The artificial radionuclide ⁹⁰Sr is the main radionuclide in radioactive environmental pollution. In this study, celery was cultured in a laboratory hydroponics system for 21 days with strontium (Sr) levels of 0 (control), 0.5, 1, 2.5, 5, and 10 mM. The changes in the Sr contents in celery leaves and roots as well as the translocation factor (TF) values (ratio of the Sr concentration in aerial plant parts to that in roots) under different Sr concentrations were studied. Additionally, the effects of Sr stress on the absorption of six nutrients, the chlorophyll content, and the biomass of the celery were investigated. The results showed that the Sr contents in celery leaves and roots increased with the increasing Sr concentration in the hydroponic solution, but the increase of the Sr concentration in roots slowed under the 10 mM Sr treatment. The mean TF values ranged from 0.40 ± 0.01 to 1.12 ± 0.17. With the increase in Sr concentration in the hydroponic medium, the contents of calcium, iron, and potassium in the celery leaves were significantly reduced, and the absorption of calcium, iron, and magnesium by roots was significantly inhibited. Compared with the control, sulfur concentration in celery roots increased significantly under the Sr treatments increasing except the 10 mM Sr treatment. The changes in chlorophyll content were consistent with those of celery biomass, and the values of both these parameters were high under the 5 mM Sr treatment.

In semiarid areas producing corn in the State of Paraiba (Brazil), despite the social and economic importance of this culture associated with some types of stress mainly in semiarid regions, as well as the soils of these regions, which in many cases have a low organic matter content, generally < 1.5%, limiting the viability of the crop. The correct management of organic fertilization via fertigation is a possibility to minimize water losses by evaporation. The objective was to evaluate the vegetative growth and productive parameters of corn (Poaceae) fertigated with bovine biofertilizer under irrigation levels. The experiment was carried out under field conditions, in the locality of the agroecology sector (UEPB, Catole do Rocha, Paraiba, Brazil). The treatments were distributed in blocks at random with four replications, in a 3 × 5 split plot scheme, represented by three irrigation depths (60, 90, and 120% of ETc—crop’s evapotranspiration) that when applied daily were considered the main plots and the subplots represented by the doses of biofertilizer (0, 20, 40, 60, and 80 mL plant⁻¹) applied biweekly via fertigation, totaling to 60 experimental plants. Plants on water stress conditions inhibit their growth and production, but when associated with biofertilizer, they result in plants with greater productive potential in semiarid conditions. The blade of 120% of the ETc provided greater growth and production of corn compared with the layers of 60 and 90% of the ETc. The 50 ml plant⁻¹ biofertilizer dose provided corn growth and production compatible with conventional cultivation.

A novel sunlight-activated double-shell Cu@Cu₂O/SiO₂ (m-pCu@Cu₂O/SiO₂) photocatalyst is presented via a combined precipitation and sol-gel methods with a mesoporous silica outer shell. After applying several characterization techniques on the m-pCu@Cu₂O/SiO₂, it was tested in the photodegradation of ciprofloxacin (CIP). The experimental results demonstrated a higher photocatalytic activity of the double-shell m-pCu@Cu₂O/SiO₂ nanophotocatalyst than the core-shell pCu@Cu₂O nanophotocatalyst under the sunlight irradiation. When the content of pCu@Cu₂O was 30 wt.%, it showed the highest activity. The Cu nanoparticles exhibited the surface plasmonic resonance (SPR) effect which increased the light absorption in the visible region of light. It also caused the rapid separation of the photoexcited e⁻/h⁺ pairs. Furthermore, the mesoporous structure of outer shell silica favors the transfer of reactants, resulting in the improved photoactivity performance for the supported pCu@Cu₂O catalyst. Central composite design (CCD) based on RSM (response surface methodology) approach was used to optimize four of the most important experimental variables. The photodegraded intermediates were identified by HPLC-Mass.

We investigated the pollution characteristics of ninety semi-volatile organic compounds (SVOCs) in the rivers and lakes of Shanghai. Total concentrations of Σ₉₀SVOCs in water and sediment samples from 30 sites ranged from 1.47 to 19.5 μg/L and 2.38 to 9.48 mg/kg, respectively. PAEs and PAHs were the major contaminant compounds found in all samples. OCPs accounted for less than 3% of the total concentrations of Σ₉₀SVOCs and other SVOCs were either not detected or only detected in trace amounts. Our results indicated that domestic swage, industrial wastewater, petroleum products, and other human activities were the pollutant sources to the water and sediment. It is noteworthy that products that contain the banned chemicals HCH and DDT are still under use within the studied areas. Ecological and health risk assessment results showed that dieldrin and BBP have the potential to cause adverse effects on the environment, while B(a)p and DBP have high carcinogenic risks to humans.

