Radial oxygen loss of Typha latifolia outperforms microbial effects in heavy metal(loid) stabilization.

Wetland plants play a critical role in the remediation of tailings pond wetlands. Their unique radial oxygen loss (ROL) and rhizosphere microbial communities can modify soil properties (e.g.

Phyllosphere microbes are associated with variety-specific accumulation of di-n-butyl phthalate in choysum ().

Plant-microbe interactions in the phyllosphere have been demonstrated to facilitate plant growth and enhance resistance to diverse stresses, but the resulting effect on bioaccumulation of contaminants in plants is rarely considered. Here, by comparing differences in the phyllosphere morphology, bacterial community assembly, and metabolites between two choysum () varieties differing in di-n-butyl phthalate (DBP) accumulation, we revealed associations between the key phyllosphere exudate (fumarate) and the recruited specific microbes that may contribute to the variety-specific DBP accumulation in choysum. Compared with the DBP-high accumulation variety (HAV), the DBP-low accumulation variety (LAV) could not only enhance the recruitment of phyllosphere microbes capable of degrading DBP by increasing fumarate secretion, but also facilitate the colonization of DBP-degrading bacteria via induction of biofilm formation, ultimately resulting in lower DBP accumulation in leaves.

Sustainable remediation of butyl xanthate-contaminated mine wastewater by combining emergent macrophyte Cyperus alternifolius with a versatile bacterial isolate.

Butyl xanthate (BuX) is an emerging pollutant due to wide use as flotation collector, posing a serious threat to ecosystem health in mining areas. Here we develop a combinational plant-microbe remediation strategy for restoration of BuX-contaminated mining areas. A novel bacterial strain that completely degraded up to 1000 mg/L of BuX within 12 h was isolated and identified as Pseudomonas monteilii W50.

Co-transport of citrate-modified biochar nanoparticles and released plant-available silicon in saturated porous media: Effect of LMWOAs and solution chemistry.

Citrate-modified biochar nanoparticles (CBCNPs) represent a promising amendment with plant-available silicon (PASi) releasing capacity. However, the co-transport behavior with released PASi remain poorly understood. This study investigated their co-transport in saturated porous media under various solution chemistry and low molecular weight organic acids (LMWOAs).

Organic-mineral colloids regulate the migration and fractionation of rare earth elements in groundwater systems impacted by ion-adsorption deposits mining in South China.

Ion-adsorption rare earth element (REE) deposits distributed in the subtropics provide a rich global source of REEs, but in situ injection of REEs extractant into the mine can result in leachate being leaked into the surrounding groundwater systems. Due to the lack of understanding of REE speciation distribution, particularly colloidal characteristics in a mining area, the risks of REEs migration caused by in situ leaching of ion-adsorption REE deposits has not been concerned. Here, ultrafiltration and asymmetric flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (AF4-ICP-MS) were integrated to characterize the size and composition of REEs in leachate and groundwater from mining catchments in South China.

The effect of the synergistic thermal treatment and stabilization on the transformation and transportation of arsenic, chromium, and cadmium in soil.

Thermal treatments commonly used to remedy organic-contaminated soils can inadvertently impact the behavior of non-targeted pollutants, notably heavy metal(loid)s in soil. This study introduces an integrated calcination-stabilization remediation strategy employing steel slag as a stabilizing agent, with a focus on elucidating the transformations and remobilization tendencies of As, Cr, and Cd. Thermal treatment alters the mobility of these elements by modifying soil properties, with pH and redox conditions playing pivotal roles.

Overlooked encounter process that affects physical behaviors of stabilized nanoscale zero-valent iron during in situ groundwater remediation.

Dynamic encountering between groundwater matrices and nanoscale zero-valent iron (NZVI) injected for in situ subsurface remediation affects NZVI's mobility and has not been well recognized. Polyacrylic acid (PAA)-stabilized NZVI (NZVI-PAA) and Mg(OH)-coated NZVI (NZVI@Mg(OH)) were investigated as representative NZVIs stabilized by enhanced electrostatic repulsion and reduced magnetic attraction, respectively. Encounters with divalent cations and humic acid (HA) induced the drastic aggregation and sedimentation (presedimentation) of NZVI-PAA owing to Lewis acid-base interactions and heteroaggregation.

