Photo-reduction of bromate in drinking water by metallic Ag and reduced graphene oxide (RGO) jointly modified BiVO4 under visible light irradiation.

Bromate (BrO3(-)), an oxyhalide disinfection by-product (DBP) in drinking water, has been demonstrated to be carcinogenic and genotoxic. In the current work, metallic Ag and reduced graphene oxide (RGO) co-modified BiVO4 was successfully synthesized by a stepwise chemical method coupling with a photo-deposition process and applied in the photo-reduction of BrO3(-) under visible light irradiation. In this composite, metallic Ag acted as an electron donor or mediator and RGO enhanced the BrO3(-) adsorption onto the surface of catalysts as well as an electron acceptor to restrict the recombination of photo-generated electron-hole pairs.

Fast removal of tetracycline from wastewater by reduced graphene oxide prepared via microwave-assisted ethylenediamine-N,N'-disuccinic acid induction method.

A green reagent of ethylenediamine-N,N'-disuccinic acid (EDDS) was reported herein for reduction of graphene oxide (GO) with microwave assistance. The characteristics of EDDS reduced graphene oxide (ERG), and the tetracycline (TC) adsorption behavior of ERG was investigated. The results showed that the deoxygenation efficiency of GO strongly depended on the EDDS amount and the ERG can be successively obtained by recycled EDDS.

Nutrient removal and lipid production by Coelastrella sp. in anaerobically and aerobically treated swine wastewater.

Coelastrella sp. QY01, a microalgae species isolated from a local pond, was identified and used for the treatment of anaerobically and aerobically treated swine wastewater (AnATSW). Microalgal growth characteristics, nutrient removal and lipid accumulation of QY01 cultivated in the initial concentration of AnATSW ranged from 63 to 319mg NH3-N/L were examined.

Acyl-homoserine lactone-based quorum sensing and quorum quenching hold promise to determine the performance of biological wastewater treatments: An overview.

Quorum sensing (QS) is a communication process between cells, in which bacteria secrete and sense the specific chemicals, and regulate gene expression in response to population density. Quorum quenching (QQ) blocks QS system, and inhibits gene expression mediating bacterial behaviors. Given the extensive research of acyl-homoserine lactone (AHL) signals, existences and effects of AHL-based QS and QQ in biological wastewater treatments are being subject to high concern.

Enhanced adsorptive removal of p-nitrophenol from water by aluminum metal-organic framework/reduced graphene oxide composite.

In this study, the composite of aluminum metal-organic framework MIL-68(Al) and reduced graphene oxide (MA/RG) was synthesized via a one-step solvothermal method, and their performances for p-nitrophenol (PNP) adsorption from aqueous solution were systematically investigated. The introduction of reduced graphene oxide (RG) into MIL-68(Al) (MA) significantly changes the morphologies of the MA and increases the surface area. The MA/RG-15% prepared at RG-to-MA mass ratio of 15% shows a PNP uptake rate 64% and 123% higher than MIL-68(Al) and reduced graphene oxide (RG), respectively.

Antibacterial properties and mechanism of graphene oxide-silver nanocomposites as bactericidal agents for water disinfection.

Providing clean and affordable drinking water without harmful disinfection byproducts generated by conventional chemical disinfectants gives rise to the need for technological innovation. Nanotechnology has great potential in purifying water and wastewater treatment. A graphene oxide-silver (GO-Ag) nanocomposite with excellent antibacterial activity was prepared and characterized by transmission electron microscope and X-ray photoelectron spectroscopy.

Growth inhibition and oxidative damage of Microcystis aeruginosa induced by crude extract of Sagittaria trifolia tubers.

Aquatic macrophytes are considered to be promising in controlling harmful cyanobacterial blooms. In this research, an aqueous extract of Sagittaria trifolia tubers was prepared to study its inhibitory effect on Microcystis aeruginosa in the laboratory. Several physiological indices of M.

Effects of modified zeolite on the removal and stabilization of heavy metals in contaminated lake sediment using BCR sequential extraction.

Sediment can be applied on land as a soil conditioner. However, toxic substances such as heavy metals within the sediment often lead to soil contamination if no proper management is conducted prior to land application. In order to reduce the bioavailable portion of heavy metals such as Pb, Cu, Zn and Cd, zeolite as a kind of stabilizer was investigated on the effect of metal stabilization in sediment.

