[Impacts of F/M Ratio on Microbial Networks in Activated Sludge].

The performance of wastewater treatment plants (WWTPs) mainly relies on the microbial community in activated sludge (AS). The food to microorganisms (F/M) ratio is an important operational parameter, the recommended value of which is between 0.2 and 0.

[Comparison of Polycaprolactone and Poly-3-hydroxybutyrate-co-3-hydroxyvalerate for Nitrogen Removal].

Two types of biodegradable polymers, polycaprolactone (PCL) and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), were used as a denitrification slow-release carbon source and a microbial carrier. By comprehensively comparing their performances in denitrification, carbon release, surface morphology, and material composition as well as their microbial community characteristics, the PHBV was determined as the better performer. It had a shorter denitrification start time, a higher denitrification rate, a lower residual organic matter concentration, and a more stable and sustained denitrification performance than PCL.

[Potential Source Environments for Microbial Communities in Wastewater Treatment Plants (WWTPs) in China].

To better understanding the microbial composition of activated sludge (AS), unique OTUs and their indicators were examined and SourceTracker was used to identify possible source environments for AS communities to thrive in 15 cities across China, based on 16S rRNA gene sequencing. This may help reveal the underlying mechanisms of AS community composition formations in various areas. The results indicated that the dominant phyla in AS in each city were similar; Proteobacteria, Bacteroidetes, and Chloroflexi made up 94.

[Characteristics and Regional Heterogeneity of Eukaryotic Microbial Community in Wastewater Treatment Plants].

Wastewater treatment plants (WWTPs) are important facilities to control water pollution and ensure the sustainable development of cities and humans. As an indispensable part of the activated sludge (AS) system, eukaryotic microbes play important roles in indicating the properties of AS, predicting the quality of the effluent, enhancing the purification effect, and ensuring a stable performance of the system in WWTPs. In this study, 61 AS samples from 14 full-scale WWTPs of Beijing, Shenzhen, and Wuxi were collected.

[Quickly enrichment of carbon in wastewater by activated sludge].

Pilot tests were carried out to investigate the absorption characteristics of the carbon source in urban wastewater by activated sludge and to analyze the carbon release from the carbon absorbed activated sludge in the settling process. The results indicated that carbon in wastewater could be quickly enriched by activated sludge. The absorption process of indissolvable organic matter could be finished as shortly as less than 10 min, while the absorption process of the dissolved organic matter was relatively slow and should consume up about 30 min.

[Dynamics of quickly absorption of the carbon source in wastewater by activated sludge].

In this paper, absorption characteristics of organic matter in municipal wastewater by three kinds of activated sludge (carbon-enriching, nitrification and denitrification sludge) were studied, and the absorption kinetic data was checked using three kinds of absorption kinetic equations based on Ritchie rate equation. The objectives of this study were to investigate the absorption mechanism of activated sludge to organic matter in municipal wastewater, and to identify the possibility of reclaiming organic matter by activated sludge. Results indicated that in the early 30 min, absorption process of organic matter by activated sludge was found to be mainly physical adsorption, which could be expressed by the Lagergren single-layer adsorption model.

[Harvest of the carbon source in wastewater by the adsorption and desorption of activated sludge].

The carbon source in municipal wastewater was adsorbed by activated sludge and then harvested through the hydrolysis of activated sludge. Results indicated that activated sludge had high absorbing ability towards organic carbon and phosphorus under continuous operation mode, and the average COD and TP absorption rate reached as high as 63% and 76%, respectively. Moreover, about 50% of the soluble carbon source was outside of the sludge cell and could be released under mild hydrolysis condition.

[Determination of kinetic parameters of activated sludge in an MBR wastewater treatment plant].

One of the main problems in application of MBR technology is lack of reliable kinetic parameters for process design. The activated sludge in the aerobic tank of an MBR municipal wastewater treatment plant was investigated therefore. Using oxygen utilization rate method, following kinetic parameters were measured: heterotrophic yield coefficient YH = 0.

[Immobilization of lignin peroxidase on spherical mesoporous material].

The spherical mesoporous particles with two-dimensional (2D) hexagonal mesopores in diameter up to 11.6 nm was fabricated in acetic acid/sodium buffer solution (pH = 3.5) by using tetramethoxysilane (TMOS) as silica source, Pluronic P123 as template and 1,3,5-triisopropylbenzene (TIPB) as swelling agent.

Evaluation of manganese peroxidase (MnP) for its ability to resist the ozonization and thereafter decolorize methyl orange.

The goal of this study was to determine whether ozone can be used to suppress bacterial growth in operating a white rot fungi reactor system. The effects of ozone dose on the activity of manganese peroxidase (MnP) and on the death rate of Escherichia coli were investigated. The results showed that at ozone dose of 0.

[Bacterial community dynamics in wastewater treatment plants based on T-RFLP profiles].

Bacterial communities in two full-scale wastewater treatment systems (system A and system B) with functional stability were monitored over 105 days using terminal restriction fragment length polymorphism (T-RFLP) based on 16S rRNA genes. During the study period, system A and system B were functionally stable. The effluent BOD concentration of two systems was always around 8 mg/L, and at the same time the effluent TN concentrations of two systems were always below 25 mg/L and 23 mg/L respectively.

[Evaluation of estrogenicity of sewage samples from Beijing, China].

The recombinant yeast estrogen screen (YES) was used to evaluate the estrogenic activities of sewage samples from every step of three sewage treatment plants (STPs) in Beijing, China. Meanwhile, eight target endocrine-disrupting compounds (EDCs) in corresponding sewage samples were simultaneously analyzed by GC/MS system to further elucidate the variations of their estrogenic activities. The results indicated that estrogenic activities could be considerably reduced by STPs with the rate of 82.