New Insights into the Role of Natural Organic Matter in Fe-Cr Coprecipitation: Importance of Molecular Selectivity.

Coprecipitation of Fe/Cr hydroxides with natural organic matter (NOM) is an important pathway for Cr immobilization. However, the role of NOM in coprecipitation is still controversial due to its molecular heterogeneity and diversity. This study focused on the molecular selectivity of NOM toward Fe/Cr coprecipitates to uncover the fate of Cr via Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS).

Co-transport of biochar nanoparticles (BC NPs) and rare earth elements (REEs) in water-saturated porous media: New insights into REE fractionation.

The present study investigated the co-transport behavior of three REEs (La, Gd, and Yb) with and without biochar nanoparticles (BC NPs) in water-saturated porous media. The presence of REEs enhanced the retention of BC NPs in quartz sand (QS) due to decreased electrostatic repulsion between BC NPs and QS, enhanced aggregation of BC NPs, and the contribution of straining. The distribution coefficients (K) in packed columns in the co-transport of BC NPs and three REEs were much smaller than in batch experiments due to the different hydrodynamic conditions.

[Retarding potential of biochar on antibiotic resistance genes in soil and the mechanisms: A review.].

Antibiotic resistance genes (ARGs) in soil pose a major challenge to global environment and health. The development of effective technologies to reduce their negative effects has implications for maintaining soil health and human health. Biochar would be a suitable control material due to its characteristics of high carbon content, large surface area, excellent adsorption capacity, and economic advantages.

Host-Endosymbiont Relationship Impacts the Retention of Bacteria-Containing Amoeba Spores in Porous Media.

Amoebae are protists that are commonly found in water, soil, and other habitats around the world and have complex interactions with other microorganisms. In this work, we investigated how host-endosymbiont interactions between amoebae and bacteria impacted the retention behavior of amoeba spores in porous media. A model amoeba species, , and a representative bacterium, B1qs70, were used to prepare amoeba spores that carried bacteria.

Significance of Non-DLVO Interactions on the Co-Transport of Functionalized Multiwalled Carbon Nanotubes and Soil Nanoparticles in Porous Media.

Derjaguin-Landau-Verwey-Overbeek (DLVO) theory is typically used to quantify surface interactions between engineered nanoparticles (ENPs), soil nanoparticles (SNPs), and/or porous media, which are used to assess environmental risk and fate of ENPs. This study investigates the co-transport behavior of functionalized multiwalled carbon nanotubes (MWCNTs) with positively (goethite nanoparticles, GNPs) and negatively (bentonite nanoparticles, BNPs) charged SNPs in quartz sand (QS). The presence of BNPs increased the transport of MWCNTs, but GNPs inhibited the transport of MWCNTs.

Transport and Retention of Poly(Acrylic Acid-co-Maleic Acid) Coated Magnetite Nanoparticles in Porous Media: Effect of Input Concentration, Ionic Strength and Grain Size.

Understanding the physicochemical factors affecting nanoparticle transport in porous media is critical for their environmental application. Water-saturated column experiments were conducted to investigate the effects of input concentration (Co), ionic strength (IS), and sand grain size on the transport of poly(acrylic acid-co-maleic acid) coated magnetite nanoparticles (PAM@MNP). Mass recoveries in the column effluent ranged from 45.

Transport and Retention of Free-Living Amoeba Spores in Porous Media: Effects of Operational Parameters and Extracellular Polymeric Substances.

Amoebas are protists that are widespread in water and soil environments. Some species are pathogenic, inducing potentially lethal effects on humans, making them a major threat to public health. Nonpathogenic amoebas are also of concern because they have the potential to carry a mini-microbiome of bacteria, either transiently or via more long-term stable transport.

Non-monotonic contribution of nonionic surfactant on the retention of functionalized multi-walled carbon nanotubes in porous media.

