Freezing-driven reduction of chromium(Ⅵ) in ice under solar light without external reductants.

This study systematically investigated the direct photoreduction of Cr(Ⅵ) in ice under simulated sunlight without external reductants. It was shown that the Cr(Ⅵ) photoreduction was observed only in ice at near-neutral pH values but not in aqueous solutions. Cr(Ⅵ) at an initial concentration of 10 μM was efficiently reduced by 75.

Construction of S/g-CN@β-BiO heterojunction and its photocatalytic degradation of toluene in the gas phase.

In this paper, a modification of g-CN was carried out by combining non-metal doping with the construction of heterojunctions, and a type II heterojunction composite, S/g-CN@β-BiO, was prepared. The phase structure, morphology, elemental composition, valence band structure, and light absorption performance of the photocatalyst were analyzed using characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The performance of the composite photocatalyst in the photocatalytic degradation of gaseous toluene, one of the typical volatile organic compounds (VOCs), under simulated solar light was studied.

Hydroxyl radical dominated ibuprofen degradation by UV/percarbonate process: Response surface methodology optimization, toxicity, and cost evaluation.

Ibuprofen (IBP) is a typical nonsteroidal anti-inflammatory drug with a wide range of applications, large dosages, and environmental durability. Therefore, ultraviolet-activated sodium percarbonate (UV/SPC) technology was developed for IBP degradation. The results showed that IBP could be efficiently removed using UV/SPC.

Polypropylene microplastics aging under natural conditions in winter and summer and its effects on the sorption and desorption of nonylphenol.

Plastics in the environment undergo various aging effects. Due to the changes in physical and chemical properties, the sorption behavior of aged microplastics (MPs) for pollutants differs from that of pristine MPs. In this paper, the most common disposable polypropylene (PP) rice box was used as the source of MPs to study the sorption and desorption behavior of nonylphenol (NP) on pristine and naturally aged PPs in summer and winter.

Adsorption of acetone, ethyl acetate and toluene by beta zeolite/diatomite composites: preparation, characterization and adsorbability.

The hierarchical porous composites (Beta/Dt) were prepared by secondary growth method using natural diatomite and beta zeolite. Moreover, XRD, SEM, and BET characterize the composite's composition, surface structure, and pore structure. The adsorbability of Beta/Dt was evaluated by adsorption of three common volatile organic compounds (VOCs) of the printing industry: acetone, ethyl acetate, and toluene.

Enhanced degradation mechanism of tetracycline by MnO with the presence of organic acids.

In this study, we constructed MnO/organic acid (OA) systems using MnO colloid, the most reactive phase of Mn(IV), and two kinds of OA (oxalic acid and l-tartaric acid). We investigated the effect of OA on tetracycline (TC) degradation by MnO. The results show that both OA obviously accelerate TC degradation by MnO.

Photochemical degradation of β-hexachlorocyclohexane in snow and ice.

Hexachlorocyclohexane (HCH), a typical organochloride pesticide, is one of the persistent organic pollutants. Despite the ban on technical grade HCH, it has been continuously observed at a steady level in the environment. The photochemical degradation of β-HCH in snow and ice under ultraviolet (UV) irradiation was investigated in this study.

Ag NPs decorated C-TiO/CdZnS Z-scheme heterojunction for simultaneous RhB degradation and Cr(VI) reduction.

In this study, heterojunction photocatalysts, XAg@C-TCZ, based on MOF-derived C-TiO and CdZnS decorated with Ag nanoparticles (Ag NPs) were successfully synthesized through hydrothermal and calcination methods. The catalytic effectiveness of XAg@C-TCZ was evaluated by simultaneous photocatalytic degradation of rhodamine B (RhB) and reduction of Cr(VI) under simulated sunlight irradiation. The presence of the Z-scheme heterojunction was demonstrated through trapping experiments, X-ray photoelectron spectroscopy (XPS), time-resolved photoluminescence (PL) investigations, and electron spin resonance (ESR) spectroscopy.

Photodegradation of dissolved organic matter of chicken manure: Property changes and effects on Zn/Cu binding property.

Untreated livestock manure contains high concentrations of dissolved organic matter (DOM), which can enter the environment through leaching and eluviation, showing an important impact on the environment. In this research, fresh chicken manure from a large-scale chicken farm was collected as the source of DOM. The infrared spectrum of the original DOM was characterized.

Removal of tetracyclines from aqueous solutions by electrocoagulation/pecan nutshell coupling processes: synergistic effect and mechanism.

The present work compared electrocoagulation (EC)/pecan shell (PS) coupling process with a simple electrocoagulation (EC) process for the removal of tetracyclines (TCs). The results indicated that the addition of appropriate PS could lead to the enhancement of the removal efficiency and decrease of operating time via synergistic influence, including conventional EC process, biomass materials adsorption, charge neutralization and coordination adsorption. The ideal condition for the coupling process was 2.

Fabrication of a magnetic ternary ZnFeO/TiO/RGO Z-scheme system with efficient photocatalytic activity and easy recyclability.

A magnetic composite based on TiO nanosheets, ZnFeO and reduced graphene oxide (RGO) was synthesized by a one-step hydrothermal synthesis method, which possessed the band structure of a Z-scheme photocatalytic system. The properties and structures of the samples were characterized by XRD, UV-Vis DRS, Raman spectroscopy, SEM, EDS, XPS and PL spectroscopy. Compared with TiO nanosheets and the TiO/RGO composite, the obtained ternary composite with 3 wt% RGO exhibited a significant enhancement in photocatalytic activities, attributed to the efficient charge separation induced by the fabricated Z-scheme system.

