Improved efficiency of reactor startup in biological aerated filter by poly(lactic acid)

2014 ◽  
Vol 15 (2) ◽  
pp. 348-355
Author(s):  
Hui Feng ◽  
Fu-yi Cui ◽  
Yi-zhong Xie ◽  
Yan Wei ◽  
Zhi-wei Zhao
Keyword(s):  
Lactic Acid ◽  
Photoelectron Spectroscopy ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Drinking Water Treatment ◽  
Ammonia Nitrogen ◽  
Poly Lactic Acid ◽  
Enhancement Effect ◽  
Biological Aerated Filter ◽  
Gradient Gel Electrophoresis ◽  
Aerated Filter

The enhancement effect of polyethylene (PE) surfaces modified with poly(lactic acid) (PLA) on formation of nitrifying biofilms in biological aerated filter (BAF) was investigated in this study. X-ray photoelectron spectroscopy, scanning electron microscope, and protein absorption analysis revealed that modified PE surfaces produced active groups, including carboxyl (O═C─O), hydroxyl (C─OH), and carbonyl (C═O), increased surface roughness, and enhanced the adsorption of both the bovine serum albumin and fibrinogen. During the startup period of 33 days, the average removal rates of ammonia nitrogen (NH3-H) were 68 and 72% before and after modification which were 36 and 43% for total nitrogen, 47 and 45% for total organic carbon. The results of denaturing gradient gel electrophoresis experiments demonstrated that modified carriers adsorbed and gathered more species of bacteria on surfaces. Thus, surface modification of PE suspended carrier by PLA improved the efficiency of reactor startup for drinking water treatment.

Treatment of the azo dye direct blue 2 in a biological aerated filter under anaerobic/aerobic conditions

2010 ◽  
Vol 61 (3) ◽  
pp. 789-796 ◽  
Author(s):  
S. González-Martínez ◽  
S. Piña-Mondragón ◽  
Ó. González-Barceló
Keyword(s):  
Azo Dye ◽  
Municipal Wastewater ◽  
Dye Removal ◽  
Ammonia Nitrogen ◽  
Final Concentration ◽  
Biological Aerated Filter ◽  
Removal Rates ◽  
Aerobic Conditions ◽  
Direct Blue ◽  
Aerated Filter

The main objective of this research was to determine the feasibility to treat the azo dye direct blue 2 together with municipal wastewater in a biological aerated filter (BAF) using lava stones as support of the microorganisms and under combined anaerobic/aerobic conditions. A 3 m high pilot biological aerated filter was fed with municipal wastewater and, after several weeks, the azo dye direct blue 2 was added to the wastewater to reach a final concentration of 50 mg/L (34 mgCOD/L). Under continuous operation, two strategies were tested: Alternating aeration (12 h anaerobic and 12 h aerobic) and combined aeration (the lower part of the filter anaerobic and the upper part aerobic). The results indicate that municipal wastewater acted as a good electron donor resulting in satisfactory COD and dye removal rates. Better dye removal (61%) was obtained with combined aeration than with alternating aeration (45%). After beginning the azo dye addition, the COD removal rates decreased from 87 to 81% for both alternating and combined aeration procedures. The average ammonia nitrogen removal, without the addition of the dye, was 73% and increased to 90% shortly after beginning the dye addition, then it decreased to 81% during the combined aeration period. Excellent nitrification was observed in the upper aerobic part of the filter. For the combined aeration phase, the conditions change from anaerobic to aerobic does not seem to affect the behavior of the COD and TSS curves.

Study on Biological Aerated Filter as Enhanced Pretreatment Process of Coagulation and Sedimentation

2013 ◽  
Vol 726-731 ◽  
pp. 1940-1944 ◽  
Author(s):  
Liang Shen ◽  
Han Xiao ◽  
Wan Qiu Yang ◽  
De Ren Miao ◽  
Xiao Ming Li
Keyword(s):  
Power Plant ◽  
Water System ◽  
Cooling Water ◽  
Ammonia Nitrogen ◽  
Secondary Effluent ◽  
Biological Aerated Filter ◽  
Sedimentation Process ◽  
Cooling Water System ◽  
Circulating Cooling Water ◽  
Aerated Filter

