Multi-level porous amorphous-activated carbon with excellent adsorption performance was prepared by a ZnCl₂-assisted pyrolysis of waste polyester textiles. Experimental parameters were optimized by using orthogonal design. Result of orthogonal design revealed that pyrolysis temperature and pyrolysis time were the dominant individual factors. Samples prepared at the optimal condition were systematically characterized by Brunauer-Emmett-Teller (BET) porosity analyzer, FT-IR spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Iodine (I₂), methylene blue (MB) and phenol (PhOH) were selected as target dyes to measure the adsorption performance. Experimental results showed that porous-activated carbon with multi-level pores could be obtained by optimizing experimental parameters. The specific surface area and total pore volume were calculated to be 846.37 m² g⁻¹ and 0.726 cm³ g⁻¹, respectively. Benefit from its multi-level rich porosity, the optimized sample possessed attractive adsorption performance toward different types of dyes. The corresponding adsorption capacity toward I₂, MB, and PhOH were calculated to be 980.48, 384.00, and 300.62 mg g⁻¹, respectively.

Bioherbicides appear as an ecofriendly alternative to synthetic herbicides, generally used for weed management, because they are supposed to have low side on human health and ecosystems. In this context, our work aims to study abiotic (i.e., photolysis) and biotic (i.e,. biodegradation) processes involved in the fate of leptospermone, a natural β-triketone herbicide, by combining chemical and microbiological approaches. Under controlled conditions, the photolysis of leptospermone was sensitive to pH. Leptospermone has a half-life of 72 h under simulated solar light irradiations. Several transformation products, including hydroxy-leptospermone, were identified. For the first time, a bacterial strain able to degrade leptospermone was isolated from an arable soil. Based on its 16S ribosomal RNA (rRNA) gene sequence, it was affiliated to the Methylophilus group and was accordingly named as Methylophilus sp. LS1. Interestingly, we report that the abundance of OTUs, similar to the 16S rRNA gene sequence of Methylophilus sp. LS1, was strongly increased in soil treated with leptospermone. The leptospermone was completely dissipated by this bacteria, with a half-life time of 6 days, allowing concomitantly its growth. Hydroxy-leptospermone was identified in the bacterial culture as a major transformation product, allowing us to propose a pathway of transformation of leptospermone including both abiotic and biotic processes.

U(VI)ₐq bioreduction has an important effect on the fate and transport of uranium isotopes in groundwater at nuclear test sites. In this study, we focus on the pH-dependent bioreduction of U(VI)ₐq in carbonate-free solutions and give mechanistic insight into the removal kinetics of U(VI)ₐq. An enhancement in the removal of U(VI)ₐq with increasing pH was observed within 5 h, e.g., from 19.4% at pH 4.52 to 99.7% at pH 8.30. The removal of U(VI)ₐq at pH 4.52 was due to the biosorption of U(VI)ₐq onto the living cells of Shewanella putrefaciens, as evidenced by the almost constant UV-vis absorption intensity of U(VI)ₐq immediately after contact with S. putrefaciens. Instead, the removal observed at pH 5.97 to 8.30 resulted from the bioreduction of U(VI)ₐq. The end product of U(VI)ₐq bioreduction was analyzed using XPS and HRTEM and identified as nanosized UO₂. An increasing trend in the biosorption of U(VI)ₐq onto heat-killed cells was also observed, e.g., ~ 80% at pH 8.38. Evidently, the U(VI)ₐq that sorbed onto the living cells at pH > 4.52 was further reduced to UO₂, although biosorption made a large contribution to the initial removal of U(VI)ₐq. These results may reveal the removal mechanism, in which the U(VI)ₐq that was sorbed onto cells rather than the U(VI)ₐq complexed in solution was reduced. The decreases in the redox potentials of the main complex species of U(VI)ₐq (e.g., [Formula: see text] and [Formula: see text]) with increasing pH support the proposed removal mechanism.

