Water, Air, & Soil Pollution最新文献

There is an urgent need by the European Union to establish baseline levels for many widespread pollutants and to set out specific levels for these under the Zero pollution action plan. To date, few systematic reviews, superseded by bibliometric analyses, have explored this issue. Even less research has been carried out to compare the efficacy of these two data extraction approaches. This study aims to address these two issues by i) constructing an inventory of the available information on urban soils, highlighting evidence gaps and measuring compliance with the Zero pollution action plan, and by ii) comparing the methods and results of these two data extraction approaches. Through Scopus and Web of Science databases, peer-reviewed articles using the terms urban soil in combination with specific urban soil threats and/or challenges were included. Notably, both approaches retrieved a similar number of initial articles overall, while the bibliometric analysis removed fewer duplicates and excluded fewer articles overall, leaving the total number of articles included in each approach as: 603 articles in the systematic review and 2372 articles in the bibliometric analysis. Nevertheless, both approaches identified the two main urban soil threats and/or challenges to be linked to soil organic carbon and/or heavy metals. This study gives timely input into the Zero pollution action plan and makes recommendations to stakeholders within the urban context.

Constructed wetlands and constructed floating wetlands are widely used for nitrogen (N) removal from surface water to combat eutrophication in freshwaters. Two main N removal pathways in freshwaters are plant biomass N uptake and denitrification, i.e. transformation of nitrate (NO₃-) to nitrous oxide (N₂O) or nitrogen gas (N₂) by different microbes possessing nirK, nirS, nosZI, and nosZII genes. In this study, we tested woodchips-based floating beds (WFBs) as a nature-based and environment-friendly method to remove nitrate-nitrogen (NO₃-N) from water. Moreover, we tested whether WFBs could support the growth of three selected plant species and the abundance of microbes on plant roots and woodchips as a proxy for WFBs’ denitrification potential. We conducted a greenhouse experiment for 90 days and measured NO₃-N removal rates from water in WFBs mesocosms during five sampling occasions. Plant biomass production, biomass N uptake, and plant morphology related to N uptake and abundance of denitrifying organisms were measured at the end of the experiment. NO₃-N removal rates were 29.17 ± 11.07, 28.18 ± 12.62, 25.28 ± 9.90, and 22.16 ± 7.79 mg L^–1 d^–1 m^–2 (mean ± standard deviation) in Glyceria maxima, Juncus effusus, Filipendula ulmaria, and unplanted WFBs treatments, respectively for whole experimental period. N content in above- and belowground biomass of studied species ranged between 0.98 – 1.15 and 1.09 – 1.28 (% dry weight), respectively. Plant relative biomass production was 215 ± 61, 67 ± 18, and 7 ± 17 (% dry weight) for G. maxima, J. effusus and F. ulmaria, respectively. Denitrifiers were detected both on plant roots and woodchips, indicating WFBs’ denitrification potential. Our study highlights that WFBs could be applied to enhance NO₃-N removal from surface water through plant biomass uptake and denitrification processes. Future studies should consider the long-term in situ application of WFBs for NO₃-N removal from water.

Abstract

The effectual prevention and control of microplastics (MPs) in an environment is of great significance and a challenging task. The extensive usage and improper disposal of plastic materials increased the quantity of MPs in the surroundings, which poses potential issues for both flora and fauna. A recent survey reported that MPs can easily accumulate in human and animal bodies, which causes several adverse health problems such as inflammation, chronic disease, neurotoxicity, oxidative stress, etc. MPs can also disturb the growth, reproduction, and survival of aquatic organisms, leading to a disruption of the food chain and ecosystem. Moreover, it acts as a toxin carrier and transports them into the biological system, leading to the accumulation of toxic compounds in the food chain that cause biomagnification. Therefore, effective MPs management is crucial to prevent and control the release of MPs into the environment. Strategies such as the 3R principle, public awareness, employing suitable solid waste management, and developing biodegradable alternatives to plastics can partially alleviate the hostile effect of MPs on the environment. However, this kind of strategy has not met the present-day demand to reduce waste MPs completely. In the future, available techniques like membrane filters, ultrasound, electrocoagulation, magnetic separation etc. must be combined with advanced technology like machine learning and artificial intelligence (MLAI) for the best performance to remove MPs. This review provides a source for further improvement for the effective prevention and control of waste MPs generation in an environment for sustainability, which can likely be achieved using appropriate technology.

