Advanced treatment of dyeing wastewater for reuse

1999 ◽  
Vol 39 (10-11) ◽  
pp. 249-255 ◽  
Author(s):  
X. Z. Li ◽  
Y. G. Zhao
Keyword(s):  
Biological Treatment ◽  
Photocatalytic Oxidation ◽  
Treatment Process ◽  
Oxidation Process ◽  
Membrane Filter ◽  
Significant Proportion ◽  
Treated Wastewater ◽  
Advanced Treatment ◽  
Dyeing Wastewater ◽  
Textile Dyeing

As one of the main pollution sources in Hong Kong, the textile dyeing and finishing industry creates a significant proportion of water pollution in nearby harbour zones. Generally speaking, conventional biological treatment processes have difficulties in degrading many dye chemicals causing high COD and colour in dyeing wastwaters. Studies using physical and chemical processes to further reduce COD and colour from dyeing wastewater have been intensively reported. The use of a photocatalytic process in the presence of TiO2 to degrade many different types of dye chemicals has been confirmed. However, how to efficiently separate and reuse TiO2 from treated wastewater became a notable problem in the application of a TiO2 photo-oxidation process. This study aims to develop an advanced treatment process for dyeing wastewater treatment. In which dyeing wastewater was initially treated by an Intermittently Decanted Extended Aeration (IDEA) reactor to initially remove those biodegradable matters and further treated by a TiO2 photocatalytic reactor as advanced treatment for complete decolorization and high COD removal. Suspended TiO2 powder used in photooxidation was separated from slurry by a membrane filter and recycled to the photoreactor continuously. The results demonstrated that photocatalytic-oxidation process could degrade those non-biodegradable organic substances in the effluent treated by the biological treatment process and also remove the colour from the effluent completely. TiO2, as catalyst, was successfully recovered by a membrane filter and continuously reused in the photoreactor. The quality of dyeing wastewater treated by the advanced treatment process can be good enough for reuse in the textile dyeing processes.

Oxidative treatment characteristics of biotreated textile-dyeing wastewater and chemical agents used in a textile-dyeing process by advanced oxidation process

2004 ◽  
Vol 49 (5-6) ◽  
pp. 137-143 ◽  
Author(s):  
B.-R. Lim ◽  
H.-Y. Hu ◽  
K.-H. Ahn ◽  
K. Fujie
Keyword(s):  
Hydrogen Peroxide ◽  
Biological Treatment ◽  
Treatment Process ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Dyeing Wastewater ◽  
Dyeing Process ◽  
Textile Dyeing ◽  
Textile Dyeing Wastewater

The oxidative treatment characteristics of biotreated textile-dyeing wastewater and typical chemicals such as desizing, scouring, dispersing and swelling agents used in the textile-dyeing process by advanced oxidation process were experimentally studied. The refractory organic matters remained in the effluent of biological treatment process without degradation may be suitable for the improvement of biodegradability and mineralized to CO2 by combined ozonation with and without hydrogen peroxide. On the other hand, the refractory chemicals contained in the scouring agent A and swelling agent may not be mineralized and their biodegradability may not be improved by ozonation. However, the BOD/DOC ratio of scouring agent B increased from 0.3 to 0.45 after ozonation. Based on the results described above, advanced treatment process involving the ozonation without and with the addition of hydrogen peroxide, followed by biological treatment was proposed for the treatment of refractory wastewater discharged from the textile-dyeing process.

Treatability of kraft pulp bleaching wastewater by biochemical and photocatalytic oxidation

1999 ◽  
Vol 40 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Işıl Akmehmet Balcıoǧlu ◽  
Ferhan Çeçen
Keyword(s):  
Biological Treatment ◽  
Kraft Pulp ◽  
Photocatalytic Oxidation ◽  
Treated Wastewater ◽  
Oxidation Reactions ◽  
Pulp Bleaching ◽  
Kraft Pulp Bleaching ◽  
Activated Sludge Reactor ◽  
Sulfate Pulp ◽  
Biological Treatability

In this study the biological treatability and TiO2 photocatalyzed oxidation characteristics of sulfate pulp bleaching effluents were investigated. The original wastes had a low biodegradability as determined by BOD5/COD ratios. Biological treatment was conducted in a batch activated sludge reactor. The non-biodegradable fraction amounted to 60% of the initial COD and compounds specific to these wastes were not removed during biotreatment. In order to enhance the biodegradability of these wastes, mixed raw effluent, C/E-H stage effluent, D/E-D stage effluent and biologically pretreated wastes were subjected to TiO2 photocatalyzed oxidation. Photocatalytic oxidation led to an increase in the BOD5/COD ratio of D/E-H stage raw and biologically treated wastewater, while chloride formation was observed in both cases in a five-hour reaction period in the presence of 1g 1−1 TiO2 and 15×10−3 M H2O2 at pH=6.5. The specific absorption values (A272nm/CODs, A254nm/CODs, A346nm/CODs, A436nm/CODs) exhibited parallel decreases during photocatalytic oxidation which indicate that oxidation reactions were nonspecific with respect to the organics present in these wastes. As a conclusion it can be suggested that biological treatment should be placed before the photocatalytic oxidation method. Even in this scheme, the application of photocatalytic oxidation could only then be favored when the COD and chloride concentrations in the wastewater were below certain values or when wastewater was diluted.

scholarly journals Integrated System for Recycling and Treatment of Hazardous Pharmaceutical Wastewater

2021 ◽  
Author(s):  
Ashraf Moursi El-Shamy ◽  
Ibrahim Abdelfattah ◽  
Abuarab ◽  
Ehab Mostafa ◽  
El-Awady ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Water Reuse ◽  
Biological Treatment ◽  
Suspended Solids ◽  
Treatment Process ◽  
Integrated System ◽  
Treated Wastewater ◽  
Pharmaceutical Wastewater ◽  
Untreated Wastewater ◽  
Nile Water

