Long-term effects of compound passivator coupled with silicon fertilizer on the reduction of cadmium and arsenic accumulation in rice and health risk evaluation.

Cadmium (Cd) and arsenic (As) are precedence-controlled contaminants in paddy soils, that can easily accumulate in rice grains. Limestone and sepiolite (LS) compound passivator can obviously reduce Cd uptake in rice, whereas Si fertilizer can effectively decrease rice As uptake. Here, the synergistic effects of the LS compound passivator coupled with Si fertilizer (LSCS) on the soil pH and availability of Si, Cd, and As, as well as rice grain Cd and As accumulation and its health risk were studied based on a 3-year consecutive field experiment.

Effects of single and combined contamination of total petroleum hydrocarbons and heavy metals on soil microecosystems: Insights into bacterial diversity, assembly, and ecological function.

Deciphering the impact of single and combined contamination of total petroleum hydrocarbons (TPH) and heavy metals on soil microecosystems is essential for the remediation of contaminated habitats, yet it remains incompletely understood. In this study, we employed high-throughput sequencing to investigate the impact of single TPH contamination, single metal contamination, and their co-contamination on soil microbial diversity, assembly mechanisms, composition, ecological function, and resistome. Our results revealed that contamination led to a reduction in alpha diversity, with single contamination displaying lower diversity compared to co-contamination, depending on the concentration of pollutants.

Insights into the Fracture Nature of Hematite from First Principles DFT Calculations.

Hematite, as an important iron source, usually crystallizes in the structure of rhombohedral R3̅c in nature. To date, reports on the major exposed surface of hematite are still inconclusive. Herein, the fracture nature of hematite is studied by the density functional theory (DFT) method.

Effects of Interfacial Hydroxylation Microstructure on Quartz Flotation by Sodium Oleate.

Quartz, a common inorganic nonmetallic mineral, is usually removed or purified by beneficiation, normally flotation. Given the strong polarity of the quartz surface, it is easy to hydrate to form a hydroxylation layer, which makes it impossible to float quartz with sodium oleate (OL) used alone. An ideal flotation method for quartz is preactivation with Ca, followed by collection with OL.

Deep purification of copper from Cu(II)-EDTA acidic wastewater by Fe(III) replacement/diethyldithiocarbamate precipitation.

Cu(II)-EDTA is a highly stable typical metal-organic complex in a wide pH range (3.0-12.0) and it is difficult to deeply purify Cu(II) by conventional precipitation methods.

Fabrication of Polyaluminium Ferric Sulfate from Bauxite Residue for Efficient Removal of Cr(VI) from Simulated Wastewater.

Bauxite residue is generated from alumina production in the alumina refining industry by the Bayer process, which requires a large amount of land resource and causes serious environmental problems. In this paper, a novel recycling strategy is proposed to rehabilitate the land and produce the polyaluminium ferric sulfate (PAFS) and siliceous gypsum byproducts from the bauxite residue. The batch experiments reveal that the maximum Cr(VI) removal efficiency of as-prepared PAFS can reach 95.

Flotation of Smithsonite From Quartz Using Pyrophyllite Nanoparticles as the Natural Non-toxic Collector.

The use of natural hydrophobic mineral nanoparticles as a collector in froth flotation has recently attracted the attention of researchers. In this article, the separation performance and mechanism of pyrophyllite nanoparticles (PNPs) on smithsonite and quartz flotation system were investigated using the method of flotation, zeta potential, contact angle, and scanning electron microscope (SEM)/energy disperse spectroscopy (EDS). The results of single mineral flotation showed that the difference in flotation recovery between smithsonite and quartz was large for NaOL, DDA, and PNP collectors in the acidic pH range, the largest of which was the PNP system.

Effects of the Goethite Surface Hydration Microstructure on the Adsorption of the Collectors Dodecylamine and Sodium Oleate.

Dodecylamine (DDA) and sodium oleate (OL) are commonly used collectors in the reverse flotation and the direct flotation of goethite. However, the flotation mechanisms of DDA and OL on the goethite surface remain unclear. In this study, the first-principles density functional theory calculations were used to reveal the role of the hydration of the goethite surface and its effects on flotation reagents from a microscopic perspective.

Interface Interaction of Benzohydroxamic Acid with Lead Ions on Oxide Mineral Surfaces: A Coordination Mechanism Study.

Surface coordination chemistry is important in areas such as adsorption, separation, and catalysts. In this work, surface coordination interactions of benzohydroxamic acid (BHA) with the lead ion [Pb(II)] adsorbed on the cassiterite surface have been investigated by first-principles calculations due to its great significance in froth flotation. Cluster calculations show that BHA possesses the weakest chelation with Pb(II) due to the electron withdrawal ability of the benzyl ring in comparison with other hydroxamic acids.

Effects of Hydration on the Adsorption of Benzohydroxamic Acid on the Lead-Ion-Activated Cassiterite Surface: A DFT Study.

The strategy of enhancing the surface activity by preadsorption of metal ions (surface activation) is an effective way to promote the adsorption of surfactant on surfaces, which is very important in surface process engineering. However, the adsorption mechanism of surfactant (collector) on the surface preadsorbed by metal ions in the explicit solution phase is still poorly understood. Herein, the effects of hydration on the adsorption of benzohydroxamic acid (BHA) onto the oxide mineral surface before and after lead-ion activation are investigated by first-principles calculations, owing to its importance in the field of flotation.

Enhanced removal of Co(II) and Ni(II) from high-salinity aqueous solution using reductive self-assembly of three-dimensional magnetic fungal hyphal/graphene oxide nanofibers.

Layer-structured graphene oxide excellent carrier for modifications; however, its poor recoverability and stability preclude its application in wastewater treatment fields. Herein, three-dimensional magnetic fungal hyphal/graphene oxide nanofibers (MFHGs) were assembled by a reductive self-assembly (RSA) strategy for the efficient capture of Co(II) and Ni(II) from high-salinity aqueous solution. The RSA strategy is inexpensive, eco-friendly and easy to scale up.

Recycling of iron and titanium resources from early tailings: From fundamental work to industrial application.

The comprehensive recovery of iron and titanium resources from early tailings were systematically attempted from fundamental work to industrial application. Geochemical characterization of the tailings was first conducted, followed by the iron recovery and titanium recovery. Iron recovery was mainly achieved through a series of magnetic separation, and titanium recovery was on the combination of magnetic pre-concentration and flotation separation.