Graphical Abstract

Lignin is an amorphous natural polymer with multifunctional phenolic network accounting for approximately 15–30% of lignocellulosic biomass. Different functional groups like carboxyl, hydroxyl, phenolic and methoxy in lignin molecule may act as suitable interaction sites for the removal of pollutants. Lignin, as an abundant and renewable bioresource, can be used to create nanofibrous membranes via electrospinning technique. Such nanofibrous membranes with elevated specific surface area, uniform fiber diameter, and high porosity may serve as highly efficient adsorbents for the entrapment of detrimental pollutants like dyes, heavy metals, particulates, etc. Hence, numerous research has been carried out to develop lignin based electrospun membranes in recent years. For example, a low-cost electrospun nano-fibrous membrane (ENM) comprising of alkali lignin/polyvinyl alcohol (PVA) was developed for effective removal of Safranine T dye. Similarly, palm fronds and banana bunch waste biomass derived lignin was successfully employed as an electrospun material for the removal of methylene blue dye. An alkali lignin/PVA ENM was developed for the adsorption of fluoxetine contaminant from its solution. This review paper provides the up-to-date information on the development and usage of eco-friendly, sustainable and cost-effective electrospun lignin nano-adsorbents for the removal of various environmental contaminants.

Rivers play pivotal role in transporting plastic litter into the ocean. The present study aimed to estimate microplastics (MPs) in Palar River (PR), that receives waste inputs of agricultural, industries, fishing, and domestic origin. Water and sediment samples were collected during low tide, at seven locations from inner check dam to mouth region. Highest concentration of MPs in water are observed at PR-6 (28.01 × 10⁴ particles.km⁻²) and the lowest was recorded at PR-4 (2.6 × 10⁴ particles.km⁻²). In sediment, highest count was detected at PR-1 (8.8 × 10² ± 226 particles.kg⁻¹ d.w) and the lowest was recorded in PR-6 (2.5 × 10² ± 14 particles.kg⁻¹d.w). MPs distribution in water is more in the outer mouth (PR-6) in comparison to inner region (PR-4). Fibres were dominating morphotype of MPs, comprised of 79.4% in water and 89.8% in sediment samples. According to size classification, the majority of particles (41.02% in water and 56.1% in sediment) were in the size range of 1 μm to 1000 μm. Characterization of MPs through Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy revealed that High Density Polyethylene (HDPE) is the dominant polymer indicating the use of plastic fishing nets and ropes along with the outfall from nearby industries may be the main contributor to the microplastic pollution in the river.

The high concentration of chlorophyll a (Chl-a) and pollutants in estuaries has led to the deterioration of marine environmental quality and a reduction in the sustainability and safety of marine ecosystems. This study analyzed the distribution characteristics of Chl-a and pollutants in the Liugu Estuary (LE) based on field survey data. By incorporating environmental factors, the water's nutritional status and nutrient limitations were evaluated. The results indicated that there were variations in the concentration range of Chl-a and pollutants between flood and non-flood seasons in the LE, with nitrogen identified as the main limiting nutrient. The correlation indicated that Chl-a and nutrient levels in the LE were influenced by a complex interplay of multiple factors. River inputs with higher pollution levels increased concentrations and reduced DO levels, limiting the rise in Chl-a concentration and the uptake of nutrients by phytoplankton. The findings of this study could provide essential information for an in-depth examination of the eutrophication characteristics of the LE and offer a scientific foundation for the restoration and management of the estuary's ecological environment.

Catechol is a substance that is commonly found in wastewaters from a variety of sectors including paper, paint, petroleum, dyes, antioxidants, pesticides, iron and steel, solvents, nylon, detergent, textile, plastic, rubber, cosmetics, and medicine. In this study, sequential electrochemical and chemical multi-polymerization of catechol was investigated for environmental pollution abatement. The effect of operating parameters like catechol concentration (2–10 g/L), ammonium persulphate (APS) concentration (2–10 g/L) and reaction temperature (20–60 °C) were evaluated using response surface methodology. Catechol concentration was determined using HPLC in a gradient mobile phase. The electrochemical behavior of the polymer was investigated by cyclic voltammetry (CV). The structural and morphological properties of polycatechol were characterized by Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy dispersive X-ray (SEM–EDX) analysis. It was observed from the SEM images a polymeric structure developed from a crystalline and heterogeneous structure when the APS concentration increased. Similarly, it was seen in SEM images that the polymers transitioned from a bulk and heterogeneous structure to a homogeneous structure as the temperature increased, and back to a heterogeneous structure as the catechol concentration increased. It was also found that catechol removal increased and reaction selectivity decreased by increasing the reaction temperature. The optimum operating conditions were found as 4 g/L catechol concentration, 9.5 g/L APS concentration, 30 °C reaction temperature with 100 cycles at 50 mV/s of electrochemical polymerization and 72 h of chemical polymerization. The results of this study show the potential of challenging new routes not only facile polymerization of organic monomers but also to decrease the undesirable pollutant concentration in the wastewater.

