[Evaluation and choice of PCR-DGGE primers in analyzing the microbial community structure of activated sludge in traditional Chinese medicine wastewater].

In the study of traditional Chinese medicine wastewater, it was discussed for the effect of different sets of 16S rDNA universal primers on DGGE fingerprinting and microbial community diversity of aerobic and anaerobic activated sludge from one traditional Chinese medicine wastewater treatment. The genome DNA of activated sludge was isolated, and eleven sets of primers were used to amplify the four variable regions of 16S rDNA, the resolution of DGGE fingerprinting and community diversity was analyzed. The results indicated that community diversity with different sets of universal primers by DGGE was obviously different.

Improving the simultaneous removal efficiency of COD and color in a combined HABMR-CFASR system based MPDW. Part 1: optimization of operational parameters for HABMR by using response surface methodology.

The aim of this study was to implement central-composite design (CCD) and response surface methodology (RSM) to optimize the operational parameters for hybrid anaerobic baffled microbial reactor (HABMR) remedying mixed printing and dyeing wastewater (MPDW). The individual and interactive effects of three variables, hydraulic retention time (HRT), pH, sludge loading rate (SLR) on the COD and color removal rates were evaluated. In the area of HRT: 12.

Linking microbial community structure to membrane biofouling associated with varying dissolved oxygen concentrations.

In order to elucidate how dissolved oxygen (DO) concentration influenced the generation of extracellular polymeric substance (EPS) and soluble microbial products (SMP) in mixed liquor and biocake, 16S rDNA fingerprinting analyses were performed to investigate the variation of the microbial community in an aerobic membrane bioreactor (MBR). The function of microbial community structure was proved to be ultimately responsible for biofouling. Obvious microbial community succession from the subphylum of Betaproteobacteria to Deltaproteobacteria was observed in biocake.

Simultaneous methane production and wastewater reuse by a membrane-based process: evaluation with raw domestic wastewater.

In this study, a membrane-based process was applied to simultaneously reclaim methane and generate reused water from raw domestic wastewater. The system was comprised of up-flow anaerobic sludge fixed bed (UAFB), anoxic sink (AS) and aerobic membrane bioreactor (MBR). The hydraulic retention time of UAFB (HRT(U)) was gradually shortened from 8h to 6h, 3h and to 1h, while the HRT of AS and MBR kept at 8 h.

[Development of a novel hybrid UAFB-anoxic-aerobic MBR for energy production and nutrients removal from domestic wastewater].

The combined treatment process making up of up-flow anaerobic sludge fixed bed (UAFB), anoxic tank and aerobic membrane bioreactor (MBR) was used to treat domestic wastewater. And the ability of reclaiming methane and reusing wastewater was investigated. The efficiency of the combined treatment process treating wastewater at optimized parameters was studied in this paper.

Fate of organic carbon in UAFB treating raw sewage: impact of moderate to low temperature.

The anaerobic biological treatment of raw sewage under low ambient temperatures was investigated in an up-flow anaerobic fixed bed (UAFB) reactor, over a 220-day trial period. The operating temperature was lowered stepwisely from 35 to 25, 20 and 15°C. Obvious accumulation of acetic acid was observed in the effluent as the temperature dropped, which almost tripled at 15°C compared to that at 35°C.

Fabrication of stainless steel mesh gas diffusion electrode for power generation in microbial fuel cell.

This study reports the fabrication of a new membrane electrode assembly by using stainless steel mesh (SSM) as raw material and its effectiveness as gas diffusion electrode (GDE) for electrochemical oxygen reduction in microbial fuel cell (MFC). Based on feeding glucose (0.5 g L(-1)) substrate to a single-chambered MFC, power generation using SSM-based GDE was increased with the decrease of polytetrafluoroethylene (PTFE) content applied during fabrication, reaching the optimum power density of 951.

A hydrodynamics-reaction kinetics coupled model for evaluating bioreactors derived from CFD simulation.

Investigating how a bioreactor functions is a necessary precursor for successful reactor design and operation. Traditional methods used to investigate flow-field cannot meet this challenge accurately and economically. Hydrodynamics model can solve this problem, but to understand a bioreactor in sufficient depth, it is often insufficient.

