scholarly journals Mechanism of 1,4-dioxane microbial degradation revealed by 16S rRNA and metatranscriptomic analyses

2017 ◽  
Vol 77 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Xiangyu Guan ◽  
Fei Liu ◽  
Jing Wang ◽  
Caoxiang Li ◽  
Xiaoxuan Zheng
Keyword(s):  
16S Rrna ◽  
Activated Sludge ◽  
Metabolic Pathway ◽  
Industrial Wastewater ◽  
Degradation Rate ◽  
Domestic Sewage ◽  
Functional Genes ◽  
Future Studies ◽  
Human Carcinogen ◽  
Activated Sludge System

Abstract 1,4-Dioxane (dioxane), a probable human carcinogen, often exists in industrial wastewater and domestic sewage. In this study, we applied 16S rRNA and metatranscriptomic methods to analyze the dioxane biodegradation mechanism by activated sludge. Tetrahydrofuran (THF) was added as an essential co-metabolite to promote the degradation of dioxane. We found the dioxane removal ratio increased with increasing THF concentrations. When the THF concentration increased from 60.0 to 200.0 mg/L, the dioxane degradation rate was stable. Three additions of ∼60.0 mg/L THF resulted in better dioxane degradation than one addition of 200 mg/L THF. Ammonia-oxidizing and denitrifying bacteria with methane monooxygenases (MOs) and ammonia MOs played the most important roles during the degradation of dioxane. Kyoto Encyclopedia of Genes and Genomes metabolic pathway and functional genes analyses showed that the activated sludge system was complex and stable when dioxane was added. In future studies, primers should be designed to identify specific bacteria and functional MO genes, which would help reveal the function of various bacteria and their MOs during dioxane degradation.

Temporal dynamics of the microbial community in an integrated fixed-film activated sludge system revealed by 16S rRNA MiSeq sequencing

2017 ◽  
Vol 62 ◽  
pp. 185-191 ◽  
Author(s):  
Bin Dong ◽  
Minghao Liu ◽  
Jie Tan ◽  
Qingqing Feng ◽  
Jinfeng Meng ◽  
...  
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Activated Sludge ◽  
Temporal Dynamics ◽  
Miseq Sequencing ◽  
Activated Sludge System ◽  
Fixed Film

scholarly journals Quantification of Hyphomicrobium Populations in Activated Sludge from an Industrial Wastewater Treatment System as Determined by 16S rRNA Analysis

2000 ◽  
Vol 66 (3) ◽  
pp. 1167-1174 ◽  
Author(s):  
A. C. Layton ◽  
P. N. Karanth ◽  
C. A. Lajoie ◽  
A. J. Meyers ◽  
I. R. Gregory ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
16S Rrna ◽  
Activated Sludge ◽  
16S Rdna ◽  
Industrial Wastewater ◽  
Bacterial Species ◽  
Treatment Plant ◽  
Rrna Gene ◽  
16S Rrna Analysis ◽  
Industrial Wastewater Treatment

ABSTRACT The bacterial community structure of the activated sludge from a 25 million-gal-per-day industrial wastewater treatment plant was investigated using rRNA analysis. 16S ribosomal DNA (rDNA) libraries were created from three sludge samples taken on different dates. Partial rRNA gene sequences were obtained for 46 rDNA clones, and nearly complete 16S rRNA sequences were obtained for 18 clones. Seventeen of these clones were members of the beta subdivision, and their sequences showed high homology to sequences of known bacterial species as well as published 16S rDNA sequences from other activated sludge sources. Sixteen clones belonged to the alpha subdivision, 7 of which showed similarity to Hyphomicrobium species. This cluster was chosen for further studies due to earlier work onHyphomicrobium sp. strain M3 isolated from this treatment plant. A nearly full-length 16S rDNA sequence was obtained fromHyphomicrobium sp. strain M3. Phylogenetic analysis revealed that Hyphomicrobium sp. strain M3 was 99% similar to Hyphomicrobium denitrificans DSM 1869T inHyphomicrobium cluster II. Three of the cloned sequences from the activated sludge samples also grouped with those ofHyphomicrobium cluster II, with a 96% sequence similarity to that of Hyphomicrobium sp. strain M3. The other four cloned sequences from the activated sludge sample were more closely related to those of the Hyphomicrobium cluster I organisms (95 to 97% similarity). Whole-cell fluorescence hybridization of microorganisms in the activated sludge with genus-specificHyphomicrobium probe S-G-Hypho-1241-a-A-19 enhanced the visualization of Hyphomicrobium and revealed thatHyphomicrobium appears to be abundant both on the outside of flocs and within the floc structure. Dot blot hybridization of activated sludge samples from 1995 with probes designed forHyphomicrobium cluster I and Hyphomicrobiumcluster II indicated that Hyphomicrobium cluster II-positive 16S rRNA dominated over Hyphomicrobium cluster I-positive 16S rRNA by 3- to 12-fold. Hyphomicrobium 16S rRNA comprised approximately 5% of the 16S rRNA in the activated sludge.

Research for Biodegradation and Bioaugmentation of Drilling Wastewater

2013 ◽  
Vol 684 ◽  
pp. 226-229
Author(s):  
Feng Xu ◽  
Jin Chuan Gu ◽  
Jin Bao
Keyword(s):  
Activated Sludge ◽  
Degradation Rate ◽  
Orthogonal Experiment ◽  
Impact Resistance ◽  
Single Strain ◽  
Optimal Ratio ◽  
Augmented System ◽  
Activated Sludge System ◽  
Degradation Rates ◽  
Drilling Site

The paper studied the degradation rate of single strain, the microorganisms agent compatibility and the bioaugmentation effects of the activated sludge system. The results showed that 10 strains screened from drilling site were able to degrade drilling wastewater. Confirm the optimal ratio of strains’ compatibility through orthogonal experiment. In augmented experiments, it showed that in the control SBR system with the COD of the effluent was in three different average levels (with two load shock), the COD degradation rates were 21.4%, 22.8% and 6.9%. In the augmented system treated with the same effluent, the degradation rates of augmented system were 64.8%, 62.78% and 66.9% respectively. It showed that the activated sludge was augmented by the mixed cultures which made the system to be more stable and improve impact resistance.