Using coagulation and sedimentation process in the advanced treatment of urban secondary effluent which can be recycled to circulating cooling water system in power plant is only perform well on CODCrand turbidity removal. But the concentrations of organic matter and NH3in effluent can not meet the requirements of circulating cooling water. Therefore, in this study, the feasibility of biological aerated filter (BAF) as a pretreatment enhancing coagulation and sedimentation process was discussed. Achieved by controlling the two operating modes: (1) secondary effluentcoagulation and sedimentationeffluent; (2) secondary effluent BAFcoagulation and sedimentation effluent.The results show that the BAF pretreatment removes ammonia nitrogen effectively, and the turbidity and CODCrof effluent of BAF-coagulation sedimentation process is much lower than individual coagulation and sedimentation process. The final effluent qualities meet the requirements of circulating cooling water system in power plant.

scholarly journals Microbial Ecology Dynamics during Rye and Wheat Sourdough Preparation

2013 ◽  
Vol 79 (24) ◽  
pp. 7827-7836 ◽  
Author(s):  
Danilo Ercolini ◽  
Erica Pontonio ◽  
Francesca De Filippis ◽  
Fabio Minervini ◽  
Antonietta La Storia ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Microbial Ecology ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Diversity Indices ◽  
Rrna Gene ◽  
Content Type ◽  
Gradient Gel Electrophoresis ◽  
Plate Counts ◽  
Relative Abundances

ABSTRACTThe bacterial ecology during rye and wheat sourdough preparation was described by 16S rRNA gene pyrosequencing. Viable plate counts of presumptive lactic acid bacteria, the ratio between lactic acid bacteria and yeasts, the rate of acidification, a permutation analysis based on biochemical and microbial features, the number of operational taxonomic units (OTUs), and diversity indices all together demonstrated the maturity of the sourdoughs during 5 to 7 days of propagation. Flours were mainly contaminated by metabolically active genera (Acinetobacter,Pantoea,Pseudomonas,Comamonas,Enterobacter,Erwinia, andSphingomonas) belonging to the phylumProteobacteriaorBacteroidetes(genusChryseobacterium). Their relative abundances varied with the flour. Soon after 1 day of propagation, this population was almost completely inhibited except for theEnterobacteriaceae. Although members of the phylumFirmicuteswere present at very low or intermediate relative abundances in the flours, they became dominant soon after 1 day of propagation. Lactic acid bacteria were almost exclusively representative of theFirmicutesby this time.Weissellaspp. were already dominant in rye flour and stably persisted, though they were later flanked by theLactobacillus sakeigroup. There was a succession of species during 10 days of propagation of wheat sourdoughs. The fluctuation between dominating and subdominating populations ofL. sakeigroup,Leuconostocspp.,Weissellaspp., andLactococcus lactiswas demonstrated. Other subdominant species such asLactobacillus plantarumwere detectable throughout propagation. As shown by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) analysis,Saccharomyces cerevisiaedominated throughout the sourdough propagation. Notwithstanding variations due to environmental and technology determinants, the results of this study represent a clear example of how the microbial ecology evolves during sourdough preparation.

Treatment of petrochemical secondary effluent by an up-flow biological aerated filter (BAF)

2016 ◽  
Vol 73 (8) ◽  
pp. 2031-2038 ◽  
Author(s):  
L. Y. Fu ◽  
C. Y. Wu ◽  
Y. X. Zhou ◽  
J. E. Zuo ◽  
Y. Ding
Keyword(s):  
Removal Efficiency ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Gas Chromatography Mass Spectrometry ◽  
Secondary Effluent ◽  
Biological Aerated Filter ◽  
Total Removal ◽  
Aerated Filter ◽  
Final Effluent