[Influence of flocculant bacterium on characteristics of aerobic granular sludge].

The aerobic granular sludge was cultivated by adding flocculant bacteria in sequencing batch airlift reactor (SBAR), the physical-chemical properties and biodegradation effect of granules were studied so as to investigate the influence of flocculant bacterium on characteristics of aerobic granular sludge. The results showed that flocculant bacterium could prompt granulation process, the aerobic granules could be successfully cultivated when the dose of flocculants was between 0-20 mL/L. The optimum dose was 10 mL/L, in this case the formation of aerobic granules needed 35d which was faster than that of 42 d in blank experiment, and SVI was around 40 mL/g, settling velocity reached 35.

CFD optimization of continuous stirred-tank (CSTR) reactor for biohydrogen production.

There has been little work on the optimal configuration of biohydrogen production reactors. This paper describes three-dimensional computational fluid dynamics (CFD) simulations of gas-liquid flow in a laboratory-scale continuous stirred-tank reactor used for biohydrogen production. To evaluate the role of hydrodynamics in reactor design and optimize the reactor configuration, an optimized impeller design has been constructed and validated with CFD simulations of the normal and optimized impeller over a range of speeds and the numerical results were also validated by examination of residence time distribution.

Polychlorinated biphenyls in global air and surface soil: distributions, air-soil exchange, and fractionation effect.

Polychlorinated biphenyl (PCB) concentrations in air and soil, measured by various research groups from around the world, were compiled and analyzed. Data for air were available from most regions, particularly in Europe and Asia. The average air concentrations (pg/m(3)) for SigmaPCB at background sites were 70 (5.

Effect of temperature on intracellular phosphorus absorption and extra-cellular phosphorus removal in EBPR process.

This study investigated the temperature influence on intracellular absorption and extra-cellular phosphorus removal by extra-cellular polymeric substance (EPS) in enhanced biological phosphorus removal (EBPR) process. Three sequencing batch reactors (SBRs) were operated in anaerobic/aerobic sequence at 5.0, 15.

Dechlorane Plus in surficial water and sediment in a northeastern Chinese river.

Surface water and sediment samples concurrently collected in Songhua River in northeastern China from May to October 2006 were analyzed for Dechlorane Plus (DP), a chlorinated flame retardant. Samples were obtained from three main areas: SHR-Rul (rural area of Songhua River), SHR-Hrb (the section of the river within the city of Harbin), and Hrb (urban waters of Harbin). The majority of SHR-Rul water samples (85%) and SHR-Hrb water samples (73%) and 33% of urban water samples (Hrb) were below the detection limit.

Enhanced bio-hydrogen production by the combination of dark- and photo-fermentation in batch culture.

In this study, some key factors, for example, diluted ratio of effluents, the ratio of dark-photo bacteria, light intensity and light/dark cycle influencing hydrogen production by combining Clostridium butyricum and immobilized Rhodopseudomonas faecalis RLD-53 in batch culture, were investigated. Experimental results showed the photo-hydrogen yield decreased when increasing diluted ratio from 1:0.5 to 1:3, and it reached the maximum value of 4368 ml-H(2)/l-effluents at the ratio of 1:0.

Effect of carbon sources on sulfidogenic bacterial communities during the starting-up of acidogenic sulfate-reducing bioreactors.

The effect of different carbon sources on the starting-up duration of sulfidogenic bioreactor and corresponding bacterial communities were investigated. The bioreactor starting-up duration was closely dependent on the complexity and availability of the carbon sources. 16S rRNA gene diversity of climax bacterial communities developed in each bioreactor had an increasing tendency for the carbon resource of lactate, acetate/ethanol, glucose and molasses.

Statistical optimization of culture condition for enhanced hydrogen production by Thermoanaerobacterium thermosaccharolyticum W16.

The optimization of culture condition for enhanced hydrogen production by Thermoanaerobacterium thermosaccharolyticum W16 was conducted using statistical experimental design and analysis. Plackett-Burman design was first used to screen the most important variables influencing hydrogen production, and subsequently central composite design was adopted to investigate the optimum value of the selected factors for achieving maximum hydrogen yield. Experimental results showed that xylose, phosphate buffer, and yeast extract had significant influence on hydrogen production and the maximum hydrogen yield of 2.

