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A membrane-free baffled microbial fuel cell (MFC) was developed to treat synthetic Cu(II) sulfate containing wastewater in cathode chamber and synthetic glucose-containing wastewater fed to anode chamber. Maximum power density of 314 mW/m(3) with columbic efficiency of 5.3% was obtained using initial Cu(2+) concentration of 6400 mg/L. Higher current density favored the cathodic reduction of Cu(2+), and removal of Cu(2+) by 70% was observed within 144 h using initial concentration of 500 mg/L. Powder X-ray diffraction (XRD) analysis indicated that the Cu(2+) was reduced to Cu(2)O or Cu(2)O plus Cu which deposited on the cathode, and the deficient cathodic reducibility resulted in the formation of Cu(4)(OH)(6)SO(4) at high initial Cu(2+) concentration (500-6400 mg/L). This study suggested a novel low-cost approach to remove and recover Cu(II) from Cu(2+)-containing wastewater using MFC-type reactor., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The electricity generation performance of a microbial fuel cell (MFC) utilizing Dioscorea zingiberensis wastewater was studied with an H-shape reactor. Indexes including pH, conductivity, oxidation peak potential and chemical oxygen demand (COD) of the anolyte were monitored to investigate the contaminants degradation performance of the MFC during the electricity generation process, besides, contaminant ingredients in anodic influent and effluent were analyzed by GC-MS and IR spectra as well. The maximum power density of the MFC could achieve 118.1 mW/m2 and the internal resistance was about 480 omega. Connected with a 1 000 omega external resistance, the output potential was about 0.4 V. Fed with 5 mL Dioscorea zingiberensis wastewater, the electricity generation lasted about 133 h and the coulombic efficiency was about 3.93%. At the end of electricity generation cycle, COD decreased by 90.1% while NH4(+) -N decreased by 66.8%. Furfural compounds, phenols and some other complicated organics could be decomposed and utilized in the electricity generation process, and the residual contaminants in effluent included some long-chain fatty acids, esters, ethers, and esters with benzene ring, cycloalkanes, cycloolefins, etc. The results indicate that MFC, which can degrade and utilize the organic contaminants in Dioscorea zingiberensis wastewater simultaneously, provides a new approach for resource recovery treatment of Dioscorea zingiberensis wastewater.

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. g. a stable voltage output of 0.478 V and a maximum power density of 536 mW/m3 were obtained at external resistance of 1 000 omega and Cu2+ concentration of 6 400 mg/L. The Cu2+ contained in wastewater could be removed effectively by the MFC process, e. g. 97.8% of Cu2+ was removed in a MFC reactor at the end of 288 h with initial Cu2+ concentration of 1 000 mg/L and external resistance of 0 omega. The cathodic products depended on cathodic reducibility, most of Cu2+ was deposited as Cu2O and a small part as Cu4 (OH), 6SO4 with lower cathodic reducibility, metal copper deposited on the cathode with higher cathodic reducibility. Using excess sludge as anodic substrate could support the MFCs for long-term operation. The acclimation stage of the exoelectrogenic bacteria on the anode had an impact on MFC performance and cathodic reduction of Cu2+, and the stability of exoelectrogenic biofilm on anode could be determined by monitoring the anode potential. The MFC with excess sludge as anodic substrate can degrade organic matter in sludge and accomplish Cu(2+) -containing wastewater treatment and copper recovery simultaneously.

The possibility of electricity generation in a single chamber microbial fuel cell fed with Dioscorea zingiberensis C. H. Wright wastewater was demonstrated, and the effects of COD and SO4(2-) concentration on MFC performance were investigated. Under the same conductivity and COD concentration, the power density generated from wastewater equaled to 80.3% of that from glucose. At low COD concentration, the electricity generation increased with increasing COD loading rates, and the maximum power density was 322 mW/m2; while the COD concentration was enhanced over 2766 mg/L, the stable times for electricity generation was reduced and the MFC could not recover to previous performance as refueling. That indicates high COD loading rates would inhibit microbial activity. The COD removal rates varied from 68.2% to 84.8%, and it decreased when COD concentration climbed up. The power density was enhanced with SO4(2-) concentration increasing up to 7716 mg/L (Conductivity > 8.19 mS/cm) after which no further improvements in power density were observed. The maximum power density of the wastewater containing SO4(2-) was lower by 14.5% on average than that of the wastewater which removed SO4(2-). And its coulombic efficiencies declined substantially as SO4(2-) concentration increasing, which imply that the SO4(2-) is deoxidized as the electron acceptor, which takes the MFC efficiency down.

