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.

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.

Removal of Nutrients and BOD from Soybean Fermentation Wastewater in a Ten-Year-Old Sequencing Batch Reactor Activated Sludge Process

1990 ◽  
Vol 22 (9) ◽  
pp. 85-92 ◽  
Author(s):  
M. Okada ◽  
K. Terazono ◽  
R. Sudo
Keyword(s):  
Activated Sludge ◽  
High Performance ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Diurnal Fluctuation ◽  
Activated Sludge Process ◽  
Subsequent Increase ◽  
Fermentation Products ◽  
Soybean Fermentation ◽  
Bod Removal

Surveys on the performance of nitrogen, phosphorus and BOD removal were carried out in a full-scale conventional, i.e. continuously aerated, sequencing batch reactor (SBR) activated sludge process which was constructed ten years ago, treating wastewater from a small factory producing soybean fermentation products. The old SBR plant, originally designed only for BOD removal, is operated with one cycle per day and aerated continuously for 19 hours per day from the start of working and wastewater inflow followed by sedimentation and decanting the next morning before work. In spite of continuous and a constant rate of aeration, DO increased rapidly immediately after the beginning of aeration, whereas it decreased down to less than 0.5 mg l−1 with the inflow of wastewater. DO increased again after work with little inflow of wastewater. The diurnal fluctuation of DO enhanced both nitrification and denitrification simultaneously in a single tank reactor with continuous aeration and resulted in high performance of nitrogen removal beyond expectation as well as BOD. The anaerobic condition and subsequent increase in DO also enhanced release and luxury uptake of phosphorus, i.e. biological removal of phosphorus. Increase in the strength of wastewater enhanced denitrification without deterioration of BOD removal. Phosphorus removal, however, was deteriorated by insufficient sludge production.

scholarly journals Research of COD and BOD Removal Efficiency in Tempeh Industrial Wastewater Treatment using Aerated Activated Sludge

2020 ◽  
Vol 9 (3S) ◽  
pp. 229-231
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Ph Value ◽  
Batch Reactor ◽  
Quality Standard ◽  
Industrial Wastewater Treatment ◽  
Environment Regulation ◽  
Bod Removal

Tempeh is the most popular food in Indonesia. The process of making tempeh requires a lot of water. The preliminary analysis of tempeh wastewater showed that the value of COD, BOD and pH are 26693 mg/l, 11204 mg/l and 3,99. This results actually do not meet the Minister of Environment regulation No.5 (2014) about quality standard of wastewater treatment for industry. The quality standard for COD, BOD and PH for tempeh wastewater are 100-300 mg/l, 50-150 mg/l, and 6-9. So, the tempeh industrial wastewater must be processed before being discharged into the environment. The aim of this study is to determine the activated sludge ability to reduce COD, BOD, and also pH value in tempeh industrial wastewater. Tempeh industrial wastewater treatment carried out in aerated batch reactor using wastewater composition 10%, 15%, and 25% (v/v) of tempeh wastewater in 500 ml as a research variables. The wastewater while the hidraulic retention time is 48 hours. The highest COD, BOD removal efficiency occured at 25% (v/v) wastewater composition each for 74,58%, 79,27%. The COD and BOD concentration after treatment are 7625,79 mg/l and 4555,7 mg/l. And pH at 25% (v/v) wastewater composition is 6,92. pH value after treatment meet quality standard of industrial wastewater from Minister of Environment regulation No.5 (2014), but COD and BOD do not meet the standards.