Antibiotic resistance has become a widely concerned issue due to the huge risk on the ecological environment and human health. China has the highest production and consumption of antibiotics than other countries. Thus, antibiotic resistance genes (ARGs) have been detected in various environmental settings (e.g., surface water, wastewater, sediment) in China. The occurrence of ARGs in these matrixes was summarized and discussed in this review. Sulfonamide resistance genes and tetracycline resistance genes were the most frequently detected ARGs in China. According to the abundance of these two classes of ARGs in the natural environment, sulfonamide resistance genes seem to be more stable than tetracycline resistance genes. Furthermore, the relationships between ARGs and antibiotics, antibiotic resistance bacteria (ARB), heavy metals, and environmental parameters (e.g., pH, organics) were also investigated. Specifically, relative abundance of total ARGs was found to correlate well with concentration of total antibiotics in aqueous phase but not in the solid phase (soil, sediment, sludge, and manure). As for relationship between ARGs and ARB, metals, and environmental parameters in different media, due to complex and variable environment, some exhibit positive correlation, some negative, while others no correlation at all. Three potential risks are discussed in the text: transmission to human, synergistic effect of different ARGs, and variability of ARGs. However, due to the complexity of the environment, more work is needed to establish a quantitative approach of ARG risk assessment, which can provide a theoretical support for the management of antibiotics and the protection of human health.

Currently, analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) are classified as one of the most emerging group of xenobiotics and have been detected in various natural matrices. Among them, monocyclic paracetamol and ibuprofen, widely used to treat mild and moderate pain are the most popular. Since long-term adverse effects of these xenobiotics and their biological and pharmacokinetic activity especially at environmentally relevant concentrations are better understood, degradation of such contaminants has become a major concern. Moreover, to date, conventional wastewater treatment plants (WWTPs) are not fully adapted to remove that kind of micropollutants. Bioremediation processes, which utilize bacterial strains with increased degradation abilities, seem to be a promising alternative to the chemical methods used so far. Nevertheless, despite the wide prevalence of paracetamol and ibuprofen in the environment, toxicity and mechanism of their microbial degradation as well as genetic background of these processes remain not fully characterized. In this review, we described the current state of knowledge about toxicity and biodegradation mechanisms of paracetamol and ibuprofen and provided bioinformatics analysis concerning the genetic bases of these xenobiotics decomposition.

Thousands of organohalogen compounds, including hazardous chemicals such as polychlorinated biphenyls (PCBs) and other persistent organic pollutants (POPs), were selectively and simultaneously detected and identified with simple, or no, purification from environmental sample extracts by using several advanced methods. The methods used were software extraction from two-dimensional gas chromatography–high-resolution time-of-flight mass spectrometry (GC × GC–HRTofMS) data, measurement by negative chemical ionization with HRTofMS, and neutral loss scanning (NLS) with GC × GC–MS/MS. Global and selective detection of organochlorines and bromines in environmental samples such as sediments and fly ash was achieved by NLS using GC × GC–MS/MS (QQQ), with the expected losses of ³⁵Cl and ⁷⁹Br. We confirmed that negative chemical ionization was effective for sensitive and selective ionization of organohalogens, even using GC × GC–HRTofMS. The 2D total ion chromatograms obtained by using negative chemical ionization and selective extraction of organohalogens using original software from data measured by electron impact ionization were very similar; the software thus functioned well to extract organohalogens. Combining measurements made by using these different methods will help to detect organohalogens selectively and globally. However, to compare the data obtained by individual measurements, the retention times of the peaks on the 2D chromatograms need to match.

Growth, development, and economic yield of agricultural crops rely on moisture, temperature, light, and carbon dioxide concentration. However, the amount of these parameters is varying with time due to climate change. Climate change is factual and ongoing so, first principle of agronomy should be to identify climate change potential impacts and adaptation measures to manage the susceptibilities of agricultural sector. Crop models have ability to predict the crop’s yield under changing climatic conditions. We used OILCROP-SUN model to simulate the influence of elevated temperature and CO₂ on crop growth duration, maximum leaf area index (LAI), total dry matter (TDM), and achene yield of sunflower under semi-arid conditions of Pakistan (Faisalabad, Punjab). The model was calibrated and validated with the experimental data of 2012 and 2013, respectively. The simulation results showed that phenological events of sunflower were not changed at higher concentration of CO₂ (430 and 550 ppm). However LAI, achene yield, and TDM increased by 0.24, 2.41, and 4.67% at 430 ppm and by 0.48, 3.09, and 9.87% at 550 ppm, respectively. Increased temperature (1 and 2 °C) reduced the sunflower duration to remain green that finally led to less LAI, achene yield, and TDM as compared to present conditions. However, the drastic effects of increased temperature on sunflower were reduced to some extent at 550 ppm CO₂ concentration. Evaluation of different adaptation options revealed that 21 days earlier (as compared to current sowing date) planting of sunflower crop with increased plant population (83,333 plants ha⁻¹) could reduce the yield losses due to climate change. Flowering is the most critical stage of sunflower to water scarcity. We recommended skipping second irrigation or 10% (337.5 mm) less irrigation water application to conserve moisture under possible water scarce conditions of 2025 and 2050.