Experimental studies were conducted on the effect of temperature on the Pb2+ biosorption with aerobic granules seeding with floccular activated sludge. The results showed that the aerobic granules manly comprised the elements of C, H, N, O and P. According to the elemental compositions of the microbial granules, the corresponding empirical formula of the granules can be determined as C5.7 H10.9 O3.9 NS0.04. ESEM results showed many coccoid bacteria were visiable on the granule surface with porous structure. Both Freundlich and Langmuir isotherm equations could describe the biosorption process well (R2 > 0.914)under various temperature (20-40 degrees C). The maximum biosorption capacity (Q(max)) increased from 80.65 mg x g(-1) (20 degrees C) to 97.09 mg x g(-1) (40 degrees C). The values of thermodynamic parameters (deltaG < 0, deltaH > 0, deltaS > 0) indicated the biosorption process was spontaneous and endothermic in nature. Moreover, the Fourier transform infrared spectroscopy (FTIR) results demonstrated that such active groups as -OH, -COOH and P = O were involved in Pb2+ biosorption but nothing to do with nitrogen-containing groups.

Corn steepwater containing 49,732.2 mg/L of chemical oxygen demand (COD) was used as fuel for a membrane electrode assembly microbial fuel cell (MEA-MFC), which could generate electricity and treat the wastewater at the same time. During a batch experiment of 94 days with a fixed 1,000 Omega external resistance, the maximum voltage output of 525.0 mV and power density of 169.6 mW/m2 were obtained after 17 days, corresponding to the current density, internal resistance and open voltage of 440.2 mA/m2, 350 Omega and 619.5 mV, respectively. However, data showed that the coulombic efficiency was only 1.6%, suggesting very limited COD was utilized for electricity generation. At the conclusion of the test, the removals of COD and ammonia-nitrogen were achieved 51.6% and 25.8%, respectively. This study demonstrates that corn steepwater can be used for power generation in MFC with simultaneous accomplishments of wastewater treatment, providing a novel approach for the safe disposal and recycle of corn steepwater.

Bottom ash, a power plant waste, was used to remove the organic pollutants in coking wastewater and papermaking wastewater. Particular attention was paid on the effect of bottom ash particle size and dosage on the removal of chemical oxygen demand (COD). UV-vis spectra, fluorescence excitation-emission matrix (FEEM) spectra, Fourier transform infrared (FTIR) spectra, and scanning electron microscopic (SEM) photographs were investigated to characterize the wastewaters and bottom ash. The results show that the COD removal efficiencies increase with decreasing particle sizes of bottom ash, and the COD removal efficiency for coking wastewater is much higher than that for papermaking wastewater due to its high percentage of particle organic carbon (POC). Different trends of COD removal efficiency with bottom ash dosage are also observed for coking and papermaking wastewaters because of their various POC concentrations. Significant variations are observed in the FEEM spectra of wastewaters after treatment by bottom ash. New excitation-emission peaks are found in FEEM spectra, and the fluorescence intensities of the peaks decrease. A new transmittance band in the region of 1400-1420 cm(-1) is observed in FTIR spectra of bottom ash after adsorption. The SEM photographs reveal that the surface of bottom ash particles varies evidently after adsorption.

The simulative wastewater containing Acid Orange 7 (AO7) of 300 mg/L was electrolytically treated by a three-phase three-dimensional electrode reactor. Particular attention was paid on the comparison of treatment efficiency of different cathodes in the system. Intermediate products and concentration of *OH and H2O2 were further investigated using HPLC, UV-Vis scan and GC-MS, with the purpose of investigating the electrolysis behavior of AO7 with different cathodes. Results showed that activated carbon fiber (ACF) cathode was more effective than graphite or stainless steel cathode. Despite all of the three investigated cathodes showed high efficiency in the decolorization of AO7 (more than 96% after 60 min of electrolysis under 20 V), the TOC removal ratio of ACF system (57.4%) was much higher than those of the other two. Although the generation of *OH and H2O2 were both found in the three systems, the concentration in the system with ACF as the cathode was much higher than those in the other two, which resulted in the better mineralization ability. Moreover, the same degradation route of AO7 was found in the three systems, which involved the generation of ketone and naphthol compounds.

