Sustainable operation of submerged Anammox membrane bioreactor with recycling biogas sparging for alleviating membrane fouling.

A submerged anaerobic ammonium oxidizing (Anammox) membrane bioreactor with recycling biogas sparging for alleviating membrane fouling has been successfully operated for 100d. Based on the batch tests, a recycling biogas sparging rate at 0.2m(3)h(-1) was fixed as an ultimate value for the sustainable operation.

Highly effective permeability and antifouling performances of polypropylene non-woven fabric membranes modified with graphene oxide by inkjet printing and immersion coating methods.

In the current study, graphene oxide (GO)-modified polypropylene non-woven fabric (PP-NWF) membranes were prepared via inkjet printing and immersion coating methods. Scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurements, pure water permeation (JPWP) and protein adsorption were tested to evaluate the impact of the GO nanosheet on the characteristics and performance of modified PP-NWF membranes. The results showed that the exfoliated GO nanosheets uniformly deposited on the membrane surface and firmly embedded into the interlaced fibers, resulting in the improvement of membrane hydrophilicity, permeability and antifouling properties comparing with original PP-NWF membranes.

Management of occupational exposure to engineered nanoparticles through a chance-constrained nonlinear programming approach.

Critical environmental and human health concerns are associated with the rapidly growing fields of nanotechnology and manufactured nanomaterials (MNMs). The main risk arises from occupational exposure via chronic inhalation of nanoparticles. This research presents a chance-constrained nonlinear programming (CCNLP) optimization approach, which is developed to maximize the nanaomaterial production and minimize the risks of workplace exposure to MNMs.

[Modeling formation of aerobic granule and influence of hydrodynamic shear forces on granule diameter].

A one-dimension aerobic granule mathematical model was established, basing on mathematical biofilm model and activated sludge model. The model was used to simulate simple aerobic granule process such as nutrients removal, granule diameter evolution, cycle performance as well as depth profiles of DO and biomass. The effluent NH4(+) -N concentration decreased as the modeling processed.

[Effect of aeration intensity on the nitrogen and phosphorus removal performance of AOA membrane bioreactors].

The ability of simultaneous phosphorus and nitrogen removal of sequencing batch membrane bioreactor run in anaerobic/oxic/ anoxic mode (AOA MBR) was examined under three aeration intensities [2.5, 3.75 and 5.

PB/PANI-modified electrode used as a novel oxygen reduction cathode in microbial fuel cell.

This study focuses on the preparation of a new type of Prussian Blue/polyaniline (PB/PANI)-modified electrode as oxygen reduction cathode, and its availability in microbial fuel cell (MFC) for biological power generation. The PB/PANI-modified electrode was prepared by electrochemical and chemical methods, both of which exhibited good electrocatalytical reactivity for oxygen reduction in acidic electrolyte. The MFC with PB/PANI-modified cathode aerated by either oxygen or air was shown to yield a maximum power density being the same with that of the MFC with liquid-state ferricyanide cathode, and have an excellent duration as indicated by stable cathode potential for more than eight operating circles.

[Coupling anaerobic baffled reactor and membrane-aerated biofilm reactor].

Based on the consistent anaerobic status of outer layer of membrane-aerated biofilm reactor (MABR) and internal anaerobic baffled reactor (ABR), MABR and ABR were started up separately. The aerating membrane module was installed into a compartment of anaerobic baffled bioreactor to form the Hybrid MAB-ABR (HMABR). After the installation of membrane module, total COD and VFA concentrations in the HMABR effluent were deceased by 59.

[Influence of controlling factors on partial nitrification performance in membrane bioreactor].

A membrane bioreactor (MBR) was developed successfully to carry out partial nitrification process. Temperature, and dissolved oxygen (DO) were investigated as the factors which may affect the results. It has been proved that the optimal operational parameters were at 35 degrees C, ammonia loading 0.

[Denitrifying phosphorus removal in MUCT-MBR].

