Sustainable treatment of nitrate-containing wastewater by an autotrophic hydrogen-oxidizing bacterium.

Bacteria are key denitrifiers in the reduction of nitrate (NO -N), which is a contaminant in wastewater treatment plants (WWTPs). They can also produce carbon dioxide (CO) and nitrous oxide (NO). In this study, the autotrophic hydrogen-oxidizing bacterium sp TH20 was isolated for sustainable treatment of NO -N in wastewater.

Ecological and toxicological assessments of anthropogenic contaminants based on environmental metabolomics.

There has long been a great concern with growing anthropogenic contaminants and their ecological and toxicological effects on living organisms and the surrounding environment for decades. Metabolomics, a functional readout of cellular activity, can capture organismal responses to various contaminant-related stressors, acquiring direct signatures to illustrate the environmental behaviours of anthropogenic contaminants better. This review entails the application of metabolomics to profile metabolic responses of environmental organisms, e.

Highly efficient ammonium removal through nitrogen assimilation by a hydrogen-oxidizing bacterium, Ideonella sp. TH17.

Ideonella sp. TH17, an autotrophic hydrogen-oxidizing bacterium (HOB), was successfully enriched and isolated from activated sludge in a domestic wastewater treatment plant (WWTP). Batch experiments were conducted to identify the cell growth and ammonium (NH-N) removal, and to verify the pathways of nitrogen utilization under different conditions.

Uranium sequestration in sediment at an iron-rich contaminated site at Oak Ridge, Tennessee via. bioreduction followed by reoxidation.

This study evaluated uranium sequestration performance in iron-rich (30 g/kg) sediment via bioreduction followed by reoxidation. Field tests (1383 days) at Oak Ridge, Tennessee demonstrated that uranium contents in sediments increased after bioreduced sediments were re-exposed to nitrate and oxygen in contaminated groundwater. Bioreduction of contaminated sediments (1200 mg/kg U) with ethanol in microcosm reduced aqueous U from 0.

Mercury methylation by Geobacter metallireducens GS-15 in the presence of Skeletonema costatum.

In this study, bacterial mercury (Hg) methylation was investigated under the influence of red-tide algae of Skeletonema costatum (S. costatum). The distribution and speciation of total mercury (THg) and methylmercury (MeHg) were profiled by employing Geobacter metallireducens (G.

Inhibitory effects of Skeletonema costatum on mercury methylation by Geobacter sulfurreducens PCA.

Algae and mercury (Hg) are ubiquitous in marine environments. In this study, we investigated the effects of a typical marine algae of diatom Skeletonema costatum on Hg methylation by an iron-reducing bacterium of Geobacter sulfurreducens (G. sulfurreducens) PCA.

Magnetic chitosan/sodium alginate gel bead as a novel composite adsorbent for Cu(II) removal from aqueous solution.

Using sodium alginate hydrogel as skeleton, in combination with chitosan and magnetic FeO, a new type of magnetic chitosan/sodium alginate gel bead (MCSB) was prepared. Adsorptive removal of Cu(II) from aqueous solutions was studied by using the MCSB as a promising candidate in environmental application. Different kinetics and isotherm models were employed to investigate the adsorption process.

Preparation of Palladium(II) Ion-Imprinted Polymeric Nanospheres and Its Removal of Palladium(II) from Aqueous Solution.

Three kinds of functional monomers, 4-vinylpridine(4-VP), 2-(allylthio)nicotinic acid(ANA), and 2-Acetamidoacrylic acid(AAA), were used to synthetize palladium(II) ion-imprinted polymeric nanospheres (Pd(II) IIPs) via precipitation-polymerization method in order to study the effects of different functional monomers on the adsorption properties of ion-imprinted materials. The results of UV spectra in order to study the interaction between template ion PdCl and functional monomers showed that there were great differences in structure after the template reacted with three functional monomers, 4-VP and ANA caused a large structural change, while AAA basically did not change. Further results on the adsorption performance of Pd(II) IIPs on Pd(II) confirmed 4-VP was the most promising candidate for the synthesis of Pd(II) IIPs with an adsorption capacity of 5.

Biomass based activated carbon obtained from sludge and sugarcane bagasse for removing lead ion from wastewater.

Sewage sludge and bagasse were used as raw materials to produce cheap and efficient adsorbent with great adsorption capacity of Pb(2+). By pyrolysis at 800 °C for 0.5 h, the largest surface area (806.

Size-dependent patterned recognition and extraction of metal ions by a macrocyclic aromatic pyridone pentamer.

A macrocyclic aromatic pyridine pentamer was found to exhibit patterned recognition of metal ions and efficiently extract larger ions, such as Cs(+), Ba(2+), Tl(+), Au(+), K(+) and Rb(+) preferentially over the other 18 smaller metal ions from the aqueous phase into the chloroform layer.