In this study, petrochemical secondary effluent was treated by a 55 cm diameter pilot-scale biological aerated filter (BAF) with a media depth of 220 cm. Volcanic rock grains were filled as the BAF media. Median removal efficiency of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) was 29.35 and 57.98%, respectively. Moreover, the removal profile of the COD, NH3-N, total nitrogen and total organic carbon demonstrated that the filter height of 140 cm made up to 90% of the total removal efficiency of the final effluent. By gas chromatography–mass spectrometry, removal efficiencies of 2-chloromethyl-1,3-dioxolane, and benzonitrile, indene and naphthalene were obtained, ranging from 30.12 to 63.01%. The biomass and microbial activity of the microorganisms on the filter media were in general reduced with increasing filter height, which is consistent with the removal profile of the contaminants. The detected genera Defluviicoccus, Betaproteobacteria_unclassified and the Blastocatella constituted 1.86–6.75% of the identified gene, enhancing the COD and nitrogen removal in BAF for treating petrochemical secondary effluent.

scholarly journals Design and Evaluation of PCR Primers for Analysis of Bacterial Populations in Wine by Denaturing Gradient Gel Electrophoresis

2003 ◽  
Vol 69 (11) ◽  
pp. 6801-6807 ◽  
Author(s):  
Isabel Lopez ◽  
Fernanda Ruiz-Larrea ◽  
Luca Cocolin ◽  
Erica Orr ◽  
Trevor Phister ◽  
...  
Keyword(s):  
Lactic Acid ◽  
16S Rdna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Bacterial Species ◽  
Pcr Primers ◽  
Fungal Species ◽  
Bacterial Populations ◽  
Gradient Gel Electrophoresis ◽  
Primer Sets

ABSTRACT Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified ribosomal DNA (rDNA) is routinely used to compare levels of diversity of microbial communities and to monitor population dynamics. While using PCR-DGGE to examine the bacteria in wine fermentations, we noted that several commonly used PCR primers for amplifying bacterial 16S rDNA also coamplified yeast, fungal, or plant DNA present in samples. Unfortunately, amplification of nonbacterial DNA can result in a masking of bacterial populations in DGGE profiles. To surmount this problem, we developed two new primer sets for specific amplification of bacterial 16S rDNA in wine fermentation samples without amplification of eukaryotic DNA. One primer set, termed WLAB1 and WLAB2, amplified lactic acid bacteria, while another, termed WBAC1 and WBAC2, amplified both lactic acid bacterial and acetic acid bacterial populations found in wine. Primer specificity and efficacy were examined with DNA isolated from numerous bacterial, yeast, and fungal species commonly found in wine and must samples. Importantly, both primer sets effectively distinguished bacterial species in wine containing mixtures of yeast and bacteria.

Covalent immobilization of enzyme on aminated woven poly (lactic acid) via ammonia plasma: evaluation of the optimum immobilization conditions

2016 ◽  
Vol 87 (10) ◽  
pp. 1177-1191 ◽  
Author(s):  
Ji Eun Song ◽  
Wha Soon Song ◽  
Sang Young Yeo ◽  
Hye Rim Kim ◽  
So Hee Lee
Keyword(s):  
Lactic Acid ◽  
Photoelectron Spectroscopy ◽  
Specific Activity ◽  
Covalent Binding ◽  
Covalent Immobilization ◽  
Poly Lactic Acid ◽  
Porcine Pancreas ◽  
Thermal Stabilities ◽  
Treatment Conditions ◽  
Immobilized Trypsin

The present study aims to develop an immobilization support from woven poly (lactic acid) (PLA) and establish the optimum immobilization conditions for trypsin. Woven PLA was modified by ammonia-based plasma treatment in order to incorporate amine groups on its surface. X-ray photoelectron spectroscopy analysis showed that the N1s composition of PLA increased significantly, from 0.66% to 5.92%, after ammonia-based plasma processing. Trypsin from porcine pancreas was immobilized onto modified woven PLA by covalent binding after activating PLA with glutaraldehyde (GA). The results indicated that the optimal GA treatment conditions were as follows: pH of 10.0, 2% GA (v/v), and 180 min crosslinking time. In addition, the optimum immobilization conditions were as follows: pH of 8.5, 10% (owf) of trypsin concentration, 30 min, and 25℃. Under the optimum conditions, the amount of immobilized enzyme on woven PLA was 0.28 mg/mg and specific activity was 3.763 U/mg. In addition, the pH and thermal stabilities of the immobilized trypsin were improved. The immobilized trypsin retained approximately 55% of its initial activity after 20 days of storage and exhibited the potential for repetitive use through approximately 15 cycles. GA crosslinking and trypsin immobilization were found to improve the roughness of the PLA surface and increase its hydrophobicity. The data indicate that modified woven PLA, used as an immobilization support, shows suitable properties for use as a biocatalytic material in enzymatic applications.