The self-designed MUCT-MBR simplifies the MUCT process with reducing reactors from 5 to 2, which greatly reduces land occupied by equipment. Instead of secondary sedimentation tank, the membrane effluent quality is quite safe, and the operation is simple. In the investigation about simultaneous phosphorus and nitrogen removal of MUCT-MBR, the results showed that: when the proportions of C, N and P in the influent were 33.

[Preparation and characterization of polyvinyl alcohol microsphere pre-coated dynamic membranes].

To alleviate membrane fouling and reduce the price of membrane module, polyvinyl alcohol microsphere pre-coated dynamic membranes (PVA-MS/PCDMs) were investigated detailedly. It was prepared when the polyvinyl alcohol microsphere of the pre-coated reagent deposited on the surface and entered the pores of porous substrate common filter cloth which was low-cost by means of circulatory filtration. The morphology and structure of PVA-MS/PCDMs were examined using scanning electron microscope (SEM), and approximate maximal separated aperture, water contact angle, pure water permeation resistance and relative Zeta potential of the membrance surface were also determined.

[Combined MBR-RO process treating high strength wastewater].

The performances of A/O-MBR/RO system for the removal of nitrogen and COD were investigated. Result indicated that most organic was removed in the A/O-MBR and the average removal efficiency was 95.6%.

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.

[Characteristics of simultaneous nitrification and denitrification in moving bed membrane bioreactor].

To investigate the removal efficiency of synthetic wastewater and characteristics of simultaneous nitrification and denitrification (SND) performances, a new type of moving bed membrane bioreactor (MBMBR) had been developed by using carriers instead of activated sludge in membrane bioreactor (MBR). Results showed that good organics removal and SND performances was achieved during the 67 d experimental period. COD, ammonium and total nitrogen removal efficiencies of MBMBR remained 88.

[Performance of constructed wetland for municipal wastewater tertiary treatment: winter and summer comparison].

An improved three-stage vertical flow constructed wetland (CW) was used for tertiary treatment of effluent from two typical Dalian municipal wastewater treatment plants. The experiments were carried out under ambient condition in Dalian for the whole year. Performances of the CW for COD, TN, NH4(+) -N and TP removal in summer (Jun.

[Simultaneous nitrification and denitrification of membrane-aerated biofilm reactor].

A carbon membrane-aerated biofilm reactor was developed to treat municipal wastewater, in which the carbon and nitrogen were removed simultaneously. The results showed that COD removal, NH4+-N removal and TN removal efficiency could reach 82.5%, 95.

[Reactivation characteristics of stored aerobic nitrifying granules].

A sequencing batch airlift reactor (SBAR) was conducted to study the performance of physical characteristics and respirometric activities during reactivation of aerobic granules after a 2-month storage time. Results showed that the color of the aerobic granules had completely become dark, the size and settleability did hardly change during the storage period. The color turned to be brownish-yellowish when the reactor was restarted for 2 weeks.

[Photocatalytic reduction of nitrate using metal-doped titania].

Metal Fe or Cu doped P25 titania was prepared using the photodeposition method and characterized by TEM, ICP, XRD and UV-Vis, further tested for photocatalytic nitrate reduction and TN removal, under 20 W UV lamp irradiation. The influencing factors such as the pH values of solution, stirring gas, metal loadings, hole scavenger formic acid amount and co-doped Ag-Cu/TiO2 are investigated and discussed in detail. The experimental results after 2 h reaction indicated that with the increase of Cu loadings, nitrate conversion increases too, while a loading of 0.

[Promoting high-temperature hydrolysis under alkaline condition].

The effect of alkaline thermal hydrolysis method on excess sludge and its characteristic parameters(such as soluble chemical oxygen demand, volatile fatty acids, ammonia-nitrogen, pH value, sludge concentration, etc.) were investigated. The results show that the addition of alkali can reduce the resistance of the sludge cells to high temperature and enhance the release and the hydrolysis of organic materials from the sludge cells with the increase of temperature, pH value and reaction time.

