scholarly journals A Performance Comparison of Anaerobic and an Integrated Anaerobic-Aerobic Biological Reactor System for the Effective Treatment of Textile Wastewater

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tasneem M. Kathawala ◽  
K. Veena Gayathri ◽  
P. Senthil Kumar
Keyword(s):  
Azo Dyes ◽  
Batch Reactor ◽  
Treatment Phase ◽  
Textile Wastewater ◽  
Performance Comparison ◽  
Biofilm Reactor ◽  
Commercial Application ◽  
Anaerobic Conditions ◽  
Root And Shoot Length ◽  
Phytotoxicity Test

The accumulation of recalcitrant azo dyes from untreated textile effluents has adversely impacted the ecosystem. The immense stability in their nature is conferred by the presence of azo bonds (N=N) in their structure. The reduction of this azo bond occurs exclusively under anaerobic conditions giving rise to colorless aromatic amines, which are carcinogenic. In the present study, a synthetic textile effluent containing mixed azo dyes such as Reactive Red, Reactive Black, and Reactive Brown, was treated using activated sludge under anaerobic conditions in a lab-scale anaerobic sequential batch reactor (An-SBR). At a concentration of 100 mg/L of mixed azo dyes, the An-SBR gave a maximum of 88% decolorization detected through UV-visible spectroscopy. Physicochemical analyses revealed 73% removal of BOD, 90% TDS removal, 69% COD removal, 4.05% TKN removal, 66% chloride removal, and 73% hardness removal. When the concentration of dyes was increased to 500 mg/L, the treatment showed a decrease in decolorization efficiency. This was then compared to a sequential anaerobic-aerobic treatment process performed in An-SBR and a laboratory-scale aerobic moving bed biofilm reactor (MBBR). The study revealed that the sequential process held more potential for commercial application than exclusively an anaerobic process. The metabolites formed during the treatment phase were extracted and analyzed by FT-IR and HPLC and identified through GC-MS analyses and were compared to those found in the untreated effluent. A phytotoxicity test was conducted on the remainder (secondary) sludge using Vigna unguiculata, and it was found to show a 50% reduction in germination and retardation in root and shoot length.

Treatment of colored textile wastewater in SBR with emphasis on the biodegradation of sulfonated aromatic amines

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
N.D. Lourenço ◽  
J.M. Novais ◽  
H.M. Pinheiro
Keyword(s):  
Azo Dyes ◽  
Aromatic Amines ◽  
Microbial Population ◽  
Textile Wastewater ◽  
Aerobic Biodegradation ◽  
Oxygen Sensitivity ◽  
Anaerobic Conditions ◽  
Textile Effluents ◽  
Primary Aromatic Amines ◽  
Reductive Decolorization

Azo dyes represent a problematic contaminant class in textile effluents because they are normally resistant to aerobic biodegradation and are consequently difficult to eliminate by conventional wastewater treatment systems. Since the mineralization of azo dyes is not likely to occur under the anaerobic conditions generally required for their reductive decolorization, anaerobic/aerobic SBR are promising systems for the decolorization of textile effluents containing azo dyes integrated with the mineralization of the resulting aromatic amines. In the present study, high decolorization yields (up to 90% with an initial dye concentration of 100 mg l-1) of a monoazo dye were achieved in the anaerobic phase of an anaerobic/aerobic SBR. However, the aromatic amines formed were not mineralized in the subsequent aerated phase. The development a bacterial community able to mineralize specific sulfonated aromatic amines was attempted in an aerobic SBR, operated downstream of the anaerobic/aerobic SBR. This attempt was not successful, since the microbial population was able to convert the primary aromatic amines, though not to full mineralization, but resulted in the identification of different chromatographic patterns arising from the bioconversion of azo dye metabolites in different oxygen-availability conditions. Oxygen-sensitivity of the involved intermediates is, however, an interfering factor possibly impairing biodegradation

scholarly journals Treatment of Mixed Azo Dyes in an Aerobic Sequential Batch Reactor and Toxicity Assessment using Vigna radiata