The adsorption retention of different antibiotics and the physical and chemical properties of soil can vary significantly, leading to differences in their retention ability in soil environments. To investigate the adsorption retention characteristics and transfer risk, as well as influential factors of spiramycin (SPI) in three different agricultural calcareous loess soils, which were studied by means of batch equilibrium method. The results show that the adsorption kinetics data can be well described by the pseudo-second-order model, and the sorption isotherms can be described by the Freundlich model. These model parameters indicate that soil organic matter (SOM) and cation exchange capacity (CEC) play a key role in the adsorption retention of SPI, while soil clay content and pH also exert some influence. Furthermore, the desorption amounts of SPI were consistently less than 35%, showing a high degree of irreversibility and a clear desorption hysteresis, making it prone to remaining retention in the soil. The adsorption amount changed little of pH value from 3 to 7. At a pH value of 7, adsorption is promoted by cation bridging between soil and SPI, and the existence of electrostatic attraction. The adsorption amount decreased when the pH value exceeded 7 dues to electrostatic repulsion. Compared with K⁺ and NH⁴⁺, the presence of high valence ions such as Ca²⁺, Mg²⁺ and ions with higher concentration has a significant inhibitory effect on adsorption. The FTIR spectral analysis of the adsorbents revealed that the adsorption retention was mainly governed by cation exchange, hydrogen bonding, and surface complexation. This study provides a scientific basis for assessing the retention ability and transfer risk of typical veterinary antibiotics in the soil environment.

Magnetic solid-phase extraction (MSPE) is a highly effective method for separating metal ions from aquatic solutions, making it a popular choice for metal ion separation. This study investigated the behavior of Fe₃O₄@SiO₂-SH core–shell composites for the adsorption and recovery of silver ions. The quality of the synthesized adsorbent was verified using XRD, FT-IR, EDS, FE-SEM, and EDAX-map analyses. Magnetic properties and surface charge changes were assessed using VSM and Zeta potential analyses. By implementing the classic OFAT method, the study evaluated the effect of various parameters on silver adsorption, such as pH, composite dosage, initial Ag⁺ concentration, temperature, and secondary metal ions. Results showed that the proposed composite had a high maximum adsorption capacity (112 mg/g) at pH = 6, ambient temperature, 0.1 g/L adsorbent dosage, and silver concentrations greater than 25 mg/L. The composite demonstrated good selectivity in Ag⁺ separation from a bimetallic solution containing silver and mercury ions. The results also showed that 1M HNO₃ and 1M HCl solutions released over 78% and 70% of absorbed ions from the composite surface, respectively. However, the HCl solution enabled the precipitation of almost all desorbed Ag⁺, providing a selective recovery of silver ions.

Pollution by heavy metals is one of the risks threating the human health and the environment, and reducing the concentrations of these pollutants constitutes a major challenge, in particular by using alternative bioremediation techniques. Actinobacteria are frequently proposed as an environmental cleaner of several emerging pollutants such as heavy metals. In this study, 24 actinobacteria resistant strains to heavy metals isolated from the Boulimat public landfill in Bejaia, Algeria, were evaluated for their heavy metal removal potential. Two different screenings were conducted, determination of minimum inhibitory concentration of the isolates to metal ions and the percentages of metals biosorption in batch experiment using the Atomic Absorption Spectroscopy. Streptomyces humidus DBPb2 strain, was selected as the most efficient isolate, identified based on morphological, physiological and 16S rRNA gene sequencing, by a highest minimum inhibitory concentrations to various metals mainly lead, with a MIC reaching 4000 mg.L⁻¹ and has proven its efficiency to reduce the concentration of Pb, Fe and Cu in batch experiments with 66.47%, 33.16% and 27.39% respectively. Rotatable Central Composite Design was used to optimize the lead bisorption yield studying the influence of four operating parameters: pH, stirring speed, incubation time, and inoculum size. The optimal conditions were found for pH= 7, at stirring speed of 84 rpm under incubation time of 3 days, and 3 agar cylinders as inoculum reaching a lead biosorption yield of 100%, for an initial concentration of 100 mg.L^-1. The metal-resistance mechanisms were identified in DBPb2 strain, the production of siderophores and cell wall bioaccumulation by the interaction of different functional groups (carboxylic, hydroxyl and amine groups) detected by infrared spectroscopy analysis. Therefore, this present study confirms the possibility of exploiting the DBPb2 strain in the bioremediation of lead from polluted environments such as soils and wastewater.