Biochar-based nano-composites for the decontamination of wastewater: A review.

Synthesizing biochar-based nano-composites can obtain new composites and combine the advantages of biochar with nano-materials. The resulting composites usually exhibit great improvement in functional groups, pore properties, surface active sites, catalytic degradation ability and easy to separation. These composites have excellent abilities to adsorb a range of contaminants from aqueous solutions.

A combined biological removal of Cd(2+) from aqueous solutions using Phanerochaete chrysosporium and rice straw.

The removal of Cd(2+) from aqueous solutions by agricultural residues rice straw combined with white rot fungus Phanerochaete chrysosporium (P. chrysosporium) was investigated. The results showed that over 99% of the total Cd(2+) (initial concentration of 150mgL(-1)) was removed at the optimal operating conditions (pH 5.

Effects of heavy metals and soil physicochemical properties on wetland soil microbial biomass and bacterial community structure.

Heavy metals (HMs) contamination is a serious environmental issue in wetland soil. Understanding the micro ecological characteristic of HMs polluted wetland soil has become a public concern. The goal of this study was to identify the effects of HMs and soil physicochemical properties on soil microorganisms and prioritize some parameters that contributed significantly to soil microbial biomass (SMB) and bacterial community structure.

An exploration of spatial human health risk assessment of soil toxic metals under different land uses using sequential indicator simulation.

A modified method was proposed which integrates the spatial patterns of toxic metals simulated by sequential indicator simulation, different exposure models and local current land uses extracted by remote-sensing software into a dose-response model for human health risk assessment of toxic metals. A total of 156 soil samples with a various land uses containing farm land (F1-F25), forest land (W1-W12) and residential land (U1-U15) were collected in a grid pattern throughout Xiandao District (XDD), Hunan Province, China. The total Cr and Pb in topsoil were analyzed.

Aging study on carboxymethyl cellulose-coated zero-valent iron nanoparticles in water: Chemical transformation and structural evolution.

To assess the long-term fate and the associated risks of nanoscale zero-valent iron (nZVI) used in the water remediation, it is essential to understand the chemical transformations during aging of nZVI in water. This study investigated the compositional and structural evolution of bare nZVI and carboxymethyl cellulose (CMC) coated nZVI in static water over a period of 90 days. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the corrosion products of nZVI and CMC-nZVI.

Degradation of atrazine by a novel Fenton-like process and assessment the influence on the treated soil.

This is the premier study reporting the remediation of atrazine contaminated soil with steel converter slag (SCS) catalyzed Fenton-like process. The effects of various operating parameters, such as SCS loads and H2O2 concentrations were evaluated with respect to the removal efficiency of atrazine. Results show the optimal SCS load and H2O2 concentration were 80gkg(-1) and 10%, respectably.

Responses of soil microbial biomass and bacterial community structure to closed-off management (an ecological natural restoration measures): A case study of Dongting Lake wetland, middle China.

Soil microbial biomass (SMB) and bacterial community structure, which are critical to global ecosystem and fundamental ecological processes, are sensitive to anthropogenic activities and environmental conditions. In this study, we examined the possible effects of closed-off management (an ecological natural restoration measures, ban on anthropogenic activity, widely employed for many important wetlands) on SMB, soil bacterial community structure and functional marker genes of nitrogen cycling in Dongting Lake wetland. Soil samples were collected from management area (MA) and contrast area (CA: human activities, such as hunting, fishing and draining, are permitted) in November 2013 and April 2014.

Traffic-related heavy metals uptake by wild plants grow along two main highways in Hunan Province, China: effects of soil factors, accumulation ability, and biological indication potential.

This study was performed to investigate pollution of traffic-related heavy metals (HMs-Zn, Pb, Cu, Cr, and Cd) in roadside soils and their uptake by wild plants growing along highways in Hunan Province, China. For this, we analyzed the concentration and chemical fractionation of HMs in soils and plants. Soil samples were collected with different depths in the profile and different distances from highway edge.

Impacts of human activity modes and climate on heavy metal "spread" in groundwater are biased.

Groundwater quality deterioration has attracted world-wide concerns due to its importance for human water supply. Although more and more studies have shown that human activities and climate are changing the groundwater status, an investigation on how different groundwater heavy metals respond to human activity modes (e.g.