Microaerophilic–aerobic sequential batch reactor for treatment of azo dyes containing simulated wastewater

2005 ◽  
Vol 40 (2) ◽  
pp. 885-890 ◽  
Author(s):  
S. Sandhya ◽  
S. Padmavathy ◽  
K. Swaminathan ◽  
Y.V. Subrahmanyam ◽  
S.N. Kaul
Keyword(s):  
Azo Dyes ◽  
Batch Reactor ◽  
Sequential Batch Reactor ◽  
Simulated Wastewater

scholarly journals Imprints of Lockdown and Treatment Processes on the Wastewater Surveillance of SARS-CoV-2: A Curious Case of Fourteen Plants in Northern India

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2265
Author(s):  
Sudipti Arora ◽  
Aditi Nag ◽  
Ankur Rajpal ◽  
Vinay Kumar Tyagi ◽  
Satya Brat Tiwari ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Target Genes ◽  
Batch Reactor ◽  
Time Frame ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Virus Removal ◽  
Untreated Wastewater ◽  
Northern India ◽  
Wastewater Samples

The present study investigated the detection of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) genomes at each treatment stage of 14 aerobic wastewater treatment plants (WWTPs) serving the major municipalities in two states of Rajasthan and Uttarakhand in Northern India. The untreated, primary, secondary and tertiary treated wastewater samples were collected over a time frame ranging from under-lockdown to post-lockdown conditions. The results showed that SARS-CoV-2 RNA was detected in 13 out of 40 wastewater samples in Jaipur district, Rajasthan and in 5 out of 14 wastewater samples in the Haridwar District, Uttarakhand with the E gene predominantly observed as compared to the N and RdRp target genes in later time-points of sampling. The Ct values of genes present in wastewater samples were correlated with the incidence of patient and community cases of COVID-19. This study further indicates that the viral RNA could be detected after the primary treatment but was not present in secondary or tertiary treated samples. This study implies that aerobic biological wastewater treatment systems such as moving bed biofilm reactor (MBBR) technology and sequencing batch reactor (SBR) are effective in virus removal from the wastewater. This work might present a new indication that there is little to no risk in relation to SARS-CoV-2 while reusing the treated wastewater for non-potable applications. In contrast, untreated wastewater might present a potential route of viral transmission through WWTPs to sanitation workers and the public. However, there is a need to investigate the survival and infection rates of SARS-CoV-2 in wastewater.

scholarly journals Determination of inert Chemical Oxygen Demand (COD) fractions of Cumhuriyet University wastewater

2013 ◽  
Vol 8 (1) ◽  
pp. 31-36
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Batch Reactors ◽  
Biological Degradation ◽  
University Campus ◽  
Activated Sludge System ◽  
Wastewater Samples

Some amounts of inert products are given into environment due to biological degradation of substrate in activated sludge system. The effluent of biological wastewater treatment consists of inert substrate in influent flow, soluble microbial products and non degradable or slowly degradable organic products. Soluble inert COD (SI) must be determined for discharge standards since it did not give any reaction in activated sludge system and was given with wastewater discharge. However particular inert COD (XI) accumulated in system depending on sludge retention time due to it is only wasted from system by wasted sludge. This study focused on inert fractions of Cumhuriyet University campus wastewater which consists of domestic, hospital and laboratory wastewaters. Experimental method was used suggested by Orhon et al. and modified by Germirli et al. in order to determine directly influent particulate and soluble inert fractions. According to the experimental procedure three aerobic batch reactors, two with the wastewater and the third with glucose were run parallel. In the reactors, the change in the soluble COD profiles is observed for a period during which all degradable COD is entirely depleted, in other words, the COD profiles reach a plateau and remain unchanged. Wastewater samples were taken equalization tank in wastewater treatment plant. The conventional parameters of campus wastewater characterization were as follows: Total COD (CT0) = 372 mg l-1, total soluble COD (STO) = 124 mg l-1, total suspended solids (TSS) =177 mg l-1, ammonia (NH3) = 31.2 mg l-1, ortho-phosphate (PO4-P) = 11.3 mg l-1 and pH=7,4 . In this study, in order to determine inert COD fractions in Cumhuriyet University campus wastewater, three aerobic batch reactor systems were used. At the end of approximately 381 h operation, COD composition of campus wastewater were found to be CT0=372 mg l-1, XS0=56 mg l-1, SS0=104 mg l-1, CS0=149 mg l-1, SI=12 mg l-1, XI=211 mg l-1, respectively.

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