Sediments may act as a source or sink of ions from water, especially phosphorus (P). After the erosion process, the challenge is to retain suspended sediments inside the watershed area. We hypothesize that weir structures may mitigate P transfer from agricultural soils to aquatic systems. To test this, the present work aimed to evaluate P chemical fractions present in bottom sediments retained in the water reservoir of weirs built in two intensive agricultural watersheds and we discuss the sink/source behavior of these sediments. Samples of bottom sediments were collected from 12 reservoirs of weirs in two smalls Brazilian watersheds. Chemical P fractionation including adsorption and desorption kinetics was performed. Total P varied from 398 to 958 mg kg⁻¹. The easily and potentially desorbed phosphorus were correlated with the clay content and the concentrations of Fe, Mn, and Al, extracted by ammonium oxalate and dithionite-citrate-bicarbonate solutions, which are the carriers of highly reactive functional groups with phosphate. Bottom sediments have high maximum adsorption capacity under unrestricted phosphorus supply condition, while under natural condition (low anthropogenic pressure), the sediments were not saturated and therefore low desorption occurred. Only 1.34% and 7.75% of total P was in readily and potentially bioavailable P forms. The bottom sediments accumulated in reservoirs from anthropogenic areas acted as P source to water, while those from preserved areas (natural pasture or riparian forest) acted as sink of P from water. The storage of water and sediment contaminated with P in reservoir of weirs may be an efficient and temporary practice to mitigate the transfer of P to watercourses.

This study investigated the impact of pyrolysis conditions on physical characteristics of date palm fronds biochars and their performances for aqueous uptake of anionic dyes—methyl orange (MO) and Eriochrome Black-T (EBT)—and cationic dyes—methylene blue (MB) and crystal violet (CV). Detailed characterization of the biochars revealed the formation of oxygen functionalities (C=O, C-O-C, and C-O), improved surface characteristics (surface area and pore volume) and high ash content at higher pyrolysis temperature and time. Biochar-derived date palm with a high surface area of 431.82 m²/g and a pore volume of 0.134 cm³/g was obtained at pyrolysis temperature and time 700 °C and 4 h, respectively. For all the four investigated dyes, the adsorption isotherm was mainly described by Redlich–Peterson isotherm model (R² > 0.95), while the adsorption kinetics well-fitted the pseudo-second order model. The biochar yielded fast dyes adsorption with maximum adsorption capacity for MB, EBT, MO, and CV dye of up to 206.61, 309.59, 163.132, and 934.57 mg/g at 200 mg/L dye concentration, respectively. The adsorption of cationic dyes was pH-independent indicating the involvement of pi–pi and chemical interactions. However, the uptake of the anionic dye was favorable at acidic conditions and was dominated by electrostatic interactions involving ion exchange and chemical reactions. The produced biochars exhibited excellent surface characteristics and enhanced adsorptive performance relative to other similar adsorbents. Thus, the direct pyrolysis of date palm fronds’ waste is a sustainable and economical approach of converting a huge quantity of wastes into excellent adsorbent for effective remediation of dye-contaminated water and wastewater.

Polluted waters are an important reservoir for antibiotic resistance genes and multidrug-resistant bacteria. This report describes the microbial community, antibiotic resistance genes, and the genetic profile of extended spectrum β-lactamase strains isolated from rivers at, Pune, India. ESBL-producing bacteria isolated from diverse river water catchments running through Pune City were characterized for their antibiotic resistance. The microbial community and types of genes which confer antibiotic resistance were identified followed by the isolation of antibiotic-resistant bacteria on selective media and their genome analysis. Four representative isolates were sequenced using next generation sequencing for genomic analysis. They were identified as Pseudomonas aeruginosa, Escherichia coli, and two isolates were Enterobacter cloacae. The genes associated with the multidrug efflux pumps, such as tolC, macA, macB, adeL, and rosB, were detected in the isolates. As MacAB-TolC is an ABC type efflux pump responsible for conferring resistance in bacteria to several antibiotics, potential efflux pump inhibitors were identified by molecular docking. The homology model of their MacB protein with that from Escherichia coli K12 demonstrated structural changes in different motifs of MacB. Molecular docking of reported efflux pump inhibitors revealed the highest binding affinity of compound MC207-110 against MacB. It also details the potential efflux pump inhibitors that can serve as possible drug targets in drug development and discovery.