Construction and optimization of a Pseudomonas putida whole-cell bioreporter for detection of bioavailable copper.

A Pseudomonas putida whole-cell bioreporter for detecting bioavailable copper was constructed by inserting a CueR-regulated sensor element upstream of a promoterless green fluorescent protein (GFP) reporter gene. The constructed bioreporter cells expressed GFP only in response to Cu and Ag when cultivated in different metal salt solutions. M9 supplemented medium provided higher sensitivity compared with LB medium.

Electrode as sole electrons donor for enhancing decolorization of azo dye by an isolated Pseudomonas sp. WYZ-2.

Pseudomonas sp. WYZ-2 was isolated from a biocathode which accelerating azo dye decolorization. When the electrode was polarized at -0.

Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis.

Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10h at initial pH 1.

Cell surface engineering of microorganisms towards adsorption of heavy metals.

Heavy metal contamination has become a worldwide environmental concern due to its toxicity, non-degradability and food-chain bioaccumulation. Conventional physical and chemical treatment methods for heavy metal removal have disadvantages such as cost-intensiveness, incomplete removal, secondary pollution and the lack of metal specificity. Microbial biomass-based biosorption is one of the approaches gaining increasing attention because it is effective, cheap, and environmental friendly and can work well at low concentrations.

Degradation of p-nitrophenol in a BES-Fenton system based on limonite.

This study confirmed the feasibility of natural limonite working as the iron catalyst for the PNP wastewater treatment in the BES-Fenton system. After the start-up period of the BES-Fenton systems, air and limonite powder were injected into the cathode chamber as the original materials for manufacturing Fenton reagents of H₂O₂ and Fe(II) respectively. The experiment parameters like pH, external resistance, limonite dosage and initial PNP concentration were investigated in this research.

Optimizing cadmium and mercury specificity of CadR-based E. coli biosensors by redesign of CadR.

The metalloprotein, CadR, was redesigned to optimize cadmium and mercury specificity of CadR-based E. coli biosensors. By truncating 10 and 21 amino acids from the C-terminal extension of CadR, CadR-TC10 and CadR-TC21 were obtained, respectively.

Bioelectrochemical recovery of ammonia-copper(II) complexes from wastewater using a dual chamber microbial fuel cell.

The cathodic reduction of complex-state copper(II) was investigated in a dual chamber microbial fuel cell (MFC). The inner resistance of MFC system could be reduced in the presence of ionizing NH(4)(+), however, mass transfer was hindered at higher ammonia concentration. Thermodynamic and electrochemical analyses indicated that the processes of complex dissociation and copper reduction were governed by the ratio of T[Cu]:T[NH(3)] and the pH of solution.

Recovery of silver from silver(I)-containing solutions in bioelectrochemical reactors.

A novel approach was tested for metallic silver recovery and power generation by using cathodic reduction in bioelectrochemical systems (BESs). In dual-chamber BESs (130 mL volume) with acetate as electron donor on anode, both Ag(+) ions and Ag(I) thiosulfate complex in catholyte were reduced on cathode. The reduction rate of Ag(+) was more rapid than the Ag(I) complex as expected by energetic analysis.

Removal of estrogens in municipal wastewater treatment plants: a Chinese perspective.

Great efforts have been made in China to retrofit and upgrade the existing municipal wastewater treatment plants (WWTPs) for enhanced removal of organic substrates and in particular nutrients. However, the removal of trace recalcitrant or hazardous organic chemicals, e.g.

Copper reduction in a pilot-scale membrane-free bioelectrochemical reactor.

A pilot-scale, membrane-free, bioelectrochemical system (BES) reactor (16L in volume) installed by five cathodes with different distance to anode was tested for the removal of copper. CuSO4 solution was used as catholyte and anaerobic microorganisms grew as anodic biocatalyst. In the reactor, Cu(II) was reduced and recovered as solid-state copper deposits on cathodes accompanied with power production.

[Treatment of Cu(2+)-containing wastewater by microbial fuel cell with excess sludge as anodic substrate].

The two-chamber microbial fuel cells (MFCs) were constructed with excess sludge as the anodic substrate and CuSO4 solution as the catholyte. The start up method, degradation of the anodic sludge, removal of the Cu2+ and products on cathode were investigated in the study. The results of batch experiments showed that Cu2+ can be used as cathodic electron acceptors, e.

Removal of copper from aqueous solution by electrodeposition in cathode chamber of microbial fuel cell.

Based on energetic analysis, a novel approach for copper electrodeposition via cathodic reduction in microbial fuel cells (MFCs) was proposed for the removal of copper and recovery of copper solids as metal copper and/or Cu(2)O in a cathode with simultaneous electricity generation with organic matter. This was examined by using dual-chamber MFCs (chamber volume, 1L) with different concentrations of CuSO(4) solution (50.3 ± 5.