2019 ◽  
Author(s):  
Akshaya Vidhya T ◽  
K Veena Gayathri ◽  
Tasneem M Kathawala
Keyword(s):  
Activated Sludge ◽  
Azo Dyes ◽  
Batch Reactor ◽  
Toxicity Assessment ◽  
Treated Wastewater ◽  
Biological Degradation ◽  
Sequential Batch Reactor ◽  
Untreated Wastewater ◽  
Phytotoxicity Test ◽  
Bod Removal

AbstractAzo dyes are the most widely used dyes in the textile industry due to their stability buttheir redundancy to degradation is of major concern, particularly to aquatic ecosystems.Unbound dye is let out in the effluent which not only adds to pollution but its toxic metabolites are known to be carcinogenic leading to severe cases of disease. Biological degradation and toxicity removal has been shown to be an easy and effective process for treating textile effluents. In the present study, a laboratory scale aerobic sequential batch reactor (SBR) was designed and operated for the analysis of degradation of mixed reactive azo dyes. Biological degradation was carried out by activated sludge process at an alkaline pH (8.5). Reactive Brown, Reactive Black and Reactive Red dyes were used in the study at a concentration of 100, 500 and 1000 mg/L in synthetic waste water. The effect of increasing dye concentration on the decolorization efficiency, COD and BOD removal along with chloride, hardness, TDS, MLSS and MLVSS was monitored. The COD removal increased from 34% to 61.15% and then dropped to 21.16% at the highest used concentration. The BOD removal decreased from 63% to 55.55% to 28.14% with increasing dye concentration. In order to remove the residual dye from the effluent, a biosorption experiment was also conducted using dried activated sludge (DAS). The DAS successfully removed more than 0.300 mg of dyes by absorption within 2 hours. A toxicity assessment was carried out by mean of a phytotoxicity test on Vigna radiate where the percentage of germination was used to detect toxic effects of untreated dye containing wastewater on plant growth. The treated wastewater showed 100% germination compared to 70% in untreated wastewater containing 100 mg/L mixed dyes confirming the efficacy of the treatment.

Modeling the performance of biodegradation of textile wastewater using polyurethane foam sponge cube as a supporting medium

2010 ◽  
Vol 62 (12) ◽  
pp. 2801-2810 ◽  
Author(s):  
Yen-Hui Lin
Keyword(s):  
Steady State ◽  
Polyurethane Foam ◽  
Textile Wastewater ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Column Test ◽  
Steady State Condition ◽  
Suspended Biomass ◽  
The Government ◽  
Carbon Dioxide Co2

A pilot-scale fixed-biofilm reactor (FBR) was established to treat textile wastewater to evaluate the feasibility of replacing conventional treatment processes that involve activated sludge and coagulation units. A kinetic model was developed to describe the biodegradation of textile wastewater by FBR. Batch kinetic tests were performed to evaluate the biokinetic parameters that are used in the model. FBR column test was fed with a mean COD of 692 mg/L of textile wastewater from flow equalization unit. The influent flow rate was maintained at 48.4 L/h for FBR column test. Experimental data and model-predicted data for substrate effluent concentration (as COD), concentration of suspended biomass in effluent and the amount of carbon dioxide (CO2) produced in the effluent agree closely with each other. Microscopic observations demonstrated that the biofilm exhibited a uniform distribution on the surface of polyurethane foam sponge. Under a steady-state condition, the effluent COD from FBR was about 14.7 mg COD/L (0.0213 Sb0), meeting the discharge standard (COD < 100 mg/L) that has been set by the government of Taiwan for textile wastewater effluent. The amount of biofilm and suspended biomass reached a maximal value in the steady state when the substrate flux reached a constant value and remained maximal. Approximately 33% of the substrate concentration (as COD) was converted to CO2 during biodegradation in the FBR test. The experimental and modeling schemes proposed in this study could be employed to design a full-scale FBR to treat textile wastewater.