Effects of oxalic acid on Cr(VI) reduction by phenols in ice.

Since Cr(VI) is highly toxic, the environmental reduction of Cr(VI) to Cr(III) has attracted significant attention. Oxalic acid, a primary component of dissolved organic matter (DOM), is widely distributed throughout the natural environment but the reduction of Cr(VI) by oxalic acid is insignificant at the low concentrations present in the environment; however, the reduction of Cr(VI) is accelerated significantly in ice. In terms of combined pollution, Cr(VI) can coexist with other organic pollutants in the environment but the impact of organic pollutants on the reduction of Cr(VI), changes to the organic pollutants themselves, and the role of oxalic acid in these reactions are unknown.

Comparison of the photoconversion of 1-chloronaphthalene and 2,3-dichlornaphthalene in water.

In this work, the photoconversion of 1-chloronaphthalene (CN-1) and 2,3-dichlornaphthalene (CN-10) under the simulated sunlight had been studied. The results showed that the photoconversion of CN-1 and CN-10 obeyed the first-order kinetics model. NO , NO , Fe and Fe extensively present in natural water can accelerate CN-1 photoconversion via generating ·OH, which may induce indirect photooxidation of CN-1.

Hydrothermal synthesis of Rb and S co-doped Ti-based TiO sheet with a thin film showing high photocatalytic activities.

TiO is considered as one of the most promising semiconductor photocatalysts used to degrade organic pollutants. Element doping has a good effect on improving the properties of TiO. Herein, by using RbSO, we explored the synthesis of Ti-based TiO sheets with a thin film through a hydrothermal reaction.

Photoconversion of 2-Chloronaphthalene in Water.

The photoconversion of 2-chloronaphthalene (CN-2) in water in a simulated sunlight system was investigated. The photoconversion efficiency, photoproducts and mechanisms were inspected, and the effects of inorganic ions (NO, NO) and fulvic acid (FA) were discussed. The results showed that CN-2 could be transformed in water under the irradiation.

The photoconversion of gamma-hexachlorocyclohexane under UV irradiation in water, snow and ice.

The photochemistry of organic pollutants has received increasing attention in ice and snow. In this work, the photoconversion of gamma-hexachlorocyclohexane (γ-HCH) under UV irradiation was investigated in water, snow and ice. The photoconversion rate, products and mechanisms were inspected, and the effect of inorganic ions (NO2(-), NO3(-), HCO3(-) and Fe(2+)) was discussed.

Photo-Fenton effect of 4-chlorophenol in ice.

The photoconversion of 4-chlorophenol (4-CP) in a simulated sunlight-Fenton system was investigated in ice and aqueous solution. It was found that the hydroxyl radical (OH) had an important effect on the photoconversion of 4-CP in both phases, but the effects of Cl(-), SO4(2-), NO3(-), and HCO3(-) were different. In aqueous solution, the photoconversion efficiency of 4-CP was proportional to the OH concentration, and hence, Cl(-) and HCO3(-) as OH scavengers prohibited the photoconversion; SO4(2-) had little effect; NO3(-) promoted the process under certain conditions owing to OH being generated by the photolysis of NO3(-).

Comparison of the photoconversion of para-chlorophenol under simulated sunlight and UV irradiation in ice.

The photochemistry of para-chlorophenol (4-CP) was studied under simulated sunlight (lambda > 300 nm) and UV irradiation by using a 125 W high-pressure mercury lamp with or without a hard glass as light source in an ice matrix. The experiments were carried out in a photochemical cold chamber reactor at -14 to -12 degrees C. The photoconversion rate, photoproducts and photoconversion mechanism of 4-CP were all inspected and compared.

[Study on running efficiency of more spots divisional influent of anaerobic baffled reactor].

The experimentation studied running efficiency of divisional influent mode to anaerobic baffled reactor (ABR) compared with single influent anaerobic baffled reactor that had four compartments. The results showed that the average soluble COD removal rate of single influent was 30%, but divisional influent anaerobic baffled reactor was 35%, and the highest value might reach to 45%, the removal rate of COD was improved over 5% than single influent anaerobic baffled reactor. The main biological processes were micro-aerobic hydrolysis and acidification, at the same time the methane-producing bacteria existed too.

Kinetics and mechanism of para-chlorophenol photoconversion with the presence of nitrite in ice.

The photochemistry of para-chlorophenol (4-CP) under UV irradiation by using a 125-W high-pressure mercury lamp as light source with the presence of nitrite in a solid water ice matrix had been studied. The experiments were carried out in a photochemical cold chamber reactor at -14 to -12 degrees C. Each influence factor of the 4-CP photoconversion kinetics in the water ice was inspected.

[Effects of grazing on architecture and small-scale pattern of grasses on artificial grassland in subtropical zone].

This study was conducted on a 5-year artificial grassland in subtropical zone of South China. The main types of established artificial grassland there were Dactylis glomerata-Lolium prenne-Trifolium repens and D. glomerata-T.

[Effect of cutting periodicity on energy allocation and architecture of Trifolium repens].

On the subtropical mountain swards, the effect of cutting periodicity on energy allocation, module density, number of branches and branching angle of T. repens were significant, With cutting periodicity raised, the energy allocation of stolon increased steadly, the caloric content of unit stolon dropped gradually, and the changing pattern of leaf density, stem density, branch number and internode's length was from low to high, and then to low. The branching intensity of T.