[Removal of Fe(Ⅱ), Mn(Ⅱ), and NH-N by Using -MnO Coated Zeolite].

-MnO/zeolite nanocomposites were prepared with natural zeolite, potassium permanganate, and manganese sulfate by oxidation-reduction precipitation, which were used to simultaneously remove Fe, Mn, and NH-N from groundwater. To investigate the performance and mechanism of Fe, Mn, and NH-N removal from groundwater by -MnO/zeolite nanocomposites, static batch experiments were conducted under different environmental conditions in a zero-oxygen atmosphere using SEM, TEM, Zeta potential, FTIR, and XPS techniques. The experimental results showed that the manganese-oxide-coated natural zeolite was -MnO, and Fe, Mn, and NH-N adsorption on the -MnO/zeolite nanocomposites could be best described with the pseudo-second-order kinetic model and the Langmuir model.

[Transformation of Ammonia in Wetland Sediments for Treatment of Mining Wastewater].

Nitrogen elements play an important role in the biogeochemical cycle of artificial wetlands. In this study, we investigated the anaerobic transformation of ammonia nitrogen and its main pathways in sediment in an artificial wetland. Results showed that the anaerobic ammonia oxidation (ANAMMOX) process and iron reduction occurred in wetland sediment, coupled with anaerobic ammonia oxidation (Feammox).

[Preparation of Magnetic Biomass Carbon by Thermal Decomposition of Siderite Driven by Wheat Straw and Its Adsorption on Cadmium].

C-FeO composite material [magnetic biomass char (MBC)] was prepared by pyrolysis of a mixture of wheat straw and siderite at 500℃. The MBC was characterized by XRF, FTIR, XRD, SEM, XPS, and a magnetic susceptibility device. The effect of contact time, pH value, initial Cd concentration, and ionic strength on the adsorption capacity of the MBC to Cd was investigated.

[Effects of Goethite, Magnetite and Gypsum on the Anaerobic Degradation of 2,4-Dichlorophenol].

2,4-dichlorophenol(2,4-DCP), a highly toxic and refractory organic compound, was commonly used in pesticide production and thus widely distributed in water and soil. Goethite, magnetite and gypsum were added into the anaerobic system which simulated the natural anaerobic process to evaluate their effects on the anaerobic degradation of 2,4-DCP. It indicated that goethite, magnetite and gypsum had no appreciable adsorption ability toward 2,4-DCP under anaerobic condition.

Simultaneous chemical oxygen demand removal, methane production and heavy metal precipitation in the biological treatment of landfill leachate using acid mine drainage as sulfate resource.

Biological treatment played an important role in the treatment of landfill leachate. In the current study, acid mine drainage (AMD) was used as a source of sulfate to strengthen the anaerobic treatment of landfill leachate. Effects of chemical oxygen demand (COD) and SO mass concentration ratio on the decomposition of organic matter, methane production and sulfate reduction were investigated and the microbial community was analyzed using the high throughout methods.

Influence of Different Electron Acceptors on the Anaerobic Degradation of Curly-Leaf Pondweed.

  Curly-leaf pondweed (Potamogeton crispus) was utilized as the representative to investigate the biodecomposition process of aquatic plants under different reducible conditions. Results showed that the methane production was inhibited when different electron acceptors (Fe(III), View Article and Find Full Text PDF

[Modeling the Environmental Behaviors and Ecological Risks of Permethrin in Chaohu Lake].

Environmental pollution caused by synthetic pyrethroid insecticides has received a great deal of attention with the increase in usage recently.To understand the occurrence, environmental processes, fate and ecological impact of permethrin in Chaohu Lake, fugacity based multimedia fate model combining species sensitivities model (SSD) were employed.The concentration distribution, and transfer fluxes were predicted under nonequilibrium steady-state condition, and the effect of input parameter on the outputs was evaluated by sensitive and uncertainty analysis.

Identification and determination of the contribution of iron-steel manufacturing industry to sediment-associated polycyclic aromatic hydrocarbons (PAHs) in a large shallow lake of eastern China.

