Environmental Stability Determines the Cytotoxicity of Metal-Organic Frameworks to a Nitrogen-Fixing Bacterium .

During widespread applications of metal-organic frameworks (MOFs), the environmental hazards and risks of MOFs have aroused great concerns. In this study, we aimed to reveal the importance of the environmental stability of MOFs on their toxicity. Two Zn-MOFs, namely, ZIF-8 with high aqueous stability and Zn-BDC with low aqueous stability, were compared directly in the toxicological evaluations of a nitrogen-fixing bacterium .

Toxicity and decomposition activity inhibition of VO micro/nanoparticles to white rot fungus Phanerochaete chrysosporium.

Vanadium dioxide (VO) is an excellent phase transition material widely used in various applications, and thus inevitably enters the environment via different routes and encounters various organisms. Nonetheless, limited information is available on the environmental hazards of VO. In this study, we investigated the impact of two commercial VO particles, nanosized S-VO and micro-sized M-VO on the white rot fungus Phanerochaete chrysosporium.

Raman spectroscopic quantification of graphene oxide in soil: Transport, surficial enrichment and environmental effects.

The transport and retention data in environmental media are indispensable for the hazard evaluations of graphene materials. Due to the complexity of soil, the transport of graphene is hard to quantify without isotope labeling. Herein, we developed 2D Raman mapping as a label-free technique to quantify graphene oxide (GO) in soil.

Reduced graphene oxide promotes the biodegradation of sulfamethoxazole by white-rot fungus Phanerochaete chrysosporium under cadmium stress.

The biodegradation of antibiotics in aquatic environment is consistently impeded by the widespread presence of heavy metals, necessitating urgent measures to mitigate or eliminate this environmental stress. This work investigated the degradation of sulfamethoxazole (SMX) by the white-rot fungus Phanerochaete chrysosporium (WRF) under heavy metal cadmium ion (Cd) stress, with a focus on the protective effects of reduced graphene oxide (RGO). The pseudo-first-order rate constant and removal efficiency of 5 mg/L SMX in 48 h by WRF decrease from 0.

Phytotoxicity of metal-organic framework MOF-74(Co) nanoparticles to pea seedlings.

Metal-organic framework (MOF) materials have unique structure and fantastic properties for wide-ranging applications. Pilot studies highlighted the toxicity and potential threats of MOF materials to the environment. In this study, we revealed the phytotoxicity of MOF-74(Co) nanoparticles (NPs) and their inhibitory effects on the photosynthesis of pea seedlings ( L.

Toxicity of VO micro/nanoparticles to nitrogen-fixing bacterium Azotobacter vinelandii.

Vanadium dioxide (VO) has been used in a variety of products due to its outstanding phase transition properties. However, as potential heavy metal contaminants, the environmental hazards and risks of VO should be systematically investigated. Biological nitrogen fixation is one of the most dominant processes in biogeochemical cycle, which is associated with nitrogen-fixing bacteria.

How accompanying ions affect soil heavy metal removal by polyepoxysuccinic acid during washing?

Soil washing with green eluent is an efficient technique to remediate heavy metal contaminated farmland. In addition to eluent, less is known about the roles of accompanying ions on heavy metal removal. We investigated the effects of accompanying ions including Fe, Mn, Ca, Mg, Al, Si and PO on the desorption of Pb and Cd in paddy and arid soils using ethylenediaminetetraacetic acid and polyepoxysuccinic acid as eluents.

Organic ligands regulate the environmental impacts of metal-organic frameworks on nitrogen-fixing bacterium Azotobacter vinelandii.

Metal-organic frameworks (MOFs) are rapidly developed materials with fantastic properties and wide applications. The increasing studies highlighted the potential threats of MOF materials to the environment. Comparing to the limited species of metal elements, the organic ligands have much higher diversity, but the influence of organic ligands on the environmental impacts of MOFs has not been revealed.

Particulate toxicity of metal-organic framework UiO-66 to white rot fungus Phanerochaete chrysosporium.

Metal-organic frameworks (MOF) are emerging materials with fantastic properties and wide applications. The release of metal ions from MOF materials is usually regarded as the origin of soluble MOF toxicity. However, whether the stable MOF particulates would induce environmental hazards is not clear.

Efficiency and comprehensive risk assessment of soil Pb and Cd by washing technique with three biodegradable eluents.

Soil washing with environmentally friendly eluents is a rapid remediation technique for farmland polluted by heavy metals. In this study, polyepoxysuccinic acid (PESA), ethylenediamine tetra (methylene phosphonic acid) sodium (EDTMPS), and phosphonyl carboxylic acid copolymer (POCA) were applied to remedy paddy and arid soils polluted by Pb and Cd. At the same time, ethylenediaminetetraacetic acid (EDTA) was used as a control eluent.

Can heavy metal pollution induce bacterial resistance to heavy metals and antibiotics in soils from an ancient land-mine?

Microbial resistance to antibiotics is a growing challenge to human health. Recent evidence has indicated that antibiotic resistance can be co-selected for by exposure to heavy metals in agricultural soils. It remains unknown if this is a concern in other environments contaminated by metals.

Remediation of heavy metal contaminated soil by biodegradable chelator-induced washing: Efficiencies and mechanisms.

Biodegradable chelators (BCs) are promising substitutes for conventional washing agents in the remediation of heavy metal contaminated soil with strong complexing ability and less cost. However, great challenges for the applications of BC-assisted washing still exist, such as the assessment of the factor affecting the efficiency of metal removal and the unclear of the metal removal mechanism. Batch washing was therefore explored to evaluate the potential for four BCs for removing Cd, Pb, and Zn from polluted soils.