[Analysis of dynamic characteristics for fermentative hydrogen-producing bacteria community and hydrogen producing capability in CSTR].

The start into the types of fermentation was carried out by pH adjustment from 4.2 to 6.0 in CSTR system.

Effect of sulfate absence and nitrate addition on bacterial community in a sulfidogenic bioreactor.

The characteristics and behavior of sulfate-reducing bacteria (SRB), methane-producing bacteria (MPB) and denitrifying bacteria (DB) were investigated by polymerase chain reaction (PCR) based methods under the transitory sulfate absence or nitrate addition conditions in a sulfidogenic continuously stirred tank reactor. The bioreactor started-up feeding with 4000 mg l(-1) COD (lactate) and 2000 mg l(-1) sulfate (SO(4)(2-)). The sulfate removal efficiency reached 3.

Back propagation neural network (BPNN) prediction model and control strategies of methanogen phase reactor treating traditional Chinese medicine wastewater (TCMW).

Based on the prototype experiment of treating herb wastewater by Up flow Anaerobic Sludge Bed and Anaerobic Filter reactor (UASBAF), an artificial neural network (ANN) model which adopts a back propagation algorithm with momentum and adaptive learning rate was established. And the effect of each parameter to the performance of the reactor was compared, using the method of partitioning connection weights (PCW). The result is pH values>influent of chemical oxygen demand (COD)>hydraulic retention time (HRT)>alkalinity.

Improving phosphate buffer-free cathode performance of microbial fuel cell based on biological nitrification.

To reduce the amount of phosphate buffer currently used in Microbial Fuel Cell's (MFC's), we investigated the role of biological nitrification at the cathode in the absence of phosphate buffer. The addition of a nitrifying mixed consortia (NMC) to the cathode compartment and increasing ammonium concentration in the catholyte resulted in an increase of cell voltage from 0.3 V to 0.

[Effect of sludge bulking on membrane fouling of MBR under low temperature].

The performance and membrane fouling of submerged membrane bioreactor were studied in the case of active sludge bulking under low temperature. The factors contributing to membrane fouling were discussed from the microorganism aspect. The results showed that COD removal efficiencies of supernatant and permeate were 85% and 92% respectively and filamentous sludge bulking had little impact on them.

[Characterization of phosphate-accumulating organisms in starting-up EBPR by FISH analysis].

Enhanced biological phosphorus removal (EBPR) process was operated in a laboratory-scale sequencing batch reactor (SBR) for one-month fed with acetate as the carbon source. The characteristic and the microbial population structure and space distribution dynamics of phosphate-accumulating organisms (PAOs) of start-up period were analyzed by fluorescent in situ hybridization (FISH). The relationship between enrichment of PAOs and phosphorus removal was discussed.

Hydrogen production by immobilized R. faecalis RLD-53 using soluble metabolites from ethanol fermentation bacteria E. harbinense B49.

In order to increase the hydrogen yield from glucose, hydrogen production by immobilized Rhodopseudomonas faecalis RLD-53 using soluble metabolites from ethanol fermentation bacteria Ethanoligenens harbinense B49 was investigated. The soluble metabolites from dark-fermentation mainly were ethanol and acetate, which could be further utilized for photo-hydrogen production. Hydrogen production by B49 was noticeably affected by the glucose and phosphate buffer concentration.

[Effect of temperature on performance of microbial fuel cell using beer wastewater].

The effects of temperature on performance and biological community structure were investigated in air-cathode microbial fuel cells (MFCs) using beer wastewater amended with 50 mmol/L phosphate buffer solution (PBS). The maximum power density decreased from 483 mW/m2 to 435 mW/m2 when the temperature varied from 30 degrees C to 20 degrees C, meanwhile just a little decreasing on coulombic efficiency and the COD removal rate were observed. Decreasing of temperature resulted in effects both on cathode potential and anode potential, but cathode potential behaved much more sensitive to temperature.