Evaluation of filamentous microorganism growth factors in an industrial wastewater activated sludge system

1998 ◽  
Vol 37 (4-5) ◽  
pp. 263-270 ◽  
Author(s):  
Caroline E. Scruggs ◽  
Clifford W. Randall
Keyword(s):  
Activated Sludge ◽  
Industrial Wastewater ◽  
Filamentous Growth ◽  
Necessary Condition ◽  
Key Factors ◽  
Filamentous Microorganism ◽  
Factors Affecting ◽  
Activated Sludge System ◽  
Filamentous Microorganisms ◽  
Do Concentration

An investigation comprising four studies was undertaken to determine possible factors affecting the growth of several different types of filamentous microorganisms present in a bulking industrial wastewater activated sludge. Results from laboratory-scale continuous-flow and full-scale studies suggested that DO concentration and F:M ratio were the likely key factors affecting filamentous growth in the activated sludge. From the results of two laboratory studies isolating the effects of DO concentration and F:M ratio on filamentous growth, favorable growth ranges of DO concentration or F:M ratio were estimated for the following filaments: Microthrix parvicella, Nocardia spp., Nostocoida limicola II, and Types 0041, 1851, and 1863. Most of the bacteria causing filamentous bulking of the activated sludge were found to be filaments typically associated with low F:M, and increasing the F:M ratio appeared to cause N. limicola II to lose its competitive advantage in the activated sludge system. Type 1863, on the other hand, was found to be a low DO filament, as DO concentrations of 0.1 mg O2/l or less appeared to be a necessary condition for its filamentous growth. Though Nocardia was found to be a low F:M filament, its growth also seemed to be affected by DO concentration, as its growth was stimulated by concentrations of 1.0 mg O2/l or greater, with a near linear relationship up to at least 5 mg O2/l.

Cost-Effective Pre-Treatment of Food-Processing Industrial Wastewater

1999 ◽  
Vol 40 (7) ◽  
pp. 17-24 ◽  
Author(s):  
F. A. El-Gohary ◽  
F. A. Nasr ◽  
H. I. Aly
Keyword(s):  
Activated Sludge ◽  
Food Processing ◽  
Industrial Wastewater ◽  
Cost Effective ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Activated Sludge System ◽  
Engineering Designs ◽  
Pre Treatment ◽  
Food Processing Wastewater

Performance of laboratory-scale aerobic and anaerobic systems treating food-processing wastewater was investigated. The results obtained showed that BOD and COD of wastewater discharged from a potato-chips factory can be reduced by 86% and 82% using UASB reactor at an organic loading rate (OLR) of 2.9 kg BOD/m3·d and a hydraulic retention time (HRT) of 18 hr. Corresponding results for an activated sludge system, operated at an OLR of 8.9 kg BOD/m3·d with a HRT of 6hr were 86% and 84%, respectively. Treatment of confectionery wastewater using UASB at a HRT of 12hr and an OLR of 4.4 kg BOD/m3.d gave satisfactory results. COD and BOD removals were 92.4% and 91.5%, respectively. The use of completely activated sludge system at a HRT of 6 hr and ORL of 8.4 kg BOD/m3.d gave lower results as compared to UASB reactor. However, characteristics of the effluents produced using the two systems were in agreement with the standards regulating discharge of industrial wastewater into the sewerage system. Based on the technical and economic evaluation of the results, engineering designs were made for the selected systems.

Determination of the impact of toxic inflows on the performance of activated sludge by wastewater characterization

1997 ◽  
Vol 36 (2-3) ◽  
pp. 45-52 ◽  
Author(s):  
A. D. Andreadakis ◽  
C. M. Kalergis ◽  
N. Kartsonas ◽  
D. Anagnostopoulos
Keyword(s):  
Activated Sludge ◽  
Uptake Rate ◽  
Industrial Wastewater ◽  
Treatment Plant ◽  
Domestic Sewage ◽  
Ammonium Uptake ◽  
Rational Approach ◽  
Biomass Characterization ◽  
Inhibition Of Nitrification ◽  
The Impact

A rational approach for the design of the activated sludge process based on wastewater and biomass characterization techniques as applied to the upgrading of the treatment plant of Volos, a city in the central part of Greece, is presented. The study investigates possible nitrification inhibition and carbon inadequacy, due to high salinity, industrial inflows and pre-precipitation by iron salts. The experimentation was carried out by means of batch Ammonium Uptake Rate (AUR) and Nitrates Uptake Rate (NUR) tests. The results show that within the studied range, 900-4000 mg l−1, chlorides did not inhibit nitrification. Contrary to this, the industrial wastewater entering the plant was found to be toxic. With the existing 1:15 ratio of industrial to total wastewater flow a 50% inhibition to the nitrification process was observed, which is higher than the 25 - 30% inhibition caused by typical domestic sewage. Industrial contributions exceeding 20% resulted in complete inhibition of nitrification. With respect to denitrification it was found that the industrial wastewater provided a suitable source of carbon, without any adverse effects on denitrification. Pre-precipitation removed about 25% of the filtered COD, thus reducing the amount of nitrates which could be rapidly denitrified. Design of the biological reactors on the basis of the findings indicate that a significant under-design may result if typical nitrification and denitrification rates obtained from the literature and practice concerning typical domestic sewage are adopted.

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