Synchronous removal of ammonium and phosphate from swine wastewater by two agricultural waste based adsorbents: Performance and mechanisms.

Two agricultural wastes, Chinese medicinal herbal residue and spent Pleurotus ostreatus substrate, were developed to remove ammonium and phosphate from swine wastewater. These adsorbents were mesoporous materials with abundant smooth layered pores, and rough protuberances and grooves, respectively. Their adsorption capacities were 1131.

Effects of soil chemical properties and fractions of Pb, Cd, and Zn on bacterial and fungal communities.

Heavy metal contamination in soils poses a serious threat to microorganisms, which play important roles in soil biogeochemical process. However, the key fractions of heavy metals affecting soil microorganisms are still unclear. In this study, DNA sequencing, redundancy and variance partition analysis were performed to investigate the combined effects of heavy metal fractions and soil chemical properties on microbial communities in Pb, Cd, and Zn co-contaminated soils.

Removal of lead, zinc and cadmium from contaminated soils with two plant extracts: Mechanism and potential risks.

Screening appropriate washing agents to remediate soils contaminated with heavy metals is crucial for decreasing metal hazards posing to environment and human health. In this study, two plant washing agents-water-extracted from Fagopyrum esculentum and Fordiophyton faberi, were applied to remove soil Pb, Zn, and Cd by washing. Results indicated that metal removals augmented with increase of washing solution concentrations, decreased with increasing pH values of the solution and followed the pseudo-second-order model depending on contact duration.

Soil washing remediation of heavy metal from contaminated soil with EDTMP and PAA: Properties, optimization, and risk assessment.

Soil washing is a rapid and efficient remediation technique for soil contaminated by heavy metals. In this study, Cd, Pb, and Zn were removed from contaminated soil by ethylenediamine tetra (methylene phosphonic acid) (EDTMP) and polyacrylic acid (PAA). We then investigated the effect of varying the concentration, pH and duration of the washing processes.

Feasibility of nanoscale zero-valent iron to enhance the removal efficiencies of heavy metals from polluted soils by organic acids.

Soil washing with natural chelators to remediate metal-contaminated soils has been gained attention by researchers. However, the abilities of the chelators to remediate the multiple metal polluted soils are less effective. This study employed zero-valent iron nanoparticle (nZVI) to enhance the removal efficiencies of citric (CA), tartaric (TA) and oxalic acids (OA), and evaluate their feasibility.

Effect of soil washing with biodegradable chelators on the toxicity of residual metals and soil biological properties.

Soil washing with chelators is a promising and efficient method of remediating metals-contaminated soils. However, the toxicity of residual metals and the effects on soil microbial properties have remained largely unknown after washing. In this study, we employed four biodegradable chelators for removal of metals from contaminated soils: iminodisuccinic acid (ISA), glutamate-N,N-diacetic acid (GLDA), glucomonocarbonic acid (GCA), and polyaspartic acid (PASP).

Feasibility of four wastes to remove heavy metals from contaminated soils.

Soil washing is one of the permanent techniques to remove heavy metals, and washing agent is a key influence factor for this technique, but there is still lack of high-efficiency, eco-friendly, and inexpensive agents. In this study, four wastes including pineapple peel (PP), soybean straw (SS), broad bean straw (BBS) and tea residue (TR) were employed to remove cadmium (Cd), lead (Pb) and zinc (Zn) in contaminated soils. The Fourier transform infrared spectroscopy (FTIR) analysis indicated that hydroxyl, carboxyl, amine, carbonyl and amide groups were involved in the interaction with metal ions by complexation or ion exchange.

Heavy metals in soils from a typical industrial area in Sichuan, China: spatial distribution, source identification, and ecological risk assessment.

Anthropogenic activities could result in increasing concentrations of heavy metals in soil and deteriorating in soil environmental quality. Topsoil samples from a typical industrial area, Shiting River Valley, Sichuan, Southwest China, were collected and determined for the concentrations of Cu, Zn, Cr, Cd, As, and Hg. The mean concentrations of these metals were lower than the national threshold values, but were slightly higher than their corresponding background values, indicating enrichment of these metals in soils in the valley, especially for Cu, Zn, and Hg.

Heavy metal removal by GLDA washing: Optimization, redistribution, recycling, and changes in soil fertility.

Soil washing, an emerging method for treating soils contaminated by heavy metals, requires an evaluation of its efficiency in simultaneously removing different metals, the quality of the soil following remediation, and the reusability of the recycled washing agent. In this study, we employed N,N-bis (carboxymethyl)-l-glutamic acid (GLDA), a novel and readily biodegradable chelator to remove Cd, Pb, and Zn from polluted soils. We investigated the influence of washing conditions, including GLDA concentration, pH, and contact time on their removal efficiencies.

Spatial variability of soil nitrogen in a hilly valley: Multiscale patterns and affecting factors.

Estimating the spatial distribution of soil nitrogen at different scales is crucial for improving soil nitrogen use efficiency and controlling nitrogen pollution. We evaluated the spatial variability of soil total nitrogen (TN) and available nitrogen (AN) in the Fujiang River Valley, a typical hilly region composed of low, medium and high hills in the central Sichuan Basin, China. We considered the two N forms at single hill, landscape and valley scales using a combined method of classical statistics, geostatistics and a geographic information system.