[Community structures of ammonia-oxidizing bacteria in activated sludge of wastewater treatment plants].

In order to investigate the community structure of ammonia oxidizing bacteria (AOB) in wastewater treatment plants and the influence of treatment process and system scale on AOB community. We investigated AOB communities in activated sludges collected from 9 wastewater treatment systems, using specific PCR followed by terminal restriction fragment length polymorphism (T-RFLP), cloning, and sequencing of amoA genes. The T-RFLP fingerprints analysis shows that there are some differences among the AOB community structures from different wastewater treatment systems, and the dominant terminal restriction fragments (T-RFs) are 354, 491 and 291 bp.

[Degradation of acid blue 45 in a white-rot fungi reactor operated under non-sterile conditions].

To operate the white-rot fungal reactor under non-sterile conditions has important significance for its practical applications. Ozone (0.0144 mg/min) was selected as the bactericide to control the bacterial contamination in a white-rot fungal reactor.

[Effect of ozone on membrane fouling in water and wastewater treatment: a research review].

As a high efficient water and wastewater treatment technology, membrane filtration has been mainly used in wastewater treatment as membrane bioreactor, in reclaiming secondary effluent,treating surface water and potable water, and etc. Membrane fouling is a main obstacle to the wide application of membrane technology. Ozone has strong oxidizing power and has been utilized widely in water and wastewater treatment.

Biodegradation of gaseous chlorobenzene by white-rot fungus Phanerochaete chrysosporium.

Objective: To evaluate the effect of white rot fungus Phanerochaete chrysosporium on removal of gaseous chlorobenzene.

Methods: Fungal mycelium mixed with a liquid medium was placed into airtight bottles. A certain amount of chlorobenzene was injected into the headspace of the bottles under different conditions.

[White rot fungi biofilter treating waste gas containing chlorobenzene].

A novel gas-solid phase bioreactor, using bamboo as support material, inoculated with white rot fungi Phanerochaete chrysosporium was established to treat waste gas containing chlorobenzene. The performance of P. chrysosporium bioreactor was examined under different conditions.

[Kinetics model for batch culture of white rot fungus].

In order to understand ligninolytic enzymes production process during culture of white rot fungus, accordingly to direct the design of fermentation process, a kinetics model was built for the batch culture of Phanerochaete chrysosporium. The parameters in the model were calibrated based on the experimental data from free and immobilized culture separately. The difference between each variable's values calculated based on kinetics model and experimental data is within 15%.

[Spatial distribution of nitrifying bacteria communities in suspended carrier biofilm].

Spatial distributions of ammonia oxidizing bacteria (AOB) and nitrobacteria in a renovated suspended carrier biofilm reactor (SCBR) were investigated by using fluorescence in situ hybridization (FISH) with 16S rRNA oligonucleotide probes in combination with confocal laser scanning microscopy (CLSM). Three bench-scale structurally identical SCBR reactors were operated under different ratios of COD to NH4(+) -N in influents, 5, 10 and 15, respectively. Each SCBR reactor was consisted of a 6 L of aeration basin and a 2L of clarifier, with the hydraulic retention time (HRT) of 1.

[Resistance analyses for recirculated membrane bioreactor].

The resistance analyses for recirculated membrane bioreactor by the resistance-in-series model and the modified gel-polarization model respectively were extended to the turbulent ultrafiltration system. The experiments are carried out by dye wastewater in a tubular membrane module, it is found that the permeate fluxes are predicted very well by these models for turbinate systems. And the resistance caused by the concentration polarization is studied; the gel layer resistance is the most important of all the resistances.

Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions.

Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions.

[Effect of trace element on the growth of white rot fungus and suppressing yeast in liquid medium].

Growth of white rot fungus in liquid medium with different trace element and effect of these medium on suppressing the growth of yeast under non-sterile were investigated in agitated Erlenmeyer flasks. Results showed that the size and amount of mycelium pellets in liquid medium with trace element and Fe 3.5 mg/L was more than that with trace element but no iron and without any trace element under sterile condition; moreover, the size and amount of mycelium pellets increased with the rise of the concentration of trace element and iron.

Effect of a suspended carrier on membrane fouling in a submerged membrane bioreactor.

In an attempt at membrane fouling control, a kind of cylindrical plastic suspended carrier was added in a submerged membrane bioreactor (SMBR) and its effect was investigated in this study. According to the transmembrane pressure (TMP) profiles and the sludge characteristics in comparative runs with and without suspended carriers, it was found that the suspended carriers added in SMBR had two effects on membrane fouling: one was the positive effect of mechanically scouring the membrane surface and the other was the negative effect of breaking up sludge flocs. Sludge particle size distribution change was mainly responsible.

[Production of ligninolytic enzymes in bioreactor].

Production of ligninolytic enzymes under nitrogen limited conditions(C/N = 56/2.2) was studied in a 5-L stirred tank bioreactor with a working volume of 2 L for obtaining higher production of ligninolytic enzymes by white rot fungus Phanerochaete chrysosporium BKM-F-1767 and its control strategy. Results show that the manganese peroxidase (MnP) and laccase (Lac) reached peak at the sixth day and the seventh day, respectively, and the variation of them with time in a batch cultivation are similar to the results by agitated Erlenmeyer flasks; however higher enzyme activity was not achieved by applying a fed-batch strategy, in which nitrogen limited medium was fed to the reactor.

[Effect of pH on suppressing the growth of other bacteria and fungi in culturing Phanerochaete chrysosporium in liquid medium].

Effect of different pH value on suppressing the growth of other bacteria and fungi in culturing Phanerochaete chrysosporium in liquid medium under non-sterile were investigated in agitated Erlenmeyer flasks. Results showed that nitrogen-limited liquid medium with pH3.6 and pH4.