Evaluation of efficiencies of radiolysis, photocatalysis and ozonolysis of modified simulated textile dye waste-water

RSC Advances ◽  
2014 ◽  
Vol 4 (96) ◽  
pp. 53921-53926 ◽  
Author(s):  
Jhimli Paul Guin ◽  
Y. K. Bhardwaj ◽  
D. B. Naik ◽  
Lalit Varshney

The efficiencies of the several advanced oxidation processes were investigated for treatment of modified simulated textile dye waste water containing Reactive Red 120 in terms of the oxygen-equivalent chemical oxidation capacity and cost of inputs.

RSC Advances ◽  
2014 ◽  
Vol 4 (75) ◽  
pp. 39941-39947 ◽  
Author(s):  
Jhimli Paul Guin ◽  
D. B. Naik ◽  
Y. K. Bhardwaj ◽  
Lalit Varshney

The comparison in the extent of % mineralization of Simulated Textile Dye Waste Water (STDWW) in three Advanced Oxidation Processes.


2017 ◽  
pp. 147
Author(s):  
Naser Jamshidi ◽  
Farzad Nezhad Bahadori ◽  
Ladan Talebiazar ◽  
Ali Akbar Azimi

Today, advanced oxidation processes (AOPs) is considered as a key and effective method for environment preservation from pollutions. In this study , advanced photochemical oxidation processes using O3/H2O2 and O3/H2O2/UV systems were investigated batch photolytic reactor in lab-scale for the degradation of bisphenol A (BPA). In ozone generator source, air, as of the initial instrument feed, changes to ozone after electrical action and reaction. The UV irradiation source was a medium-pressure mercury lamp 300 W that was immerse in the wastewater solution with in 1.5 liter volume reactor. The reaction was influenced by the pH, the input concentration of H2O2, the input concentration of BPA, ozone dosage, chemical oxidation demand (COD) and UV irradiation time. Results showed that at initial bisphenol A concentration of 100 mg/l will completely degrade after 60 minutes by using O3/H2O2 in the pH range from 9.8 to 10 and by adding UV, it will happen in less than 36 minutes in the pH range of 3 to 10. The O3/H2O2/UV process reduced COD to 75 percents.


2020 ◽  
Vol 42 ◽  
pp. e7
Author(s):  
Joanna Cysneiros Silva ◽  
Rayany Magali da Rocha Santana ◽  
Graziele Elisandra do Nascimento ◽  
Alex Leandro Andrade de Lucena ◽  
Ana Maria Ribeiro Bastos da Silva ◽  
...  

Studies and research have been developed around the world on environmental pollution. Among the most diverse types of pollutants, textile dyes have attracted attention in the Brazilian Northeast. These compounds, besides being persistent, resist to the conventional treatments applied in the wastewater treatment plants. Thus, the present study evaluated the degradation of the mixture of direct red 23, direct red 227 and direct orange 26 dyes by advanced oxidation processes (AOPs). It was observed that the homogeneous AOPs were more efficient, being able to degrade 100% of the chromophoric groups after the optimization of the variables [H2O2], [Fe] and pH. The reaction kinetics for the photo-Fenton process followed a pseudo-first order non-linear model, with rapid decay of the concentrations in the first 60 min. Aiming to have a methodology capable of predicting the degradation efficiency for the studied processes, it was verified that the artificial neural networks MLP 4-9-3 and MLP 5-6-3 well represent the data from the homogeneous and heterogeneous processes, respectively. A toxicity study was carried out using seeds, bacteria and microcrustaceans and it was found that the intermediate compounds formed during the treatment process act differently for each of them.


Author(s):  
Aline Aparecida Carvalho França ◽  
José Machado Moita Neto ◽  
Maria Alexsandra de Sousa Rios ◽  
Alexandre Diógenes Pereira ◽  
Marcos Antônio Tavares Lira ◽  
...  

2001 ◽  
Vol 44 (9) ◽  
pp. 173-180 ◽  
Author(s):  
J. Dewulf ◽  
H. Van Langenhove ◽  
E. De Smedt ◽  
S. Geuens

Treatment of chlorinated organic compounds in waste gases is difficult because of several reasons: these compounds are dioxin precursors when incinerated, and also biological treatment is difficult because of a limited number of suitable microbial degradation pathways. On the other hand, since the 1990s, a new generation of chemical oxidation techniques has been introduced in water treatment. Advanced Oxidation Processes (AOPs) are based on a combination of UV/H2O2, UV/O3 or H2O2/O3. The combinations result in the generation of OH-radicals, which subsequently attack the organic pollutants. In this work, the treatment of a gas stream (240 L/h) loaded with 20-40 ppmv trichloroethylene (TCE) is presented. Therefore, a combination of an absorption process in a bubble column with a liquid H2O2/O3 initiated oxidation, was investigated. Removal efficiencies, depending on the dosed H2O2 and O3, up to 94% were found. The production of chloride ions was investigated: the Cl-atoms from the removed TCE could be found back as chloride ions. Next to the experimental work, attention was paid to the mechanisms taking place in the proposed concept. Here, a simulation model was developed, considering gas/liquid mass transfer of TCE and ozone, axial liquid dispersion, advective gas and liquid transport and about 29 chemical reaction steps. The modelling allowed a better understanding of the technique and gives insight in its possibilities and limitations. Finally, it can be concluded that the proposed technique shows interesting perspectives: it is able to transform chlorine in chlorinated solvents into chloride ions effectively at ambient temperature conditions.


2006 ◽  
Vol 129 (1) ◽  
pp. 60-67 ◽  
Author(s):  
B. Bayarri ◽  
O. González ◽  
M. I. Maldonado ◽  
J. Giménez ◽  
S. Esplugas

Chlorophenols (CPs) are toxic nonbiodegradable pollutants. In recent decades, several alternative processes for the treatment of these compounds have been investigated. Advanced Oxidation Processes (AOPs) are some of the most promising technologies. Among them, the UV-based AOPs [O3+Fe(II)+UV, photo-Fenton, UV+Fe(III), UV+H2O2, photocatalysis and photolysis] have previously been studied for the degradation of 2,4-dichlorophenol (DCP) in an aqueous solution at laboratory scale. In this paper, these techniques are compared and kinetic constants and pseudoquantum yields are estimated. O3−+Fe(II)+UV and photo-Fenton seem to be the most effective. To study scale-up of these processes from the laboratory to a pilot plant operating with sunlight, equivalent photocatalytic experiments were carried out in such installations. The results are promising and show trends similar to those obtained in the laboratory with lamps. The data obtained have been used to calculate some scale-up factors, which have been employed to make a rough estimation of the amount of waste water that can be treated by the solar AOPs studied. The results obtained are encouraging and prove the feasibility of this type of technology.


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