scholarly journals Bioremediation and Detoxification of Synthetic Wastewater Containing Triarylmethane Dyes by Aeromonas hydrophila Isolated from Industrial Effluent

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Chimezie Jason Ogugbue ◽  
Thomas Sawidis
Keyword(s):  
Aeromonas Hydrophila ◽  
Growth Parameters ◽  
Industrial Effluent ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Color Removal ◽  
Synthetic Wastewater ◽  
Operational Parameters ◽  
Operational Conditions ◽  
Triarylmethane Dyes

Economical and bio-friendly approaches are needed to remediate dye-contaminated wastewater from various industries. In this study, a novel bacterial strain capable of decolorizing triarylmethane dyes was isolated from a textile wastewater treatment plant in Greece. The bacterial isolate was identified as Aeromonas hydrophila and was shown to decolorize three triarylmethane dyes tested within 24 h with color removal in the range of 72% to 96%. Decolorization efficiency of the bacterium was a function of operational parameters (aeration, dye concentration, temperature, and pH) and the optimal operational conditions obtained for decolorization of the dyes were: pH 7-8, 35∘C and culture agitation. Effective color removal within 24 h was obtained at a maximum dye concentration of 50 mg/L. Dye decolorization was monitored using a scanning UV/visible spectrophotometer which indicated that decolorization was due to the degradation of dyes into non-colored intermediates. Phytotoxicity studies carried out using Triticum aestivum, Hordeum vulgare, and Lens esculenta revealed the triarylmethane dyes exerted toxic effects on plant growth parameters monitored. However, significant reduction in toxicity was obtained with the decolorized dye metabolites thus, indicating the detoxification of the dyes following degradation by Aeromonas hydrophila.

scholarly journals Niche Differentiation among Three Closely RelatedCompetibacteraceaeClades at a Full-Scale Activated Sludge Wastewater Treatment Plant and Putative Linkages to Process Performance

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Veronica R. Brand ◽  
Laurel D. Crosby ◽  
Craig S. Criddle
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Niche Differentiation ◽  
Full Scale ◽  
Pure Oxygen ◽  
Operational Parameters ◽  
Metabolic Potential ◽  
Operational Conditions

ABSTRACTMultiple clades within a microbial taxon often coexist within natural and engineered environments. Because closely related clades have similar metabolic potential, it is unclear how diversity is sustained and what factors drive niche differentiation. In this study, we retrieved three near-complete Competibacter lineage genomes from activated sludge metagenomes at a full-scale pure oxygen activated sludge wastewater treatment plant. The three genomes represent unique taxa within theCompetibacteraceae. A comparison of the genomes revealed differences in capacity for exopolysaccharide (EPS) biosynthesis, glucose fermentation to lactate, and motility. Using quantitative PCR (qPCR), we monitored these clades over a 2-year period. The clade possessing genes for motility and lacking genes for EPS biosynthesis (CPB_P15) was dominant during periods of suspended solids in the effluent. Further analysis of operational parameters indicate that the dominance of the CPB_P15 clade is associated with low-return activated sludge recycle rates and low wasting rates, conditions that maintain relatively high levels of biomass within the system.IMPORTANCEMembers of the Competibacter lineage are relevant in biotechnology as glycogen-accumulating organisms (GAOs). Here, we document the presence of threeCompetibacteraceaeclades in a full-scale activated sludge wastewater treatment plant and their linkage to specific operational conditions. We find evidence for niche differentiation among the three clades with temporal variability in clade dominance that correlates with operational changes at the treatment plant. Specifically, we observe episodic dominance of a likely motile clade during periods of elevated effluent turbidity, as well as episodic dominance of closely related nonmotile clades that likely enhance floc formation during periods of low effluent turbidity.