Abstract This study aimed to investigate an integrated system that can deal with different pharmaceutical wastewater. Pharmaceutical wastewater was subjected to biological, chemical, and advanced oxidation according to its pollutant’s nature. Wastewater with high Total Suspended Solids (TSS 480 mg/l) was subjected to a conventional chemical treatment process utilizing different coagulants. The best results obtained by using Calcium Oxide and Alum aided with Calcium Oxide where, the removal efficiency of COD was 46.8% and 51 %. Highly loaded pharmaceutical wastewater (COD 9700 mg/l, BOD/COD 0.16) had been subjected to Fenton oxidation, removal of COD reached 80.4%, and the ratio of BOD/COD is enhanced to 0.6. Photocatalysis by using different nanomaterials was applied to pharmaceutical wastewater containing 10 mg/l of phenols. Phenol is completely removed by using Mesoporous TiO2 after 90 min irradiation and after 120 min in the case of TiO2/P25 and TiO2/UV 100 nanocomposites while it is removed by 40% in case of using Mesoporous TiO2/Ta2O5. Effluent treated water from previous routes was subjected to biological treatment and followed with disinfection by using UV as post-treatment. Final COD was 40 and it matches with Egyptian practice code for water reuse in agriculture. Results showed also using treated wastewater in irrigation of Barley and Bean seeds achieved germination ratio up to 71% in Barely and 70% in Bean compared with that irrigated with Nile water which reached 70% and 75%, while it was about 16.6% and 30% in case of irrigation with untreated wastewater.

Real time control for minimizing effluent concentrations during storm water events

1996 ◽  
Vol 34 (3-4) ◽  
pp. 127-134 ◽  
Author(s):  
Ulf Nyberg ◽  
Bengt Andersson ◽  
Henrik Aspegren
Keyword(s):  
Real Time ◽  
Biological Treatment ◽  
Treatment Process ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Real Time Control ◽  
Operational Strategies ◽  
Time Control ◽  
Practical Experiences ◽  
Biological Treatment Process

Increased flow rates due to stormwater at the Klagshamn wastewater treatment plant occasionally cause hydraulic overloading of the activated sludge process resulting in sludge loss from the secondary clarifiers. To minimize these problems different operational strategies have been evaluated at the plant. Practical experiences have shown the benefits of using in-line storage for flow equalization even if the available volumes may seem small in comparison to the total daily flow rate during stormwater occasions. Step feed operation at the treatment plant can be used to further ease the problems with sludge loss. By-pass of primary treated wastewater can finally be used to avoid hydraulic overloading of the biological treatment process. By combining these strategies in a real time control system, the need for erecting off-line storage volumes can be minimized.

Decolorization and biodegradability of dyeing wastewater treated by a TiO2-sensitized photo-oxidation process

1996 ◽  
Vol 34 (9) ◽  
pp. 49-55 ◽  
Author(s):  
Z. Li X. ◽  
Zhang M.
Keyword(s):  
Biological Treatment ◽  
Oxidation Process ◽  
Oxygen Demand ◽  
Dyeing Wastewater ◽  
Colour Removal ◽  
Photo Oxidation ◽  
Treatment Processes ◽  
Dyeing Effluent ◽  
Wastewater Samples ◽  
Biological Treatment Process

Colour substances in dyeing effluents normally cause certain difficulties in traditional biological treatment processes due to their nonbiodegradable nature. It is necessary to remove colour from dyeing effluents with the help of some physical or chemical treatment processes. This study aims to investigate the colour removal from dyeing wastewater using a TiO2-sensitized photo-oxidation process and the biodegradability of the products formed in the wastewater. Synthetic dyeing wastewater samples were exposed to near UV radiation at a wavelength of 350 nm in the presence of TiO2 and aeration. The results show that most dyes used in the experiment can be degraded by the sensitized photo-oxidation successfully. Colour removal from the wastewater was above 95% after 4-6 hours treatment. It was found that there was a relationship between the chemical oxygen demand (COD), total organic carbon (TOC) and biochemical oxygen demand (BOD). While COD and TOC in the wastewater were decreased during the reaction, BOD was found to be increased, which implies that the TiO2-sensitized photo-oxidation can enhance the biodegradability of the dyeing wastewater. As a process, it might be an effective method to remove colour and to further remove COD after treating dyeing effluent by a conventional biological treatment process.

Evaluation of predominant reaction mechanisms for the Fenton process in textile dyeing wastewater treatment

2004 ◽  
Vol 49 (4) ◽  
pp. 91-96 ◽  
Author(s):  
W. Bae ◽  
S.H. Lee ◽  
G.B. Ko
Keyword(s):  
Comparative Evaluation ◽  
Large Scale ◽  
Treatment Process ◽  
Great Part ◽  
Fenton Oxidation ◽  
Fenton Process ◽  
Plant Analysis ◽  
Dyeing Wastewater ◽  
Textile Dyeing ◽  
Textile Dyeing Wastewater

This research quantitatively evaluated the predominant reactions in a large-scale Fenton process that treated dyeing wastewaters and suggested an economical and effective treatment process. Through plant analysis, it was found that a great part of the COD was removed by ferric coagulation. The comparative evaluation of Fenton oxidation and ferric coagulation revealed that ferric coagulation was the predominant mechanism to remove COD and colour. In Fenton oxidation, the removal efficiencies of SCOD and colour were 67.7% and 84.7%, respectively. In ferric coagulation, those of SCOD and colour were 60.8% and 62.0%, respectively. A combined process with iron coagulation/precipitation and Fenton oxidation reduced the hydrogen peroxide dosage by over 40% compared to a conventional dosage.

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