Enhanced-nitrogen removal through Fe(III)-triggered partial dissimilatory nitrate reduction to ammonium coupling with anammox in anammox bioreactor.

Anammox is recognized as a prospective alternative for future biological nitrogen removal technologies. However, the nitrate by-products produced by anammox bacteria limit its overall nitrogen removal efficiency below 88 %. This study introduced Fe(III) into the anammox bioreactor to enhance the nitrogen removal efficiency to approximately 95 %, surpassing the biochemical limit of 88 % imposed by anammox stoichiometry.

Anaerobic ammonium oxidation coupled to iron(III) reduction catalyzed by a lithoautotrophic nitrate-reducing iron(II) oxidizing enrichment culture.

The last two decades have seen nitrogen/iron-transforming bacteria at the forefront of new biogeochemical discoveries, such as anaerobic ammonium oxidation coupled to ferric iron reduction (feammox) and lithoautotrophic nitrate-reducing ferrous iron-oxidation (NRFeOx). These emerging findings continue to expand our knowledge of the nitrogen/iron cycle in nature and also highlight the need to re-understand the functional traits of the microorganisms involved. Here, as a proof-of-principle, we report compelling evidence for the capability of an NRFeOx enrichment culture to catalyze the feammox process.

[Treatment of bromoamine acid wastewater by combined ALR-BAC process].

Combined ALR-BAC was used to treat bromoamine acid wastewater. The results showed that the ALR system could run steadily for over 1 months at the BAA concentration 650 mg x L(-1) after one-month acclimation, the decoloration rate of BAA was reached to about 90% within 12 h, and the removal rate of COD was about 50%, the precipitation performance of the suspended microorganism was good. When the influent bromoamine acid concentration was above 200 mg x L(-1), the decolorization products of BAA were easy to undergo auto-oxidation and the yellow intermediate products which were difficult to biodegrade were formed.

[Fly ash-catalyzed oxidation of p-nitro phenol with H2O2].

Fly ash was investigated as a catalyst in the oxidation of p-nitro phenol (PNP) with H2O2 at ambient temperature and pressure. The physical and chemical properties of fly ash were analyzed. The effects of fly ash composition, pretreatment methods and other parameters (such as dosage, pH, reaction time and oxidant concentration) on PNP removal rate were studied.

[Decolorization of azo dyes using quinone reductase and quinoid compounds].

Using quinoid redox mediator and bacterial cellular quinone reductase, we investigated the decolorization ability of gene-engineered strain Escherichia coli YB and the effects of methylhydroquinone (MHQ) pretreatement on decolorization performance of E. coli JM109 and anaerobic sludge. The results indicate that lawsone is an effective accelerator for azo dye decolorization by E.

[Adsorption property of chitosan composite resin for nitrite-nitrogen].

A novel composite resin of chitosan supported by activated carbon was prepared using the emulsification cross-linking technique. The adsorption properties of the resin for NO2(-)-N were studied. It is found that there are many developed micropores on the surface of the resin.

[Decoloration and bioaugmentation on azo dye by immobilized genetically engineered strain].

Decoloration and bioaugmentation on azo dye are investigated by using immobilized genetically engineered strain Escherichia coli JM109 (pGEX-AZR) on marcroporous foam carriers. The kinetics of the acid red GR decolorization by the immobilized E. coli JM109 (pGEX-AZR) accords with Andrews model proved by our experiments, and the kinetic parameters, mu(max,c), K(c) and K(ic), are found to be 49.