Seventeen polycyclic aromatic hydrocarbon (PAH) compounds were determined in surface sediments collected from the Chaohu Lake (a large shallow lake in eastern China) and its tributaries. Both diagnostic ratios and a receptor model (positive matrix factorization, PMF) were applied to identify and determine the contribution of a local iron-steel manufacturing plant located in the Nanfei River (NFR) to the Chaohu Lake basin. The results show that sites located in the downstream of the steel plant contained concentrations of 17 PAH (ΣPAH) approximately two orders of magnitudes higher than those from other sites.

[Preparation of -FeO Catalyst by Heat Treatment of Natural Limonite for Selective Catalytic Reduction of NO by NH].

Natural limonite was used as a precursor to prepare -FeO via thermal treatment. The influences of reaction temperature, manganese oxides existing in limonite and coexisting SO and HO on the catalytic reduction activity of the prepared-FeO were evaluated, and the activity of SCR was compared with that of -FeO, by means of XRD, XRF, XPS, NH-TPD, FT-IR and so on. The results showed that because the surface acidity of -FeO is stronger, the SCR temperature window of -FeO was 200-350℃ being broader than that of -FeO (200-300℃), and in the active temperature window, the NO removal reached over 99%.

[Photocatalytic Degradation of Gaseous Toluene by a Photo-Fenton Reaction].

In this study, the performance of photo-Fenton reaction on decomposition of toluene was investigated by a flowing column using toluene as a representative of volatile organic pollutants (VOCs). The effects of initial pH, H2O2 concentration, Fe2+ concentration, initial concentration of toluene on degradation of toluene by photo-Fenton reaction were evaluated. Mass spectrometry and gas chromatograph were utilized to detect the products.

Occurrence, compositional distribution, and toxicity assessment of pyrethroid insecticides in sediments from the fluvial systems of Chaohu Lake, Eastern China.

Surface sediment-associated synthetic pyrethroid insecticides (SPs) are known to pose high risks to the benthic organisms in Chaohu Lake, a shallow lake of Eastern China. However, the pollution status of the lake's tributaries and estuaries is still unknown. The present study was conducted to investigate the occurrence, compositional distribution, and toxicity of 12 currently used SPs in the surface sediments from four important tributaries, as well as in the sediment cores at their estuaries, using GC-MS for quantification.

Occurrence, source identification and ecological risk evaluation of metal elements in surface sediment: toward a comprehensive understanding of heavy metal pollution in Chaohu Lake, Eastern China.

In the present study, surface sediment samples from 48 sites covering the whole water area and three main estuaries of Chaohu Lake were collected to determine the concentrations of 25 metal elements using microwave-assisted digestion combined with ICP-MS. Spatial variation, source appointments, and contamination evaluation were examined using multivariate statistical techniques and pollution indices. The results show that for the elements Cd, Pb, Zr, Hf, U, Sr, Zn, Th, Rb, Sn, Cs, Tl, Bi, and Ba, which had higher coefficients of variation (CV), the concentrations were significantly higher in the eastern lake than in the western lake, but other elements with low CV values did not show spatial differences.

Component analysis and heavy metal adsorption ability of extracellular polymeric substances (EPS) from sulfate reducing bacteria.

Extracellular polymeric substances (EPS) play an important role in the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB). In this paper, Desulfovibrio desulfuricans was used as the test strain to explore the effect of heavy metals on the components and adsorption ability of EPS. Fourier-transform infrared (FTIR) spectroscopy analysis results showed that heavy metals did not influence the type of functional groups of EPS.

Comparison of hematite-facilitated anaerobic digestion of acetate and beef extract.

The effect of hematite with different specific surface areas (SSA) on anaerobic methanogenic process was investigated in this study using two different carbon sources (acetate or beef extract). Comparative analyses showed that methane generation rate, microbial growth and the starting-up duration were all significantly enhanced by hematite. The reduction rate of high SSA hematite was 2.

PAHs in sediment cores at main river estuaries of Chaohu Lake: implication for the change of local anthropogenic activities.

In the present study, 28 polycyclic aromatic hydrocarbons (PAHs) were investigated in four sediment cores collected from the main river estuaries of Chaohu Lake, one of the severely polluted lakes in China. The results indicate that elevated concentrations of total PAHs (Σ28PAH) were found in the samples from the estuary of Nanfei River (ENF), considering BaP-based total toxicity equivalent (TEQ-BaP) and toxic unit (TU) results; there are potential adverse environmental implications. The total organic carbon (TOC) played an important role on the accumulation of PAHs at ENF and the estuary of Tongyang River (ETY).

