Effects of coexisting goethite or lepidocrocite on Fe(II)-induced ferrihydrite transformation pathways and Cd speciation.

The efficacy of ferrihydrite in remediating Cd-contaminated soil is tightly regulated by Fe(II)-induced mineralogical transformations. Despite the common coexistence of iron minerals such as goethite and lepidocrocite, which can act as templates for secondary mineral formation, the impact of these minerals on Fe(II)-induced ferrihydrite transformation and the associated Cd fate have yet to be elucidated. Herein, we investigated the simultaneous evolution of secondary minerals and Cd speciation during Fe(II)-induced ferrihydrite transformation in the presence of goethite versus lepidocrocite.

The community dynamic alterations mechanisms of traveling plastics in the Pearl River estuary with the salinity influence.

Most ocean plastics originate from terrestrial emissions, and the plastisphere on the plastics would alter during the traveling due to the significant differences in biological communities between freshwater and marine ecosystems. Microorganisms are influenced by the increasing salinity during traveling. To understand the contribution of plastic on the alteration in biological communities of plastisphere during traveling, this study investigated the alterations in microbial communities on plastics during the migration from freshwater to brackish water and saltwater.

Influence of calcium carbonate on ferrihydrite bio-transformation and associated arsenic mobilization/redistribution.

The sulfate-reducing bacteria (SRB)-induced ferrihydrite transformation is an important cause for arsenic (As) contamination in the aquifer near mining area. Calcium carbonate (CaCO) is widespread and has the potential of regulating As fate directly or indirectly. However, the influence of CaCO on ferrihydrite transformation and the associated As mobilization/redistribution in SRB-containing environments remains unclear.

Birnessite enhanced Cr(III) oxidation during subsurface geochemical processes: Role of Mn(III)-induced nonphotochemical reactive oxygen species.

Cr(III) oxidation by birnessite was the dominant geologic source of Cr(VI), which increases the environmental mobility and toxicity of Cr, threatening ecological safety. Photochemically hydroxyl radical (•OH) generated by birnessite was widely accepted to be the dominant reactive oxygen species (ROS) oxidating Cr(III). However, birnessite and Cr mainly co-exist in dark subsurface soils, with contribution of nonphotochemical ROS remaining unclear.

The role of interface interaction between iron/sulfate-reducing bacteria (ISRB) and goethite in sulfur (S) redox cycling couple with Cd immobilization.

Microbial sulfate reduction leads to the formation of various chalcophile trace metal sulfides, thereby immobilizing chalcophile trace metals in sediments. Iron/sulfate-reducing bacteria (ISRB) are ubiquitous in soils and sediments, its ability to reduce Fe(III) (oxyhydr)oxides and biogeochemical significance have attracted much attention. This research investigated the effect of the goethite and ISRB induced S cycle on cadmium mobility.

Novel magnetic adsorbents based on oyster and clam shells for the removal of cadmium in soil.

Magnetic adsorbents can effectively remove heavy metals from soil. However, the magnetization process may reduce availability of adsorption sites, making it challenging to balance magnetic and adsorption properties. In this study, oyster shell (OS) and clam shell (CS) material was magnetized by an improved chemical co-precipitation method.

The interaction between organic acids and green rust-Co(II): Mineralogical changes of green rust and redistribution of Co(II).

Green rust (GR), as a vital intermediate product during the formation of various iron oxides, exists with organic matters and metals contaminants in natural environments. Understanding the effects of these natural factors on the transformation process of GR into iron oxides and the environmental behaviors of heavy metals and organic matters during process are critical for environmental quality management, but the fundamental identification of the interaction mechanisms between them and GR is still challenging. In this study, the transformation mechanisms of Co-bearing green rust (GR-Co) synthesized by co-precipitation, and the redistribution behaviors of Co(II) in an environment containing oxalic acid (OA) and citric acid (CA) were clarified.

Efficient Desulfurizer Recycling during Spent Lead-Acid Batteries Paste Disposal by Zero-Carbon Precursor Hypothermic Smelting.

Recycling of spent lead-acid batteries (LABs) is extremely urgent in view of environmental protection and resources reuse. The current challenge is to reduce high consumption of chemical reagents. Herein, a closed-loop spent LABs paste (SLBP) recovery strategy is demonstrated through NaMoO consumption-regeneration-reuse.

Photochemical Origins of Iron Flocculation in Acid Mine Drainage.

Acid mine drainage (AMD) raises a global environmental concern impacting the iron cycle. Although the formation of Fe(III) minerals in AMD-impacted waters has previously been reported to be regulated by biological processes, the role of abiotic processes remains largely unknown. This study first reported that a photochemical reaction coupled with O significantly accelerated the formation of Fe(III) flocculates (i.

Transformation of 17β-estradiol to estrone by unknown wild-type enzyme in commercial arylsulfatase from Helix pomatia.

This work for the first time reported the complete transformation of 17β-estradiol (E2) to estrone (E1) by unknown wild-type enzyme present in the widely used commercial arylsulfatase derived from Helix pomatia. It was found that acetate could effectively inhibit the unknown enzyme with a half inhibitory concentration (IC) of 140.9 μM, while phosphate and citrate showed no inhibition.

Enhanced removal of tetracycline in light-dark tandem by FeCu-doped carbon composites derived from waste cotton fabrics.

It is of great significance to develop an energy-efficient and external oxidant-free strategy for antibiotics removal. In this study, the novel light-dark tandem strategy was established to enhance tetracycline (TC) removal by bifunctional FeCu-doped carbon composites (FeCu@BC) derived from waste cotton fabrics. Interestingly, over 95 % TC was removed by FeCu@BC under light alone and dark alone in 10 min, with the same preferred conditions of pH 7.

