Norfloxacin (NOR), an antibiotic widely used in livestock and poultry production, has become ubiquitous in the aquatic and terrestrial ecosystems as a result of veterinary excretion of the parent compound or its active metabolites. The sorption of NOR onto humic acid (HA) may influence the fate of NOR in the environment. In the present study, HA was extracted from sewage sludge in different composting stages of days 0, 10, 30, and 70 to investigate the sorption of NOR onto HA as affected by the humification degree of HA. The results of elemental and Fourier transform infrared (FTIR) spectrum analyses showed that the contents of aromatic and carboxylic groups in HA increased with composting time, indicating an increase of humification degree. The result of sorption experiments demonstrated that the HA had a high sorption capacity for NOR with strong nonlinearity. A two-stage sorption was observed in the sorption process with an equilibration time of 48 h. Both the Freundlich model (Adj. R² range 0.988–0.994) and Langmuir model (Adj. R ² range 0.917–0.928) fitted well with all sorption isotherms of the HA samples of different humification degrees. Moreover, the increase of sorption distribution coefficient (K d) value with composting time indicated that the sorption affinity of HA for NOR increased with increasing humification degree of HA. The major sorption mechanism was the interaction between NOR and rich aromatic moieties and carboxylic group in the HA.

Mn-Zn ferrite (Mn₁ ₋ ₓZnₓFe₂O₄, x = 0.2, 0.4, 0.6, and 0.8) nanomaterials were prepared by bioleaching and hydrothermal synthesis from waste Zn-Mn batteries. The materials were characterized by XRD, SEM, BET, VSM, CEC, and isoelectric point. It turned out when x = 0.4, synthesized Mn-Zn ferrite had best performance which was nanoferrite crystal structure with a specific surface area that reached 37.77 m²/g, the saturation magnetization was 62.85 emu/g, and isoelectric point and the CEC value were 7.33 and 43.51 mmol/100 g, respectively. In addition, the adsorption characteristics on Ni²⁺ were explored. The results of experiment suggested that data was more in line with the Freundlich model compared with Langmuir and Dubinin-Radushkevich isotherm models. Kinetics studies showed that pseudo-second-order kinetics was more suitable for describing the Ni²⁺ adsorption process where the maximum theoretical adsorption quantity was 52.99 mg/g. Thermodynamic parameters indicated the adsorption process can be spontaneous as an endothermic reaction, and warming was advantageous to adsorption. Besides, the adsorbent could be reused for six cycles with high removal efficiency. The magnetic and adsorptive properties of the adsorbent were promising, which had a high application value. Graphical abstract Fabrication process of nanometer ferrite by biological technology and hydrothermal synthesis for removal of Ni2+

Contrasting soil profiles (coarse-textured and fine-textured) treated with brilliant blue (BB) dye tracer, inorganic nitrogen (N) and phosphorus (P) concentrations along and between stained preferential flow pathways were examined for an irrigated and overfertilised maize monoculture system at the Mediterranean central Chile. The PO4-P concentrations were 2- to 10-fold higher in areas with BB than in areas without BB below 0.5-m soil depth in both soils. This elevated concentration was attributed to transport through cracks in fine-textured soil and finger flow in coarse-textured soil. The highest PO4-P value (13 mg kg⁻¹) was found in areas with BB at the fine-textured soil. There were no significant differences in inorganic N concentration between areas with and without BB for both soils, which suggest that the effects of preferential flow are less important for inorganic N forms. There was a strong significant (p < 0.01) positive correlation between PO4-P and NH4-N concentrations in the fine-textured soil, and the amounts retained were clearly proportional to the clay content. Strategies for reducing N and P losses must be placed on good agronomic management of irrigated maize cropping system including accurate calculation of N and P fertiliser rates and establishment of suitable mitigation measures such as cover cropping.