scholarly journals Influence of Artisan Bakery- or Laboratory-Propagated Sourdoughs on the Diversity of Lactic Acid Bacterium and Yeast Microbiotas

2012 ◽  
Vol 78 (15) ◽  
pp. 5328-5340 ◽  
Author(s):  
Fabio Minervini ◽  
Anna Lattanzi ◽  
Maria De Angelis ◽  
Raffaella Di Cagno ◽  
Marco Gobbetti
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactic Acid Bacterium ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Type I ◽  
Content Type ◽  
Stable Species ◽  
Mature Type ◽  
Gradient Gel Electrophoresis ◽  
Permutation Analysis

ABSTRACTSeven mature type I sourdoughs were comparatively back-slopped (80 days) at artisan bakery and laboratory levels under constant technology parameters. The cell density of presumptive lactic acid bacteria and related biochemical features were not affected by the environment of propagation. On the contrary, the number of yeasts markedly decreased from artisan bakery to laboratory propagation. During late laboratory propagation, denaturing gradient gel electrophoresis (DGGE) showed that the DNA band corresponding toSaccharomyces cerevisiaewas no longer detectable in several sourdoughs. Twelve species of lactic acid bacteria were variously identified through a culture-dependent approach. All sourdoughs harbored a certain number of species and strains, which were dominant throughout time and, in several cases, varied depending on the environment of propagation. As shown by statistical permutation analysis, the lactic acid bacterium populations differed among sourdoughs propagated at artisan bakery and laboratory levels.Lactobacillus plantarum,Lactobacillus sakei, andWeissella cibariadominated in only some sourdoughs back-slopped at artisan bakeries, andLeuconostoc citreumseemed to be more persistent under laboratory conditions. Strains ofLactobacillus sanfranciscensiswere indifferently found in some sourdoughs. Together with the other stable species and strains, other lactic acid bacteria temporarily contaminated the sourdoughs and largely differed between artisan bakery and laboratory levels. The environment of propagation has an undoubted influence on the composition of sourdough yeast and lactic acid bacterium microbiotas.

scholarly journals Attapulgite suspension filter material for biological aerated filter to remove CODMn and ammonia nitrogen in micro-polluted drinking water source

2020 ◽  
Vol 46 (4) ◽  
Author(s):  
Kai Xu ◽  
Jiahao Wang ◽  
Jiacheng Li ◽  
Zijie Wang ◽  
Zizeng Lin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Source ◽  
Filter Material ◽  
Ammonia Nitrogen ◽  
Drinking Water Source ◽  
Biological Aerated Filter ◽  
Aerated Filter

scholarly journals FLUENT Simulation Design and Optimization of Biological Aerated Filter

2022 ◽  
Vol 2148 (1) ◽  
pp. 012037
Author(s):  
Shuqin Wang ◽  
Zhiqiang Zhang ◽  
Ning Wang ◽  
Wenqi Zhao ◽  
Chungang Yuan
Keyword(s):  
Particle Size ◽  
Dissolved Oxygen ◽  
Removal Efficiency ◽  
Ammonia Nitrogen ◽  
Design Parameters ◽  
Biological Aerated Filter ◽  
Simulation Design ◽  
Initial Concentration ◽  
Design And Optimization ◽  
Aerated Filter

Abstract In this paper, a small biological aerated filter for experimental use was designed, and a method was explored to optimize the nitrogen removal efficiency by using FLUENT software to simulate the particle size of the filler, the amount of the filler, the initial concentration of ammonia nitrogen, dissolved oxygen and other operating parameters. Through the simulation experiment, the optimal design parameters of the particle size of filler, the amount of filler, the initial concentration of ammonia nitrogen and the dissolved oxygen of the biological aerated filter are 4mm, 60%, 15% and 1.5%, respectively, when the removal efficiency of ammonia nitrogen exceeds 30% reported in the literature. It provides a reference for the experimental research and practical application of biological aerated filter (BAF) denitrification.

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