The concentration of nonionic surfactants like Triton X-100 (TX100) can influence the transport and fate of emerging contaminants (e.g., carbon nanotubes) in porous media, but limited research has previously addressed this issue.

Factors influencing heavy metal availability and risk assessment of soils at typical metal mines in Eastern China.

China exemplifies the serious and widespread soil heavy metal pollution generated by mining activities. A total of 420 soil samples from 58 metal mines was collected across Eastern China. Total and available heavy metal concentrations, soil physico-chemical properties and geological indices were determined and collected.

Co-transport and competitive retention of different ionic rare earth elements (REEs) in quartz sand: Effect of kaolinite.

The increasing excavation and utilization of rare earth elements (REEs) have resulted in an elevated release of these elements into the environment. Therefore, investigating the transport behavior of REEs is critical for a comprehensive understanding of their geochemical cycles and to propose potential pollution control strategies. This study investigated the transport, co-transport, and competitive retention of three REEs: La (a light REE), Gd (a middle REE), and Yb (a heavy REE), as well as the co-transport of REEs and kaolinite (a representative clay mineral) in porous media.

Mechanisms of Pb and/or Zn adsorption by different biochars: Biochar characteristics, stability, and binding energies.

Biochar has been widely studied as an amendment for use in remediation of water and soil contaminated with heavy metals such as Pb and Zn, but the effects of biochar characteristics, including stability, on the competitive adsorption of Pb and Zn by biochars from various sources are incompletely understood. In this work, biochars from three different feedstocks, including rice straw (RS), chicken manure (CM), and sewage sludge (SS), were prepared at two pyrolysis temperatures, 550 and 350 °C, and tested to investigate the influence of their stabilities and other characteristics on their adsorption of Pb and Zn in both single- and binary-metal systems. RS biochar had the highest carbon and hydrogen contents, greatest number of functional groups (e.

Interactions of CeO nanoparticles with natural colloids and electrolytes impact their aggregation kinetics and colloidal stability.

The aggregation kinetics and colloidal stability of CeO-NPs in the presence of monovalent or divalent electrolytes, as well as inorganic (kaolin and goethite) and organic (humic acid, HA) colloids were evaluated using time-resolved dynamic light scattering, advanced spectroscopic tools, and theoretical calculations. Critical coagulation concentrations for CeO-NPs were generally lower in CaCl than that in NaCl electrolyte. The negatively charged kaolin accelerated CeO-NPs aggregation due to electrostatic attraction, whilst opposite phenomenon was observed for the positively charged goethite in NaCl solution.

Improved longevity of nanoscale zero-valent iron with a magnesium hydroxide coating shell for the removal of Cr(VI) in sand columns.

Nanoscale zero-valent iron (NZVI) has been engineered as an attractive tool for in-situ groundwater remediation. However, the poor mobility and aqueous corrosion of NZVI in the porous subsurface have hindered its practical applications. In this research, the NZVI surface was coated with a novel Mg(OH) shell (NZVI@Mg(OH)) to improve the feasibility of NZVI for remediation.

Co-transport of multi-walled carbon nanotubes and sodium dodecylbenzenesulfonate in chemically heterogeneous porous media.

Multi-walled carbon nanotubes (MWCNTs) are increasing used in commercial applications and may be released into the environment with anionic surfactants, such as sodium dodecylbenzenesulfonate (SDBS), in sewer discharge. Little research has examined the transport, retention, and remobilization of MWCNTs in the presence or absence of SDBS in porous media with controlled chemical heterogeneity, and batch and column scale studies were therefore undertaken to address this gap in knowledge. The adsorption isotherms of SDBS on quartz sand (QS), goethite coated quartz sand (GQS), and MWCNTs were determined.

Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils.

Batch and saturated soil column experiments were conducted to investigate sorption and mobility of two C-labeled contaminants, the hydrophobic chlordecone (CLD) and the sulfadiazine (SDZ), in the absence or presence of functionalized multi-walled carbon nanotubes (MWCNTs). The transport behaviors of CLD, SDZ, and MWCNTs were studied at environmentally relevant concentrations (0.1-10 mg L) and they were applied in the column studies at different times.