scholarly journals Comparison of coagulation, ozone and ferrate treatment processes for color, COD and toxicity removal from complex textile wastewater

2017 ◽  
Vol 76 (5) ◽  
pp. 1001-1010 ◽  
Author(s):  
Sameena N. Malik ◽  
Prakash C. Ghosh ◽  
Atul N. Vaidya ◽  
Vishal Waindeskar ◽  
Sera Das ◽  
...  
Keyword(s):  
Spinacia Oleracea ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Optimal Dose ◽  
Contaminant Removal ◽  
Potassium Ferrate ◽  
Comparative Performance ◽  
Oxidation Treatment ◽  
Chromophore Group ◽  
Treatment Processes

In this study, the comparative performance of coagulation, ozone, coagulation + ozone + coagulation and potassium ferrate processes to remove chemical oxygen demand (COD), color, and toxicity from a highly polluted textile wastewater were evaluated. Experimental results showed that ferrate alone had no effect on COD, color and toxicity removal. Whereas, in combination with FeSO4, it has shown the highest removal efficiency of 96.5%, 83% and 75% for respective parameters at the optimal dose of 40 mgL−1 + 3 ml FeSO4 (1 M) in comparison with other processes. A seed germination test using seeds of Spinach (Spinacia oleracea) also indicated that ferrate was more effective in removing toxicity from contaminated textile wastewater. Potassium ferrate also produces less sludge with maximum contaminant removal, thereby making the process more economically feasible. Fourier transform infrared spectroscopy (FTIR) analysis also shows the cleavage of the chromophore group and degradation of textile wastewater during chemical and oxidation treatment processes.

scholarly journals Photocatalytic and Biological Oxidation Treatment of Real Textile Wastewater

2021 ◽  
Author(s):  
Teklit Gebregiorgis
Keyword(s):  
Developing Countries ◽  
Large Volume ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Chemical Oxidation ◽  
Biological Oxidation ◽  
Industrial Site ◽  
Economic Activities ◽  
Oxidation Treatment

With rapidly growing urbanization and industrialization in developing countries, a large volume of wastewater is produced from industries that contain chemicals generating high environmental risks, which could affect health and socio-economic activities if not treated properly. In this study, the discoloration of wastewater containing azo dyes by chemical oxidation process combined with a biological treatment was evaluated and applied on real textile wastewater generated from one Ethiopian industrial site. The use of TiO2 as a photocatalyst and the effect of the addition of H2O2 on color removal were investigated. Photocatalysis was followed by aerobic biological treatment and their combination resulted in 93.3 and 90.4% removal of color and chemical oxygen demand (COD), respectively. These results revealed that the combination of photocatalytic and biological treatment approach shows a promising potential for the removal of color from real textile wastewater.

scholarly journals Photocatalytic and biological oxidation treatment of real textile wastewater

2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Teklit Gebregiorgis Ambaye ◽  
Kiros Hagos
Keyword(s):  
Biological Treatment ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Cost Effective ◽  
Pilot Scale ◽  
Chemical Oxidation ◽  
Color Removal ◽  
Oxidation Treatment ◽  
Low Energy Consumption ◽  
Direct Extrapolation

Abstract In this study, the discoloration of wastewater containing azo dyes by chemical oxidation process combined with a biological treatment was evaluated and applied to real textile wastewater generated from one Ethiopian industrial site. The use of TiO2 as photocatalyst and the effect of the addition of H2O2 on color removal was first investigated. Photocatalysis was followed by aerobic biological treatment, and their combination resulted in a high extent of color removal (93.3%) and chemical oxygen demand (COD) reduction (90.4%). This was reached without pH correction and with low energy consumption compared to the implementation of AOPs alone. This study performed with real textile wastewater allows the direct extrapolation of the data for the design of a cost-effective and applicable treatment procedure at a pilot scale. Graphic abstract

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

The Characteristics of Community Wastewater Biological Treatment Processes in Taiwan

1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan
Keyword(s):  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Field Investigation ◽  
Oxidation Ditch ◽  
Trickling Filter ◽  
Rotating Biological Contactor ◽  
Treatment Processes ◽  
Treatment Characteristics ◽  
Sludge Thickening