[Effect of extra-cellular polymeric substances on filtration of modified non-woven fabric in membrane bio-reactor].

The effect of extra-cellular polymeric substances (EPS) on filtration of polyvinyl alcohol modified polypropylene non-woven in submerged membrane bioreactor (SMBR) was investigated by statistical method. The results show that soluble extra-cellular polymeric substances (EPSs) of activated sludge on the non-woven modules surface, components (protein/carbohydrate, P/C) of EPSs and relative hydrophobicity (RH) have a significant influence on filtration performance of module B, the Pearson's correlation coefficient (r(p)) related to membrane fouling resistance are 0.868, 0.

[Effects of aeration intensity on characteristics of aerobic granules in sequencing batch airlift reactor (SBAR)].

This study investigated the physical performances of mature aerobic granules in SBAR, including granular shape and structure, mean size and granular relative strength, and cell metabolic activities to excrete extracellular polymeric substances (EPS), and nitrification and microbial activity, which performed visible differences at superficial upflow velocity of 1.8 cm x s(-1) and 0.9 cm x s(-1) respectively.

[Preparation and characterization of cross-linked polyvinyl alcohol microspheres as a novel precoating reagent in dynamic membrane].

In order to modify the membrane surface by adsorbing a precoated layer, cross-linked polyvinyl alcohol microspheres were prepared via an emulsion polymerization that PVA cross linked with glutaraldehyde which was extracted by anhydrous aether. Effects of concentration of PVA solution, the volume ratio of aqueous phase to oil phase, the selection of surface active agent (SAA) and its concentration on the stabilization of emulsion were studied. When the concentration of PVA solution was 2.

Isolation and characterization of comprehensive polychlorinated biphenyl degrading bacterium, Enterobacter sp. LY402.

A Gram-negative bacterium, named LY402, was isolated from contaminated soil. 16S rDNA sequencing and measurement of the physiological and biochemical characteristics identified it as belonging to the genus Enterobacter. Degradation experiments showed that LY402 had the ability to aerobically transform 79 of the 91 major congeners of Aroclor 1242, 1254, and 1260.

[Start-up of carbon tube membrane-aerated biofilm reactor for completely autotrophic nitrogen removal].

A laboratory-scale membrane-aerated biofilm bioreactor (MABR) equipped with nonwoven fabrics support around the gas-permeable carbon tube was developed for single-stage autotrophic nitrogen removal based on partial nitrification and anaerobic ammonium oxidization. Initially, the reactor was inoculated with nitrifying biomass. By decreasing the air pressure in the lumen of carbon tube step by step, We can obtain stable nitrite accumulation.

[Innovative application of carbon tube aerated membranes to enhance anaerobic baffled reactor for wastewater treatment].

New type hybrid biological reactor was developed by initiating the carbon membrane aeration in ABR which was augmented with carbon aerated membranes to improve wastewater treatment by removing COD, NH4(+) -N and TN. The results showed that on the conditions of intra-membrane pressure of 0.025 MPa, HRT 24 h, influent COD 2000 mg/L, NH4(+) -N 50 mg/L, simultaneous nitrification and denitrification was happened, and COD and NH4(+) -N decreased from 156 mg/L, 36 mg/L to 45 mg/L, 6 mg/L respectively after the membrane aeration with biofilm was initiated in the third compartment of ABR.

[Effect of humic acids on determining polyhydroxy phenol by flow-injection chemiluminescence].

Flow-injection chemiluminescence was applied to determine the trace polyhydroxy phenol in environment (soil and water). Based on the comparison of several different chemiluminescence systems and optimization, an alkaline luminol-NaIO4 system for determinating polyhydroxy phenol was chosen. During the process of polyhydroxy phenol determination, the effect of dissolved humic acid (HA) on the determination of phenol by this chemiluminescence system was also considered, which generally coexists in soil and water widely.