A quinoline-degrading bacterium QL2, which utilizes quinoline as sole source of carbon, nitrogen and energy, was isolated from activated sludge in a coke-plant wastewater biological treatment system. According to the morphological characteristics, physiological and biochemical characteristics, and sequence analysis of 16S rRNA, the strain was identified as Rhodococcus sp.. The optimal temperature, initial pH, and shaker rotary speed for strain QL2 utilizing quinoline are 35-42 degrees C, pH 8-9, and 150 r/min, respectively. Extra nitrogen sources stimulate the isolate growth on quinoline, and inorganic nitrogen better than organic nitrogen, NH4+ -N better than NO3(-) -N. The degradation reaction of quinoline by strain QL2 can be described with zero order kinetic equation within the initial quinoline concentrations of 60-680 mg/L. When the initial concentration was 150 mg/L, quinoline was degraded completely in 8 hours and TOC removal efficiency was 70% in 14 hours. This bacterium produced pigmented compounds, and ring nitrogen was released into the growth medium as ammonium. The main intermediate in the degradation pathway was 2-hydroxyquinoline by the analysis of HPLC and GC/MS. With a broad range of substrate utilization, the strain can degrade phenol, naphthalene, pyridine, and some other kinds of aromatic compounds.

Coking wastewater was treated by A/O process of biological filter with a special kind of carrier. The wastewater contained much more phenolic compounds with about 2000 mg/L of COD and 260 mg/L of NH4+ -N. The A/O system could achieve average removal efficiencies of 87.0% and 91.6% for COD and NH4+ -N, respectively, when HRT was 60 h. The NH4+ -N in the effluent could meet the first level of National Discharge Standard at optimal operation condition. The phenolic compounds with low molecular weight could be fully biodegraded by A/O system. The organic compounds in the effluent were in the relative molecular weight range of 10,000-30,000 and contained --OH, C==O, C--O and phenyl group. Based on the support and protection of the carrier, a great number of microorganisms adhered and immobilized on the outer and inner surface of carrier, which contributed to a simultaneous removal of COD, NH4+ -N and TN. The A/O system biological filter showed a characteristic of steady performance and resistance ability during the operation period.

Advanced treatment of coking wastewater was investigated experimentally with coagulation and zero-valent iron (ZVI) processes. Particular attention was paid to the effect of dosage and pH on the removal of chemical oxygen demand (COD) in the two processes. The results showed that ZVI was more effective than coagulation for advanced treatment of coking wastewater. The jar tests revealed that maximal COD removal efficiency of 27.5-31.8% could be achieved under the optimal condition of coagulation, i.e. 400mg/L of Fe(2)(SO(4))3 as coagulant at pH 3.0-5.0. On the other hand, the COD removal efficiency could be up to 43.6% under the idealized condition of ZVI upon 10 g/L active carbon and 30 g/L iron being dosed at pH 4.0. The mechanisms for COD removal in ZVI were dominated by coagulation, precipitation and oxidation-reduction. ZVI would also enhance the biodegradability of effluent by increasing BOD5/COD from 0.07 to 0.53. Moreover, some ester compounds could be produced in the reaction. Although ZVI was found more efficient than coagulation in eliminating low molecular weight (<2000 Da) compounds in the wastewater, there were still a few residual contaminants which could hardly be eliminated by either of the process.

A special kind of carrier was used to immobilize effective microorganisms B350M in a biological aerated filter (BAF) react system for treatment of oil field wastewater, which is of salinity > 0.5%, lack of N and P, and contains low organic matter. Through the biodegradation system operated for 142d, the react system can achieve average degradation efficiency 90.5%, 74.4%, 85.6%, 100% for oil, TOC, COD and H2S, when HRT was 4h and COD volumetric load was 1.07 kg/(m3 x d). GC-MS results show that the organic substance in wastewater contain 27 different kind substances, a majority (23) of alkane and a minority (4) of aromatic substances. C14H30 to C28H58 in influent could be decomposed into small molecular substance efficiently, especially the C18H38 to C28H58, and also polycyclic aromatic hydrocarbons (PAHs) such as Phenanthrene. The react system had a good diversity, because the carriers provide agreeable air and water condition for microorganisms, to resist high salinity and toxic pollutant. Filamentous microorganisms were observed in a great deal and will not cause foaming and bulking in BAF reactor by immobilization.