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.

scholarly journals Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge

2021 ◽  
Vol 11 (4) ◽  
pp. 1889 ◽  
Author(s):  
Agnieszka Micek ◽  
Krzysztof Jóźwiakowski ◽  
Michał Marzec ◽  
Agnieszka Listosz ◽  
Tadeusz Grabowski
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Treated Wastewater ◽  
Contaminant Removal ◽  
Nitrogen And Phosphorus ◽  
Wastewater Samples ◽  
Polish Law

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

Semicentralized greywater and blackwater treatment for fast growing cities: how uncertain influent characteristics might affect the treatment processes

2017 ◽  
Vol 75 (7) ◽  
pp. 1722-1731 ◽  
Author(s):  
J. Tolksdorf ◽  
P. Cornel
Keyword(s):  
Treatment Plant ◽  
Oxygen Demand ◽  
Flexible Design ◽  
Model Calculations ◽  
Effluent Quality ◽  
Fast Growing ◽  
Treatment Processes ◽  
Reference Plant ◽  
Design Values ◽  
Pr China

The SEMIZENTRAL infrastructure approach has been developed for fast growing cities, to meet their challenges regarding water supply as well as biowaste and wastewater (WW) treatment. The world's first full-scale SEMIZENTRAL Resource Recovery reference plant has been implemented in Qingdao (PR China). Greywater (GW) and blackwater (BW) are collected and treated separately. Measurement of influent concentrations revealed significant differences, compared with the design values. Values from the literature for GW and BW characteristics vary more markedly than for municipal WW; recommended design values are still lacking. Moreover, cross-connections between GW and BW can influence the influent characteristics considerably. Consequences for the design of GW and BW treatment are evaluated for boundary conditions, which require high effluent quality for both treatment modules. Model calculations illustrate the significant influence of uncertain WW characteristics on the required aeration basin volume and oxygen demand for GW and BW treatment; however, uncertainties are considerably reduced for the combination of these modules. Thus, a flexible design of the treatment plant is required. A possible concept for such a design is presented.

Incorporating sulfur reactions and interactions with iron and phosphorus into a general plant-wide model

2018 ◽  
Vol 79 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Hélène Hauduc ◽  
Tanush Wadhawan ◽  
Bruce Johnson ◽  
Charles Bott ◽  
Matthew Ward ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Optimization Design ◽  
Oxygen Demand ◽  
Phosphorus Release ◽  
Sulfur Cycle ◽  
Precipitate Formation ◽  
Treatment Processes ◽  
Whole Plant ◽  
Plant Process ◽  
P Removal

Abstract Sulfur causes many adverse effects in wastewater treatment and sewer collection systems, such as corrosion, odours, increased oxygen demand, and precipitate formation. Several of these are often controlled by chemical addition, which will impact the subsequent wastewater treatment processes. Furthermore, the iron reactions, resulting from coagulant addition for chemical P removal, interact with the sulfur cycle, particularly in the digester with precipitate formation and phosphorus release. Despite its importance, there is no integrated sulfur and iron model for whole plant process optimization/design that could be readily used in practice. After a detailed literature review of chemical and biokinetic sulfur and iron reactions, a plant-wide model is upgraded with relevant reactions to predict the sulfur cycle and iron cycle in sewer collection systems, wastewater and sludge treatment. The developed model is applied on different case studies.

Surface Oxidation Behaviour of Cubic BN Powders

2014 ◽  
Vol 602-603 ◽  
pp. 544-547
Author(s):  
Xin Yan Yue ◽  
Yue Zhang ◽  
Jian Jun Wang ◽  
Wei Wang ◽  
Hong Qiang Ru
Keyword(s):  
Heat Treatment ◽  
Surface Oxidation ◽  
Mass Gain ◽  
Oxidation Behaviour ◽  
Experimental Results ◽  
Oxidation Temperature ◽  
Oxidation Reactions ◽  
Oxidation Treatment ◽  
Treatment Processes