Heavy metals in road dust from Xiandao District, Changsha City, China: characteristics, health risk assessment, and integrated source identification.

The physicochemical properties and the contents of metals (Cu, Zn, Pb, Cd, Cr, and Fe) in 51 road dust samples from Xiandao District (XDD) were investigated. Enrichment factor (EF), multivariate statistics, geostatistics, and health risk assessment model were adopted to study the spatial pollution pattern and to identify the priority pollutants and regions of concern and sources of studied metals. The mean EFs revealed the following order: Cd > Zn ≈ Pb ≈ Cu > Cr.

Easily separated silver nanoparticle-decorated magnetic graphene oxide: Synthesis and high antibacterial activity.

Silver nanoparticle-decorated magnetic graphene oxide (MGO-Ag) was synthesized by doping silver and Fe3O4 nanoparticles on the surface of GO, which was used as an antibacterial agent. MGO-Ag was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy dispersive X-ray (EDS), X-ray diffraction (XRD), Raman spectroscopy and magnetic property tests. It can be found that magnetic iron oxide nanoparticles and nano-Ag was well dispersed on graphene oxide; and MGO-Ag exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus.

Efficacy of carbonaceous nanocomposites for sorbing ionizable antibiotic sulfamethazine from aqueous solution.

This paper investigated the key factors and mechanisms of sulfamethazine (SMT) sorption on a novel carbonaceous nanocomposite, and the effects of harsh aging on SMT sorption in the presence and absence of soil and before as well as after aging. The carbonaceous nanocomposites were synthesized by dip-coating straw biomass in carboxyl functionalized multi-walled carbon nanotubes solution and then pyrolyzed at 300 °C and 600 °C in the absence of air. The sorption performance of high temperature carbonaceous nanocomposite on SMT was excellent, as measured sorption distribution coefficient in the order of 10(3)-10(5.

Chromate removal by surface-modified nanoscale zero-valent iron: Effect of different surface coatings and water chemistry.

This study investigated the correlation between the colloidal stability and reactivity of surface-modified nano zero-valent iron (SM-nZVI) as affected by the surface coating (i.e., polyacrylic acid [PAA] and starch) under various geochemical conditions.

[Effect of pretreatment by solid-state fermentation of sawdust on the pelletization and pellet's properties].

We pretreated sawdust (Castanopsis fissa Rehd.et Wils) by solid state fermentation (SSF) with Phanerochaete chrysosporium, and then compressed it into pellets with the moisture content of 15% and the pressure of 98 MPa, to solve the problem of low density, low Meyer hardness, high water uptake, and short storage period of pellet in the woody pellet industry. We studied the effects of fermentation time on pelletization and pellets's characteristics (including energy consumption, density, Meyer hardness, and hydrophobicity).

A method for heavy metal exposure risk assessment to migratory herbivorous birds and identification of priority pollutants/areas in wetlands.

Wetlands are important habitats for migratory birds but have been degraded by many anthropogenic factors including heavy metal contamination. Birds inhabiting wetlands are exposed to pollutants. In this study, a method for exposure risk assessment of migratory herbivorous birds and identification of priority pollutants/areas was developed and employed in East Dongting Lake wetland (EDT).

Aggregate-based sub-CMC Solubilization of Hexadecane by Surfactants.

Solubilization of hexadecane by two surfactants, SDBS and Triton X-100, at concentrations near the critical micelle concentration (CMC) and the related aggregation behavior was investigated in this study. Solubilization was observed at surfactant concentrations lower than CMC, and the apparent solubility of hexadecane increased linearly with surfactant concentration for both surfactants. The capacity of SDBS to solubilize hexadecane is stronger at concentrations below CMC than above CMC.

Nanoporous Au-based chronocoulometric aptasensor for amplified detection of Pb(2+) using DNAzyme modified with Au nanoparticles.

The authors herein described an amplified detection strategy employing nanoporous Au (NPG) and gold nanoparticles (AuNPs) to detect Pb(2+) ions in aqueous solution. The thiol modified Pb(2+)-specific DNAzyme was self-assembled onto the surface of the NPG modified electrode for hybridizing with the AuNPs labeled oligonucleotide and for forming the DNA double helix structure. Electrochemical signal, redox charge of hexaammineruthenium(III) chloride (RuHex), was measured by chronocoulometry.