The widespread use of glyphosate has permeated not only small- and large-scale agriculture, but also the fight against drug trafficking and illicit crops. Health, alimentary security, and the rights of peasant and indigenous communities have been compromised in countries with intensive use of glyphosate-based herbicides. In 2015, the International Agency for Research on Cancer classified this substance as probably carcinogenic to humans, leading to the suspension of aerial glyphosate spraying the same year in countries like Colombia, where glyphosate has been extensively used in illicit crop eradication. Notwithstanding, according to a study of the U.S. Geological Survey, traces of glyphosate and its main degradation product, AMPA, remain in soil year after year. This underscores the urgency and importance of assessing new technologies to degrade glyphosate present in soils and waterbodies without leaving persistent byproducts. The aim of this study was to evaluate Lysinibacillus sphaericus’ glyphosate uptake as a carbon and phosphorous source by a sarcosine-mediated metabolic pathway that releases glycine as final degradation product. To accomplish this, molecular and analytic evidence were collected in vitro from sarcosine oxidase activity, a key enzyme of a degradation pathway which releases byproducts that are easy to incorporate into natural biosynthesis routes.

The regeneration of adsorbent by thermal method may transfer the adsorbed organic pollutants into the air phase. Herein, manganese and cerium are loaded on adsorbent as catalyst to mineralize the adsorbed organic pollutants during regeneration. The modified adsorbent is characterized by scanning electron microscope-energy dispersive spectrometer, Brunauer Emmett Teller-Barrett Joyner Halenda, and X-ray photoelectron spectroscopy. Regeneration of modified adsorbent is evaluated by adsorbent yield and mineralization percentage of the absorbed organic pollutants. The results demonstrate that the mineralization percentage of tetracycline increased about 100% after the modification. Besides, the loaded catalyst can significantly reduce the regeneration temperature. Furthermore, cerium can reduce the adverse impact causes by manganese which will decrease the adsorption capacity of adsorbent. Kinetics, equilibrium, thermodynamic, and other adsorption properties of modified adsorbent towards tetracycline are further studied. The theoretical maximum of adsorption capacity calculated by Langmuir model is 196.4 mg g⁻¹, and the kinetics of adsorption fits pseudo-second-order model. The adsorption of tetracycline on the adsorbent is feasible, spontaneous, and endothermic. The properties of synthesized composite material are stable; the yield of Ce/Mn/Al₂O₃ adsorbent can keep higher than 95% even after five adsorption/regeneration cycles. This research provides another perspective on the design and regeneration of adsorbent, which focus on reducing the secondary pollution during adsorbent regeneration process.

The handling and management of municipal solid waste (MSW) are major challenges for solid waste management in developing countries. Open dumping is still the most common waste disposal method in India. However, landfilling also causes various environmental, social, and human health impacts. The generation of heavily polluted leachate is a major concern to public health. Engineered barrier systems (EBSs) are commonly used to restrict potentially harmful wastes by preventing the leachate percolation to groundwater and overflow to surface water bodies. The EBSs are made of natural (e.g., soil, clay) and/or synthetic materials such as polymeric materials (e.g., geomembranes, geosynthetic clay liners) by arranging them in layers. Various studies have estimated the human health risk from leachate-contaminated groundwater. However, no studies have been reported to compare the human health risks, particularly due to the leachate contamination with different liner systems. The present study endeavors to quantify the human health risk to contamination from MSW landfill leachate using multiple simulations for various EBSs. To quantify the variation in health risks to groundwater consumption to the child and adult populations, the Turbhe landfill of Navi Mumbai in India has been selected. The leachate and groundwater samples were collected continuously throughout January–September in 2015 from the landfill site, and heavy metal concentrations were analyzed using an inductively coupled plasma system. The LandSim 2.5 Model, a landfill simulator, was used to simulate the landfill activities for various time slices, and non-carcinogenic human health risk was determined for selected heavy metals. Further, the uncertainties associated with multiple input parameters in the health risk model were quantified under a Monte Carlo simulation framework.