With the widespread use of natural pyrethrins and pyrethroids to defend pest insects, people had the sustained interest in the potential risk to environment and human health. However, the research about natural pyrethrins and beta-cypermethrin induction of cytotoxicity is still seldom. This study is about the cytotoxic effects of these on human non-target cells in vitro. The cytotoxic effect of natural pyrethrins and beta-cypermethrin on QSG7701 cells were researched by using various bioassays in vitro. The results suggested that with the natural pyrethrin concentration increased, the viability of QSG7701 cells were inhibited increasingly, and the IC₅₀ value as calculated was approximately 42.54 and 18.68 μg/mL after the cells were treated 24 and 48 h. The proliferative potential of QSG7701 cells treated with 40 μg/mL natural pyrethrins 6 and 12 h was decreased by 67.44 and 94.74%, dramatic enhancement ROS, collapse of mitochondrial membrane potential, DNA exhibit severity of impairment, and chromatin DNA condensation. However, beta-cypermethrin has lower toxicity than natural pyrethrins. The IC₅₀ values of beta-cypermethrin were all > 80 μg/mL, and the colony formation expression was decreased by 15.26 and 19.09%, which implied that natural pyrethrins are more significantly cytotoxic and potentially genotoxic to human hepatocyte cells.

Filamentous mat-forming algae are increasingly impairing freshwater resources. To restore water utility, reactive management programs often involve application of copper-based algaecides. Copper algaecide formulations can differ significantly, and this research outlined an advanced approach to evaluate formulation efficiency for controlling filamentous algae. Two common algal species (Lyngbya wollei, Pithophora varia) were used to assess copper internalization and adsorption as well as relation to control among copper formulations. Captain® XTR achieved control (7-day EC₈₅) of L. wollei with internal copper concentrations of 0.78 and 0.76 mg Cu/g based on chlorophyll a content or filament viability, respectively. Cutrine® Ultra achieved control of L. wollei based on filament viability only at 0.85 mg Cu/g. Internalized copper concentrations required for control following Captain XTR exposures were similar for P. varia, 0.81 and 0.95 mg Cu/g, whereas Cutrine Ultra and copper sulfate did not elicit control nor attain the critical internal copper threshold. The relationship between internalized copper and responses, among all formulations, was significant (P < 0.0001) with R² values of 0.920 and 0.935 for L. wollei and 0.807 and 0.826 for P. varia based on filament viability and chlorophyll a content, respectively. Formulation efficiency, internalized copper versus total amended, was greatest with Captain XTR (average 0.17), followed by Cutrine Ultra (0.13), and copper sulfate (0.09). By measuring the efficiency of a specific algaecide and the corresponding amount required to achieve control of targeted algal biomass, management objectives can be achieved while decreasing environmental loads of copper, number of treatments, and operational costs.

This study developed a new adsorbent, specifically activated carbon-loaded silver nanoparticles (AgNPs-AC) by coating the silver nanoparticles (AgNPs) onto activated carbon (AC). The obtained AgNPs-AC were characterized by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The ability of AgNPs-AC to remove methylene blue (MB) was evaluated using different experimental factors, these being pH solution, contact time, adsorbent dose, and initial MB concentration. Results indicated that the highest adsorption capacity of MB onto AgNPs-AC was obtained when the AC was loaded onto AgNPs at the impregnation ratio of 0.5% w/w for AC and AgNPs. The best conditions in which AgNPs-AC could remove MB were as follows: pH 10, contact time lasting 120 min, and adsorbent dose being 250 mg/25 mL solution. In this scenario, the maximum adsorption capacity of MB onto AgNPs-AC was 172.22 mg/g. The adsorption isothermal equilibrium was well described by the Langmuir, Freundlich and Sips models. The Sips equations had the highest correlation coefficient value (R² = 0.935). The pseudo-first-order and pseudo-second-order kinetic models agree well with the dynamic behavior of the adsorption of dye MB on AgNPs-AC.

Groundwater resources can be impacted by contamination from geogenic and anthropogenic inputs but it can be difficult to disentangle contaminant sources. In this study, we investigated the sources and distribution of NO₃ and As in Goshen Valley, UT, a semi-arid alluvial basin in the western USA that contains geothermal waters, playa soils, agriculture, and legacy mining. Surface water, springs, and wells were analyzed for As and NO₃ concentrations in relation to major ions, trace elements, and stable isotopes in water (δ¹⁸O and δD), and other isotopic tracers. Major ion concentrations showed high spatial variability ranging from freshwater to brackish water, with the highest salinity found in geothermal springs and springs discharging from playa sediments (Playa Springs). Radiogenic ⁸⁷Sr/⁸⁶Sr ratios in the Playa Springs suggest that Sr is sourced from crystalline basement rocks. The highest NO₃ concentrations were found in groundwater beneath agricultural areas, particularly dairy farms, with isotopic values indicating manure, not fertilizers, as the major source. Many of the NO₃-contaminated wells contained old groundwater (based on ¹⁴C and ³H), suggesting that reinfiltration of pumped groundwater may be a source of NO₃ pollution. The Playa Springs also had the highest As concentrations, with moderate As concentrations found in other geothermal springs. Wells containing moderate As concentrations were found in areas where the groundwater interacts with alluvial sediments or carbonate rocks. Surprisingly, nearby mining and mineral processing seems to have minimal effect on As contamination in the alluvial aquifer. This study has implications for understanding water quality in regions that are impacted by multiple potential contaminant sources.