Influence of macromolecules and electrolytes on heteroaggregation kinetics of polystyrene nanoplastics and goethite nanoparticles in aquatic environments.

Fate and transport of nanoplastics in aquatic environments are affected by their heteroaggregation with minerals in the presence of macromolecules. This study investigated the heteroaggregation of polystyrene nanoplastics (PSNPs) with goethite nanoparticles (GNPs) under the influence of macromolecules [humic acid (HA), bovine serum albumin (BSA), and DNA] and electrolytes. Under 1 mg C/L macromolecule, raising electrolyte concentration promoted heteroaggregation via charge screening, except that calcium bridging with HA also enhanced heteroaggregation at CaCl concentration above 5 mM.

Influence of tartaric acid on the electron transfer between oxyanions and lepidocrocite.

Iron oxide minerals control the environmental behavior of trace elements. However, the potential effects of electron transfer directions by iron oxides between organic acids and trace elements remain unclear. This study investigates the redox capacity of tartaric acid (TA) with chromate (Cr(Ⅵ)) or arsenate (As(V)) on lepidocrocite (Lep) from the perspective of electron transfer.

An Anti-Scaling Strategy for Electrochemical Wastewater Treatment: Leveraging Tip-Enhanced Electric Fields.

Electrode scaling poses a critical barrier to the adoption of electrochemical processes in wastewater treatment, primarily due to electrode inactivation and increased internal reactor resistance. We introduce an antiscaling strategy using tip-enhanced electric fields to redirect scale-forming compounds (e.g.

The effect of goethite aging on Cd adsorption: Constraints of mineral condensation and surface site density.

Iron (hydr)oxides, as natural geosorbents, play a crucial role in retaining toxic heavy metals, and their aging process greatly influences heavy metals distributions and migration in soil systems. However, limited attention has been given to the interaction between heavy metals and crystalline-aged goethite. In this study, we investigated the sorption behavior and sorption mechanism of cadmium (Cd) with freshly synthesized or aged goethite.

Sulfidation of Cd-Sch during the microbial sulfate reduction: Nanoscale redistribution of Cd.

Schwertmannite (Sch) is found in environments abundant in iron and sulfate. Microorganisms that utilize iron or sulfate can induce the phase transition of Schwertmannite, consequently leading to the redistribution of coexisting pollutants. However, the impact of the molar ratio of sulfate to iron (S/Fe) on the microbial-mediated transformation of Schwertmannite and its implications for the fate of cadmium (Cd) have not been elucidated.

Acetate anions intercalated Fe/Mg-layered double hydroxides modified biochar for efficient adsorption of anionic and cationic heavy metal ions from polluted water.

The simultaneous removal of anionic and cationic heavy metals presents a challenge for adsorbents. In this study, acetate (Ac-) was utilized as the intercalating anion for layered double hydroxide (LDH) to prepare a novel biochar composite adsorbent (Ac-LB) designed for the adsorption of Pb(II), Cu(II), and As(V). By utilizing Ac- as the intercalating anion, the interlayer space of the LDH was enlarged from 0.

Effect of biochar-derived DOM on contrasting redistribution of chromate during Schwertmannite dissolution and recrystallization.

Biochar-derived dissolved organic matter (BDOM), is extensively involved in the recrystallization of minerals and the speciation alteration of associated toxic metals. This study investigates how BDOM extracted from tobacco petiole (TP) or tobacco stalk (TS) biochar influences the speciation repartitioning of Cr(VI) in environments impacted by acid mine drainage (AMD), focusing on interactions with secondary minerals during Schwertmannite (Sch) dissolution and recrystallization. TP-BDOM, rich in lignin-like substances, slowed down the Cr-Sch dissolution and Cr release under acidic conditions compared to TS-BDOM.

CaAl-Layered Double Hydroxides-Modified Biochar Composites Mitigate the Toxic Effects of Cu and Pb in Soil on Pea Seedlings.

Compound contamination of soil with heavy metals copper (Cu) and lead (Pb) triggered by mining development has become a serious problem. To solve this problem, in this paper, corncob kernel, which is widely available and inexpensive, was used as the raw material of biochar and modified by loading CaAl-layered double hydroxides to synthesize biochar-loaded CaAl-layered double hydroxide composites (CaAl-LDH/BC). After soil remediation experiments, either BC or CaAl-LDH/BC can increase soil pH, and the available phosphorus content and available potassium content in soil.

The effect of heavy precipitation on the leaching of heavy metals from tropical coastal legacy tailings.

The continued growth in demand for mineral resources has led to a large amount of mining wastes, which is a major challenge in the context of carbon neutrality and climate change. In this study, runoff migration, batch leaching, and column experiments were used to investigate the short-, medium-, and long-term leaching of heavy metals from legacy tailings, respectively; the cumulative metal release kinetic equations were established, and the long-term effects of tailings leaching were verified by HYDRUS-1D. In runoff migration experiments, surface dissolution of tailings and the co-migration of adsorbed soil particles by erosion were the main carriers in the early stages of leachate formation (Mn ∼ 65 mg/L and SO up to 2697.

Arsenic redistribution associated with Fe(II)-induced jarosite transformation in the presence of polygalacturonic acid.

Jarosite exists widely in acid-sulfate soil and acid mine drainage polluted areas and acts as an important host mineral for As(V). As a metastable Fe(III)-oxyhydoxysulfate mineral, its dissolution and transformation have a significant impact on the biogeochemical cycle of As. Under reducing conditions, the trajectory and degree of abiotic Fe(II)-induced jarosite transformation may be greatly influenced by coexisting dissolved organic matter (DOM), and in turn influencing the fate of As.