Dechlorination of trichloroethylene by immobilized autotrophic hydrogen-bacteria and zero-valent iron.

The efficiency of removing trichloroethylene (TCE) using co-immobilized zero-valent iron and autotrophic hydrogen-bacteria has been studied in this research. Laboratory results show that the combined physicochemical and biological system is much superior to either physicochemical or biological system alone in dechlorination of TCE. In addition to catalyzed hydrogenolysis reactions occurring between hydrogen gas and zero-valent iron particle surface, as well as autotrophic dechlorination of hydrogen-bacteria, the FeS produced by sulfate-reducing bacteria also contributes to the catalytic dechlorination mechanisms.

Reductive dechlorination of trichloroethylene by combining autotrophic hydrogen-bacteria and zero-valent iron particles.

The objective of this study was to evaluate the dechlorination rate (from an initial concentration of 180 micromol l(-1)) and synergistic effect of combining commercial Fe(0) and autotrophic hydrogen-bacteria in the presence of hydrogen, during TCE degradation process. In the batch test, the treatment using Fe(0) in the presence of hydrogen (Fe(0)/H(2)), showed more effective dechlorination and less iron consumption than Fe(0) utilized only (Fe(0)/N(2)), meaning that catalytic degradation had promoted transformation of TCE, and the iron was protected by cathodic hydrogen. The combined use of Fe(0) and autotrophic hydrogen-bacteria was found to be more effective than did the individual exercise even though the hydrogen was insufficient during the batch test.

PVA-alginate immobilized cells for anaerobic ammonium oxidation (anammox) process.

The feasibility of an anaerobic ammonium oxidation (anammox) process combined with a cell-immobilization technique for autotrophic nitrogen removal was investigated. Anammox biomass was cultivated from local activated sludge and achieved significant anammox activity in 6 months. The development of a mature anammox biomass was confirmed by fluorescence in situ hybridization (FISH) analysis and off-line activity measurements.

Partial nitrification of ammonium-rich wastewater as pretreatment for anaerobic ammonium oxidation (Anammox) using membrane aeration bioreactor.

A lab-scale membrane aeration bioreactor (MBR) system was developed for treating synthetic ammonium-rich wastewater to yield an appropriate NO(2)(-)/NH(4)(+) mixture as a pretreatment for anaerobic ammonium oxidation (Anammox). The effluent with a suitable NO(2)(-)/NH(4)(+) ratio (1:1 to 1:1.3) was obtained in 24 h using the developed MBR system under suitable conditions.

Characterization and use of high surface area activated carbons prepared from cane pith for liquid-phase adsorption.

Carbonaceous adsorbents with controllable surface areas were chemically activated with KOH at 780 degrees C from char that had been carbonized from cane pith at 450 degrees C. The pore properties including the BET surface area, pore volume, pore size distribution, and mean pore diameter of these activated carbons were characterized and derived using the t-plot method based on N(2) adsorption isotherms. The activated cane pith carbons, with KOH/char ratios of 2-6, exhibited BET surface areas ranging from 912 to 2299 m(2) g(-1).

Pore structure and adsorption performance of the KOH-activated carbons prepared from corncob.

Carbonaceous adsorbents with controllable surface area were chemically activated with KOH at 780 degrees C from chars that were carbonized from corncobs at 450 degrees C. The pore properties, including BET surface area, pore volume, pore size distribution, and mean pore diameter of these activated carbons, were characterized by the t-plot method based on N(2) adsorption isotherms. Two groups are classified according to the types of adsorption/desorption isotherms.

Degradation of 2-chlorophenol via a hydrogenotrophic biofilm under different reductive conditions.

This research studies the 2-chlorophenol (2-CP) degradation by the hydrogenotrophic biofilm cultivated in three silicone-tube membrane bioreactors under the conditions of denitrification (DN), sulfate-reduction (DS) and dechlorination (DC). Experimental results showed that after acclimation for more than four months with 2-CP, the respective 2-CP removal efficiency was 95% in DN, 94% in DS and 95% in DC reactors, under the condition of influent 2-CP 25 mg/l with hydraulic retention time (HRT) of 15 h. The metabolic pathway of 2-CP was different in different reactors.

Performance of subsurface flow constructed wetland taking pretreated swine effluent under heavy loads.

Subsurface flow constructed wetlands (SSFCW) subjected to changing of loading rates are poorly understood, especially when used to treat swine waste under heavy loads. This study employed a SSFCW system to take pretreated swine effluent at three hydraulic retention times (HRT): 8.5-day HRT (Phase I), 4.

Reductive dechlorination of 2-chlorophenol in a hydrogenotrophic, gas-permeable, silicone membrane bioreactor.

A gas-permeable silicone membrane bioreactor was used to cultivate the biofilm under hydrogenotrophic condition for reductive dechlorination of 2-chlorophenol (2-CP). The anaerobic sludge obtained from a swine wastewater treatment plant was immobilized by polyvinyl alcohol (PVA) so as to form a biofilm on the surface of the silicone tube. After acclimating for about 4 months, the bioreactor showed a high dechlorinating performance.

Nitrogen removal from wastewater using a double-biofilm reactor with a continuous-flow method.

Wastewater microorganisms of nitrification and denitrification were cultivated to compose two biofilm modules, termed the permeable support bioreactor (PSB) and the membrane feeding substrate bioreactor (MFSB). PSB and MFSB were combined in a single tank to develop a double-biofilm reactor, which was used to treat nitrogen contaminants in wastewater. With a membrane supplement of substrates (O(2) and CH(3)OH), the D.