It is necessary to determine an environmentally friendly method of reusing the vast amount of coal waste that is generated during coal preparation. This study evaluates the applicability of using weathered coal waste in a permeable reactive barrier to prevent groundwater contamination. Coal waste, with different weathering degrees, was obtained from two coal mining sites in South Jeolla Province, Korea. The reactivities of the coal waste with inorganic contaminants, such as copper, cadmium, and arsenic, were examined in batch and column experiments. The batch experiment results indicate that the coal waste removal efficiencies of copper (99.8%) and cadmium (95.4%) were higher than those of arsenic (71.0%). The maximum adsorption capacities of coal waste for copper, cadmium, and arsenic calculated from the Langmuir isotherm model were 4.440 mg/g, 3.660 mg/g, and 0.718 mg/g, respectively. The equilibrium of adsorption was attained within 8 h. The column experiment results reveal that the coal waste effectively removed inorganic contaminants under flow-through conditions. Faster breakthrough times were observed in single solute system (As(V) = 19.3 PV, Cu(II) = 47.6 PV) compared with binary solute system (As(V) = 27.8 PV, Cu(II) = 65.4 PV). To confirm the applicability of using coal waste in a groundwater environment, its decontamination ability was analyzed at low concentrations and under various pH conditions. To examine the potential ecological risks in the subsurface environment, a test to determine acute toxicity to Daphnia magna and a toxic characteristic leaching procedure (TCLP) test were conducted. The coal waste was found to satisfy appropriate standards. The acute toxicity test also confirmed the ecological safety of using coal waste in a groundwater environment. The acceptably high capacity and fast kinetics of inorganic contaminant sorption by the coal waste indicate it could potentially be employed as a reactive material. The recycling and application of this abundant waste material will contribute to solving both coal waste disposal and water pollution problems.

Although environment protection efforts worldwide, the chemistry and biological contamination of waters represents an important challenge to be overcome, especially regarding its contamination by domestic wastewater effluents. In this context, this research presented an analysis by using an innovative wastewater treatment system for domestic effluents based on the electro-oxycoagulation approach implanted in wastewater treatment station located at Palma Sola, Santa Catarina, Brazil. We evaluated samples from domestic effluent (before and after treatment), fountain water, and river water collected from the municipality water system, as well as investigated the residual compound yielded by wastewater treatment. In these samples, we performed physicochemical analysis, investigation of viable helminth eggs, and toxicity and microbiological measurements before and after the treatment. Further, the levels of contaminant metals by X-ray fluorescence-based technique were analyzed. Results show an improvement in the quality of treated water, as demonstrated by microbiological, physicochemical, toxicity, and metal analysis of effluent after treatment. After treatment, river water and fountain water levels of metals in accordance with the maximum limits allowed by Brazilian regulatory agencies. Analysis of residual compound indicated that the workers that handle the residue were not contaminated with the identified metals. Thus, the electro-oxycoagulation-based method demonstrated high efficiency for the treatment of domestic effluents and further prevents contamination of the rivers by the released effluent without treatment.

A series of Ho-modified Mn/Ti catalysts with various content of Ho were prepared by impregnation method, and the low-temperature catalytic performance was tested. Techniques of BET, SEM, XRD, H₂-TPR, and XPS were carried out to research the effects of Ho modification on the physicochemical properties of Mn/Ti catalysts. Results showed that appropriate Ho addition could reduce the starting temperature of Mn/TiO₂ catalyst to 100 °C. 0.2HoMn/Ti exhibiting a wider temperature range of 140~220 °C with nearing 100% NOₓ conversion. It was found that the 0.2HoMn/TiO₂ catalyst possessed a better dispersion of active component, enhanced redox capacity, a higher concentration of Mn⁴⁺ species, and a larger amount of Oᵦ content on the catalyst surface, which are all likely predominant factors related to the excellent SCR activity. Additionally, Ho improved the Lewis acid sites and enhanced the adsorption and activation ability of NH₃, as well as the NO to NO₂ oxidation ability. The selective catalytic reduction with ammonia (NH₃-SCR) deNOₓ mechanism over HoMn/Ti catalysts obeyed both the Eley–Rideal (E-R) and Langmuir–Hinshelwood (L-H) mechanisms under low-temperature reaction conditions.