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.

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 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.

When the smoke disappears: dealing with extinguishing chemicals in firefighting wastewater

2014 ◽  
Vol 69 (8) ◽  
pp. 1720-1727 ◽  
Author(s):  
E. N. P. Courtens ◽  
F. Meerburg ◽  
V. Mausen ◽  
S. E. Vlaeminck
Keyword(s):  
Nitrogen Removal ◽  
Biological Treatment ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Batch Tests ◽  
Treatment Processes ◽  
Anammox Activity ◽  
Cost Calculations ◽  
Fire Extinction ◽  
Adequate Nutrient

Water is not enough. Nowadays, numerous chemicals are used for fire extinction. After use, however, these may unintentionally enter sewerage systems. In order to safely treat firefighting wastewater (FFWW), knowledge of the potential effects of these chemicals on biological treatment processes is essential. This study characterized and mimicked the composition of FFWW containing two powders, three foams and one foam degrader. Nitrogen (162–370 mg NH4+-N L−1) and phosphorus (173–320 mg PO43−-P L−1) concentrations exceeded discharge limits, whereas chemical and biological oxygen demand, suspended solids and detergent concentrations remained sufficiently low. Adequate nutrient removal could be obtained through FeCl3 addition and nitrification/denitrification with acetate as substrate. In batch tests, residual nitrifying activities of 84, 81, 89, 95 and 93% were observed in the presence of powders, foams, foam degrader, synthetic and real FFWW, respectively. All categories showed higher denitrification rates than the control. Although the powders at first seemed to inhibit anammox activity at 82%, after pH correction anammox was fully feasible, allowing nitrogen removal through oxygen-limited nitrification/denitrification (OLAND). Detailed cost calculations indicated that OLAND could save 11% of capital and 68% of operational costs compared to nitrification/denitrification, identifying OLAND as the most recommendable process for nitrogen removal from firefighting wastewaters.

scholarly journals Innovative Biological Treatment Processes for Wastewater in Canada

2003 ◽  
Vol 38 (2) ◽  
pp. 243-265 ◽  
Author(s):  
Catherine N. Mulligan ◽  
Bernard F. Gibbs
Keyword(s):  
Biological Treatment ◽  
Waste Treatment ◽  
Oil Spills ◽  
Metal Removal ◽  
Oxygen Demand ◽  
High Rate ◽  
Future Research ◽  
New Developments ◽  
Treatment Processes ◽  
Stage Of Development

Abstract Biological treatment of wastewater has been employed successfully for many types of industries. Aerobic processes have been used extensively. Production of large amounts of sludge is the main problem and methods such as biofilters and membrane bioreactors are being developed to combat this phenomenon. Anaerobic waste treatment has undergone significant developments and is now reliable with low retention times. The UASB, the original high rate anaerobic reactor, is now becoming less popular than the EGSB reactor. New developments such as the Annamox process are highly promising for nitrogen removal. For metal removal, processes such as biosorption and biosurfactants combined with ultrafiltration membranes are under development. Biosurfactants have also shown promise as dispersing agents for oil spills. If space is available, wetlands can be used to reduce biological oxygen demand (BOD), total suspended solids (TSS), nutrients and heavy metals. These innovative processes are described in this paper in terms of applications, the stage of development, and future research needs particular to Canada.

scholarly journals Combined Chemical-Biological Treatment of Effluents from Soil Remediation Processes by Surfactants Solutions Flushing

2012 ◽  
Vol 19 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Elżbieta Hallmann ◽  
Renata Tomczak-Wandzel ◽  
Krystyna Mędrzycka
Keyword(s):  
Wastewater Treatment ◽  
Soil Remediation ◽  
Biological Treatment ◽  
Aerobic Degradation ◽  
Fenton Process ◽  
Cod Reduction ◽  
Treatment Processes ◽  
Oil In Water ◽  
Wastewater Samples ◽  
Surfactant Removal

Combined Chemical-Biological Treatment of Effluents from Soil Remediation Processes by Surfactants Solutions Flushing In recent years combined chemical-biological wastewater treatment processes have received increasing interest. In the present study wastewater from soil remediation processes were treated by means of 1-step processes like Fenton, aerobic degradation and 2-steps combined method. The effluents resulting from soil remediation processes consist of high surfactant concentration solutions, mobilized oils and oil-in-water (o/w) emulsions. The effectiveness of wastewater treatment was evaluated by COD reduction and surfactant removal. The application of Fenton process alone showed around 80% of COD and surfactant removal, and in case of aerobic process only 60% of COD and 50% of surfactant removal was accomplished. However, the maximum COD reduction and surfactant removal from wastewater samples, above 90%, was obtained in aerobic degradation with Fenton process as pretreatment. Thus, the Fenton process could be effectively applied as a pretreatment step to improve the reduction of both COD and surfactant from wastewater resulting from soil remediation.