Efficient treatment of dairy processing wastewater in a laboratory scale Intermittently Aerated Sequencing Batch Reactor (IASBR)

2018 ◽  
Vol 85 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Peter Leonard ◽  
Emma Tarpey ◽  
William Finnegan ◽  
Xinmin Zhan
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Wastewater Treatment Plant ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Operational Parameters ◽  
Dairy Processing

This Research Communication describes an investigation into the viability of an Intermittently Aerated Sequencing Batch Reactor (IASBR) for the treatment of dairy processing wastewater at laboratory-scale. A number of operational parameters have been varied and the effect has been monitored in order to determine optimal conditions for maximising removal efficiencies. These operational parameters include Hydraulic Retention Time (HRT), Solids Retention Time (SRT), aeration rate and cycle length. Real dairy processing wastewater and synthetic wastewater have been treated using three laboratory-scale IASBR units in a temperature controlled room. When the operational conditions were established, the units were seeded using sludge from a municipal wastewater treatment plant for the first experiment, and sludge from a dairy processing factory for the second and third experiment. In experiment three, the reactors were fed on real wastewater from the wastewater treatment plant at this dairy processing factory. These laboratory-scale systems will be used to demonstrate over time that the IASBR system is a consistent, viable option for treatment of dairy processing wastewater in this sector. In this study, the capacity of a biological system to remove both nitrogen and phosphorus within one reactor will be demonstrated. The initial operational parameters for a pilot-scale IASBR system will be derived from the results of the study.

Practical automatic control of a sequencing batch reactor for toxic wastewater treatment

2011 ◽  
Vol 63 (4) ◽  
pp. 782-788 ◽  
Author(s):  
A. M. Pat ◽  
A. Vargas ◽  
G. Buitrón
Keyword(s):  
Wastewater Treatment ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Measurement Data ◽  
Sole Source ◽  
Synthetic Wastewater ◽  
Dissolved Oxygen Concentration ◽  
Operational Parameters ◽  
Operational Conditions ◽  
On Line

This paper investigates the application of a practical and robust control strategy for the operation of a sequencing batch reactor (SBR) used for toxic wastewater treatment. The strategy sets the operational conditions of the SBR based on the on-line information collected during the previous batch. In particular, it sets the exchange volume of the reactor, as well as the batch reaction duration by optimizing the amount of mass of substrate in the influent treated per time unit. The optimization uses an experimentally calibrated mathematical model of the previous SBR cycle, found using the on-line dissolved oxygen concentration measurement data. The results show the applicability of the methodology to treat synthetic wastewater containing 4-chlorophenol as model toxic compound as sole source of carbon and energy. It correctly detects changes in the influent concentration and appropriately sets the operational parameters of the process.

Multistep Optimization and Residue Disposal Study for Electrochemical Treatment of Textile Wastewater Using Aluminum Electrode

2013 ◽  
Vol 11 (1) ◽  
pp. 31-46 ◽  
Author(s):  
Seema Singh ◽  
Vimal Chandra Srivastava ◽  
Indra Deo Mall
Keyword(s):  
Input Parameter ◽  
Textile Wastewater ◽  
Operating Conditions ◽  
Color Removal ◽  
Optimum Operating ◽  
Aluminum Electrode ◽  
Operational Parameters ◽  
Electrode Gap ◽  
Ec Mechanism ◽  
Removal Efficiencies

Abstract This paper reports multistep optimization studies on electrochemical (EC) treatment of textile wastewater containing three dyes namely basic orange 30, basic violet 16 and basic green 4 using an aluminum electrode. Chemical oxygen demand (COD) and color removal efficiencies were maximized in a batch EC experimental reactor. In first step, Plackett–Burman (PB) design was used to sort most effective factors amongst the various factors namely current density (j), time (t), electrode gap (g), temperature (T), initial pH (pHo) and NaCl salt concentration (m) that affected the removal efficiency. In the next step, steepest accent/descent method and Box–Behnken (BB) design methods were utilized to evaluate the optimum electrochemical conditions. In BB design, three operational parameters, namely j: 117.64–196.07 A/m2; t: 150–210 min and pHo: 3.5–5.5 were taken as input parameter whereas COD removal (Y1) and color removal (Y2) were taken as responses of the system. At the optimum operating conditions of j = 185.30 A/m2, t190 min and pHo 5, more than 70.5% COD and 98.2% color removal efficiencies were observed. Field emission scanning electron microscopy of aluminum electrodes, scum and sludge has been carried out to understand the EC mechanism.

scholarly journals Assessing the current state of housing and infrastructure in the concentrated immigrant areas in Ho Chi Minh City

2016 ◽  
Vol 19 (2) ◽  
pp. 28-37
Author(s):  
Ha Bui Manh ◽  
Duy Nguyen Ngoc ◽  
Hien Nguyen Quoc
Keyword(s):  
Removal Efficiency ◽  
Ph Effect ◽  
Absorbed Dose ◽  
Textile Wastewater ◽  
Color Removal ◽  
Synthetic Wastewater ◽  
H2o2 Concentration ◽  
Radiation Technology ◽  
Current State ◽  
Initial Ph