The textile industries are characterized as one of the biggest consumers of potable water and chemical products throughout its process, being responsible for the elevated wastewater generation with intense coloration and wide polluting potential. In this context, the present study proposes the development and application of a new coagulant material for textile wastewater treatment. The proposed coagulant (α-Fe₂O₃-MO) was composed by hematite nanoparticles (α-Fe₂O₃) obtained by a simple non-pollutant methodology, associated with Moringa oleifera (MO) seeds saline extract compounds. Coagulation/flocculation (CF) efficiency was evaluated by removal of physicochemical parameters such as apparent color, turbidity, and compounds with absorption at UV₂₅₄ₙₘ (UV₂₅₄ₙₘ) through CF tests carried out on Jar test equipment and sedimentation carried out in the presence and absence of external magnetic field (600 k Am⁻¹). Kinetics sedimentation was from 0 to 90 min. The use of this new coagulant allowed the removal of 92.37% for apparent color, 91.43% for turbidity, and 46.09% for UV₂₅₄ₙₘ, indicating that the proposed coagulant association was efficient in the treatment of this type of wastewater under external magnetic field with only 10 min of sedimentation. In addition, the resulting sludge from CF process was tested as base material for a new coagulant synthesis, demonstrating great reuse potential. Therefore, the new proposed coagulant, composed of α-Fe₂O₃ and the compounds present in the seed extract of MO, has applicability for textile wastewater treatment demonstrating high removal rate for all evaluated parameters with cost reduction in the proposed treatment for this wastewater.

Simultaneous removal of oil droplets and hexavalent chromium from synthetic wastewater of chromium plating and chromate conversion coating plants by electrocoagulation in a new cell design was studied under different conditions of pH, initial Cr⁶⁺ concentration, NaCl concentration, and current density. Under optimum conditions, more than 90% of oil content and Cr⁶⁺ were removed. Percent removal was found to increase with decreasing Cr⁶⁺; high Cr⁶⁺ concentrations tend to passivate the aluminum anode and decrease the percent removal of Cr⁶⁺ and oil. The effect of NaCl concentration shows a maximum percent removal at 1.5%. The pH range 4–5 was found to give the highest percent removal. Increase of current density was found to improve the percent removal of Cr⁶⁺ and oil droplets. The favorable effect the combined oil and Cr⁶⁺ removal on the capital and operating costs of wastewater remediation was pointed out. Potential merits of the present cell design compared to the traditional parallel plate cell were highlighted.

Phytoremediation is a cost-effective and environmentally friendly technology using plants for the cleanup of both inorganic and organic contaminated sites. In this study, a pot culture experiment has been conducted for 180 days in a greenhouse to examine the capability of Koelreuteria paniculata on pyrene (Pyr) dissipation in contaminated soil. Three treatments were employed and they were: (1) polluted soil with K. paniculata fine roots addition (T1), (2) polluted soil with planted seedlings (T2), and (3) polluted soil (C). Results showed Pyr concentration in soils was reduced by 21.4, 36.2, and 86.4% by natural losses, fine roots addition, and planted K. paniculata treatments, respectively, meaning plants substantially enhanced the dissipation of Pyr from soil. Cultivated K. paniculata seedlings significantly increased soil total nitrogen (TN), total organic carbon, dissolved organic carbon (DOC), and microbial biomass carbon, but not total phosphorus, when compared to the control. The removal efficiency of Pyr was lower in the adding of fine roots treatment than in the planted K. paniculata treatment. The principal component analysis indicated the promotional dissipation of Pyr in soil by planted K. paniculata was likely attributed to increased microbial quantity and activity, DOC, and TN content in the rhizosphere. Our results suggest that K. paniculata is a suitable plant species used in phytoremediation for Pyr-contaminated soils and the efficiency on the dissipation of Pyr is considerably enhanced using living plants than adding dead organic matters. The study provided a reference for the application of K. paniculata in the remediation of Pyr-contaminated soil.