Competitive adsorption of heavy metal by extracellular polymeric substances (EPS) extracted from sulfate reducing bacteria.

Competitive adsorption of heavy metals by extracellular polymeric substances (EPS) extracted from Desulfovibrio desulfuricans was investigated. Chemical analysis showed that different EPS compositions had different capacities for the adsorption of heavy metals which was investigated using Cu(2+) and Zn(2+). Batch adsorption tests indicated that EPS had a higher combined ability with Zn(2+) than Cu(2+).

[Effect of the interaction of microorganisms and iron oxides on arsenic releasing into groundwater in Chinese Loess].

A large part of groundwater in the Chinese Loess Plateau area is characterized by high arsenic concentration. Anaerobic bacteria have been considered to play key roles in promoting arsenic releasing from loess to groundwater. However, this hypothesis remains unconfirmed.

Synthetic effect between iron oxide and sulfate mineral on the anaerobic transformation of organic substance.

Synthetic effect between sulfate minerals (gypsum) and iron oxide (hematite) on the anaerobic transformation of organic substance was investigated in the current study. The results showed that gypsum was completely decomposed while hematite was partially reduced. The mineral phase analysis results showed that FeS and CaCO3 was the major mineralization product.

[Effect of natural and hydrothermal synthetic goethite on the release of methane in the anaerobic decomposition process of organic matter].

The effects of natural goethite (NGt) and synthetic goethite (SGt) on the release of methane in the anaerobic biochemical system consisted of dissimilatory iron-reducing bacteria (DIRB) and methane-producing bacteria (MPB) were investigated through batch tests with sodium acetate as the carbon source. To explore the effects and mechanisms of both mineral materials on the release of methane in the anaerobic decomposition process of organic matter in the presence of DIRB, the main gas components and total organic carbon (TOC) , total inorganic carbon (TIC), and Fe2+ in the aqueous phase of the experimental process were determined and XRD analyses were conducted for the solid-phase product. Moreover, the minerals were analyzed by specific surface area (BET), X-ray diffraction (XRD), X-ray fluorescence (XRF).

PAHs in the Chinese environment: levels, inventory mass, source and toxic potency assessment.

This paper presents a systematic but preliminary study on the levels, inventory mass, emission sources and risk of exposure to PAHs in China by examining 14 polycyclic aromatic hydrocarbons (from the 16 priority PAHs listed by the U.S. EPA, excluding naphthalene and acenaphthylene) in four main environmental media (air, water, soil and sediment).

Feasibility of anaerobic digested corn stover as biosorbent for heavy metal.

Anaerobic digested (AD) corn stover collected from a lab-scale reactor was used as bioadsorbent to remove the heavy metal in aqueous solution. Effects of contact time and initial heavy metal concentrations on the removal process of Cu(2+) and Cd(2+) were investigated. The maximum adsorption capacities of AD corn stover obtained from Langmuir isotherm models were 83.

[Denitrification water treatment with zeolite composite filter by intermittent operation].

The zeolite composite filters (ZCF) with the size of4-8 mm were prepared using raw zeolite (0.15-0.18 mm) as the main material and the cement as binder.

Halogenated organic contaminants (HOCs) in sediment from a highly eutrophicated lake, China: occurrence, distribution and mass inventories.

Halogenated organic contaminants (HOCs) including 16 polybrominated diphenyl ethers (PBDEs) and 37 polychlorinated biphenyls (PCBs) were determined in 49 surfacial sediments from Chaohu Lake, a highly eutrophicated lake, China. PBDEs were detected in almost samples with the range of the total concentration (defined as Σ(16)PBDEs) from 0.84 to 86.

[Experimental study on acid mine drainage treatment using mine tailings of Xiangsi Valley, Tongling, China].

Mine tailings in Xiangsi Valley, Tongling, China, is a typical skarn-type tailing with high contents of carbonates. This study designed dynamic leaching experiments to investigate the efficiency of this tailing under the acid mine drainage treatment. During 80 d trial period, the physical and chemical properties of influents were fixed and the effluents were monitored.