In order to improve the sinterability of the cBN, surface oxidation treatment was conducted to form a B2O3 film on the surface of the cBN powders. The cBN powders (d50 = 7.5 μm) were used as original powders. The heat treatment processes were 500, 800, 900, 950, 980 and 1000 °C holding for 30 minutes, respectively. The oxidation reactions which probably happened were calculated based on the thermodynamics. The experimental results showed that the oxidation starting temperature of cBN powders was higher than 800 °C. The higher the oxidation temperature, the greater the mass gain of the cBN powders.

scholarly journals A prototype of textile wastewater treatment using coagulation and adsorption by Fe/Cu nanoparticles: Techno-economic and scaling-up studies

2021 ◽  
Vol 11 ◽  
pp. 184798042110411
Author(s):  
Ahmed S Mahmoud ◽  
Mohamed K Mostafa ◽  
Robert W Peters
Keyword(s):  
Oxygen Demand ◽  
Textile Wastewater ◽  
Scaling Up ◽  
Influential Factor ◽  
Prototype System ◽  
Relative Importance ◽  
Total Treatment Cost ◽  
Adsorption Models ◽  
Removal Efficiencies ◽  
Textile Wastewater Treatment

This study aims to investigate the efficiency of a pilot prototype system comprising coagulation/flocculation, filtration, and nano-bimetallic iron/copper (Fe/Cu) degradation and adsorption units for the removal of chemical oxygen demand (COD), biological oxygen demand (BOD), color, total nitrogen (TN), total phosphorus (TP), and TSS from real textile wastewater. The total removal efficiencies of the system were 96, 98, 82, 69, 88, and 97%, respectively, using 0.5 g/L ferric chlorides as a coagulant under an optimum adsorption condition of pH 6.0, nano-dosage 1.4 g/L, contact time 80 min, and stirring rate 250 r/min at room temperature. Adsorption isotherms indicated that the removal of COD and TP obeys both Koble–Corrigan and Freundlich adsorption models, removal of color obeys both Koble–Corrigan and Hill adsorption models, and removal of TN and TSS obeys Koble–Corrigan and Khan models, respectively. Avrami kinetic models adequately describe the adsorption data for COD, BOD, TN, and TSS, while pseudo-second-order and intraparticle models described the removal mechanism of color and TSS, respectively. An artificial neural network (ANN) with r2-value exceeding 0.98 is accurate and can be used with confidence in predicting removal efficiencies of the targeted parameters. Sensitivity analysis results showed that the initial concentration was the most influential parameter for TSS removal with relative importance greater than 25%, while the bimetallic Fe/Cu dosage was the most influential factor for all other studied parameters with relative importance greater than 40%. The total treatment cost of the proposed system per m3 after scaling up was found to be US$4.5 for reuse of the treated water for the irrigation of forest trees.

scholarly journals Short investigation on occurrence and removal of semivolatiles during wastewater treatment processes

2021 ◽  
Vol 3 (2) ◽  
pp. 130-140
Author(s):  
Maria Diana Puiu ◽  
Keyword(s):  
Wastewater Treatment ◽  
Organic Contaminants ◽  
Biological Treatment ◽  
Organic Matter Content ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Matter Content ◽  
Physical Treatment ◽  
Dissolved Air Flotation ◽  
Treatment Processes

The food industry wastewater is known to present a high organic matter content, due to specific raw materials and processing activities. Even if these compounds are not directly toxic to the environment, high concentrations in effluents could represent a source of pollution as discharges of high biological oxygen demand may impact receiving river's ecosystems. Identifying the main organic contaminants in wastewater samples represents the first step in establishing the optimum treatment method. The sample analysis for the non-target compounds through the GC-MS technique highlights, along with other analytical parameters, the efficiency of the main physical and biological treatment steps of the middle-size Wastewater Treatment Plant (WWTP). Long-chain fatty acids and their esters were the main abundant classes of non-target identified compounds. The highest intensity detection signal was reached by n-hexadecanoic acid or palmitic acid, a component of palm oil, after the physical treatment processes with dissolved air flotation, and by 1-octadecanol after biological treatment.

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