Decolorization from synthetic wastewater containing Reactive Red 24 (RR24) using gamma Cobalt-60 ray was investigated. The influence of the irradiation dose, initial pH, initial dye and hydrogen peroxide (H2O2) concentration were evaluated. The pH effect has proved that lower decolorization efficiency was observed in alkaline medium as compared to the neutral and acid medium. While color removal efficiency increased with increasing absorbed dose. A synergistic effect of gamma radiation with H2O2 was applied and the results showed that H2O2 accelerated decolorization process, however when the dosage of H2O2 exceeded the optimal concentration, the color removal efficiency attained saturation and even reduced. The color removal efficiencies achieved over 99% at the dose of 4 kGy, initial pH 7, initial dye concentrationof 100 mg/L and H2O2 concentration of 3mM. These results highlighted the potential of radiation technology for dye removal from textile wastewater.

Upgrading Wastewater Treatment by Water Hyacinth in Developing Countries

1990 ◽  
Vol 22 (7-8) ◽  
pp. 153-160 ◽  
Author(s):  
Pradeep Kumar ◽  
R. J. Garde
Keyword(s):  
Wastewater Treatment ◽  
Water Hyacinth ◽  
Treatment Plant ◽  
Cod Removal ◽  
Treatment System ◽  
Synthetic Wastewater ◽  
Second Phase ◽  
Treatment Unit ◽  
Batch Studies ◽  
New Treatment

With increasing stress on existing wastewater treatment systems, it is necessary either to upgrade the treatment unit(s) or install an entirely new treatment plant. Obviously, the upgrading is preferred over the alternative of having a new system. Keeping this in view, in the present project, an attempt has been made to explore the possibility of upgrading existing facultative ponds using water hyacinth. Bench-scale batch studies were designed to compare the performance of hyacinth treatment system with facultative ponds. Investigations were carried out with synthetic wastewater having COD in the range of 32.5-1090 mg/l. The efficiency of COD removal in water hyacinth ponds was 15-20 percent more than the facultative ponds. Based on the results, an empirical model has been proposed for COD removal kinetics. In the second phase of the project a hyacinth pond was continuously operated. BOD, COD, TS, TN, TP, pH, and DO were regularly monitored. However, the DO of the effluent from hyacinth treatment system was considerably reduced. Effluent should be aerated before it is discharged. The results indicate that the existing facultative ponds can be stalked with water hyacinth to improve their performance as well as hyacinth treatment systems can be installed to support the conventional treatment.

Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
Author(s):  
F. Fdz-Polanco ◽  
M. D. Hidalgo ◽  
M. Fdz-Polanco ◽  
P. A. García Encina
Keyword(s):  
Polyethylene Terephthalate ◽  
Loading Rate ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Foam Formation ◽  
Organic Loading ◽  
Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

Textile Wastewater Reuse: Ozonation of Membrane Concentrated Secondary Effluent

1999 ◽  
Vol 40 (4-5) ◽  
pp. 99-105 ◽  
Author(s):  
A. Lopez ◽  
G. Ricco ◽  
R. Ciannarella ◽  
A. Rozzi ◽  
A. C. Di Pinto ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Acute Toxicity ◽  
Wastewater Treatment Plant ◽  
Textile Industry ◽  
Nonionic Surfactants ◽  
Wastewater Reuse ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Secondary Effluent ◽  
Complete Disappearance

Among the activities appointed by the EC research-project “Integrated water recycling and emission abatement in the textile industry” (Contract: ENV4-CT95-0064), the effectiveness of ozone for improving the biotreatability of recalcitrant effluents as well as for removing from them toxic and/or inhibitory pollutants has been evaluated at lab-scale. Real membrane concentrates (pH=7.9; TOC=190 ppm; CDO=595 ppm; BOD5=0 ppm; Conductivity=5,000 μS/cm; Microtox-EC20=34%) produced at Bulgarograsso (Italy) Wastewater Treatment Plant by nanofiltering biologically treated secondary textile effluents, have been treated with ozonated air (O3conc.=12 ppm) over 120 min. The results have indicated that during ozonation, BOD5 increases from 0 to 75 ppm, whereas COD and TOC both decrease by about 50% and 30 % respectively. As for potentially toxic and/or inhibitory pollutants such as dyes, nonionic surfactants and halogenated organics, all measured as sum parameters, removals higher than 90% were achieved as confirmed by the complete disappearance of acute toxicity in the treated streams. The only ozonation byproducts searched for and found were aldehydes whose total amount continuously increased in the first hour from 1.2 up to 11.8 ppm. Among them, formaldehyde, acetaldehyde, glyoxal, propionaldehyde, and butyraldehyde were identified by HPLC.