Colour removal from fermentation industry effluents

1999 ◽  
Vol 40 (1) ◽  
pp. 331-338 ◽  
Author(s):  
B. Inanc ◽  
F. Ciner ◽  
I. Ozturk
Keyword(s):  
Surface Waters ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Ozone Treatment ◽  
Lime Treatment ◽  
Colour Removal ◽  
Treatment Processes ◽  
Iron Salts ◽  
Coagulation And Flocculation ◽  
Annual Total

Large amounts of effluents from the fermentation industry are characterized by high COD and colour. Although significant reduction in COD is achieved through biological treatment processes, a substantial amount of colour remains. Coagulation and flocculation with alum and iron salts are not effective for colour removal. This is due to the nature of colour causing compounds which are almost totally dissolved and resistant to biodegradation. Hence, fermentation industries face difficulties in discharging their coloured effluents into either sewers or surface waters. In this study, colour removal from biological treatment plant effluents of a fermentation industry with lime and ozone was investigated experimentally. Optimum lime dose for reducing the colour to values around 1000 Pt-Co was found as 10.0 g/l, while 0.9 g/l ozone was necessary to obtain the same residual colour. Economic evaluation has indicated that cost of lime treatment was 1.3 to 1.4 USD/m3 while it was 2.5 USD/m3 for ozone treatment. Annual total costs for lime and ozone treatment were also estimated as 2 million USD and 3.65 million USD, respectively.

scholarly journals Biological Treatment of Wastewater Containing Automotive Antifreeze Solution Using a Packed Column

2021 ◽  
Author(s):  
M.ADNAN A. Khan
Keyword(s):  
Biological Treatment ◽  
Removal Rate ◽  
Packed Column ◽  
Oxygen Demand ◽  
Biological Degradation ◽  
Time Intervals ◽  
Flow Rates ◽  
Simulated Wastewater ◽  
Wastewater Samples ◽  
Bod Removal

Simulated wastewater samples containing antifreeze were treated biologically using a packed column as an aerator. The objective of this project is to determine the rate of biological degradation of ethylene glycol at different air flow rates, liquid flow rates, and varied seeding rates at different time intervals, to achieve the highest removal rate of the BOD. The biological oxygen demand (BOD) of the wastewater was measured. Under a liquid flowrate of 5.5 kg m̃²s̃¹ the BOD removal increased when the air flowrate was increased from 0.0069 to 0.0414 kg m̃²s̃¹. However, further increases of the air flowrate beyond 0.0138 kg m̃²s̃¹ did not affect the BOD removal rate significantly. On the other hand, with a constant air flowrate when the liquid flowrate was increased from 5.5 to 11, 16.5, and 27.5 kg m̃²s̃¹, the percent BOD removal appeared to decrease slightly. It was also found that the increase in amount of seeding has no significant effect on BOD removal. The averaged BOD removal of about 90% was obtained after 72 hours of the wastewater treatment.

Efficiency of the Coagulation-Flocculation Method for the Treatment of Dye Mixtures Containing Disperse and Reactive Dye

2007 ◽  
Vol 42 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Pei Wen Wong ◽  
Tjoon Tow Teng ◽  
Nik Abdul Rahman Nik Norulaini
Keyword(s):  
Oxygen Demand ◽  
Textile Wastewater ◽  
Reactive Dye ◽  
Settling Time ◽  
Test Method ◽  
Colour Removal ◽  
Cod Reduction ◽  
Jar Test ◽  
Wastewater Samples ◽  
Ph Range

Abstract The coagulation-flocculation method was used to treat aqueous solutions containing varying ratios of commercial disperse and reactive dyes. The effectiveness of this method was assessed using such coagulants as alum, polyaluminium chloride (PACl) and MgCl2, and an anionic coagulant aid. The jar test method was used to measure the effects of pH and coagulant type and dosage on colour removal and chemical oxygen demand (COD) reduction. The effect of coagulant aid on floc settling time was also measured. The results showed that the coagulant dosage needed to achieve optimum colour removal and COD reduction increased as the percentage of reactive dye in the mixture increased. Alum and PACl performed effectively in a lower pH range (pH 3.8 to 5.2), whereas MgCl2 performed effectively in a higher pH range (pH 10.4 to 10.9). PACl was more effective than MgCl2 and alum, achieving >99% colour removal and 96.3% COD reduction using a smaller quantity of the coagulant. The addition of coagulant aid improved floc settling time. These results show that PACl is more effective than MgCl2 and alum in removing both colour and COD in the treatment of the industrial textile wastewater samples.

The Toxicity of Organic Chemicals to Treatment Processes

1992 ◽  
Vol 25 (3) ◽  
pp. 23-31 ◽  
Author(s):  
D. J. W. Blum ◽  
R. E. Speece
Keyword(s):  
Hydrogen Bond ◽  
Biological Treatment ◽  
Treatment Process ◽  
Molecular Volume ◽  
Process Stability ◽  
Hydrogen Bond Donor ◽  
Treatment Processes ◽  
Linear Solvation Energy ◽  
Ic50 Concentration ◽  
Biological Treatment Process

The IC50 concentration was determined for a common set of narcotic chemicals to three classes of environmental organisms - aerobic heterotrophs, methanogens and Nitrosomonas as well as to MicrotoxR. The toxicity was well modeled using the linear solvation energy relationship which incorporates molecular volume, polarity/polarizability, hydrogen bond donor acidity and hydrogen bond donor basicity. Chemical characteristics which contribute to a chemical's toxicity are discussed. The relative toxicity to these different classes of environmental microorganisms is discussed and the implications to biological treatment process stability are considered.

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