the risk-based prioritization methodology and regional risk assessment methodology allowed a high discrimination in the screening of contaminated sites associated with different attributes, such as farmland, residential areas, contaminant level, number of people, area, storage quality, site service life, and surrounding communities, the DRSA allowed the identification of contamination strength (CS) and contamination potential (CP).

Fresh produce irrigated with surface water that may contain pathogens such as enteric viruses can lead to outbreaks of foodborne viral illnesses. In the current study, we performed real-time PCR (qPCR) to monitor the presence of enteric viruses such as human adenoviruses (HAdVs), hepatitis A virus (HAV), rotavirus group A (RVA), and norovirus GI (NoV GI) in surface water and fresh produce that were grown using this surface water in Egypt. Samples were collected on four occasions from different sites located in the Delta and in Greater Cairo, Egypt. Of the 32 water samples and 128 fresh produce samples, 27/32 (84.3%) and 99/128 (77.3%), respectively, were positive for at least one virus. HAdV (30/32) with a mean viral load = 1.5 × 10⁷ genome copies/L (GC/L) was the most commonly detected virus in water, followed by RVA (16/32, with a mean viral load = 2.7 × 10⁵ GC/L), HAV (11/32, with a mean viral load = 1.2 × 10⁴ GC /L), and NoV GI (10/32, with a mean viral load = 3.5 × 10³ GC/L). Additionally, HAdV (71/128, with a mean viral load = 9.8 × 10⁵ GC/g) was also the most commonly detected virus in the fresh produce, followed by NoV GI (43/128, with a mean viral load = 4.5 × 10³ GC/g), HAV (33/128, with a mean viral load = 6.4 × 10³ GC/g), and RVA (25/128, with a mean viral load = 1.5 × 10⁴ GC/g). Our results indicate that fresh produce may be contaminated with a wide range of enteric viruses, and these viruses may originate from virus-contaminated irrigation water. Moreover, this fresh produce may serve as a potential vector for the transmission of viral foodborne illnesses. These findings are important for future risk assessment analysis related to water/foodborne viruses. Graphical abstract . Please provide caption for Graphical AbstractGraphical abstract showing sample collection and processing

Sago bark (SB) and empty fruit bunch (EFB) are available abundantly as agricultural waste in Sarawak. This study was conducted to investigate the physicochemical characteristics of SB and EFB as composting materials and used as a plant growth medium. The SB and EFB composts were prepared in a separate container by mixing chicken manure as compost accelerator and wood chips as a bulking agent in dry weight equivalent ratio (1:1:1). The maturity and stability of compost in 60-day composting periods were evaluated via physicochemical characterization of the composts in terms of pH, elemental content, total ash content, moisture content and nutrient analyses. The effect of the compost usage as growth medium was assessed towards water spinach and green mustard via seed germination and pot study. After 2 months, the colour of both composts was dark brown with an earthy smell. The acidic pH of the initial composting stage has changed into alkaline pH after 60 days of composting. Total NPK present in the SB and EFB composts were 0.96% and 1.21%, respectively. The germination index (GI) for the studied vegetables was above 100%, while the pot study showed that vegetables in compost media has higher growth compared to the control, after 14 days. SB and EFB are renewable waste which can be used as an excellent compost and able to improve the quality of the soil.

Polycaprolactone nanocapsules (PCL) containing pretilachlor were prepared, and Fourier transform infrared spectroscopy, atomic force microscopy, and transmission electron microscopy were used for their structural and morphological investigations. The results revealed that the nanocapsules had irregular shape and their particles size was in the range of 70–200 nm. The encapsulation efficiency of pretilachlor was measured as 99.5 ± 1.3% using high-performance liquid chromatography analysis. The physicochemical stability studies over 60 days showed that the nanocapsules were stable in the suspension without any aggregation. The herbicide activity was examined in a pre-emergence manner using barnyard grass as a target plant and rice as a non-target plant. The nanoformulation had no negative effect on rice plant. However, its effect on barnyard grass was significant. The cytotoxicity analysis indicated that the nanocapsulated herbicide is less toxic rather than the commercial formulation. Therefore, encapsulation of pretilachlor in PCL nanocapsules can be used effectively to construct environmentally friendly PCL-herbicide systems in agriculture.

Under flooded conditions in paddy soil, the mobility of As increases while the mobility of Cd decreases. The opposite geochemical behavior of As and Cd makes it difficult to reduce their mobilities simultaneously. Our recent study found that combined applications of biochar and zero-valent iron successfully reduced the mobilities of As and Cd simultaneously. On this basis, in the present study, an iron-modified biochar (Fe-BC) was developed, and its effect on decreasing the accumulations of As and Cd in rice was verified in a 2-year field trial. In addition, previous studies indicated that silicon fertilizer can also reduce As and Cd accumulation in rice grain. Hence, the effect of the combined or separate application of Fe-BC and silica sol on As and Cd accumulation in rice grain was investigated. Over the 2-year field trial, the grain yields decreased in the following order: iron-modified biochar plus silica sol (Fe-BC plus Si) > silica sol (Si) > Fe-BC > control (CK). Concentrations of As and Cd in brown rice were in the order: Fe-BC plus Si < Si ≈ Fe-BC < CK. The treatments of Fe-BC and Fe-BC plus Si significantly increased the soil pH and thus decreased available As and available Cd in the soil. In addition, significantly positive correlations between available As and As in brown rice and between available Cd and Cd in brown rice were found. In conclusion, co-application of iron-modified biochar and silica sol should be a recommended strategy to reduce the accumulation of As and Cd in rice grains.

The PM₂.₅ as one of the main pollutants in Tehran city has a devastating effect on human health. Knowing the key parameters associated with PM₂.₅ concentration is essential to take effective actions to reduce the concentration of these particles. This study assesses the relationship between meteorological (humidity, pressure, temperature, precipitation, and wind speed) and environmental parameters (normalize difference vegetation index and land surface temperature of MODIS satellite data) on PM₂.₅ concentration in Tehran city. The Geographically Weighted Regression (GWR) was employed to assess the impact of key parameters on PM₂.₅ concentrations in winter and summer. For this purpose, first the seasonal average of meteorological data were extracted and synchronized to satellite data. Then, using the ordinary least square model, the important parameters related to PM₂.₅ concentration were determined and evaluated. Finally, using the GWR model, the relationships between parameters related to PM₂.₅ concentration were analyzed. The results of this study indicate that meteorological and environmental parameters in winter season (71%) have a much higher ability to explain PM₂.₅ concentration than summer season (40%). In winter, PM₂.₅ concentration has a negative correlation with vegetation at most parts of the study area, a negative correlation with LST in the western and a positive correlation in the eastern part of the study area, a positive correlation with temperature, and a negative correlation with wind speed in the northeastern part of the study area. Precipitation has a positive correlation with PM₂.₅ concentration in most parts of the study area in both seasons. But, it was investigated in case of higher precipitation (more than 2 mm), PM₂.₅ concentration decreases. But, there is no negative relationship in any of the dependent parameters with PM₂.₅ concentration in summer. In this season, the air temperature parameter showed a high correlation with PM₂.₅ concentration. Also, spatial variations of the local coefficients for all parameters are higher in winter than in summer.