scholarly journals Hydrogen Production by Fluidized Bed Reactors: A Quantitative Perspective Using the Supervised Machine Learning Approach

J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 266-287
Author(s):  
Zheng Lian ◽  
Yixiao Wang ◽  
Xiyue Zhang ◽  
Abubakar Yusuf ◽  
Lord Famiyeh ◽  
...  
Keyword(s):  
Machine Learning ◽  
Hydrogen Production ◽  
Fluidized Bed ◽  
Biomass Gasification ◽  
Supervised Machine Learning ◽  
Fluidized Bed Reactors ◽  
Hydrogen Yield ◽  
Carbon Conversion ◽  
Operational Parameters ◽  
Operational Conditions

The current hydrogen generation technologies, especially biomass gasification using fluidized bed reactors (FBRs), were rigorously reviewed. There are involute operational parameters in a fluidized bed gasifier that determine the anticipated outcomes for hydrogen production purposes. However, limited reviews are present that link these parametric conditions with the corresponding performances based on experimental data collection. Using the constructed artificial neural networks (ANNs) as the supervised machine learning algorithm for data training, the operational parameters from 52 literature reports were utilized to perform both the qualitative and quantitative assessments of the performance, such as the hydrogen yield (HY), hydrogen content (HC) and carbon conversion efficiency (CCE). Seven types of operational parameters, including the steam-to-biomass ratio (SBR), equivalent ratio (ER), temperature, particle size of the feedstock, residence time, lower heating value (LHV) and carbon content (CC), were closely investigated. Six binary parameters have been identified to be statistically significant to the performance parameters (hydrogen yield (HY)), hydrogen content (HC) and carbon conversion efficiency (CCE)) by analysis of variance (ANOVA). The optimal operational conditions derived from the machine leaning were recommended according to the needs of the outcomes. This review may provide helpful insights for researchers to comprehensively consider the operational conditions in order to achieve high hydrogen production using fluidized bed reactors during biomass gasification.

scholarly journals Quantitative Characterization of Geotrichum candidum Growth in Milk

2021 ◽  
Vol 11 (10) ◽  
pp. 4619
Author(s):  
Petra Šipošová ◽  
Martina Koňuchová ◽  
Ľubomír Valík ◽  
Monika Trebichavská ◽  
Alžbeta Medveďová
Keyword(s):  
Growth Parameters ◽  
Mechanistic Model ◽  
Geotrichum Candidum ◽  
Activity Level ◽  
Effect Of Temperature ◽  
Operational Parameters ◽  
Quantitative Characterization ◽  
Essential Knowledge ◽  
Cardinal Temperatures

The study of microbial growth in relation to food environments provides essential knowledge for food quality control. With respect to its significance in the dairy industry, the growth of Geotrichum candidum isolate J in milk without and with 1% NaCl was investigated under isothermal conditions ranging from 6 to 37 °C. The mechanistic model by Baranyi and Roberts was used to fit the fungal counts over time and to estimate the growth parameters of the isolate. The effect of temperature on the growth of G. candidum in milk was modelled with the cardinal models, and the cardinal temperatures were calculated as Tmin = −3.8–0.0 °C, Topt = 28.0–34.6 °C, and Tmax = 35.2–37.2 °C. The growth of G. candidum J was slightly faster in milk with 1% NaCl and in temperature regions under 21 °C. However, in a temperature range that was close to the optimum, its growth was slightly inhibited by the lowered water activity level. The present study provides useful cultivation data for understanding the behaviour of G. candidum in milk and can serve as an effective tool for assessing the risk of fungal spoilage, predicting the shelf life of dairy products, or assessing the optimal conditions for its growth in relation to the operational parameters in dairy practices.

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