Biological Phosphorus Removal in a Sequencing Batch Moving Bed Biofilm Reactor

1999 ◽  
Vol 40 (4-5) ◽  
pp. 161-168 ◽  
Author(s):  
H. Helness ◽  
H. Ødegaard
Keyword(s):  
Phosphorus Removal ◽  
Batch Reactor ◽  
Complete Removal ◽  
Biofilm Reactor ◽  
Biological Phosphorus Removal ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Biofilm Carrier ◽  
Biofilm Process ◽  
Biological Phosphorus

Experiments have been carried out with biological phosphorus removal in a sequencing batch moving bed biofilm reactor (SBMBBR) with a plastic biofilm carrier (Kaldnes) suspended in the wastewater. The aim of the research leading to this paper was to evaluate biological phosphorus removal in this type of biofilm process. Biological phosphorus removal can be achieved in a moving bed biofilm reactor operated as a sequencing batch reactor. In order to achieve good and stable phosphorus removal over time, the length of the anaerobic period should be tuned to achieve near complete removal of easily biodegradable COD in the anaerobic period. The total COD-loading rate must at the same time be kept high enough to achieve a net growth of biomass in the reactor. Use of multivariate models based on UV-absorption spectra and measurements of the redox potential show potential for control of such a process.

scholarly journals Characterization of a hybrid sequencing batch reactor system for treatment of wastewater using suspended microbial aggregates and biofilms

2021 ◽  
Author(s):  
Romeo Gabriel Dumitrache
Keyword(s):  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Characteristic Parameter ◽  
Biofilm Reactor ◽  
Phosphorus Loading ◽  
Hybrid Reactor ◽  
Wagon Wheel ◽  
Suspended Biomass ◽  
Biofilm Support

A moving bed biofilm reactor was studied for its capability of carbon oxidation and nitrification. The hybrid system made use of suspended biomass in the forms of microbial aggregates and attached biomass in the form of biofilms on suspended carriers. The carriers used for biofilm support were made of polyethylene and have a wagon wheel shape. The carrier fill ratio, which is defined as the volume ratio of carrier to the whole reactor was a key characteristic parameter of the reactor. The experimental runs used different carrier filling ratios from 25 to 50% to determine the optimal operating value for this type of hybrid reactor. Also the nutrient conditions were modified to test the capacity of the system to adapt to various changes in phosphorus loading in the influent wastewater. The results showed that for an influent chemical oxygen demand (COD) of 600 mg/L, ammonia of about 24 mg/L and hydraulic reaction time of 6 hours there was no difference in the performance of the system under the different carrier filling rations.

Chemical and Biological Treatment of Dyes

2020 ◽  
pp. 170-204
Author(s):  
Kiran Meghwal ◽  
Reema Agrawal ◽  
Srishti Kumawat ◽  
Nirmala Kumari Jangid ◽  
Chetna Ameta
Keyword(s):  
Azo Dyes ◽  
Aquatic Environment ◽  
Industrial Wastewater ◽  
Biological Treatment ◽  
New Technologies ◽  
Aquatic Organisms ◽  
Textile Wastewater ◽  
Important Concern ◽  
Industrial Needs ◽  
Living Being

Life of living or non-living being depends on water; in short, water is life. But these days, with the growing industrialization, it is spoiling a lot. Wastewater contains contaminants like acids, bases, toxic organic and inorganic dissolved solids, and colors. Out of them, the most undesirable are colors caused mainly by dyes. Color and other compounds present in water are always not desirable for domestic or industrial needs. The wastes of dyes are predominant amongst all the complex industrial wastewater. This water is dark in color and highly toxic, blocking the sunlight and affecting the ecosystem. Among all the dyes, azo dyes contribute to commercial dyes used widely in textile, plastic, leather, and paper industries as additives. The removal and degradation of azo dyes in aquatic environment is important because they are highly toxic to aquatic organisms. For every industry, clean technology has become an important concern. In this chapter, the authors discuss about existing processes as well as promising new technologies for textile wastewater decolorisation.

Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment

2006 ◽  
Vol 54 (9) ◽  
pp. 181-189 ◽  
Author(s):  
D.H. Shin ◽  
W.S. Shin ◽  
Y.-H. Kim ◽  
Myung Ho Han ◽  
S.J. Choi
Keyword(s):  
Wastewater Treatment ◽  
Textile Wastewater ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Dyeing Wastewater ◽  
Moving Bed Biofilm Reactor ◽  
Combined Process ◽  
Chemical Coagulation ◽  
Moving Bed ◽  
Textile Wastewater Treatment

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2.In the MBBR process, 85% of COD and 70% of color (influent COD=807.5 mg/L and color=3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT=44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.

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